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WO2025062183A1 - Cathéter flexible renforcé et procédés d'utilisation et de fabrication - Google Patents

Cathéter flexible renforcé et procédés d'utilisation et de fabrication Download PDF

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Publication number
WO2025062183A1
WO2025062183A1 PCT/IB2024/000521 IB2024000521W WO2025062183A1 WO 2025062183 A1 WO2025062183 A1 WO 2025062183A1 IB 2024000521 W IB2024000521 W IB 2024000521W WO 2025062183 A1 WO2025062183 A1 WO 2025062183A1
Authority
WO
WIPO (PCT)
Prior art keywords
catheter
shaft
reinforcement
lumen
drive shaft
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
PCT/IB2024/000521
Other languages
English (en)
Inventor
Ronan Keating
Diarmuid CONROY
Eamon Brady
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Whiteswell Ltd
Original Assignee
Whiteswell Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Whiteswell Ltd filed Critical Whiteswell Ltd
Publication of WO2025062183A1 publication Critical patent/WO2025062183A1/fr
Pending legal-status Critical Current
Anticipated expiration legal-status Critical

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Classifications

    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M60/00—Blood pumps; Devices for mechanical circulatory actuation; Balloon pumps for circulatory assistance
    • A61M60/10—Location thereof with respect to the patient's body
    • A61M60/122—Implantable pumps or pumping devices, i.e. the blood being pumped inside the patient's body
    • A61M60/126—Implantable pumps or pumping devices, i.e. the blood being pumped inside the patient's body implantable via, into, inside, in line, branching on, or around a blood vessel
    • A61M60/13—Implantable pumps or pumping devices, i.e. the blood being pumped inside the patient's body implantable via, into, inside, in line, branching on, or around a blood vessel by means of a catheter allowing explantation, e.g. catheter pumps temporarily introduced via the vascular system
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M60/00—Blood pumps; Devices for mechanical circulatory actuation; Balloon pumps for circulatory assistance
    • A61M60/20—Type thereof
    • A61M60/205—Non-positive displacement blood pumps
    • A61M60/216—Non-positive displacement blood pumps including a rotating member acting on the blood, e.g. impeller
    • A61M60/221—Non-positive displacement blood pumps including a rotating member acting on the blood, e.g. impeller the blood flow through the rotating member having both radial and axial components, e.g. mixed flow pumps
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M60/00—Blood pumps; Devices for mechanical circulatory actuation; Balloon pumps for circulatory assistance
    • A61M60/40—Details relating to driving
    • A61M60/403—Details relating to driving for non-positive displacement blood pumps
    • A61M60/408—Details relating to driving for non-positive displacement blood pumps the force acting on the blood contacting member being mechanical, e.g. transmitted by a shaft or cable
    • A61M60/411—Details relating to driving for non-positive displacement blood pumps the force acting on the blood contacting member being mechanical, e.g. transmitted by a shaft or cable generated by an electromotor
    • A61M60/414—Details relating to driving for non-positive displacement blood pumps the force acting on the blood contacting member being mechanical, e.g. transmitted by a shaft or cable generated by an electromotor transmitted by a rotating cable, e.g. for blood pumps mounted on a catheter
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M25/00—Catheters; Hollow probes
    • A61M25/0021—Catheters; Hollow probes characterised by the form of the tubing
    • A61M25/0023—Catheters; Hollow probes characterised by the form of the tubing by the form of the lumen, e.g. cross-section, variable diameter
    • A61M25/0026—Multi-lumen catheters with stationary elements
    • A61M2025/0036—Multi-lumen catheters with stationary elements with more than four lumina
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M25/00—Catheters; Hollow probes
    • A61M25/0043—Catheters; Hollow probes characterised by structural features
    • A61M25/0045—Catheters; Hollow probes characterised by structural features multi-layered, e.g. coated
    • A61M2025/0046—Coatings for improving slidability
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M25/00—Catheters; Hollow probes
    • A61M25/0043—Catheters; Hollow probes characterised by structural features
    • A61M25/005—Catheters; Hollow probes characterised by structural features with embedded materials for reinforcement, e.g. wires, coils, braids
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M25/00—Catheters; Hollow probes
    • A61M25/0043—Catheters; Hollow probes characterised by structural features
    • A61M25/005—Catheters; Hollow probes characterised by structural features with embedded materials for reinforcement, e.g. wires, coils, braids
    • A61M25/0051—Catheters; Hollow probes characterised by structural features with embedded materials for reinforcement, e.g. wires, coils, braids made from fenestrated or weakened tubing layer
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M25/00—Catheters; Hollow probes
    • A61M25/01—Introducing, guiding, advancing, emplacing or holding catheters
    • A61M25/0102—Insertion or introduction using an inner stiffening member, e.g. stylet or push-rod

Definitions

  • the present disclosure generally relates to the field of fluid management procedure for the treatment of fluid management disorders in a patient, and related components and methods.
  • the present disclosure is directed to reinforced flexing catheter shaft used in intravascular blood pumps and designed to operate in low friction liners to allow pump operation at high speed without generating frictional heat.
  • devices with a reinforced flexing catheter shaft of the disclosure may be used in intravascular blood pumps designed to operate in low friction liners. This enables operating the pump at high speed without generating frictional heat and allowing the catheter shaft to conform to the anatomy of the patient.
  • the present disclosure provides a catheter shaft comprising a multilumen tubing with a drive shaft extending therethrough.
  • the drive shaft is configured to operate a blood pumping impeller with the catheter shaft.
  • the present disclosure provides a catheter shaft configured to prevent bodily fluid ingress into the annual space between the low friction liner and the drive shaft.
  • the present disclosure provides a catheter shaft comprising an elongate reinforcement configured to limit axial extension or axial compression of the catheter shaft when the catheter shaft is advanced through tortuous anatomy or placed in a tortuous configuration.
  • the present disclosure provides an elongate tubular reinforcement which comprises an architecture that allows the catheter shaft to easily conform to the patient anatomy while setting a pre-programmed blending limit on the catheter shaft.
  • an indwelling catheter assembly comprising a catheter shaft having a central lumen, a distal end and a proximal end, wherein the catheter shaft comprises a drive shaft disposed in the central lumen, and a catheter shaft reinforcement having an initial low resistance to bending.
  • the central lumen comprises a low friction wear resistant material.
  • the central lumen comprises a tight gap clearance fit with the drive shaft defining an annular gap between the drive shaft and the central lumen.
  • the annular gap comprises a lubricant seal along at least a portion of its length.
  • the lubricant seal comprises Poly- alpha-olefin, in some embodiments. In some embodiments, the lubricant seal comprises an aluminum complex thickener. In some embodiments, the lubricant seal comprises a National Lubricating Grease Institute (NLGI) consistency number of 2-3. In some embodiments, the lubricant seal has an NLGI number of ⁇ 2.
  • NLGI National Lubricating Grease Institute
  • the drive shaft comprises a low second moment of area and a drive shaft neutral axis.
  • the catheter shaft further comprises a plurality of control lumens.
  • at least one control lumen comprises one or more pressure sensing lumens, in some embodiments.
  • the pressure sensing lumen is configured to receive a pressure sensor, in some embodiments.
  • at least one control lumen comprises a restrictor lumen.
  • at least one control lumen comprises a catheter flushing lumen.
  • at least one control lumen comprises a sensing lumen to accommodate a sensor, in some embodiments.
  • at least one control lumen comprises a lumen to accommodate a stiffening wire.
  • the catheter shaft reinforcement is configured to control the neutral axis of the catheter shaft.
  • the catheter shaft further comprises a protective out jacket and a drive shaft liner.
  • the drive shaft liner forms the inner most layer of the catheter shaft.
  • the drive shaft linear comprises a low friction polymeric material.
  • the catheter shaft reinforcement comprises a tubular member having a reinforcement cut pattern.
  • the reinforcement cut pattern comprises a jigsaw pattern.
  • the reinforcement cut pattern comprises a plurality of tubular ring members.
  • the reinforcement cut pattern comprises a plurality of separate ring members that are geometrically coupled.
  • the reinforcement cut pattern comprises a continuous coil of that is geometrically coupled.
  • the reinforcement cut pattern comprises a laser cut gap.
  • the catheter shaft reinforcement comprises a tubular member consisting of a continuous interlocking coil.
  • the catheter shaft reinforcement comprises a tubular member consisting of a continuous interlocking coil with an outer protective sleeve.
  • the catheter shaft reinforcement comprises a tubular member consisting of a continuous interlocking coil that limits bending, in some embodiments.
  • the catheter shaft reinforcement comprises a tubular member consisting of a continuous interlocking coil that limits bending and length extension during bending.
  • the catheter shaft reinforcement comprises a tubular member consisting of a continuous interlocking coil, and a secondary concentric coil that further limits bending.
  • the catheter shaft reinforcement comprises a tubular member consisting of a continuous interlocking coil with a reflowed polymer jacket that further limits the bending radius while sealing the tube.
  • the catheter shaft reinforcement comprises a tubular member consisting of a continuous interlocking coil with a reflowed polymer jacket that incorporates a plurality of control lumens.
  • the sheath comprises a sheath shaft, a sheath hub, a sheath control shaft, a sheath manifold, and a sheath restrictor balloon.
  • the catheter shaft is connected to the catheter manifold at the proximal end and connected to the catheter pump assembly at the distal end.
  • the catheter blood pump system further comprises a motor.
  • the central lumen terminates adjacent to the motor.
  • the drive shaft is connected to the motor.
  • the catheter shaft reinforcement is configured to control the neutral axis of the catheter shaft.
  • the restrictor lumen is configured for the inflation or expansion of a restrictor mounted on the catheter pump assembly.
  • the restrictor comprises an inflatable elastomeric member with an inflation space.
  • the restrictor lumen extends to the catheter manifold.
  • the catheter manifold further comprises a catheter restrictor inflation stopcock.
  • the catheter shaft further comprises a protective outer jacket and a drive shaft liner. Further, the protective outer jacket forms the outermost layer of the catheter shaft, in some embodiments. In some embodiments, the protective outer jacket comprises a soft flexible polymeric jacket.
  • an elongate catheter assembly comprising a catheter shaft comprising a multi-lumen tubing; a catheter shaft reinforcement, wherein the catheter shaft reinforcement forms a second innermost layer of the catheter shaft; a protective outer jacket, wherein the protective outer jacket forms an outermost layer of the catheter shaft; and a drive shaft liner, wherein the drive shaft liner forms a first innermost layer of the catheter shaft.
  • the drive shaft liner comprises a low friction polymeric material.
  • the catheter shaft reinforcement comprises a tubular member having a reinforcement cut pattern.
  • the reinforcement cut pattern comprises a jigsaw pattern.
  • the reinforcement cut pattern comprises a plurality of tubular ring members.
  • the reinforcement cut pattern comprises a plurality of separate ring members that are geometrically coupled.
  • the reinforcement cut pattern comprises a laser-cut gap.
  • the multilumen tubing envelops the catheter shaft reinforcement. Further, the multilumen tubing extends from the catheter pump assembly to the catheter manifold, in some embodiments. In some embodiments, the multilumen tubing comprises a plurality of control lumens.
  • At least one control lumen comprises one or more pressure sensing lumens. Further, in some embodiments, the pressure sensing lumen is configured to receive a pressure sensor. In some embodiments, at least one control lumen comprises a restrictor lumen. In some embodiments, at least one control lumen comprises a catheter flushing lumen. In some embodiments, at least one control lumen comprises a sensing lumen to accommodate a sensor.
  • the protective outer jacket comprises a soft-flexible polymeric jacket. Further, the protective outer jacket comprises an expanded state, in some embodiments. In some embodiments, the protective outer jacket comprises a plurality of compressed states.
  • aspects of the disclosure include methods for assessing a catheter.
  • the method comprises determining one or more of: the fatigue performance of a drive shaft of the catheter; the maximum bending strain of the catheter shaft; and the torque stress on the drive shaft associated with the transmission of torsional energy when a pump of the catheter is operating.
  • determining the maximum bending strain comprises: determining the bending strain on the drive shaft while the catheter is bent into its most extreme geometry by the formula:
  • the torque stress on the drive shaft associated with the transmission of torsional energy when a pump of the catheter is operating is determined by the formula: where:
  • FIG. la provides a schematic illustration of an exemplary catheter blood pump system 1 in accordance with the present disclosure.
  • FIG. lb shows a close-up schematic illustration of an exemplary catheter blood pump assembly 101 in accordance with an embodiment of the present disclosure.
  • FIG. 1c shows a close-up schematic illustration of the catheter blood pump assembly 101 in accordance with one embodiment of the present disclosure.
  • FIG. 2a provides a schematic illustration of an exemplary catheter blood pump in accordance with one embodiment of the present disclosure.
  • FIG. 2b provides an illustration of the bending stiffness properties of three catheter shafts, in accordance with some embodiments of the present disclosure.
  • FIG. 3a provides a side-elevation view schematic illustration of an exemplary catheter shaft and a proximal portion of a catheter pump assembly in accordance with one embodiment of the present disclosure.
  • FIG. 3b provides a cross sectional view schematic illustration of the catheter shaft in accordance with one embodiment of the present disclosure.
  • FIG. 4a provides a side elevation view schematic illustration of an exemplary catheter shaft and a proximal portion of a catheter pump assembly in accordance with one embodiment of the present disclosure.
  • FIG. 4b is a cross-sectional view schematic illustration of the catheter shaft in accordance with one embodiment of the present disclosure.
  • FIG. 4c is a side-elevation view schematic illustration of a variation to the construction of the catheter shaft in accordance with one embodiment of the present disclosure.
  • FIG. 5a is a close-up schematic illustration of an exemplary catheter shaft reinforcement of a catheter shaft, in accordance with one embodiment of the present disclosure.
  • FIG. 5b is a close-up schematic illustration of an exemplary catheter shaft reinforcement of a catheter shaft, in accordance with one embodiment of the present disclosure.
  • FIG. 5c is a close-up schematic illustration of an exemplary catheter shaft reinforcement of a catheter shaft, in accordance with one embodiment of the present disclosure.
  • FIGS. 6a - 6c are schematic illustrations of an exemplary catheter shaft reinforcement of a catheter shaft, in accordance with the respective embodiment the present disclosure.
  • FIG. 7 provides fatigue data presented in a chart.
  • FIG. 8 provides fatigue data presented in a chart.
  • FIG. 9 provides fatigue data present in a chart.
  • FIGS. 10a - lOd provide schematic illustrations of an exemplary catheter shaft reinforcement of a catheter shaft, in accordance with the respective embodiment the present disclosure.
  • FIGS. Ila - 11c provide schematic illustrations of an exemplary catheter shaft reinforcement of a catheter shaft, in accordance with the respective embodiment the present disclosure.
  • FIGS. 12a - 12g provide schematic illustrations of exemplary catheter shaft reinforcements of a catheter shaft, in accordance with the respective embodiments of the present disclosure.
  • the present disclosure provides an intravascular catheter blood pump system and related components designed for treating patients suffering with bodily fluid disorders including acute decompensated heart failure (ADHF), congestive heart failure (CHF), edema, and ascites.
  • ADHF acute decompensated heart failure
  • CHF congestive heart failure
  • edema edema
  • ascites ascites.
  • distal or proximal are used in the following description with respect to a position or direction relative to the treating physician. “Distal” or “distally” are a position distant from or in a direction away from the physician. “Proximal” or “proximally” or “proximate” are a position near or in a direction toward the physician.
  • FIGS, la through 1c provide schematic illustrations of an intravascular catheter blood pump system 1, in accordance with exemplary embodiments of the present disclosure.
  • the catheter blood pump system 1 may be configured to treat the patient by supporting a pressure reduction in a portion of a blood vessel, which may include with respect to a downstream or upstream region of the blood vessel.
  • the reduction in pressure in a portion of a blood vessel supports the removal of excess fluid from the patient (decongestion) suffering with a fluid overload condition.
  • decongestion therapies may be delivered by the catheter blood pump system 1 alone, or in conjunction with drug therapies.
  • Non-limiting drug therapies include those known in the art in such procedures, which may include diuretic therapy and/or vasodilative therapy.
  • the catheter blood pump system 1 comprises a system configured to lower pressure at the outflow of one or more lymphatic ducts.
  • this reduced pressure at the outflow supports drainage of interstitial fluid back to the vascular compartment, and may relieve excessive interstitial pressure in critical organs such as the heart and kidneys.
  • the pressure when the pressure is lowered by the catheter blood pump system 1 at the outflow of a lymphatic duct, this in turn stimulates lymph flow and there is an increase in the rate at which lymph fluid passes through the lymphovenous junction (LVJ).
  • LVJ lymphovenous junction
  • lymphatic engorgement In fluid overloaded patients with elevated central venous pressure, an increase in the rate of lymph flow has been shown to reduce lymphatic engorgement and reduces the pressure in the lymphatic system. This reduction in engorgement and pressure in the lymphatic network allows interstitial fluid to drain into the lymphatic capillaries, thus creating new lymph fluid. As the new lymph fluid is conveyed to the venous system via the lymphatic duct, the lymphovenous junction fluid overload in the interstitial tissues is reduced and the patient decongestion progresses.
  • the lymphatic system includes two important lymphatic ducts, the right lymphatic duct and the left lymphatic duct (also called the thoracic duct). Either duct is a potential target for therapy using the devices and methods of the present disclosure incorporating a reinforced flexible catheter shaft, as described herein. However, since the thoracic duct system drains approximately 75% of the body, it represents a preferred target for therapy. Nevertheless, in certain aspects, the methods and devices of the disclosure are used in the right or right and left lymphatic ducts.
  • the catheter blood pump system 1 may include a system configured to enhance blood flow through one or more kidneys by lowering the pressure in veins that drain blood from the kidneys.
  • the catheter blood pump system 1 may be configured for deployment in the arterial system to provide mechanical circulatory support systemically, to a portion of the systemic circulation, and/or or to a particular organ.
  • the mechanical circulatory support may be used, for example, to treat patients with ADHF, chronic heart failure patients, patients in cardiogenic shock, or patients suffering with edema.
  • the catheter blood pump system 1 may be configured for placement in the thoracic aorta. In another variation, the catheter blood pump system 1 may be configured and placed in the abdominal aorta. In another variation, the catheter blood pump system 1 may be configured and placed in a branch vessel of the aorta. [0066] In another aspect, the catheter blood pump system 1 may be configured for deployment in a cardiac chamber to provide mechanical circulatory support to a patient suffering with left ventricular dysfunction or right ventricular dysfunction of biventricular dysfunction.
  • the catheter blood pump system 1 includes an elongate catheter assembly 2, a sheath 3 and a console 4.
  • the console may be provided as an assembled unit (i.e., multiple components provided either on a mobile cart 52 or other carrier).
  • the console may include a controller 51 and computing system operably associated with the system for controlling operation of the blood pump system.
  • the computing system may interface with a control system architecture comprising, in non-limiting examples, one or more of a computer, a processor, a network, and a graphical user interface (GUI) 50 to allow the user to interact with and control the operation of the blood pump system.
  • GUI graphical user interface
  • the console via the user interface, may include one or more input/output mechanisms, such as a keyboard, knobs, buttons, scroll wheels, or the like, with which a user can interact so as to operate the system.
  • the user interface may be a touchscreen integrated into the structural architecture of the console.
  • the user interface may be physically connected to the system, may be integrally formed with the system, or may be located remotely.
  • the user interface may be a handheld device, e.g., a smart tablet, a smart phone, or a specialty device produced for the device.
  • the elongate catheter assembly 2 may include a catheter shaft 100 having a catheter distal end 102 and a catheter proximal end 109.
  • the catheter distal end 102 is configured for placement and operation in the vasculature of a patient.
  • the catheter proximal end 109 is configured to extend from the patient and at least partially interconnect the catheter pump assembly 101 of the catheter distal end 102 to a motor 5 located at a proximal region of the catheter proximal end 109.
  • the catheter distal end 102 is configured to conform to the anatomy of the blood vessels of the patient into which it is advanced, placed and operated.
  • the catheter proximal end 109 is connected to the catheter manifold 114 and is configured to allow the catheter manifold 114 to be placed in a variety of positions on the body or apparel of the patient.
  • the shaft of the catheter proximal end 109 must thus be conformable and capable to assuming an undulating configuration to allow comfortable placement of the catheter manifold 114 on or relative to the patient.
  • the sheath 3 and the catheter pump assembly 101 are placed in their respective vessels and the sheath access site 106 is fixed.
  • the catheter manifold 114 and the sheath manifold 113 may be couplable and decouplable and may be then fixed to the patient’s body or apparel with proximal manifold fixation 117 and/or distal manifold fixation 116.
  • the proximal manifold fixation 117 and distal manifold fixation 116 may comprise taping the manifolds, clipping the manifolds and/or stitching the manifolds to the patient or the apparel of the patient.
  • the catheter manifold 114 may also include a catheter flushing luer 120, which is configured to flush at least one gap that exists between the moving impeller 126 and at least one of the static surfaces that are immediately adjacent the moving impeller 126.
  • the catheter flush luer 120 may be connected to a fluid transmission lumen 123c and the fluid transmission lumen 123c extends the length of the catheter shaft 100 and is configured to deliver flushing fluid to at least one of the gaps (distal or proximal) between the impeller 126 and an adjacent static surface within the pump assembly 101.
  • the drive shaft 112 may be connected to an impeller 126 in the catheter pump assembly 101 at its distal end and to the motor 5 at the proximal end of the drive shaft 112.
  • the drive shaft 112 transmits, in operation, rotational energy from the motor 5 through the central lumen 111 of the catheter shaft 100 to the impeller 126 of the catheter pump assembly 101.
  • Drive shaft fatigue failure is a significant technical impediment to the design of a catheter blood pump in which the motor and the impeller are spaced apart. This technical impediment may produce an acute issue in devices in which the impeller operates at high speeds (>10,000 RPM). This is especially true when the indwelling part of the catheter shaft is flexible and configured to conform to the anatomy of the patient and when the part of the catheter that extends external of the patient has to conform to a variety of potential manifold or motor placement positions. As the drive shaft rotates the impeller, it is subject to torque loading that is required to drive the impeller to pump the blood. Stresses on the drive shaft from catheter bending are further compounded with the torque stresses from rotating the catheter.
  • the present disclosure provides drive shafts 112 having excellent fatigue characteristics, including when the catheter shaft 100, in use, comprises a plurality of curves, including curves in multiple planes along the catheter shaft’s length, and even when a range of torque inputs are transmitted through the drive shaft 112 to drive the impeller 126.
  • Another advantageous feature of the present disclosure are drive shafts 112 and catheter shafts that in combination are configured and able to operate in indwelling applications for long periods of time and at drive shaft speeds that vary during therapy from about 2,000 RPM in standby situations to about 10,000 at “low speed” operation and even at speeds of up to 40,000 RPM or higher in parts of the therapy that require “high speed” operation and pumping.
  • the endurance limit (5e) 503 also called the fatigue limit, is the loading stress below at which an infinite number of loading cycles can be applied to a material or system without causing a fatigue failure of the material or system.
  • FIG. 8 shows an adaption of the S-N curve to the drive shafts of this disclosure.
  • the S-N Curve 520 comprises a plot of the maximum stress 522 in the drive shaft versus the number of drive shaft rotations 521 to drive shaft failure.
  • the maximum stress 522 in the drive shaft is equal to or lower than the endurance limit 523 then the drive shaft can operate an infinite number of shaft rotations 521 without failure.
  • FIG. 8 shows an example of a pump assembly and drive shaft designed to operate for 1 x 10 7 cycles.
  • a vertical line 525 at 1 x 10 7 cycles until it contacts the S-N curve and drawing a horizontal line from the point of intersection, a corresponding maximum stress 524 in the drive shaft fatigue can be determined.
  • This maximum stress 524 in the drive shaft corresponds to the maximum stress that is permissible in the drive shaft having a drive shaft life of 1 x 10 7 rotations without a drive shaft fatigue failure.
  • the drive shafts of this disclosure are generally elongate cylindrical members.
  • the drive shaft has a constant second moment of area about the neutral axis at any given cross section irrespective of the rotation of the drive shaft.
  • the drive shaft comprises a rod like member.
  • Rod like members typically have a constant second moment of area about the neutral axis irrespective of the angular displacement of the rod like member.
  • the drive shaft comprises a tubular member.
  • Tubular members also typically have a constant second moment of area about the neutral axis irrespective of the angular displacement of the tubular member.
  • the drive shaft comprises a plurality of members arranged at equal distances about a neutral axis.
  • the drive shaft comprises a plurality of members arranged at equal angles about a neutral axis.
  • the present disclosure provides methods for evaluating the fatigue performance of a drive shaft, such as those described and incorporated in the devices provided herein.
  • such methods include, determining a Rm-N curve representing the radius of curvature 552 (designated “r m ”) of a drive shaft neutral axis versus the number of rotations 551 (designated “n”), of the drive shaft (112, 212, 312 etc.); determining an intercept of the desired number of cycles (“n”) and the radius of curvature (“r m ”) falling on or near the Rm-N curve.
  • the minimum permissible radius of curvature 552 is the drive shaft endurance limit radius 553.
  • the minimum permissible radius of curvature can be evaluated from the Rm-N chart by drawing a vertical line 555 at the desired number of cycles until it intercepts the Rm-N curve and then drawing a horizontal line from the point of interception to the Rm axis to identify the corresponding minimum fatigue radius 554.
  • the present disclosure also provide methods for determining safe bending strains on a drive shaft (112, 212, 312) configured to operate within the catheter central lumen.
  • this can be calculated by first determining the bending strain associated with the most extreme geometric configuration into which the catheter shaft (100, 200, 300 etc.) is placed when in use. This can then be compared to the elastic strain limit of the drive shaft material and the fatigue limit of the drive shaft to determine a safe operating range for the drive shaft.
  • catheter reinforcements of the disclosure to be tailored to ensure that, during use within a patient, the drive shaft (112, 212, 312) never experiences bending strains outside its safe operational range.
  • the device and methods of the disclosure are designed to protect the drive shaft (112, 212, 312) from strains falling outside the elastic range of the material.
  • the present disclosure also provide methods and devices designed and able to protect the drive shaft (112, 212, 312) from strains that are beyond the fatigue limit for the drive shaft (112, 212, 312) in its blood pumping application.
  • the bending strain can be calculated from elongation or compression at the external surfaces of the drive shaft using the following formula:
  • Ci 2nr m c 2 2n r m + 0)
  • the drive shaft (112, 212, 312 etc.) may also experience stresses and strains from pumping blood. Tortional energy is transmitted from the motor 5, to the impeller 126 of the pump assembly 101, through the drive shaft (112, 212, 312 etc.). Consequently, as the rotation of the drive shaft increases to pump a greater volume, this may cause the drive shaft (112, 212, 312 etc.) to be increasingly loaded in torsion during use as this pumping energy is transmitted to it.
  • the blood pumps 1 of this disclosure are configured to operate at speeds of up to 10,000 RPM, 20,000 RPM, 30,000 RPM, 40,000 RPM, 50,000 RPM, at higher speeds and at intermediate speeds.
  • the present disclosure provides methods for assessing torque stress resulting from blood pumping during operation.
  • the torque stress on the drive shaft (112, 212, 312) associated with the transmission of torsional energy to the pump assembly 101 is calculated from the torque on the drive shaft (112, 212, 312 etc.) using the following formula: 0T T ⁇ 2J
  • the outside diameter of the drive shaft (112, 212, 312 etc.) arrangement is less than or equal to 0.20mm over at least a portion of the length of the drive shaft.
  • the outside diameter of the drive shaft (112, 212, 312 etc.) arrangement is less than or equal to 0.15mm over at least a portion of the length of the drive shaft.
  • the outside diameter of the drive shaft (112, 212, 312 etc.) arrangement is less than or equal to 0.10mm over at least a portion of the length of the drive shaft.
  • the outside diameter of the drive shaft (112, 212, 312 etc.) arrangement is between about 0.10mm and about 0.15mm, or between about 0.15mm and about 0.20mm, or between about 0.20mm and about 0.25mm, or between about 0.25mm and about 0.30mm over at least a portion of the length of the drive shaft.
  • the drive shaft (112, 212, 312 etc.) comprises an elastic metallic material.
  • the drive shaft (112, 212, 312 etc.) comprises a material with an elastic limit of 4% or greater.
  • the drive shaft (112, 212, 312 etc.) comprises a material with an elastic limit of 6% or greater.
  • the drive shaft (112, 212, 312 etc.) comprises a material with an elastic limit of 7% or greater. In one embodiment the drive shaft (112, 212, 312 etc.) comprises a material with an elastic limit of approximately 8%. In one embodiment the drive shaft (112, 212, 312 etc.) comprises a super elastic or shape memory material. In one embodiment the drive shaft (112, 212, 312 etc.) comprises a material with an elastic limit of between about 4% and about 10%. In one embodiment the drive shaft (112, 212, 312 etc.) comprises a material with an elastic limit of between about 4% and about 8%. In one embodiment the drive shaft (112, 212, 312 etc.) comprises a super elastic or shape memory material that has been thermally treated to exhibit high elasticity (recoverable strain) at a temperature of 37 degrees Celsius.
  • the endurance limit of the drive shaft 112 is shown using a parameter disclosed herein as the “fatigue radius limit” 553.
  • the fatigue radius limit 553 is defined as the radius of curvature above which an infinite number of loading cycles can be applied to a drive shaft 112 without causing a fatigue failure of the drive shaft 112.
  • the drive shaft 112 comprises a fatigue radius limit of 100mm or greater. In certain aspects, the drive shaft 112 comprises a fatigue radius limit of 75mm or greater. In certain aspects, the drive shaft 112 comprises a fatigue radius limit of 50mm or greater. In certain aspects, the drive shaft 112 comprises a fatigue radius limit of 25mm or greater. In certain aspects, the drive shaft 112 comprises a fatigue radius limit of 15mm or greater. In certain aspects, the drive shaft 112 comprises a fatigue radius limit of between 100mm and 1mm. In certain aspects, the drive shaft 112 comprises a fatigue radius limit of 50mm or greater. In certain aspects, the drive shaft 112 comprises a fatigue radius limit of
  • the drive shaft 112 comprises a fatigue radius limit of
  • the drive shaft 112 comprises a fatigue radius limit of
  • the drive shaft 112 comprises a fatigue radius limit of between 100mm and 1mm.
  • the drive shaft 112 is configured to operate within the catheter central lumen 111 of the catheter shaft 100 for at least 1.0 X 10 7 revolutions. In certain aspects, the drive shaft 112 is configured to operate within the catheter central lumen 111 of the catheter shaft 100 for at least 1.0 X 10 8 revolutions. In certain aspects, the drive shaft 112 is configured to operate within the catheter central lumen 111 of the catheter shaft 100 for at least 1.0 X 10 9 revolutions.
  • the drive shaft 112 comprises a drive shaft neutral axis 127a.
  • the drive shaft neutral axis 127a comprises the line within the body of the drive shaft 112 which undergoes neither compression nor extension when the drive shaft 112 is bent into a curved configuration in its elastic range.
  • the neutral axis 127a lies on or very close to the central axis of the rod like drive shaft.
  • the drive shaft neutral axis 127a thus interconnects all the points of the drive shaft 112, which exhibit neither extension nor compression when the drive shaft 112 is placed in a curved or bent or tortuous configuration.
  • the catheter shaft 100 comprises a catheter reinforcement or support structure 125 configured to prevent the catheter shaft 100 from assuming a radius of curvature that is less than the fatigue radius limit 553 of the drive shaft 112.
  • the catheter support structure 125 comprises a tubular metallic reinforcement.
  • the tubular metallic reinforcement may comprise a non-continuous tubular structure.
  • the tubular metallic reinforcement comprises a porous structure.
  • the tubular metallic reinforcement comprises a laser cut structure.
  • the catheter support structure 125 comprises a compliant state in which the catheter support structure comprises a low resistance to bending and a lock-up state in which the catheter support structure 125 comprises a high resistance to bending.
  • the catheter support structure 125 comprises the compliant state when the radii of curvature of its central axis are greater than a limit radius 130.
  • the radius of curvature of a catheter shaft 100, in use is variable and it is possible for the catheter support structure 125, in operation, to be simultaneously in the compliant state and in the lock-up state.
  • the catheter shaft 100 may simultaneously have a plurality of segments wherein the catheter support structure 125 is in the locked-up state and a second plurality of segments wherein the catheter support structure 125 is in the compliant state.
  • a segment of the catheter shaft 100 is in the locked-up state and the catheter shaft 100 experiences further bending forces, those forces will be resisted by the segments of the catheter shaft 100 that are locked-up and those bending stresses will be absorbed by the segments of the catheter shaft 100 that are in the compliant state.
  • the catheter support structure 125 is flexible and compliant and can assume complex multiplanar curves with a low resistance to bending - i.e., a low bending stiffness.
  • the lock-up configuration is triggered in the catheter support structure 125 when the radius of curvature of the axis of the catheter support structure 125 is equal to the limit radius 130.
  • the support structure offers substantially more resistance to further bending than when in the compliant state.
  • the catheter support structure 125 is stiffer in bending in the lock-up state than in the compliant state.
  • the bending stiffness of the support structure 125 in the lock-up state is at least about 200% the bending stiffness of the support structure 125 in the compliant state.
  • the bending stiffness of the catheter support structure 125 in the lock-up state is at least about 300% the bending stiffness of the catheter support structure 125 in the compliant state.
  • the bending stiffness of the catheter support structure 125 in the lock-up state is at least about 400% the bending stiffness of the catheter support structure 125 in the compliant state.
  • the bending stiffness of the catheter support structure 125 in the lock-up state is about 500% the bending stiffness of the catheter support structure 125 in the compliant state.
  • the bending stiffness of the catheter support structure 125 in the lock-up state is between 200% and 500% the bending stiffness of the catheter support structure 125 in the compliant state.
  • the bending stiffness curve for a reinforcement of the disclosure comprises a bending stress, in Pascals, plotted on the y-axis of a chart versus the radius of curvature of the reinforcement, in millimeters, plotted on the of the x-axis of the chart.
  • the bending stiffness chart undergoes a distinct change in slope when the radius of curvature of the reinforcement goes below the limit radius 130.
  • the limit radius 130 of the catheter support structure 125 comprises a radius of less than 100mm. In certain aspects, the limit radius 130 of the catheter support structure 125 comprises a radius of less than 80mm. In one embodiment the limit radius 130 of the catheter support structure 125 comprises a radius of less than 60mm. In certain aspects, the limit radius 130 of the catheter support structure 125 comprises a radius of less than 50mm. In certain aspects, the limit radius 130 of the catheter support structure 125 comprises a radius of less than 40mm. In certain aspects, the limit radius 130 of the catheter support structure 125 comprises a radius of less than 40mm. In preferred aspects, the limit radius 130 of the catheter support structure 125 comprises a radius of between 30mm and 100mm.
  • the catheter distal end 102 may include a catheter pump assembly 101, which has been designed and configured for safe, anti-thrombotic and anti-hemolytic operation in contact with human blood during the treatment of the patient.
  • a catheter pump assembly 101 may comprises a pump inlet region 132, a blood acceleration channel 131, an expandable restrictor 129 encircling the blood acceleration channel 131 and a pump outlet region 133.
  • the pump inlet region 132 may comprise a plurality of inlet openings and the pump outlet region 133 comprises a plurality of outlet opens.
  • the blood acceleration channel 131 may comprise a cylindrical lumen defined by an outer wall the cylindrical lumen interconnecting the pump inlet region 132 with the pump outlet region 133 and the pump assembly 101 further comprises an impeller 126 disposed in the cylindrical lumen of the blood acceleration channel 131.
  • the impeller 126 is preferably mounted on a bearing arrangement 134, which bearing arrangement 134 is configured to facilitate the rotation of the impeller 126 within the blood acceleration channel 131 without contact with any of the surfaces of the blood acceleration channel 131.
  • the bearing arrangement 134 is optimally configured to control axial and radial positioning of the impeller 126.
  • the impeller 126 may further be connected/coupled to the drive shaft 112 and is configured to rotate in response to rotational energy delivered by the drive shaft 112.
  • the catheter shaft 100 may further comprise a plurality of control lumens 123.
  • At least one pressure sensing lumen 123a extends proximally from a pressure sensing port 173 in the catheter distal shaft 102 to the proximal end of the proximal catheter shaft 109 and allows at least one catheter pressure sensor 128 to measure pressure at a region adjacent to the catheter distal shaft 102 and transmit said pressure measurement through a pressure sensing cable 162 in the catheter pressure sensing lumen 123a to the console 4.
  • the pressure sensor 128 may provide intermittent, or preferably, continuous pressure readings to the console 4 during operation and including during treatment of the patient.
  • the console 4 is configured to receive said at least one plurality of pressure readings, analyze the data and control the operation of the catheter blood pump system 1 based on the analysis of said at least one plurality of pressure readings.
  • the controller of the console 4 changes the speed of the motor 5 as a result of said analysis.
  • the controller of the console 4 activates an alarm as a result of said analysis.
  • the controller of the console 4 displays pressure data or a pressure data chart as a result of said analysis.
  • the controller of the console 4 provides, in response to such analysis, a prompt to a person operating the device, said prompt suggesting that a change in the speed of the motor 5 is needed as a result of the analysis.
  • the person receiving the prompt may accept or decline the suggestion (e.g., by voice command or other input), at which point the console controls the speed of the motor 5 accordingly.
  • At least one control lumen 123 which may be a second control lumen 123, may comprise a restrictor inflation lumen 123b configured for the inflation of a balloon restrictor 129 located on the catheter distal end 102.
  • the restrictor inflation lumen 123b is fluidically connected to the interior space of the balloon restrictor 129 and extends proximally to the catheter manifold 114. In the catheter manifold 114, the restrictor inflation lumen 123b fluidically connects to the catheter balloon inflation stopcock 121.
  • the catheter balloon stopcock 121 can thus be used in combination with a syringe or other inflation device to inflate the balloon restrictor 129, hold the balloon restrictor 129 in an inflated state, adjust the inflated diameter of the balloon restrictor 129 and deflate the balloon restrictor 129.
  • At least one control lumen 123 which may be a third control lumen 123 may comprise a catheter flushing lumen 123c configured to transmit biological fluids to the catheter pump assembly 101.
  • At least one control lumen 123 which may be at least a fourth control lumen, comprises a sensing lumen 123d configured to accommodate a sensor.
  • the sensor is configured to measure an electrical property of the patient’s blood or bodily tissue or both.
  • the electrical property measured by the electrical sensor may comprise impedance, resistance, permittivity, and conductivity.
  • the distal region of the drive shaft 112 may be fixedly coupled to the impeller 126 of the catheter pump assembly 101.
  • a proximal region of the drive shaft 112 is coupled to a central shaft that extends from the rotor of the motor 5.
  • the coupler that connects the rotor of the motor 5 to the drive shaft 112 may be configured to transmit rotational energy of the motor 5 to the drive shaft 112.
  • the coupling comprises a sliding coupling wherein some axial motion of the drive shaft 112 relative to the motor 5 is facilitated in operation but the drive shaft 112 and the shaft of the motor 5 rotate one to one during operation of the catheter blood pump assembly 101.
  • the sheath 3 is configured to be inserted into a patient’s blood vessel at an access site 106.
  • the sheath 3 may include a dilator (not shown) to help dilate the vessel and achieve smooth vascular access.
  • the dilator is disposable, and once vascular access is achieved the dilator is removed and discarded.
  • the sheath 3 may comprise a sheath shaft 105, sheath hub 107, a sheath control shaft 110, sheath manifold 113, sheath restrictor balloon 104 and sheath cable 118.
  • the sheath shaft 105 comprises a large inner lumen sized to facilitate the delivery and removal of the catheter shaft 100 and catheter pump assembly 101.
  • the sheath shaft 105 comprises a restriction balloon 104 mounted adjacent its distal end and a sheath tip 103 at the sheath shaft 105 distal end.
  • the restriction balloon 104 is configured when inflated to restrict fluid flow in the vessel in which it is placed.
  • the sheath balloon 104 is placed in an access vein such as the internal jugular, subclavian, femoral, or iliac vein.
  • the sheath hub 107 comprises a gasket arrangement, the gasket arrangement configured to allow the introduction and removal of devices through the sheath 3 without significant blood loss.
  • the sheath 3 further comprises a catheter locking mechanism 108, the catheter locking mechanism 108 configured to lock the catheter shaft 100 to the sheath 3 when the pump assembly 101 is placed at the target location in the blood vessel (vein or artery).
  • the sheath 3 further comprises a sheath control shaft 110.
  • the sheath control shaft 110 comprises a shaft with a plurality of lumens therein.
  • a first lumen of sheath control shaft 110 is configured to facilitate the inflation of the sheath restrictor 104 via the sheath balloon inflation stopcock 122.
  • a second lumen of sheath control shaft 110 is configured to accommodate a pressure sensor at the distal end of the sheath shaft 105, adjacent the restrictor balloon 104.
  • a third lumen of sheath control shaft 110 is configured to facilitate the flushing of the large inner lumen of the sheath shaft 105 with biological fluids.
  • the sheath manifold 113 is configured to nest with the catheter manifold 114.
  • the pressure sensor of the sheath 3 is connected to the console 4 via sheath cable 118.
  • the catheter shaft 100 is connected to a catheter manifold 114 at the proximal end of the catheter proximal shaft 109.
  • the motor 5 is mounted in two a vibration absorbing caps within the catheter manifold 114 and the drive shaft of the motor 144 is coupled to the catheter drive shaft 112.
  • the catheter cable 119 extends between the manifold 114 and the console 4.
  • the catheter cable 119 interconnects the motor 5 and the console 4.
  • the catheter cable 119 transmits power and information about the speed of the motor shaft between the console 4 and the motor 5.
  • the catheter cable 119 also carries the pressure sensor shaft 162 which conveys pressure measurement data to the console 4.
  • the catheter cable 119 also comprises at least one inflation lumen and a plurality of sensor cables.
  • both the sheath 3 and the catheter 2 of the catheter blood pump system 1 are fixed to allow stable and continuous operation.
  • the sheath 3 may be sutured to the skin of the patient or may be held steadfast with a stat-lock device.
  • the catheter shaft 100 is then locked to the sheath 3 with a catheter to sheath locking mechanism 108.
  • the catheter 2 to sheath locking mechanism 108 is mounted on the catheter shaft 100 and slides along the catheter shaft 100 and is coupled to the sheath hub 107, the coupling to the sheath hub 107 activating the locking between the sheath 3 and catheter shaft 100.
  • the catheter to sheath locking mechanism 108 further comprises a compressible tubular gasket with an inner lumen the tubular gasket configured to slide over the catheter shaft 100.
  • the tubular gasket is compressed and in the compressed state its inner lumen (diameter) contracts onto the surface of the catheter shaft 100 and locks to the surface of the catheter shaft 100.
  • FIG. 2a a catheter 2 of the catheter blood pump system 1, in accordance with an embodiment of the present disclosure is described.
  • the catheter shaft 100 of the catheter 2 is shown navigating a series of curves of different diameters.
  • the distal catheter shaft 102 is shown conforming to a first large curve 152a.
  • This first large curve 152a comprises a curve that is much larger in radius than the limit radius 130 of the catheter shaft 100 and so the catheter shaft 100 easily conforms to the first large curve 152a as of course does the catheter shaft reinforcement 125.
  • the catheter shaft 100 In conforming to the first large curve 152a, the catheter shaft 100 is configured such that there is no net reduction in the catheter shaft length nor increase in catheter shaft length under the influence of the bending forces required to induce the first large curve 152a. This is not to say that there is no compression nor extension.
  • material on the inside of the first large curve is strained compressively and material on the outside of the first large curve 152a is strained extensively.
  • the catheter shaft reinforcement 125 is configured to control the neutral axis of the catheter shaft 100.
  • the catheter shaft reinforcement 125 comprises a stiff material with a geometric configuration and the combination of these ensures that it is stronger in compression than the combination of the protective outer jacket 160, the multilumen tubing 161 and the drive shaft liner 163.
  • the catheter shaft 100 is placed in a curved configuration the mechanical drive of one or more of the protective outer jackets 160, the multilumen tubing 161 and the drive shaft liner 163 to shorten in length is resisted by the relatively higher compressive strength of the catheter shaft reinforcement 125.
  • the catheter shaft reinforcement 125 further comprises a stiff material with a geometric configuration, the combination of which ensures that it is stronger in tensile mode than the combination of the protective outer jacket 160, the multilumen tubing 161 and the drive shaft liner 163.
  • the catheter shaft 100 is placed in a curved configuration the mechanical drive of one or more of the protective outer jackets 160, the multilumen tubing 161 and the drive shaft liner 163 to increase in length is resisted by the relatively higher tensile strength of the catheter shaft reinforcement 125.
  • the neutral axis 127b of the catheter shaft 100 is substantially colinear with the neutral axis 127a of the drive shaft 112. In this configuration produces no net strain on the catheter shaft neutral axis 127b meaning that there is also no net strain on the drive shaft 112 when the catheter assumes the first large curve 152a.
  • the principles outlined in this paragraph and the preceding paragraph apply equally to the first large curve 152a, the second large curve 152b, the first limit curve 151 and the second limit curve 150 of the catheter shafts of the present disclosure.
  • Such analysis may also be used in methods for assessing devices, such as those of the present disclosure, and those otherwise lacking the features of a reinforced catheter shaft.
  • the catheter shaft 100 Proximal of the first large curve 152a, the catheter shaft 100 is seen conforming to a portion of a second large curve 152b.
  • the radius of the second large curve 152b is smaller than the radius of the first large curve 152a but it is still larger than the limit radius 130 of the catheter shaft 100.
  • the limit radius 130 of the catheter shaft 100 is the radius at which the catheter shaft reinforcement 125 locks up.
  • the catheter shaft 100 will not assume a curve with a radius that is smaller than the limit radius 130 of the catheter shaft 100.
  • the limit radius 130 of the catheter shaft 100 is the radius at which the catheter shaft reinforcement 125 locks up.
  • the catheter shaft 100 is shown conforming to a portion of a first limit curve 151.
  • the radius of the first limit curve 151 is equal to the limit radius 130 of the catheter shaft 100 and the catheter shaft 100 will not conform to a curve that has a smaller radius than this limit. It is at this diameter that the catheter shaft reinforcement 125 of the catheter shaft 100 locks up thus preventing the catheter shaft assuming a tighter curve.
  • the catheter shaft 100 is shown conforming to a second limit curve 150 over a substantial portion of the circumference of the second limit curve 150.
  • the second limit curve 150 while having the same magnitude of curvature as the first limit curve 151 is formed in the opposite direction.
  • the second limit curve 150 causes the catheter shaft 100 to bend in the opposite direction to the first limit curve and so the two curves in combination represent a significant challenge for most catheter systems.
  • the catheter shaft reinforcement 125 of the present disclosure allows the catheter shaft 100 to assume both curves at the same time without difficulty. As with the first limit curve 151, the catheter shaft 100 will not conform to a curve that is smaller than the second limit curve 150. While the curves 152, 151 and 150 of FIG. 2a are all coplanar, it will be appreciated that catheter shafts 100 of the present disclosure can conform to complex 3D undulating curves and where the same principles apply as described above.
  • FIG. 2b illustrates the bending stiffness 180 properties of three catheter shafts 100 in accordance with the present disclosure across a range of radii of curvature 181.
  • bending stiffness curves 186 can be created and these can be tailored to specific anatomic needs and configurations of the patient.
  • These bending stiffness curves 186 are generally characterized by three regions, as exemplified below.
  • the catheter shaft 100 Across a first region 182 the radii of curvature 181 are generally below the limit radius 183 of the catheter shafts 100. In this region, the catheter shaft 100 is easy to bend and flex and conforms to any given radius of curvature 181 without much resistance. A second region 184 starts once the radius of curvature 181 of the catheter shaft 100 is reduced to the limit radius 183. At radii or curvature 181 that are below the limit radius 183, the catheter shaft 100 behaves in a much stiffer fashion as the reinforcement locks up and in the locked- up state the reinforcement comprises more general deformation of the material of the reinforcement of the catheter shaft 100.
  • the bending stiffness 180 properties of the first catheter shaft as a function of radius of curvature 181 of the catheter shaft is represented on bending stiffness curve 186a.
  • the bending stiffness 180 properties of the second catheter shaft 100 as a function of radius of curvature 181 of the catheter shaft is represented on curve 186b and the bending stiffness 180 properties of the third catheter shaft as a function of radius of curvature 181 of the catheter shaft is represented on curve 186c.
  • the chart of FIG. 2b depicts a Y axis and an X-axis with bending stiffness 180 values being charted relative to the Y-axis and the radius of curvature 181 values being charted relative to the X-axis.
  • the first region 182a of the curve 186a ends when the catheter shaft reaches its limit radius 183a. At the limit radius 183a, the articulation regions reach the limit of articulation and the reinforcement locks up. Deforming the reinforcement of the catheter shaft below the limit radius 183a requires more general deformation of the material of the reinforcement of the catheter shaft. This is manifested on the curve 186a as a sharp increase in the bending stiffness 180 with very little reduction in radius of curvature 181. It is this sharp increase in bending stiffness 180 with little reduction in radius of curvature 181 that defines the “lock up” state of this particular catheter shaft of the disclosure. Deformation in the second region 184a of the curve 186a comprises general elastic deformation of the reinforcement of the catheter shaft.
  • This plastic deformation region 185a of the curve 186a can generally considered to be a failure or prefailure state and its presentation is thus somewhat academic.
  • the bending stiffness curve 186b of FIG. 2b shows that in a second embodiment of a catheter shaft is generally less stiff that the first catheter shaft. Its reduced stiffness may be attributed to the use of a less stiff reinforcement, or a different cut pattern/geometry, or a smaller diameter reinforcement, or a reduced wall thickness of reinforcement or a more flexible articulating feature design or a combination of the preceding.
  • the bending stiffness curve 186b of the second catheter shaft also comprises three distinct regions.
  • the first region of the curve 182b is characterized by the bending radii of curvature 181 of the catheter shaft being greater than the limit radius 183b for the catheter shaft.
  • This first region of the curve 182b comprises a low bending stiffness generally plateau region and corresponds to the flexing of articulation features of the reinforcement 125 of the catheter shaft.
  • the flexing of articulation features comprises the flexing of connectors in the structure of a laser cut pattern (or pattern produce using any other means known in the art, such as milling, waterjet, and additive manufacture techniques) of the reinforcement.
  • the flexing of articulation features comprise the relative movement of adjacent rings of the reinforcement with respect to each other.
  • the first region 182b of the curve 186b ends when the catheter shaft reaches its limit radius 183b. At the limit radius 183b, the articulation regions reach their limit of articulation and the reinforcement locks up. Deforming the reinforcement of the second catheter shaft below the limit radius 183b requires more general deformation of the material of the reinforcement of the catheter shaft. This is shown on the curve 186b as a sharp increase in the bending stiffness 180 with very little reduction in radius of curvature 181. It is this sharp increase in bending stiffness 180 with little reduction in radius of curvature 181 comprises the “lock up” state of catheter shafts of the disclosure.
  • bending deformation in the second region 184b of the curve 186b comprises general elastic deformation of the material of the reinforcement of the catheter shaft.
  • the shape of the curve 186b in this general elastic second region 184b comprises a generally linear relationship between decreasing radius of curvature 181 (deformation) and bending stiffness 180. Beyond the second region 184b further reductions in the radius of curvature 181 of the catheter shaft lead to general plastic deformation of the reinforcement of the catheter shaft.
  • This plastic deformation region 185b of the curve 186b can generally considered to be a failure or pre-failure state.
  • the bending stiffness 180 properties of the third catheter shaft as a function of radius of curvature 181 of the catheter shaft is represented on bending stiffness curve 186c.
  • FIGS. 3a and 3b illustrate variants of the catheter 2 of the catheter blood pump system 1, in accordance with respective embodiments of the present disclosure.
  • FIG. 3a illustrates a side-elevation view of the catheter shaft 100
  • FIG. 3b shows a cross- sectional view of the catheter shaft 100 at section A-A.
  • FIG. 3a also shows the interconnection of the catheter shaft distal end 102 with the pump assembly cuff 174 at the proximal end 172 of the pump assembly 101 and illustrating a portion of the pump inlet region 175.
  • the catheter 2 may comprise a catheter shaft 100, catheter pump assembly 101, drive shaft 112 and catheter manifold 114 (not shown).
  • the catheter shaft 100 of the catheter 2 comprises an elongate assembly 171 the elongate assembly comprising a multi-lumen tubing 161, catheter shaft reinforcement 125, protective outer jacket 160 and a drive shaft liner 163.
  • the catheter shaft 100 may further comprise four concentric layers each layer providing the catheter 2 with functionality to the operation of the catheter blood pump system 1.
  • the catheter shaft reinforcement may have a wall thickness 165 tailored to specific anatomic needs and/or configurations of a patient.
  • the drive shaft liner 163 comprises the inner most layer of the catheter shaft 100.
  • the drive shaft liner 163 is configured to envelop the drive shaft 112 and is sized to provide a running clearance fit with the drive shaft 112 such that the drive shaft 112 can operate at high rotational speed within the drive shaft liner 163 without generating friction or unwanted heat.
  • a running clearance fit comprises a fit between the drive shaft 112 and the drive shaft liner 163 whereby the annular gap 166 between the two is sufficiently large to allow the drive shaft 112 to operate at high rotational speeds without generating frictional heat and at the same time at least a portion of the annular gap 166 is sufficiently small such that the drive shaft 112 in operation is rotationally guided by the drive shaft liner 163 to rotate around a stable axis within the drive shaft liner 163.
  • the drive shaft liner 163 comprises a low friction material, which is preferably a polymeric material or coating.
  • the drive shaft liner 163 comprises fluoropolymer or a polyether ether ketone, or a PTFE material or a PTFE filled material, or a polyoxymethylene or a nylon 11 or a nylon 12.
  • the annular gap 166 is preferably configured to resist the capillary action of blood and blood plasma.
  • capillary action means the ability of biological fluids such as blood, plasma, and lymph fluid to penetrate and travel along small gaps or crevices.
  • the annular gap 166 between the drive shaft 112 and the drive shaft liner 163 is resistant to the capillary action of biological fluids.
  • the material of the surface of the drive shaft liner 163 comprises a material that is repulsive to biological fluid wetting.
  • the material of the surface of the drive shaft 112 comprises a material that is repulsive to biological fluid wetting.
  • the material of the surfaces of both the drive shaft liner 163 and the drive shaft 112 comprises a material that is repulsive to biological fluid wetting.
  • the annular gap 166 comprises a grease or other hydrophobic lubricating material with sufficient viscosity and resiliency.
  • the grease fills the annular gap 166 along at least a portion of the length of the annular gap 166.
  • the grease is selected from those greases that are repulsive to biological fluid wetting and/or capillary action.
  • the grease is selected to modify the friction between the drive shaft 112 and the drive shaft liner 163.
  • the grease comprises a viscous oily substance. In this embodiment, the grease performs as a lubricating seal, preventing blood or biological fluid ingress over the drive shaft 112.
  • Viscosity is a critical parameter of lubricating grease which measures its resistance to flow. Viscosity of greases generally have an inverse relationship with temperature such that as operating temperature increases the viscosity of the grease decreases which in turn decreases its resistance to flow or migration. An important characteristic relating to grease viscosity is the Viscosity Index.
  • the viscosity index (VI) is an arbitrary, unit-less measure of a fluid's change in viscosity relative to temperature change. A lubricant with high VI does not thin as readily as low VI lubricants at elevated temperatures. This is relevant to the present disclosure where increasing RPMs increases the operating temperature in the annular gap 166.
  • Silicone or Ester Poly-alpha-olefin based lubricants are used as they offer a high VI and hydrolytic stability and favorable lubricating properties.
  • the viscous grease may be comprised of one or more components.
  • the grease is comprised of a base oil and a thickener.
  • the base oil is preferably ester Poly-alpha-olefin based with a polyurea thickener.
  • the base oil viscosity and quantity of thickener can be varied to accommodate pressure head and drive shaft liner velocity requirements.
  • Alternative thickeners can be utilized to improve the resistance of the grease to biological fluids such as aluminum, lithium or calcium complexes.
  • a Poly-alpha-olefin base oil is paired with an aluminum complex thickener to improve washout and migration of the grease.
  • Poly-alpha-olefin and mineral oil are mixed with an aluminum complex thickener.
  • PFPE Perfluoropolyether
  • PTFE thickeners PFPE-/PTFE-pastes
  • high and medium consistency dimethyl silicone greases may be utilized.
  • Another important characteristic in relation to grease selection is the NLGI consistency number which expresses a measure of the relative hardness of a grease used for lubrication as established by the National Lubricating Grease Institute and illustrated in the table below.
  • the NLGI number of the grease used in the annular gap 166 has an NLGI number in the range of 0-4. In a preferred embodiment the NLGI number is in the range of 0-2 to optimize lubricating performance. In a further embodiment, where preventing grease washout and providing resistance to blood pressure, and blood pressure fluctuations is critical, an NLGI number of 2-3 is optimal.
  • the second innermost layer of the catheter shaft 100 comprises the reinforcement 125 which envelops the drive shaft liner 163 along at least a portion of its length.
  • the reinforcement 125 comprises a tubular member made from a rigid material with a reinforcement cut pattern 170, the reinforcement cut pattern 170 is configured to modify some of the mechanical properties of the reinforcement 125 while leaving other mechanical properties of the reinforcement 125 unaffected.
  • the reinforcement cut pattern 170 is configured to significantly reduce the bending stiffness of the reinforcement 125 while the hoop strength of the reinforcement 125 is substantially unchanged by the reinforcement cut pattern 170.
  • the reinforcement cut pattern 170 gives rise to a desirable asymmetry in the mechanical properties of the reinforcement 125 with the cut pattern 170 versus the tubular member from which the reinforcement 125 is derived. In one example of this asymmetry of mechanical properties, the tensile modulus and compressive modulus of the tubular member from which the reinforcement 125 is derived are similar whereas the tensile modulus is much lower than the compressive modulus of the reinforcement 125 with the cut pattern 170.
  • the cut pattern 170 of the reinforcement 125 of Fig 3a comprises a jigsaw pattern.
  • the cut pattern 170 results in a tubular reinforcement 125 that consists of plurality of tubular ring members 176.
  • the cut pattern 170 results in the reinforcement 125 comprising a plurality of separate ring members 176 that are geometrically coupled.
  • the geometric coupling of the ring members 176 comprises opposing features that nest together, for example, as described herein, “male” and “female” “jigsaw” features nesting together.
  • the geometric coupling comprises a first ring member 176a coupled to a second ring member 176b wherein the first ring member 176a comprises a plurality of male and female shaped dove tail features around its circumference and the second ring member 176b comprises a plurality of male and female shaped dove tail features around its circumference and each of the male dovetail features of the first ring member 176a nests with female dovetail features of the second ring member 176b and each of the female features of the first ring member 176a nests with male dovetail features of the second ring member 176b.
  • the nesting arrangement 177 of the ring members 176 is configured to be self-stabilizing.
  • the pattern comprises more than two shapes that nest together to form a jigsaw pattern.
  • the self-stabilizing ring members 176 comprises a plurality of ring members 176 whereby the cut pattern 170 leads to a nesting arrangement 177 of the ring members 176 and the nesting arrangement 177 holds the ring members 176 together without need for additional connecting or joining features.
  • the plurality self-stabilizing ring members 176 thus act as a single tube with its own set of mechanical properties that are different from the tube from which the ring members 176 originated.
  • the cut pattern 170 comprises a gap 169, which is preferably a laser cut gap 169, and the size of the cut gap 169 has an impact on the mechanical properties of the resulting reinforcement 125. Smaller cut gaps 169 tend to result in a reinforcement 125 whose mechanical properties are closer to the mechanical properties of the tube of origin whereas larger cut gaps 169 tend to result in a reinforcement 125 tubes whose mechanical properties are different to the tube of origin.
  • the multilumen tubing 161 sits on top of the reinforcement 125 and envelops the reinforcement 125.
  • the multilumen tubing 161 extends from the pump assembly 101 at its distal end 102 to the manifold 114 at its proximal end 109.
  • the multilumen tubing 161 comprises an inner lumen 135 and an outer diameter and a wall thickness.
  • the wall thickness of the multilumen tubing 161 is sufficient to accommodate a plurality of additional lumens.
  • the multilumen tubing 161 further comprises a plurality of control lumens 123 angularly spaced apart within the wall thickness of the multilumen tubing 161 and extend at least a portion of the length of the multilumen tubing 161.
  • At least one first control lumen 123a comprises one or more pressure sensing lumens and is configured to receive a pressure sensor 128.
  • the pressure sensor 128 placed in fluidic communication with a fluid inlet port 173 at its distal end such that the pressure sensor 128 can sense the pressure adjacent the inlet port 173 and the pressure sensor 128 is in electronic communication with the console 4 at its proximal end such that the pressure sensor 128 can transmit sensed pressure information to the console 4.
  • the inlet port 173 may be placed in number of positions on the catheter 2 and indeed there may be multiple inlet ports 173 and multiple pressure sensing lumens 123a and multiple pressure sensors 128.
  • the inlet port 173 and pressure sensor 128 is located proximally adjacent the pump assembly 101. In certain aspects, the inlet port 173 and pressure sensor 128 is positioned on the pump assembly 101.
  • a pressure sensing lumen 123a of the multilumen tubing 161 is extended through or across the pump assembly 101 and an inlet port 173 and pressure sensor 128 is positioned on a distal region of the pump assembly 101.
  • the pressure sensing lumen 123 a of the multilumen tubing 161 is extended through or across the pump assembly 101 and an inlet port 173 and pressure sensor 128 is located distal of the pump assembly 101.
  • a second control lumen 123b of the multilumen tubing 161 is configured for the inflation or expansion of a restrictor 129 mounted on the pump assembly 101.
  • the restrictor 129 comprises an inflatable elastomeric member with an inflation space 136 into which saline or biologically compatible fluid is pumped to expand the restrictor 129.
  • the inflation space 136 of the restrictor 129 comprises a sealed expandable cavity that is substantially torus shaped.
  • the second control lumen 123b comprises a pathway for fluid to ingress and egress to the otherwise sealed inflation space 136.
  • the restrictor 129 and the distal end of the multilumen tubing 161 are spaced apart and the second control lumen 123b comprises a tube that extends from the distal end of the multilumen tubing 161 into fluid connection with the inflation space 136 of the restrictor 129.
  • the second control lumen 123b of the multilumen tubing 161 extends proximally to a device configured for the inflation and/or deflation of the restrictor 129.
  • the second control lumen 123b extends to the manifold 114 and the manifold 114 comprises a catheter restrictor inflation stopcock 121.
  • the catheter restrictor inflation stopcock 121 is configured such that it can be connected to an inflation/deflation device to allow the user to control the inflation or deflation of the restrictor 129.
  • a third control lumen 123c of the multilumen tubing 161 is configured for the delivery of biologically compatible fluids to the pump assembly 101.
  • the third control lumen 123 c extends the length of the catheter shaft 100 from a catheter flush luer 120 at the proximal end exterior of the patient to the pump assembly 101 at the distal end.
  • the catheter flush luer 120 is configured for connection to a fluid flushing device or a fluid infusion pump which can deliver biological fluid to the pump assembly as a relatively constant low volume rate.
  • the distal end of third control lumen 123c is connected to the bearing arrangement 134 of the pump assembly 101 and by continuous infusion and/or positive fluid pressure prevents blood from entering the bearing arrangement 134.
  • third control lumen 123c is connected to at least one gap at the proximal or distal end of the impeller 126 (not shown) and at least partially prevents blood ingress into the at least one gap thereby preventing clot formation or build up in the at least one gap.
  • distal end of third control lumen 123c is connected to at least one region of high blood shear of the pump assembly 101 and the infusion of biologically compatible fluid into said region of high blood shear forms a protective barrier on the surface of the at least one high shear region and at least partially prevents clot formation or clot build up in the at least one high shear region of the pump assembly 101.
  • a fourth control lumen 123 d of the multilumen tubing 161 comprises a sensing lumen, or a steering lumen for the catheter shaft distal 102, or a shaping lumen to shape the catheter distal end 102.
  • a stiffening wire may be inserted into a control lumen along at least a portion of its length creating an increased bending resistance along this portion further customizing bending stiffness along the length of the catheter.
  • the multilumen tubing 161 comprises the outer most layer of the catheter shaft 100 over at least a portion of the length of the catheter 2.
  • the protective outer jacket 160 comprises the outermost layer of the catheter shaft 100.
  • the protective outer jacket 160 is configured to envelop the other layers of the catheter shaft 100 over at least a portion of the length of the catheter shaft 100.
  • the protective outer jacket 160 comprises a soft flexible polymeric jacket and is configured to sit within the sheath 3 extending from the sheath hub 107 proximally to the sheath distal tip 103 or beyond when the pump assembly 101 is operational.
  • the protective outer jacket 160 comprises an expanded state and a plurality of compressed states. When the catheter shaft 100 is not placed in the sheath 3 the protective outer jacket 160 assumes the expanded state and in the expanded state assumes its full diameter and shape.
  • the outer dimensions of the protective outer jacket 160 comprises a close fit or an interference fit with the inner diameter of the sheath shaft 105.
  • the inner diameter of the sheath tip 103 is however smaller than the inner diameter of the sheath shaft 105 and when the catheter shaft 100 is advanced through the sheath 3 into the operating position of the pump assembly 101 the protective outer jacket 160 assumes a first compressed state in its interaction with the sheath tip 103.
  • the catheter blood pump system 1 has the significant advantage of preventing blood from migrating into the annular space between the outer surface of the catheter shaft 100 and the inner surface of the sheath shaft 105.
  • This annular space comprises an isolated space and can be flushed with saline or other biological fluids and the combination of the flushing and sealing ensures that clot cannot form between the catheter 2 and the sheath 3 even during extended operation of the catheter blood pump system 1.
  • the protective outer jacket 160 comprises a second compressed state during the delivery of the catheter pump assembly 101 to the treatment location and during the removal of the guidewire thereafter.
  • the catheter 2 is advanced over a rapid exchange guidewire (typically a 0.014” or 0.018” diameter guidewire). Since the guidewire is rapid exchange then the guidewire travels through the lumen of the sheath 3 side by side with the catheter shaft 100.
  • the guidewire is placed in position in the patient and then the catheter 2 is advanced over the guidewire to the target location.
  • the catheter shaft 100 (including the protective outer jacket 160) is advanced through the inner lumen of the sheath shaft 105 side by side with the guidewire which is stationary during the delivery of catheter to the treatment location.
  • This step requires the protective outer jacket 160 to assume the second compressed state.
  • the guidewire and protective outer jacket 160 comprise an interference fit with the inner lumen of the sheath shaft 105 and this second compressed state of the protective outer jacket 160 enables the catheter 2 to be smoothly advanced through the sheath 3 and over the guidewire.
  • the protective outer jacket 160 preferably comprises a low friction material.
  • the compressible protective outer jacket 160 comprises a soft deformable material.
  • the compressible protective outer jacket 160 comprises a soft-porous material.
  • the compressible protective outer jacket 160 comprises smooth outer surface and a geometrically profiled inner surface, the geometrically profiled inner surface comprising empty spaces for material deformation, compression or buckling.
  • the compressible protective outer jacket 160 extends only a portion of the length of the catheter shaft 100 and comprises a smooth geometric transition with the catheter shaft 100.
  • FIGS. 4a and 4b alternative embodiments of catheter shaft 200 of the catheter blood pump system 1, in accordance with the present disclosure are described.
  • FIG. 4a shows a side elevation view of the catheter shaft 200 whereas
  • FIG. 4b shows a cross sectional view of the catheter shaft 200 at section B-B.
  • the catheter 2 comprises a catheter shaft 200, catheter pump assembly 201, drive shaft 212 and catheter manifold 214 (not shown).
  • the catheter shaft 200 of the catheter 2 comprises an elongate assembly the elongate assembly comprising a multilumen tubing 261, catheter shaft reinforcement 225, protective outer jacket 260 and a drive shaft liner 263.
  • the catheter shaft 200 further comprises a plurality of concentric layers.
  • the drive shaft liner 263 comprises the inner most layer of the catheter shaft 200 and is configured to envelop the drive shaft 212 and is sized to provide a running clearance fit with the drive shaft 212 such that the drive shaft 212 can operate at high rotational speed within the drive shaft liner 263 without generating friction or unwanted heat.
  • a running clearance fit comprises a fit between the drive shaft 212 and the drive shaft liner 263 whereby the annular gap 266 between the two is sufficiently large to allow the drive shaft 212 to operate at high rotational speeds without generating frictional heat and at the same time at least a portion of the annular gap 266 is sufficiently small such that the drive shaft 212 in operation is rotationally guided by the drive shaft liner 263 to rotate around a stable axis within the drive shaft liner 263.
  • the drive shaft liner 263 comprises a low friction polymeric material.
  • the drive shaft liner 263 comprises fluoropolymer or a polyether ether ketone, or a PTFE material or a PTFE filled material, or a polyoxymethylene or a nylon 11 or a nylon 12.
  • the annular gap 266 is preferably configured to resist the capillary action of blood and blood plasma.
  • capillary action hereby means the ability of biological fluids such as blood, plasma, and lymph fluid to penetrate and travel along small gaps or crevices of the catheter 2.
  • the annular gap 266 between the drive shaft 212 and the drive shaft liner 263 is resistant to the capillary action of biological fluids.
  • the material of the surface of the drive shaft liner 263 comprises a material that is repulsive to biological fluid wetting.
  • the material of the surface of the drive shaft 212 comprises a material that is repulsive to biological fluid wetting.
  • the material of the surfaces of both the drive shaft liner 263 and the drive shaft 212 comprises a material that is repulsive to biological fluid wetting.
  • the annular gap 266 comprises a grease.
  • the grease fills the annular gap 266 along at least a portion of the length of the annular gap 266.
  • the grease is selected from those greases that are repulsive to biological fluid wetting and/or capillary action.
  • the grease is selected to modify the friction between the drive shaft 212 and the drive shaft liner 263.
  • the grease comprises a viscous oily substance.
  • at least a portion of the annular gap 266 comprises a hydrophobic biocompatible grease, said grease selected so as to lubricate the rotational action of the drive shaft 212 while also acting as a capillary resistive barrier to biological fluid migration into the annular gap.
  • Viscosity is a critical parameter of lubricating grease which measures its resistance to flow. Viscosity of greases generally have an inverse relationship with temperature such that as operating temperature increases the viscosity of the grease decreases which in turn decreases its resistance to flow or migration. An important characteristic relating to grease viscosity is the Viscosity Index.
  • the viscosity index (VI) is an arbitrary, unit-less measure of a fluid's change in viscosity relative to temperature change. A lubricant with high VI does not thin as readily as low VI lubricants at elevated temperatures. This is relevant to the current disclosure where increasing RPMs increase the operating temperature in the annular gap 166.
  • the viscous grease may be comprised of one or more components.
  • the grease is comprised of a base oil and a thickener.
  • the base oil is preferably ester Poly-alpha-olefin based with a polyurea thickener.
  • the base oil viscosity and quantity of thickener can be varied to accommodate pressure head and drive shaft liner velocity requirements.
  • Alternative thickeners can be utilized to improve the resistance of the grease to biological fluids such as aluminum, lithium, or calcium complexes.
  • a Poly-alpha-olefin base oil is paired with an aluminum complex thickener to improve washout and migration of the grease.
  • Perfluoropolyether (PFPE) based oils with PTFE thickeners, PFPE- /PTFE-pastes, and high and medium consistency dimethyl silicone greases may be utilized to form the grease barrier.
  • the aluminum complex thickener helps the lubricant to stay in place and forms a protective film on the surfaces it lubricates.
  • the second innermost layer of the catheter shaft 200 comprises the reinforcement 225 which envelops the drive shaft liner 263 along at least a portion of its length.
  • the reinforcement 225 comprises a tubular member made from a rigid material with a reinforcement cut pattern 270, the reinforcement cut pattern 270 is configured to modify some of the mechanical properties of the reinforcement 225 while leaving other mechanical properties of the reinforcement 225 unaffected.
  • the reinforcement cut pattern 270 is configured to significantly reduce the bending stiffness of the reinforcement 225 while the hoop strength of the reinforcement 225 is substantially unchanged by the reinforcement cut pattern 270.
  • the reinforcement cut pattern 270 gives rise to a desirable asymmetry in the mechanical properties of the reinforcement 225 with the cut pattern 270 versus the tubular member from which the reinforcement 225 is derived.
  • the tensile modulus and compressive modulus of the tubular member from which the reinforcement 225 is derived are similar whereas the tensile modulus is much lower than the compressive modulus of the reinforcement 225 when the cut pattern 270 is implemented on the reinforcement 225.
  • the cut pattern 270 of the reinforcement 225 of FIG. 4a comprises a jigsaw pattern.
  • the cut pattern 270 results in a tubular reinforcement 225 that consists of plurality of tubular ring members 276.
  • the cut pattern 270 results in the reinforcement 225 comprising a plurality of separate ring members 276 that are geometrically coupled.
  • the geometric coupling of the ring members 276 comprises male and female jigsaw features nesting together.
  • the geometric coupling comprises a first ring member 276a coupled to a second ring member 276b wherein the first ring member 276a comprises a plurality of male and female shaped dove tail features around its circumference and the second ring member 276b comprises a plurality of male and female shaped dove tail features around its circumference and each of the male dovetail features of the first ring member 276a nests with female dovetail features of the second ring member 276b and each of the female features of the first ring member 276a nests with male dovetail features of the second ring member 276b.
  • the nesting arrangement 277 of the ring members 276 is configured to be self-stabilizing.
  • the self-stabilizing ring members 276 comprises a plurality of ring members 276 whereby the cut pattern 270 leads to a nesting arrangement 277 of the ring members 276 and the nesting arrangement 277 holds the ring members 276 together without need for additional connecting or joining features.
  • the plurality self-stabilizing ring members 276 thus act as a single tube with its own set of mechanical properties that are different from the tube from which the ring members 276 originated.
  • the cut pattern 270 comprises a plurality of cut gaps 269 (preferably laser cut) wherein each laser cut gap 269 (highlighted) circumnavigates the circumference of the reinforcement 225 and the size of the cut gap 269 has an impact on the mechanical properties of the resulting reinforcement 225.
  • Smaller cut gaps 269 tend to result in a reinforcement 225 whose mechanical properties are closer to the mechanical properties of the tube of origin whereas larger cut gaps 269 tend to result in a reinforcement 225 tubes whose mechanical properties are different to the tube of origin.
  • the multilumen tubing 261 sits on top of the reinforcement 225 and envelops the reinforcement 225.
  • the multilumen tubing 261 extends from the pump assembly 201 at its distal end 202 to the manifold 214 at its proximal end 209.
  • the multilumen tubing 261 comprises an inner lumen 211 and an outer diameter and a wall thickness.
  • the wall thickness of the multilumen tubing 261 is sufficient to accommodate a plurality of additional lumens in the wall of the multilumen tubing 261.
  • the multilumen tubing 261 further comprises a plurality of control lumens 223 angularly spaced apart within the wall thickness of the multilumen tubing 261 and extending at least a portion of the length of the multilumen tubing 261.
  • At least one first control lumen 223a comprises one or more pressure sensing lumens and is configured to receive a pressure sensor 228, the pressure sensor 228 configured for placement in fluidic communication with a fluid inlet port 273 at its distal end such that the pressure sensor 228 can sense the pressure adjacent the inlet port 273 and the pressure sensor 228 is in electronic communication with the console 4 at its proximal end such that the pressure sensor 228 can transmit sensed pressure information to the console 4.
  • the inlet port 273 may be placed in number of positions on the catheter 2 and indeed there may be multiple inlet ports 273 and multiple pressure sensing lumens 223a and multiple pressure sensors 228.
  • the inlet port 273 and pressure sensor 228 is located proximally adjacent the pump assembly 201. In certain aspects, the inlet port 273 and pressure sensor 228 is positioned on the pump assembly 101. In an embodiment, the pressure sensing lumen 223a of the multilumen tubing 261 is extended through or across the pump assembly 201 and an inlet port 273 and pressure sensor 228 is positioned on a distal region of the pump assembly 201. In certain aspects, the pressure sensing lumen 223 a of the multilumen tubing 161 is extended through or across the pump assembly 201 and an inlet port 273 and pressure sensor 228 is located distal of the pump assembly 201.
  • At least one first control lumen 223a comprises two first control lumens 223a wherein the first of the two first control lumens 223a comprises a lumen configured for the placement of a first pressure sensor internal to the catheter shaft 100 and adjacent the inlet port 273 with the second of the two first control lumens 223a configured to transmit pressure to a pressure sensor that is proximal and external of the catheter shaft 100.
  • This arrangement allows the first of the two first control lumens 223a to be calibrated during treatment with reference to the pressure sensor that is proximal and external of the catheter shaft 100.
  • a second control lumen 223b of the multilumen tubing 261 is configured for the inflation or expansion of a restrictor 229 mounted on the pump assembly 201.
  • the restrictor 229 comprises an inflatable elastomeric member with an inflation space 236 into which saline or biologically compatible fluid is pumped to expand the restrictor 229.
  • the inflation space 236 of the restrictor 229 comprises a sealed expandable cavity that in one embodiment is substantially torus shaped.
  • the second control lumen 223b comprises a pathway for fluid to ingress and egress to the otherwise sealed inflation space 236.
  • the restrictor 229 and the distal end of the multilumen tubing 261 are spaced apart and the second control lumen 223b comprises a tube that extends from the distal end of the multilumen tubing 261 into fluid connection with the inflation space 236 of the restrictor 229.
  • the second control lumen 223b of the multilumen tubing 261 extends proximally to a device configured for the inflation and/or deflation of the restrictor 229.
  • the second control lumen 223b extends to the manifold 214 and the manifold 214 comprises a catheter restrictor inflation stopcock 221.
  • the catheter restrictor inflation stopcock 221 is configured such that it can be connected to an inflation/deflation device to allow the user to control the inflation or deflation of the restrictor 229.
  • a third control lumen 223c of the multilumen tubing 261 is configured for the delivery of biologically compatible fluids to the pump assembly 201.
  • the third control lumen 223 c extends the length of the catheter shaft 200 from a catheter flush luer 220 at the proximal end exterior of the patient to the pump assembly 201 at the distal end.
  • the catheter flush luer 220 is configured for connection to a fluid flushing device or a fluid infusion pump which can deliver biological fluid to the pump assembly as a relatively constant low volume rate.
  • the distal end of third control lumen 223c is connected to the bearing arrangement 234 of the pump assembly 201 and by continuous infusion and/or positive fluid pressure prevents blood from entering the bearing arrangement 234.
  • the distal end of third control lumen 223c is connected to at least one gap at the proximal or distal end of the impeller 226 (not shown) and at least partially prevents blood ingress into the at least one gap thereby preventing clot formation or build up in the at least one gap.
  • the distal end of third control lumen 223c is connected to at least one region of high blood shear of the pump assembly 201 and the infusion of biologically compatible fluid into said region of high blood shear forms a protective barrier on the surface of the at least one high shear region and at least partially prevents clot formation or clot build up in the at least one high shear region of the pump assembly 201.
  • a fourth control lumen 223 d of the multilumen tubing 261 comprises a sensing lumen, or a steering lumen for the catheter shaft distal 202, or a shaping lumen to shape the catheter distal end 202.
  • the multilumen tubing 261 comprises the outer most layer of the catheter shaft 200 over at least a portion of the length of the catheter 2.
  • the protective outer jacket 260 comprises the outermost layer of the catheter shaft 200. polymeric jacket and is configured to sit within the sheath 3 extending from the sheath hub 107 proximally to the sheath distal tip 103 or beyond when the pump assembly 201 is operational.
  • the protective outer jacket 260 comprises an expanded state and a plurality of compressed states. When the catheter shaft 200 is not placed in the sheath 3 the protective outer jacket 260 assumes the expanded state and in the expanded state assumes its full diameter and shape.
  • the outer dimensions of the protective outer jacket 260 comprises a close fit or an interference fit with the inner diameter of the sheath shaft 105.
  • the inner diameter of the sheath tip 103 is however smaller than the inner diameter of the sheath shaft 105 and when the catheter shaft 200 is advanced through the sheath 3 into the operating position of the pump assembly 201 the protective outer jacket 260 assumes a first compressed state in its interaction with the sheath tip 103.
  • the catheter blood pump system 1 has the significant advantage of preventing blood from migrating into the annular space between the outer surface of the catheter shaft 200 and the inner surface of the sheath shaft 105.
  • This annular space comprises an isolated space and can be flushed with saline or other biological fluids and the combination of the flushing and sealing ensures that clot cannot form between the catheter 2 and the sheath 3 even during extended operation of the catheter blood pump system 1.
  • the protective outer jacket 260 comprises a second compressed state during the delivery of the catheter pump assembly 201 to the treatment location and during the removal of the guidewire thereafter.
  • the catheter 2 is advanced over a rapid exchange guidewire (typically a 0.014” or 0.018” diameter guidewire). Since the guidewire is rapid exchange then the guidewire travels through the lumen of the sheath 3 side by side with the catheter shaft 200.
  • the guidewire In advance of the delivery of the catheter 2 to the treatment location, the guidewire is placed in position in the patient and then the catheter 2 is advanced over the guidewire to the target location.
  • the catheter shaft 200 (including the protective outer jacket 260) is advanced through the inner lumen of the sheath shaft 105 side by side with the guidewire which is stationary during the delivery of catheter 2 to the treatment location.
  • This step requires the protective outer jacket 260 to assume the second compressed state.
  • the guidewire and protective outer jacket 260 comprise an interference fit with the inner lumen of the sheath shaft 105 and this second compressed state of the protective outer jacket 260 enables the catheter 2 to be smoothly advanced through the sheath 3 and over the guidewire.
  • the protective outer jacket 260 preferably comprises a low friction material.
  • the compressible protective outer jacket 260 comprises a soft deformable material.
  • the compressible protective outer jacket 260 comprises a soft- porous material.
  • the compressible protective outer jacket 260 comprises smooth outer surface and a geometrically profiled inner surface, the geometrically profiled inner surface comprising empty spaces said empty spaces facilitating material deformation, compression or buckling of at least a portion of the wall of the protective outer jacket 260.
  • the material deformation, compression and/or buckling of at least a portion of the wall of the protective outer jacket 260 provides a resilient longitudinal track into which the guidewire sits between the protective outer jacket 260 and the inner lumen of the sheath shaft 105.
  • the protective outer jacket 260 comprises a thick-walled compressive section and a thin-walled non compressive section wherein the thick-walled compressive section of the protective outer jacket 260 extends over that portion of the catheter shaft 200 that will be positioned inside the sheath 3 during the operation of the pump assembly 201 and the thin-walled non compressive section is positioned distal of the tip of the sheath 3 and extends into connection with the proximal end of the pump assembly 201.
  • the compressible protective outer jacket 160 extends only a portion of the length of the catheter shaft 100 and comprises a smooth geometric transition with the catheter shaft 100.
  • the drive shaft 212 comprises a drive shaft neutral axis 227.
  • the drive shaft neutral axis 227 comprises the line that is substantially concentric with the drive shaft 212 and which interconnects all the points of the drive shaft 212 which exhibit neither extension nor compression when the drive shaft 212 is placed in a curve or bend or in a tortuous configuration.
  • the catheter shaft 200 is configured to protect the drive shaft neutral axis 227 from assuming pathways in use where a radius of curvature of the drive shaft neutral axis 227 is less than the fatigue radius limit 553 of the drive shaft 212.
  • the catheter shaft 200 comprises a catheter reinforcement or support structure 225 configured to prevent the catheter shaft 200 from assuming a radius of curvature that is less than the fatigue radius limit 553 of the drive shaft 212.
  • the neutral axis 227 of the catheter shaft 200 is substantially colinear with the neutral axis of the drive shaft 212.
  • At least one pressure sensing lumen 223a extends proximally from a pressure sensing port 273 in the catheter distal shaft 202 to the proximal end of the proximal catheter shaft 209 and allows at least one catheter pressure sensor 228 (not shown) to measure pressure at a region adjacent to the pressure sensing port 273 of catheter distal shaft 102 and transmit said pressure measurement through a pressure sensing cable 262 in the catheter pressure sensing lumen 223a to the console 4.
  • the pressure sensor 128 is configured to provide continuous pressure data to the console 4 during operation and including during treatment of the patient.
  • the console 4 is configured to receive said at least one plurality of pressure data readings, analyze the data and control the operation of the catheter blood pump system 1 based on the analysis of said at least one plurality of pressure readings.
  • FIG. 4c illustrates an alternative embodiment of the catheter 200 as shown in FIGS. 4a and 4b and so the foregoing descriptions may apply to the catheter features of FIG. 4c, except as described below.
  • the protective outer jacket 260 in this variation extends distally from the manifold 114 and stops at or proximal of the distal end of the catheter reinforcement 225.
  • the catheter shaft 200 comprises a plurality of catheter transition fillets 231.
  • the catheter transition fillets 231 comprise substantially conical features that provide at least one smooth transition between various segments of the catheter shaft 200.
  • a first catheter transition fillets 231 provides a transition between the protective outer jacket 260 and the catheter shaft reinforcement 225.
  • a second catheter transition fillet 231 provides a smooth transition between the catheter reinforcement 225 and the multilumen tubing 261.
  • a third catheter transition fillet 231 provides a smooth transition between the multilumen tubing 261 and the proximal end of the pump assembly 201.
  • FIG. 4C illustrates the multilumen tubing 261 in a cross-sectional view which was not shown in FIG. 4a.
  • At least one catheter pressure sensor 228 sits within the at least one pressure sensing lumen 223 a of the multilumen tubing 261 with the pressure sensing cable 262 extending proximally from the catheter pressure sensor 228 to the console 4.
  • the drive shaft liner 263 sits in the inner lumen of the multilumen tubing 261.
  • the catheter drive shaft 212 sits within the central lumen 211 of the catheter shaft 200.
  • the drive shaft liner 263 comprises a different material to the material of the multilumen tubing 261. In certain aspects, the drive shaft liner 263 is integral with the multilumen tubing 261. In an embodiment, the central lumen 211 comprises a lumen in the multilumen tubing 261.
  • FIGS. 5a, 5b and 5c schematically illustrate a catheter shaft reinforcement 325 of a catheter shaft 300, in accordance with the respective embodiments of the present disclosure.
  • the catheter shaft reinforcement 325 comprises a reinforcement central axis 336 the reinforcement central axis 325 comprising a line that is concentric with the central axis of the catheter shaft 300.
  • the reinforcement central axis 336 comprises a straight configuration 336a when the catheter shaft 300 is straight, as shown in FIG. 5a and a curved configuration 336b when the catheter shaft 300 is curved or bent as shown in FIG. 5b.
  • the catheter shaft reinforcement 325 comprises a stiff polymeric or metallic tube 350 with at least one laser cut 369 that extends fully through the wall thickness 365 of the stiff polymeric or metallic tube 350.
  • At least one laser cut 369 comprises a laser cut pattern 370.
  • the laser cut pattern 370 comprises a pattern that extends at least once around the circumference of the stiff polymeric or metallic tube 350.
  • the cut pattern 370 is configured to allow the central axis 336 of the stiff polymeric or metallic tube 350 to assume the curved configuration 336b.
  • the catheter reinforcement 325 comprises a plurality of ring members 380.
  • the plurality of ring members 380 comprise an interpenetrating structure 381.
  • the interpenetrating structure 381 a feature of first ring member 380a interpenetrates a corresponding feature of a second ring member 380b wherein said first ring member 380a and second ring member 380b are adjacent members.
  • the interpenetrating structure 381 comprises a plurality of in-series ring members 380 wherein adjacent ring members 380 interpenetrate each other.
  • the laser cut pattern 370 comprises a laser cut gap 337.
  • the laser cut gap 337 can be adjusted to change the properties of the stiff polymeric or metallic tube 350 of the catheter shaft reinforcement 325. It will be noted with reference to Fig. 5b that when the central axis 336 of the stiff polymeric or metallic tube 350 is in the curved configuration 336b that at least some of the laser cut gaps 337 that lie on the outer side of the central axis 336 comprise enlarged laser cut gaps 332. Similarly, when the central axis 336 of the stiff polymeric or metallic tube 350 is in the curved configuration 336b that at least some of the laser cut gaps 337 that lie on the inside side of the central axis 336 comprise decreased laser cut gaps 333.
  • This expansion and compression of at least some of the laser cut gaps 337 in the curved configuration 336b allows the stiff polymeric or metallic tube 350 of the disclosure to flex at a low bending force. While some of the laser cut gaps 337 are expanding other gaps are compressing or getting smaller. Eventually, as the bending radius decreases at least some of the laser cut gaps 337 close and the stiff polymer of metal of a first ring member 380a abuts the stiff polymer of metal of a second ring member 380b and the bending stiffness of the shaft increases rapidly. Eventually all ring members 380 abut adjacent ring members and the shaft locks up and becomes very stiff at a minimum radius of curvature. Preferably this minimum allowed radius of curvature is greater than or equal to the limit radius described elsewhere in this specification.
  • the laser cut pattern 370 comprises a pitch 334 wherein the pitch 334 comprises the axial distance along the catheter reinforcement 325 at which the laser cut pattern 370 starts to repeat itself.
  • the pitch 334 comprises the pitch of a substantially helical cut pattern.
  • the pitch 334 comprises the pitch of a cut pattern that comprises a plurality of ring members 380.
  • the laser cut pattern 370 comprises a plurality of dovetails 335.
  • the catheter reinforcement 325 comprises a plurality of ring members 380 and adjacent ring members 380 are connected by at least one dovetail joint 335a.
  • Each of the dovetails 335 of the dovetail joint 335a comprises a dovetail angle 338 and adjustment of the dovetail angle 338 of the dovetail joints 335a changes the mechanical properties of the catheter reinforcement 325.
  • the arrangements described above allow the bending stiffness, minimum radius of curvature of a catheter shaft 325 can be controlled by adjusting any combination of (i) the stiffness of the polymeric or metallic tube 350, (ii) the pitch 334 of the laser cut pattern, (iii) the laser cut gap 337 dimensions, (iv) the wall thickness of the polymeric or metallic tube 350, (v) the laser cut pattern 370.
  • FIGS. 6a, 6b and 6c schematically illustrates alternative embodiments of a catheter shaft reinforcement 425 of a catheter shaft 400, in accordance with the present disclosure.
  • the catheter shaft reinforcement 425 comprises a reinforcement central axis 436.
  • the reinforcement central axis 436 comprises a straight configuration 436a, as shown in FIG. 6a and a curved configuration 436b as shown in FIG. 6b.
  • the catheter shaft reinforcement 425 comprises a stiff polymeric or metallic tube 450 with at least one laser cut 469 that extends fully through the wall thickness 465 of the stiff polymeric or metallic tube 450.
  • at least one laser cut 469 comprises a laser cut pattern 470.
  • the laser cut pattern 470 comprises a repeating pattern that repeats along the length of the stiff polymeric or metallic tube 450.
  • the cut pattern 470 is configured to allow the central axis 436 of the stiff polymeric or metallic tube 450 to assume a plurality of curved configurations 436b.
  • the laser cut pattern 470 of the catheter reinforcement 425 comprises a plurality of partially circumferential slots 468.
  • the partially circumferential slots comprise an increased laser cut gap 432 and a decreased laser cut gap 433 in the curved configuration.
  • the partially circumferential slots 468 comprise terminal ends 467.
  • the catheter reinforcement 425 comprises a plurality of partially circumferential slots 468 along the length of the catheter reinforcement 425 and the plurality of partially circumferential slots 468 comprises a first circumferential slot 468a and a second circumferential slot 468b, the terminal ends 467 of both the first circumferential slot 468a and second circumferential slot 468b arranged so as to create at least one articulating connector 439 between the first circumferential slot 468a and the second circumferential slot 468b.
  • the terminal ends 467 of the first circumferential slot 468a and second circumferential slot 468b comprises T shaped laser cuts 469.
  • the T shaped laser cuts 469 are in one variant configured so as to make the articulating connector 439 longer and this reduces stress in the articulating connector 439 when it articulates in response to the catheter reinforcement 425 being placed in a curved configuration 436b.
  • the articulating connector 439 comprises a strut like member and is configured to bend and flex like a beam in response to the bending and/or flexing of the catheter shaft 400.
  • the articulating connecter 439 comprises a connector length 441 and a connector width 440 and wherein the connector length 441 and connector width 440 are adjustable to change the mechanical properties of the catheter reinforcement 425 and thus the catheter shaft 400.
  • the terminal ends 467 of the first circumferential slot 468a and second circumferential slot 468b comprises an axial laser cut, said axial laser cut acutely angled with respect to the first circumferential slot 468a and/or the second circumferential slot 468b.
  • the terminal ends 467 of the first circumferential slot 468a and second circumferential slot 468b comprises a curved laser cut, at least a portion of said curved laser cut substantially normal to the first circumferential slot 468a and/or the second circumferential slot 468b.
  • the laser cuts 469 comprise a laser cut gap width 469a and the laser cut gap width 469a can be adjusted.
  • the laser cut pattern 470 further comprises a repeating pattern with the repeating pattern comprising a pitch 434.
  • the properties of the catheter reinforcement 425 including the limit bending radius 430 can be at least partially defined by adjusting the laser cut gap width 469a and the pitch 434 of the repeating laser cut pattern 470. It will be noted with reference to FIG. 6c that there are two or more circular bands 442 within one repeating pattern 434. This is because adjacent partially circumferential slots 468 are angularly offset with respect to each other.
  • the angular offset is the angle by which the terminal ends 467 of adjacent partially circumferential slots 468 are offset with respect to each other. Where the offset angle is 180 degrees then there will be two circular bands 442 per pitch 434. Where the offset angle is 120 degrees then there will be three circular bands 442 per pitch 434.
  • the laser cut pattern 470 is configured to define a monolithic tubular structure 471 that comprises a plurality of in series ring members 480 the ring members 480 being interconnected by a plurality of articulating connectors 439.
  • the cut pattern 470 comprises a plurality of tubular ring members 442. Unlike earlier embodiments adjacent tubular ring members 442 of the cut pattern 470 are integral with each other. Each ring member 442 of this embodiment comprises a circular band of the stiff polymeric or metallic tube 450 that lies between adjacent partially circumferential slots 468. Adjacent ring members 442 are interconnected with one or more articulating connectors 439. The cut pattern 470 results in the reinforcement 425 comprising a plurality of rigid circular bands 442 that are geometrically integrated into a single body with flexible articulating connectors 439.
  • FIGS. 10a to lOd schematically illustrate a catheter shaft reinforcement 625 of a catheter shaft 600 of a catheter blood pump 1, in accordance with the respective embodiments of the present disclosure.
  • the catheter shaft reinforcement 625 comprises a protective outer jacket 660, a reinforcement central axis in straight state 636 as shown in FIG. 10a and a curved state 637 as shown in FIG. lOd.
  • the catheter shaft reinforcement 625 comprises a reinforcement lumen 640 as shown in FIG. 10b and FIG. 10c, and a stiff polymeric or metallic tube with laser cuts 669 that extends fully through the wall thickness 665 of the shaft reinforcement 625.
  • the laser cut 669 comprises a laser cut pattern 670.
  • the laser cut pattern 670 is configured to define a monolithic tubular structure 671 that are interconnected by a plurality of articulating connectors 639.
  • the monolithic structure comprises a plurality of metallic collars 627 interconnected by a plurality of articulating connectors 639.
  • the articulating connectors 639 are arranged so as to make equiangular connections between adjacent metallic collars 627.
  • the laser cuts 669 comprise substantially rectangular cuts or stadium shaped cuts.
  • the laser cuts 669 extend circumferentially around at least a part of the circumference of the tubular structure 671.
  • the laser cuts 669 extend helically circumferentially around at least a part of the circumference of the tubular structure 671.
  • the articulating connectors 639 comprises a tapering cross section.
  • the laser cuts 669 comprise an increased laser cut gap 632 and a decreased laser cut gap 633 in the curved configuration 637.
  • the laser cut pattern 670 further comprises a repeating pattern with the repeating pattern comprising a pitch 634.
  • the properties of the catheter reinforcement 625 including the limit bending radius 630c at the neutral axis can be at least partially defined by adjusting the laser cut gaps 626 and the pitch 634 of the repeating laser cut pattern 670.
  • the laser cut gap 626 remains substantially unchanged at the neutral axis.
  • the laser cut gap 626 increases to an expanded gap 630b on the outer surface of the reinforcement 625 and to a compressed gap 630a on the inner surface of the reinforcement 625 in the curved configuration 637.
  • FIGS. Ila, 11b and 11c schematically illustrate a catheter shaft reinforcement 725 of a catheter shaft 700 of a catheter blood pump 1, in accordance with the respective embodiments of the present disclosure.
  • the catheter shaft reinforcement 725 comprises a protective outer jacket 760, a reinforcement central axis in straight state 736 as shown in FIG. Ila and a curved state 737 as shown in FIG. 11c.
  • the catheter shaft reinforcement 725 comprises a reinforcement lumen 740 and a stiff polymeric or metallic tube with laser cuts 769 that extends fully through the wall thickness 765 of the shaft reinforcement 725.
  • the laser cut 769 comprises a laser cut pattern 770.
  • the laser cut pattern 770 is configured to define a monolithic tubular structure 771 that are interconnected by a plurality of articulating connectors 739.
  • the laser cuts 769 comprise an increased gap 732 and a decreased gap 733 in the curved state 737.
  • the laser cut pattern 770 further comprises a repeating pattern with the repeating pattern comprising a half pitch 734.
  • the properties of the catheter reinforcement 725 including the limit bending radius 730 can be at least partially defined by adjusting the laser cut 769 so as to alter the properties of the increased gap 732 and the decreased gap 733 in the curved state 737 and the pitch 734 of the repeating laser cut pattern 770.
  • the cut pattern 770 comprises a helical cut pattern 772.
  • the pitch 734 of the helical cut pattern 772 comprises a multi-start arrangement.
  • the multi-start arrangement comprises the intertwining of adjacent laser cuts. With the intertwining of adjacent laser cuts, two or more laser cuts circumnavigate the metallic tube in a parallel, rather than a serial arrangement.
  • the cut pattern comprises a plurality of struts and at least one strut comprises an arc shaped strut 773.
  • FIGS. 12a, 12b, 12c, 12d, 12e, and 12f schematically illustrate a catheter shaft reinforcement 825 of a catheter shaft 800 of a catheter blood pump 1, in accordance with the respective embodiments of the present disclosure.
  • the catheter shaft reinforcement 825 is optimally enclosed within a polymeric sheath (not shown) to prevent blood ingress to or through the reinforcement 825 which is optimally fabricated using a stainless steel such as 304 or 316.
  • the sleeve may be configured
  • the catheter shaft reinforcement 825 shown in FIG. 12a comprises a proximal 803 and distal end 802 and is coiled about an axis 836, at a defined pitch 834 into tubular form from a profile 810 configured to interlock over its entire length.
  • the catheter shaft reinforcement 825 may include a protective outer jacket 860 and a reinforcement lumen 840 as illustrated in FIG.
  • FIG. 12b is a cross sectional view of the profile 825.
  • the profile may incorporate a bottom lip 815, a top lip 820, a bend limit step 823, and a bending gap 870.
  • the step 823 defines the wall thickness of the reinforcement and the bending gap 870 defines the bending limit radius, the shorter the bending gap 870 the larger the bend that the reinforcement will take before it is limited from further bending.
  • the top and bottom lips, 820 and 810 respectively, form an interlock 824 that connects and secures the profile over its length.
  • the interlock may have a connected height 865 configured to further define the bending gap and bending limit radius.
  • An advantage of this concept is that the tubing’s axial stretch may be limited which is a desirable feature that limits relative movement of components that may run through the reinforcement 825.
  • a restrictor coil 875 may be incorporated into the reinforcement 825, in the space defined by the bending gap 870 to further limit its bending.
  • the coil may extend over a portion or over the entire length of the catheter shaft reinforcement 825.
  • varying bend radii may be incorporated along the length of the catheter.
  • the proximal end 803 may incorporate the restrictor coil 875 over the portion of the catheter that is external to the patient where a larger bend radius limit may be preferable and the distal end, without the restrictor coil 875, would incorporate a smaller bending radius which may allow easier delivery through the vasculature while still limiting the bend radius.
  • the restrictor coil may be preferably comprised of a spring tempered stainless steel or nitinol if a lower flexural modulus is desirable.
  • the catheter shaft reinforcement 825 comprises a tubular member consisting of a continuous interlocking coil.
  • the catheter shaft reinforcement 825 comprises a tubular member consisting of a continuous interlocking coil with an outer protective sleeve.
  • the catheter shaft reinforcement 825 comprises a tubular member consisting of a continuous interlocking coil that limits bending.
  • the catheter shaft reinforcement 825 comprises a tubular member consisting of a continuous interlocking coil that limits bending and length extension during bending.
  • the catheter shaft reinforcement 825 comprises a tubular member consisting of a continuous interlocking coil, and a secondary concentric coil that further limits bending.
  • a catheter shaft 800 may be comprised of the reinforcement 825 with a reflowed polymer tube 890.
  • the tube 890 is placed over the reinforcement 825 and a heat shrink tubing is placed over the tube 890.
  • this assembly is placed in an oven set to a temperature that shrinks but does not melt the heat shrink but melts or softens the polymer tube, the polymer tube reflows and is attached to the reinforcement 825 when it cools. The heat shrink is then removed and an assembly comprising the reinforcement 825 and tube 890 remains. During the reflow process the tube 890 flows into the bending gap 870 further limiting the bending radius.
  • the additional restriction may be easily tailored by changing the durometer of the polymer tube 890 and the restriction to a hard bend limit is felt by the user as a gradual increase of resistance rather than a hard stop.
  • the prevention of blood ingress to the reinforcement and additional bend limit restriction may be achieved in one process step.
  • the restrictor coil 875 and polymer tube embodiments may be combined to vary the bending radius over the length or multiple polymer tubes or differing durometer and/ or wall thickness may be reflowed over the length of the reinforcement 825 to achieve multiple bend radius limits over the length of the catheter shaft 800.
  • the reflowed polymer tube may be comprised of a multi lumen tube 897 that incorporates a plurality of control lumens 880, 881, 882, and 883.
  • the control lumens may be configured in accordance with previous embodiments to provide a number of functionalities including but not limited to: pressure sensor housing, inflation channels, flush channels, stiffening wire housing.
  • a similar reflow process could be used to create this embodiment but removable wires 888 may be placed in each control lumen to maintain patency during the heatshrinking process.
  • a variety of thermoplastic elastomers are suitable materials for the reflowed polymer tube 890 or multilumen tube 897.
  • PolyEther-Block- Amide (Pebax) is available from shores 35-72D and is a good example of a product family suitable for this application.
  • Thermosfplastic urethanes such as the Pellethane, also available in a variety of durometers, are preferable with longer implant times due to their excellent biocompatibility.
  • the catheter shaft reinforcement 825 comprises a tubular member having a reinforcement cut pattern 870.
  • the catheter shaft reinforcement 825 comprises a tubular member consisting of a continuous interlocking coil 895 with a reflowed polymer jacket that further limits the bending radius while sealing the tube.
  • the catheter shaft reinforcement 825 comprises a tubular member consisting of a continuous interlocking coil with a reflowed polymer jacket that incorporates a plurality of control lumens.
  • the reinforcement cut pattern 870 comprises a continuous coil that is geometrically coupled.

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  • Health & Medical Sciences (AREA)
  • Heart & Thoracic Surgery (AREA)
  • Engineering & Computer Science (AREA)
  • Biomedical Technology (AREA)
  • Mechanical Engineering (AREA)
  • Anesthesiology (AREA)
  • Cardiology (AREA)
  • Hematology (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Animal Behavior & Ethology (AREA)
  • General Health & Medical Sciences (AREA)
  • Public Health (AREA)
  • Veterinary Medicine (AREA)
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Abstract

La présente divulgation concerne de manière générale le domaine des procédures de gestion des fluides pour le traitement de troubles de gestion des fluides chez un patient, et des composants et des procédés associés. En particulier, la présente invention concerne des tiges de cathéter de flexibles renforcées utilisées dans des pompes à sang intravasculaires et conçus pour fonctionner dans des gaines à faible frottement pour permettre un fonctionnement de la pompe à des vitesses élevées sans générer de chaleur de frottement.
PCT/IB2024/000521 2023-09-22 2024-09-18 Cathéter flexible renforcé et procédés d'utilisation et de fabrication Pending WO2025062183A1 (fr)

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US63/539,956 2023-09-22

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Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6913601B2 (en) * 1994-12-07 2005-07-05 Heartport, Inc. Method for delivering a fluid to the coronary ostia
US10420537B2 (en) * 2015-03-27 2019-09-24 Shifamed Holdings, Llc Steerable medical devices, systems, and methods of use
US20200008887A1 (en) * 2017-02-08 2020-01-09 Terumo Kabushiki Kaisha Medical device, system, and method for treating observed heart conditions
US20210113752A1 (en) * 2019-10-17 2021-04-22 Forqaly Medical(Shanghai) Co., Ltd. Flexible Shaft Structure Insulating Wear Particles by Perfusion
US20220118171A1 (en) * 2019-01-22 2022-04-21 Cm Technologies, Inc. Enema device
US11446045B2 (en) * 2014-06-13 2022-09-20 Neuravi Limited Devices and methods for removal of acute blockages from blood vessels
US20230035207A1 (en) * 2018-08-23 2023-02-02 Nuvera Medical, Inc. Medical tool positioning devices, systems, and methods of use and manufacture
US20230061168A1 (en) * 2021-08-29 2023-03-02 DePuy Synthes Products, Inc. Annealing of Discrete Sections of a Reinforcement Layer to Modulate Stiffness of a Catheter
US11660426B2 (en) * 2019-02-26 2023-05-30 White Swell Medical Ltd Devices and methods for treating edema
US11730551B2 (en) * 2020-02-24 2023-08-22 Canon U.S.A., Inc. Steerable medical device with strain relief elements

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6913601B2 (en) * 1994-12-07 2005-07-05 Heartport, Inc. Method for delivering a fluid to the coronary ostia
US11446045B2 (en) * 2014-06-13 2022-09-20 Neuravi Limited Devices and methods for removal of acute blockages from blood vessels
US10420537B2 (en) * 2015-03-27 2019-09-24 Shifamed Holdings, Llc Steerable medical devices, systems, and methods of use
US20200008887A1 (en) * 2017-02-08 2020-01-09 Terumo Kabushiki Kaisha Medical device, system, and method for treating observed heart conditions
US20230035207A1 (en) * 2018-08-23 2023-02-02 Nuvera Medical, Inc. Medical tool positioning devices, systems, and methods of use and manufacture
US20220118171A1 (en) * 2019-01-22 2022-04-21 Cm Technologies, Inc. Enema device
US11660426B2 (en) * 2019-02-26 2023-05-30 White Swell Medical Ltd Devices and methods for treating edema
US20210113752A1 (en) * 2019-10-17 2021-04-22 Forqaly Medical(Shanghai) Co., Ltd. Flexible Shaft Structure Insulating Wear Particles by Perfusion
US11730551B2 (en) * 2020-02-24 2023-08-22 Canon U.S.A., Inc. Steerable medical device with strain relief elements
US20230061168A1 (en) * 2021-08-29 2023-03-02 DePuy Synthes Products, Inc. Annealing of Discrete Sections of a Reinforcement Layer to Modulate Stiffness of a Catheter

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