WO2021191701A1

WO2021191701A1 - Infusion flow indicator device

Info

Publication number: WO2021191701A1
Application number: PCT/IB2021/051519
Authority: WO
Inventors: Daniel Thorvaldsen; Jonas GARTMANN; Martin BATLINER; Flavio PERUCCHI; Arno SUTER
Original assignee: Onefusion AG
Current assignee: Onefusion AG
Priority date: 2020-03-24
Filing date: 2021-02-23
Publication date: 2021-09-30
Anticipated expiration: 2022-09-24
Also published as: GB202004218D0

Abstract

This disclosure describes infusion flow indicator devices and methods for using the devices. In some embodiments, such infusion flow indicator devices are used to indicate whether infusate is flowing through an infusion tube toward the patient, or if there is no infusate flow. For example, when using an elastomeric pump to deliver an infusate to the patient through an infusion tube, the infusion flow indicator device can be used to readily determine infusate flow. In some embodiments, a housing of the infusion flow indicator device defines a channel that is configured to releasably receive and clamp onto the infusion tube.

Description

INFUSION FLOW INDICATOR DEVICE

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of United Kingdom Application Serial No. 2004218.0, filed March 24, 2020. The disclosure of the prior application is considered part of (and is incorporated by reference in) the disclosure of this application.

TECHNICAL FIELD

The disclosure relates to systems and methods for infusing a patient with a therapeutic fluid.

BACKGROUND

Elastomeric infusion pumps are used in the medical field to administer or infuse liquid pharmaceutical agents (infusate) to subjects. Depending on the pump's size, the pharmaceutical agent inside the elastomeric reservoir can be delivered over a time varying between thirty minutes to seven days. The rate of the infusate flow is typically controlled by a flow restrictor or filter in the tubing of the system. The flow rate of the infusate is typically very low, such as approximately 0.5 ml/hour to 20 ml/hour.

SUMMARY

This disclosure describes infusion flow indicator devices and methods for using the devices. Such infusion flow indicator devices can be used in conjunction with conventional infusion systems. For example, in some embodiments the infusion flow indicator devices are used to indicate infusate flow within the infusion tubing of an elastomeric infusion pump (which can be a conventional elastomeric infusion pump). Such elastomeric infusion pumps are designed to deliver an infusate to a patient, and comprise components such as a pressurized infusate reservoir, an infusion tube, a clamp and a patient connector. In some implementations of such an elastomeric infusion pump, the pressurized infusate reservoir comprises an elastic inner compartment to store the infusate and an outer compartment. There a positive pressure, i.e. greater than atmospheric pressure, exists between the inner compartment and the outer compartment. In some implementations of elastomeric infusion pumps the pressure that drives the infusate can be created in other ways. When the clamp on the infusion tube is opened, the infusate is driven towards the patient by effect of the positive pressure within the pressurized infusate reservoir. The flow rate of the infusate is dependent on several parameters, such as the viscosity of the infusate, the positive pressure within the pressurized infusate reservoir, height difference between infusate reservoir and the patient connection, the flow resistance from the pressurized infusate reservoir to the patient connector, the venous pressure of the patient, etc. In some designs, a second infusion tube with a smaller inner diameter is used to limit the flow rate of the infusate. In other designs, filters are used in line with the infusion tube.

In some implementations, the pressurized infusate reservoir is filled with an infusate, the patient connector is connected to a patient and the clamp is opened so that the infusate flows towards the patient. In some designs, the patient can store the elastomeric infusion pump in a pouch that is worn around the hips. The elastomeric infusion pump can be worn and used from several hours up to several days. In many cases, patients leave the hospital and use the elastomeric pump at home.

In some designs, the elastomeric pump comprises a clamp that can be used to occlude the flow of the infusate. In some designs, the clamp is fixed on the infusion tubing in a way that the infusion tubing is led through holes that are a part of the clamp body. By pressing a certain member of the clamp body and compressing the clamp, the clamp can be used to occlude the infusion tubing and thereby restrict the infusate flow. In some designs, the clamp body comprises a latch that holds the clamp in place and continues to restrict the flow of the infusate within the infusion tubing without any interaction of a user. By pressing a certain other member of the clamp body, the latch, the clamp and thus the restriction of the flow maybe released.

In some embodiments, the infusion flow indicator comprises a housing defining a channel to releasably receive an infusion tube, a flow rate sensor a user interface and electronic controls. The housing defining the channel to releasably receive an infusion tube can be configured to releasably clamp the infusion tube in the channel, for example by using two housing shells that are interconnected by a hinge and held closed with a closing mechanism such as a latch. The housing can be designed in a way that the infusion tube can be coupled and re-coupled by a clinician or the patient. In other designs, the housing can be designed in a way that the infusion tube can be coupled and re-coupled by the manufacturer of the infusion flow indicator, the manufacturer of the elastomeric pump (or a sub-assembly of it) but not by a clinician or the patient.

In some embodiments, the flow rate sensor is designed to abut the infusion tube from the outside of the infusion tube. In other embodiments, the flow rate sensor is part of the tube and inside the fluidic channel. In some designs, the flow rate sensor is designed to releasably attach to the infusion tube (e.g., abut thereto). In other designs, the flow rate sensor is permanently attached to the infusion tube. The flow rate sensor comprises a heater and one or more temperature sensors. In one design, the flow rate sensor comprises a heater and two temperature sensors. In one design, the two temperature sensors are placed on each side of the heater, where the heater is in the middle of the two temperature sensors. In some embodiments, the heater is powered with a constant voltage, with a constant current, with a constant temperature, with a constant power input or a combination of any of the above. In some designs, the signal from the temperature sensors are used to generate a signal that is dependent on the flow rate within the infusion tubing, among other parameters. In some designs, the difference in temperature between the two temperature sensors is used to generate a signal that is dependent on the flow rate within the infusion tube.

The user interface may comprise a display, one or more LEDs, a foil keyboard, one or more buttons, acoustic signals, vibration signals, and the like, or a combination of any of the above. In one embodiment, the user interface comprises one button and one LED. In another embodiment, the user interface comprises a display, three LEDs, and a button.

The electronic controls may comprise a possibility to utilize software to control the electronics, in other designs the electronic controls comprise an analog circuit or a digital circuit. The infusion flow indicator devices described herein can also include an on board energy source such as one or more batteries. In some embodiments, the electronic controls may include one or more devices for facilitating wireless communications to and/or from the infusion flow indicator devices. For example, in some embodiments the electronic controls include devices for communication via Bluetooth, WiFi, near field communication (NFC), and the like.

In some embodiments, a valve position switch or sensor is included to detect the state (e.g., the open or closed position) of the valve member of the infusion flow indicator device. For example, the valve position switch or sensor can detect whether the valve member is in an open state or a closed state and communicate the detected state to the electronic controls.

In some embodiments, the infusion flow indicator device comprises a valve member positioned to press on an outside of the infusion tube while the infusion tube is engaged in the channel. The valve member may be openable such that the infusion tube is unrestricted by the valve member and closable to fully occlude the infusion tube. In some designs, the valve member may be operated by a user to open and close the valve member. In other designs, the valve member may be operated by any form of actuator, such as a linear driver, a servomotor or a piezo-effect actuator to open and close the valve member.

When an infusion tube is used to deliver an infusate to the patient, the infusion flow indicator device may be used to determine if the infusate is flowing towards the patient or if there is no occurrence of infusate flow. For example, when using an elastomeric pump to deliver an infusate to the patient, the infusion flow indicator device can be used to quickly determine flow. In some embodiments where the housing is configured to releasably clamp the infusion tube in the channel, this has to be established first. The flow rate sensor is configured to receive signals dependent on the flow rate of the infusate within the infusion tube. In some designs, the flow of the infusate is intentionally occluded. This can be achieved by closing a valve member positioned to press on an outside of the infusion tube. The closing of a valve member can be achieved by any form of actuator, such as a linear driver, a servo or a piezoelectric mechanism. Alternatively, or in addition it can be achieved by the user actuating the valve member. In some designs, the valve member is used as a button of the user interface and is used to both occlude the infusion tube and as a user input to the infusion flow indicator device to indicate that the flow testing should be initiated. Alternatively, or in addition, the clamp may be used to occlude the flow. In the state of an occluded infusion tube, the signal received from the flow rate sensor can be used as reference value of an occluded tube. Next, the mechanism occluding the infusion tube may be released again, which will lead to an unrestricted infusion tube. This might be achieved by moving the actuator or manually eliminating the occlusion of the infusion tube by releasing pressure generated by the valve member or by opening the tube clamp. Now the infusion tube is in an unrestricted state (i.e., unrestricted by the valve member or tube clamp). If the flow of infusate through the infusion tube is now occurring, the signal received from the flow rate sensor will be different from the reference flow rate signal/value (e.g., voltage) received in the occluded state of the infusion tube. If there is no flow of infusate occurring, the signal/value received from the flow rate sensor will be equal to or very similar to the reference flow rate signal/value received in the occluded state of the infusion tubing. In some designs, the electronic controls are utilized to detect whether there is a significant difference in the two flow rate signals and to generate an output to the user interface, indicating whether there is a flow of infusate within the infusion tube with the valve member or tube clamp released.

In other embodiments, the indication of infusate flow in the infusion tube will be achieved without occluding the infusion tube. When powering on the flow rate sensor, the response in temperature signals to the temperature increase can be monitored and yields a certain pattern. In one implementation, the amplitude of the signal and the time to reach the amplitude can be indicators for an occurrence of infusate flow within the infusion tube or not. In such a design, the electronic controls will power on the flow rate sensor, increasing the heat of the heater and reading out the signals from the temperature sensors. The signal response will be monitored and compared to a reference signal that has been stored within the electronic controls. In some embodiments, the reference signal has been stored during a calibration process. In some designs, the flow rate sensor is permanently coupled to the infusion tube and the calibration process can take place at any time between the production process at the manufacturer and the beginning of the infusion. Alternatively, or in addition, the flow rate sensor may be releasably coupled to the infusion tubing. Then, the calibration process may be carried out any time after the coupling of the flow rate sensor to the infusion tube.

One of the advantages of using a flow rate indicator device as disclosed herein is that it yields a fast and clear indication about the occurrence of infusate flow in the infusion tube. With elastomeric pumps, it is typically very hard for the clinician or the patient to get an indication of the flow of infusate. When the elastomeric pump is connected to the patient by the clinician, it is possible to immediately confirm whether there is flow of the infusate within the infusion tubing using of the flow rate indicator devices disclosed herein.

Another advantage provided by the flow rate indicator devices as disclosed herein is that the devices can give fast and clear feedback to the patient at home.

Many times the patient may have the feeling that the infusate is not being properly delivered, and a hospital visit is necessary. The infusion flow indicator devices disclosed herein allow fast and clear feedback to the patient, and the patient can thereby avoid unnecessary hospital visits.

Another advantage provided by the flow rate indicator devices as disclosed herein is that sometime the flow of infusate might be inadvertently interrupted without the patient noticing it. Thus, the medication delivery is interrupted and the therapy disturbed. An interaction with clinical staff to re-establish the flow of infusate and the continuation of the therapy would usually be necessary. However, the infusion flow indicator devices described herein allow fast and clear feedback and can indicate whether hospital visits or other interactions with clinical staff are necessary to avoid complications.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an axonometric view of an elastomeric infusion pump and a flow indicator device according to some embodiments.

FIG. 2a shows an axonometric view of an elastomeric infusion pump and a flow indicator device according to some embodiments, where the housing configured to releasably clamp an infusion tube is shown in an open state.

FIG. 2b shows an axonometric view of an elastomeric infusion pump and a flow indicator device according to some embodiments, where the housing configured to releasably clamp an infusion tube is shown in a closed state.

FIG. 3a shows a partial cut-away view of a flow indicator device according to some embodiments.

FIG. 3b shows a partial cut-away view of a flow indicator device according to some embodiments where the user manually interacts with the valve member.

FIG. 4 shows an enlarged partial cut-away view of the arrangement of the flow rate sensor, the valve member, the control electronics and the infusion tube according to some embodiments.

FIG. 5a shows a partial cut-away view of a flow indicator device according to some embodiments.

FIG. 5b shows a partial cut-away view of a flow indicator device according to some embodiments where the user manually interacts with the clamp.

FIGs. 6a and 6b show a signal response of the flow rate sensor. FIG. 7 shows a partial cut-away view of a flow indicator device and the arrangement of a flow rate sensor that is permanently coupled to the infusion tube according to some embodiments.

DETAILED DESCRIPTION OF THE DRAWINGS

This disclosure describes infusion flow rate indicator devices and methods for indicating flow of a therapeutic fluid.

Referring to FIG. 1, an example elastomeric pump includes a pressurized infusate reservoir 100, an infusion tube 90, a clamp 80 and a patient connector 110. The pressurized infusate reservoir 100 has been pre-filled with an infusate. Once the clamp 80 is in an opened state, the infusate is driven by the positive pressure within the pressurized infusate reservoir 100 through the infusion tube 90 and the patient connector 110 towards the patient.

An example infusion flow indicator device 10 includes a housing 20 (that defines a channel to releasably receive the infusion tube 90 as described further below) and a user interface 60. In this embodiment, the user interface 60 includes one button 61 and one LED 62. In one embodiment, the button 61 acts also as valve member 40. That is, when pressing the button 61, the infusion tube 90 is occluded by the valve member 40.

FIG. 2a depicts the infusion flow indicator device 10 where the housing 20 defines a channel 30 whereby the housing 20 is configured to releasably clamp onto the infusion tube 90. The housing 20 includes the upper housing shell 21 and the lower housing shell 22, connected by a hinge 23. The housing 20 is depicted in the open state. The lower housing shell 22 includes the channel 30 to releasably receive an infusion tube 90. In this Figure, the infusion tube 90 is depicted inside the channel 30 that releasably receives the infusion tube 90.

FIG. 2b depicts the infusion flow indicator device 10 with the housing 20 closed such that it is releasably clamping the infusion tube 90 therein. The housing 20 includes the upper housing shell 21 and the lower housing shell 22, connected by the hinge 23. The housing 20 is depicted in the closed and operative state.

Referring also to FIG. 3a, in some embodiments the infusion flow indicator device 10 includes a valve member 40, a flow rate sensor 50, the user interface 60 and electronic controls 70. The depicted example user interface 60 includes at least one button 61, one or more LEDs 62, and one display 63. The button 61 is at the same time a valve member 40 movably coupled to the housing 20 and positioned to press on an outside of the infusion tube 90 while the infusion tube 90 is engaged in the channel 30.

The infusion flow indicator device 10 can also include an on board energy source such as one or more batteries. In some embodiments, the electronic controls 70 may include one or more devices for facilitating wireless communications to and/or from the infusion flow indicator devices. For example, in some embodiments the electronic controls 70 include devices for communication via Bluetooth, WiFi, near field communication (NFC), and the like.

A valve position sensor 71 detects the state (e.g., the open or closed position) of the valve member 40 and communicates it to the electronic controls 70. In this depiction, the valve member 40 is in an open state and the flow of the infusate in the infusion tube 90 is not restricted. The flow rate sensor 50 can output a signal reflecting the flow rate of the infusate and communicate it to the electronic controls 70.

Referring also to FIG. 3b, the button 61, which is also the valve member 40, can be manually pressed by the user (e.g., patient or clinician). In this depiction, the valve member 40 is in the closed state restricting/blocking all flow of infusate in the infusion tube 90. The flow rate sensor 50 outputs a signal that reflects no flow of the infusate in the infusion tube 90, and communicates the signal to the electronic controls 70. The valve position sensor 71 communicates the state (closed position) of the valve member 40 to the electronic controls 70.

An instruction to press the button 61 may be communicated to the user by the user interface 60. The instruction to keep holding the button 61, or to keep holding the button 61 for a certain amount of time, maybe communicated to the user by the user interface 60. The instruction to release the button 61 may be communicated to the user by the user interface 60. The information about whether or not there is a flow of infusate inside the infusion tube 90 may be communicated to the user by the user interface 60.

Referring also to FIG. 4, in some embodiments the flow rate sensor 50 releasably abuts against, but is not attached to, the outside of the infusion tube 90. In this embodiment the flow rate sensor 50 comprises a heater 51 and two temperature sensors 52. The heater 51 is arranged between the two temperature sensors 52. The flow rate sensor 50 (and substitutable functional variations thereof) is/are described in more detail in the Applicant’s PCT applications that are published as WO2018/154407 and WO2019/175836, which are hereby incorporated by reference in their entireties and for all purposes.

Referring also to FIG. 5a, as an alternative to the embodiment described in relation to FIGs. 3a-4, in some embodiments the infusion flow indicator device 10 includes a housing 20, user interface 60, a flow rate sensor 50 and electronic controls 70. The clamp 80 on the infusion tube 90 may be used to occlude the flow of the infusate. In this depiction, the clamp 80 is in the open state and not occluding the infusate flow. The flow rate sensor 50 outputs a signal reflecting the infusate flow rate within the infusion tube 90 and communicates it to the electronic controls 70.

Referring also to FIG. 5b, the clamp 80 can be manually closed by the user. In this depiction, the clamp 80 is in the closed state, totally occluding the flow of infusate inside the infusion tube 90. The flow rate sensor 50 outputs a signal that reflects an occluded infusion tube 90, no flow of the infusate, and communicates the signal to the electronic controls 70. Thereafter, the electronic controls 70 can compare the signal(s) output from the flow rate sensor 50 before closing the clamp 80 to the signal(s) output from the flow rate sensor 50 after closing the clamp 80. Using the comparison, the electronic controls 70 can determine whether or not there was flow of infusate when the clamp 80 was open (i.e., in the normal operative condition).

Referring to FIG. 6a, in some embodiments the electronic controls 70 receive an example signal output 120 from the flow rate sensor 50. After the valve member 40 is pressed and the infusion tube 90 is thereby occluded, the electronic controls 70 receive a signal 121 output after the occlusion of tube 90. After releasing the valve member 40 the electronic controls receive a signal 122 output after release of occlusion of the tube 90. In this depiction, the change in the signal output 120 is substantial, which indicates that at the open state of the valve member 40 there is an infusate flow in the infusion tube 90 present. The electronic controls 70 can assess the change in the signal output (121 versus 122) and thereby determine that infusate was flowing while the valve member 40 was open (as desired for successful performance of the infusion pump therapy).

Referring to FIG. 6b, in some embodiments the electronic controls 70 receive another example signal output 120 from the flow rate sensor 50. After the valve member 40 is pressed and the infusion tube 90 is occluded, the electronic controls 70 receive a signal 121 output after the occlusion of tube 90. After releasing the valve member 40 the electronic controls 70 receive a signal 122 output after release of the occlusion of the tube 90. In this depiction, the change in the signal output 120 is negligible. Accordingly, the electronic controls 70 will be able to determine that at the open state of the valve member 40 there is essentially no infiisate flow in the infusion tube 90 and the medication of the patient is interrupted. To differentiate between flow and no flow, a threshold of signal change may be defined and used by the electronic controls 70. In other embodiments, algorithms may be used by the electronic controls 70 to differentiate between the state of flow and no flow after receiving the signal output 120.

Referring now to FIG. 7, in other example embodiments the infusion flow indicator device 10 includes a housing 20, a user interface 60 and electronic controls 70. In this example embodiment, the flow rate sensor 50 is permanently coupled to the infusion tube 90 and can be connected to the infusion flow indicator device 10 by a flow rate sensor connector 53. In this design, the flow rate sensor connector 53 includes a cable 54 and a connector jack 55. In other embodiments, the flow rate sensor connector 53 includes only a connector jack 55. In other embodiments, the flow rate sensor connector 53 includes a wireless power source and a wireless communication device. In this depiction, the flow rate sensor 50 is powered on and the signal response is communicated to the electronic controls 70. The pattern of the signal response is then evaluated by the electronic controls 70 to differentiate between a state of flow of the infiisate within the infusion tube 90 and a state of no flow of the infiisate within the infusion tube 90. In some embodiments, the flow rate sensor 50 is placed close to the pressurized infiisate reservoir 100, in other embodiments the flow rate sensor 50 is placed close to the patient connector 110, in other embodiments the flow rate sensor 50 is placed at anyplace between the pressurized infiisate reservoir 100 and the patient connector 110.

Claims

WHAT IS CLAIMED IS:

1. An infusion flow indicator device comprising: a housing defining a channel to releasably receive an infusion tube; a valve member movably coupled to the housing and positioned to press on an outside of the infusion tube while the infusion tube is engaged in the channel, the valve member being: (i) openable such that the infusion tube is unrestricted by the valve member and (ii) closable to occlude the infusion tube; a flow rate sensor coupled to the housing and configured to detect flow of an infusate in the infusion tube while the infusion tube is engaged in the channel; a user interface; and electronic controls configured to: receive signals output from the flow rate sensor; determine whether the signals output from the flow rate sensor indicate that flow of the infusate in the infusion tube was detected by the flow rate sensor; and output a signal to the user interface that indicates whether the flow rate sensor detected the flow of the infusate in the infusion tube.

2. The device of claim 1, wherein the valve member is manually closable by a user of the infusion flow indicator device.

3. The device of claim 2, further comprising a valve position sensor arranged to detect: (i) an open position of the valve member and (ii) a closed position of the valve member, the valve position sensor arranged to output signals to the electronic controls reflecting the detected position of the valve member,

4. The device of claim 2, wherein the flow rate sensor outputs the signals indicating whether the flow rate sensor detected the flow of the infusate in the infusion tube in response to closure of the valve member.

5. The device of claim 2, wherein the valve member is normally open such that the valve member is open except when the valve member is manually closed by the user.

6. The device of claim 1, wherein the flow rate sensor abuts the outside of the infusion tube while the infusion tube is engaged in the channel.

7. The device of claim 1, wherein the flow rate sensor comprises: a first temperature sensor; a second temperature sensor; and a heater, wherein the heater is arranged between the first and second temperature sensors.

8. The device of claim 7, the signals output from the flow rate sensor are based on a difference between a first signal output from the first temperature sensor and a second signal output from the second temperature sensor while the heater is activated.

9. The device of claim 1, wherein the housing is configured to releasably clamp the infusion tube in the channel.

10. The device of claim 1 , wherein the flow rate sensor is configured to detect the flow of the infusate in the infusion tube in a range from 0.5 ml/hour to 20 ml/hour.

11. An infusion flow indicator device comprising: a housing defining a channel to releasably receive an infusion tube; a flow rate sensor coupled to the housing and configured to detect flow of an infusate in the infusion tube while the infusion tube is engaged in the channel; a user interface; and electronic controls configured to: receive signals output from the flow rate sensor; determine whether the signals output from the flow rate sensor indicate that flow of the infusate in the infusion tube was detected by the flow rate sensor; and output a signal to the user interface that indicates whether the flow rate sensor detected the flow of the infusate in the infusion tube.

12. The device of claim 11, wherein the device is configured to output a first user instruction, via the user interface, to close a clamp on the infusion tube.

13. The device of claim 12, wherein the device is configured to, after outputting the first user instruction, activate the flow rate sensor at a first time to detect the flow of the infusate while the clamp is closed.

14. The device of claim 13, wherein the device is configured to, after the signal output from the flow rate sensor is received by the electronic controls in response to the flow rate sensor being activated at the first time, output, a second user instruction, via the user interface, to open the clamp on the infusion tube.

15. The device of claim 14, wherein the device is configured to, after outputting the second user instruction, activate the flow rate sensor at a second time to detect the flow of the infusate while the clamp is open.

16. The device of claim 15, wherein the electronic controls are configured to determine whether the signals output from the flow rate sensor indicate that flow of the infusate in the infusion tube was detected by the flow rate sensor by comparing the signals received from the flow rate sensor at the first and second times.

17. The device of claim 11, wherein the flow rate sensor abuts the outside of the infusion tube while the infusion tube is engaged in the channel, and wherein the flow rate sensor comprises: a first temperature sensor; a second temperature sensor; and a heater.

18. The device of claim 17, wherein the heater is arranged between the first and second temperature sensors.

19. The device of claim 18, the signals output from the flow rate sensor are based on a difference between a first signal output from the first temperature sensor and a second signal output from the second temperature sensor while the heater is activated.

20. The device of claim 11, wherein the housing is configured to releasably clamp the infusion tube in the channel.