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WO2008067617A1 - Cathéter à ultrasons et procédé - Google Patents

Cathéter à ultrasons et procédé Download PDF

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Publication number
WO2008067617A1
WO2008067617A1 PCT/AU2007/001898 AU2007001898W WO2008067617A1 WO 2008067617 A1 WO2008067617 A1 WO 2008067617A1 AU 2007001898 W AU2007001898 W AU 2007001898W WO 2008067617 A1 WO2008067617 A1 WO 2008067617A1
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WIPO (PCT)
Prior art keywords
scan
catheter
image
anatomical
region
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PCT/AU2007/001898
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English (en)
Inventor
Andrew Madry
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Cuoretech Pty Ltd
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Cuoretech Pty Ltd
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Priority claimed from AU2006906881A external-priority patent/AU2006906881A0/en
Application filed by Cuoretech Pty Ltd filed Critical Cuoretech Pty Ltd
Publication of WO2008067617A1 publication Critical patent/WO2008067617A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B8/00—Diagnosis using ultrasonic, sonic or infrasonic waves
    • A61B8/44—Constructional features of the ultrasonic, sonic or infrasonic diagnostic device
    • A61B8/4483—Constructional features of the ultrasonic, sonic or infrasonic diagnostic device characterised by features of the ultrasound transducer
    • A61B8/4488—Constructional features of the ultrasonic, sonic or infrasonic diagnostic device characterised by features of the ultrasound transducer the transducer being a phased array
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B6/00—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment
    • A61B6/52—Devices using data or image processing specially adapted for radiation diagnosis
    • A61B6/5211—Devices using data or image processing specially adapted for radiation diagnosis involving processing of medical diagnostic data
    • A61B6/5229—Devices using data or image processing specially adapted for radiation diagnosis involving processing of medical diagnostic data combining image data of a patient, e.g. combining a functional image with an anatomical image
    • A61B6/5247—Devices using data or image processing specially adapted for radiation diagnosis involving processing of medical diagnostic data combining image data of a patient, e.g. combining a functional image with an anatomical image combining images from an ionising-radiation diagnostic technique and a non-ionising radiation diagnostic technique, e.g. X-ray and ultrasound
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B8/00—Diagnosis using ultrasonic, sonic or infrasonic waves
    • A61B8/12—Diagnosis using ultrasonic, sonic or infrasonic waves in body cavities or body tracts, e.g. by using catheters
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B8/00—Diagnosis using ultrasonic, sonic or infrasonic waves
    • A61B8/42—Details of probe positioning or probe attachment to the patient
    • A61B8/4245—Details of probe positioning or probe attachment to the patient involving determining the position of the probe, e.g. with respect to an external reference frame or to the patient
    • A61B8/4254—Details of probe positioning or probe attachment to the patient involving determining the position of the probe, e.g. with respect to an external reference frame or to the patient using sensors mounted on the probe
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B8/00—Diagnosis using ultrasonic, sonic or infrasonic waves
    • A61B8/44—Constructional features of the ultrasonic, sonic or infrasonic diagnostic device
    • A61B8/4483—Constructional features of the ultrasonic, sonic or infrasonic diagnostic device characterised by features of the ultrasound transducer
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B8/00—Diagnosis using ultrasonic, sonic or infrasonic waves
    • A61B8/48—Diagnostic techniques
    • A61B8/483—Diagnostic techniques involving the acquisition of a 3D volume of data
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B6/00—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment
    • A61B6/50—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment specially adapted for specific body parts; specially adapted for specific clinical applications
    • A61B6/503—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment specially adapted for specific body parts; specially adapted for specific clinical applications for diagnosis of the heart
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B8/00—Diagnosis using ultrasonic, sonic or infrasonic waves
    • A61B8/08—Clinical applications
    • A61B8/0883—Clinical applications for diagnosis of the heart

Definitions

  • the present invention relates to an ultrasound catheter and ultrasound method for obtaining an image.
  • the present invention relates to an ultrasound method for obtaining an endocardial surface image.
  • a familiar application for sonar methods in medical imaging is in ultrasound imaging of unborn babies.
  • the real time data that can be acquired and displayed as an image imparts a great deal of information to the clinician and patient.
  • This paper describes a system in which ultrasound is used to determine the position and orientation of a passive marker on an instrument tip where the instrument is being used in an invasive technique such that direct vision is impossible.
  • the position and orientation determined is used to drive a robot so the surgeon can manipulate the instrument accordingly.
  • ICE intracardiac echocardiography
  • RFCA radio frequency catheter ablation
  • AF is associated with significant morbidity and is a leading cause of stroke in the elderly.
  • the prevalence of AF increases with age from 1.7 % in those aged 60 - 64 years to 11.6 % in those over the age of 75 years.
  • Total morbidity and cardiovascular mortality are significantly increased in patients with AF compared with controls.
  • the lifetime risk of developing AF is 20-25%.
  • RFCA In RFCA an electrode that is part of a catheter is manipulated against an inner surface of a chamber of the heart and used to ablate cardiac cells that are associated with the arrhythmia or fibrillation.
  • RFCA is an effective therapy for the treatment of many cardiac arrhythmias however, one of the major complications associated with RFCA is the risk of thromboembolism which can go undetected using standard RFCA alone. This risk can be reduced by combining RFCA with ICE to detect thrombus formation during ablation in real time. This allows the clinician to take appropriate steps to prevent the thrombus from having harmful affects on the patient.
  • thromboembolism is a significant risk factor associated with RFCA.
  • Combining ICE with RFCA also allows the position of the electrode, contact of the electrode with endocardial surface, and detection of catheter migration to be observed accurately and in real time.
  • AcuNav catheter available from Acuson Inc., Mountain View, California, U.S.A.
  • the AcuNav catheter has a linear 64-element 1 dimensional (1D) transducer array that provides a 2D scan in a sector. To look in a particular plane the AcuNav must be twisted. Additionally, the 64-elements in this catheter make it very complex.
  • a method of obtaining ultrasound images is described in US Patent 6443894 to Sumanaweera et al. and assigned to Acuson Corporation.
  • the method applies surface detection techniques to medical sonar imaging in which a boundary of a 3-D region, for example an endocardial surface, is determined from ultrasound data representing the 3-D structure and then an image is rendered from another set of different ultrasound data representing the three-dimensional region wherein the rendering is performed as a function of the boundary.
  • To reconstruct the data frames to provide a 3-D image the method relies on position information.
  • the catheter to obtain an image of the endocardial surface or a part of the endocardial surface the catheter must be randomly swept across the endocardial surface and then each image acquired in the sweep is aligned using whatever data is available, such as position information. Constructing such sweeps into meaningful and accurate images is complex.
  • WO 2006/081410 the publication of PCT application PCT/US2006/002909, describes a method that makes use of orthogonal current pulses to an electrode arrangement on an ultrasound catheter to yield 3-D positional data as taught by Wittkampf in US 5983126 and US 5697377, to determine the location of the catheter which is used to indicate on a context map what portion of the heart is displayed in the ultrasound image.
  • the image in the context map can be used to build a geometry of a larger portion of the heart.
  • the invention is broadly directed to a method and catheter for ultrasound scanning of an anatomical region.
  • the invention makes use of the discovery that a first scan can be analysed to determine a region for making a second scan.
  • the invention resides in a method for obtaining an anatomical ultrasound image including the steps of: scanning a first region of an anatomical surface sonically to produce a first scan; analysing the first scan to select an appropriate second region of the anatomical surface for a second scan; scanning the second region of the anatomical surface sonically to produce a second scan; and producing an image of the anatomical surface from the first scan and the second scan to thereby obtain the anatomical ultrasound image.
  • the invention resides in a system for obtaining an anatomical image, the system including: a catheter for scanning a first region of an anatomical surface sonically to produce a first scan; a processor coupled to be in communication with the catheter, the processor for analysing the first scan to select an appropriate region of the anatomical surface for a second scan to be performed sonically by the catheter and for producing an image from the first scan and the second scan.
  • the system may include a first processor for analysing the first scan to select an appropriate region for the second scan and a second processor that produces an image from the first scan and the second scan.
  • the system may also include a display for displaying the image produced by processor.
  • the invention resides in a computer program product said computer program product comprising: a computer usable medium and computer readable program code embodied on said computer usable medium for obtaining an anatomical ultrasound image, the computer readable code comprising: a computer readable program code device (i) configured to cause the computer to analyse a first scan of an anatomical surface to select an appropriate second region of the anatomical surface for a second scan; a computer readable program code device (ii) configured to cause the computer to obtain a second region of the anatomical surface; and a computer readable program code device (iii) configured to cause the computer to produce an image of the anatomical surface from the first scan and the second scan.
  • the first scan may be analysed to detect an anatomical feature.
  • the first scan may be analysed to determine a position for the second scan.
  • the first scan may be analysed to determine a distance for the second scan. In any of the above forms the first scan may be analysed to determine an angle for the second scan.
  • the anatomical feature may be a surface.
  • the surface may be detected by a threshold technique or a surface detection algorithm.
  • the first scan may be an interferometric scan.
  • the first scan and the second scan may be obtained from two transducers spaced apart by a known distance.
  • a robot may be used to move the catheter from the first position to the second position.
  • the display may include a static image of the anatomical surface.
  • the static image may be manipulated to match the image of the anatomical surface produced by the processor.
  • an ensonified region may be displayed in a visually distinct manner.
  • the image may include a persistence.
  • the invention resides in a catheter for obtaining an endocardial surface image, the catheter comprising: a body housing a first transducer line element and a second transducer line element wherein the line elements extend in a length parallel to a length of the body and are housed at a known distance from each other.
  • the catheter body may house a first group of elements and a second group of elements, wherein each transducer element in the first and second groups extends in a direction parallel to the body and are housed a known distance from each other.
  • the catheter may further comprise a transponder for locating a device,
  • the device located may be part of the catheter.
  • the device located may be external to the catheter. Further features of the present invention will become apparent from the following detailed description.
  • FIG. 1 is a schematic diagram showing a system according to one embodiment of the invention.
  • FIG. 2 is a flow chart showing the steps of a method according to a first embodiment of a method of the invention
  • FIG. 3 is a schematic diagram showing a cross-section of a catheter scanning an endocardial surface
  • FIG. 4 is a schematic diagram showing a catheter according to one embodiment of the invention.
  • FIG. 5 is a schematic diagram of a catheter according to a second embodiment of the invention.
  • FIG. 6 is a schematic diagram showing a catheter according to a third embodiment of the invention.
  • FIG. 7 is a cross-sectional view of the catheter according to the third embodiment of the invention.
  • FIG. 8 is a cross-sectional view of a catheter according to a fourth embodiment of the invention.
  • FIG. 9 is a schematic diagram showing a catheter according to a fifth embodiment of the invention.
  • FIG. 10 is a flow chart showing the steps of a method according to a second embodiment of the invention. DETAILED DESCRIPTION QF THE INVENTION
  • the invention relates to a method of imaging using ultrasound, most likely with an ultrasound catheter.
  • the invention may be used in medical and clinical imaging.
  • the invention will be described with reference to endocardial surface imaging, however it is understood that the invention is not so limited, for example the invention can be used in imaging of any anatomical region including a intrabody cavity where an ultrasound probe may be used.
  • Suitable anatomical regions include a heart, a stomach and a bowel.
  • FIG. 1 there is shown a system 100 that has a first sonar transducer line element 102 and a second sonar transducer line element 103. These two line elements 102, 103 are positioned within a chamber of a heart 104 via a catheter 106, usually inserted along an artery or vein but possibly by direct puncture of a pericardium.
  • Transducer line elements 102, 103 extend parallel to one another and extend in line with the length of the body of catheter 106. Although in FIG. 1 each line element 102, 103 is represented by a single solid line it is understood that line elements 102, 103 are made up of multiple sub- elements (not shown). The sub-elements are described below with reference to FIG. 9.
  • Each sub-element transmits a fan-shaped beam that extends perpendicular to the longitudinal axis of catheter 106 and perpendicular to the face of the line element 102, 103 of which it is part.
  • a single sub-element gives 1 D data.
  • the elevation is the angle above or below the plane of the transducer and the bearing is the angle in the plane of the transducer. It is desirable to be able to unambiguously measure the location of a signal return in bearing and elevation.
  • a measure of phase delay between the return signal at line element 102 and the return signal at line element 103 can be used to discriminate in the elevation direction.
  • line elements 102, 103 obtain data in the form of a scan or swath.
  • the region that is scanned is called the ensonified area.
  • the data that is obtained is referred to as a scan.
  • Scans or signals from line elements 102, 103 are amplified, filtered and digitized by signal conditioner 108.
  • the conditioned scans are analysed in a computer 110 to extract significant parameters such as data relevant to the endocardial surface.
  • the extracted parameters are displayed in various ways on display 112.
  • One conditioned scan can be displayed as an image in isolation or it can be combined with one or more other conditioned scans to build a mosaic endocardial surface image.
  • the steps involved in working the invention are shown in FIG. 2.
  • the method 220 includes step 222 in which a first region or swath of an endocardial surface is scanned to produce a first scan.
  • the first scan is analysed to select an appropriate second region or swath of the endocardial surface to target for a second scan.
  • FIG. 3 illustrates one example of the type of analysis that is performed on the first scan.
  • Catheter 102 is shown in cross-section in FIG. 3.
  • line element 102 only is shown in FIG. 3.
  • catheter 106 having line element 102 will scan a first swath of the endocardial surface indicated by the solid lines.
  • catheter 106 is rotated and/or twisted so that line element 102 is moved it will scan the second swath of the endocardial surface indicated by the dashed lines.
  • a rotation of angle ⁇ will scan a second swath that borders the first swath only when endocardial surface 116 is at an appropriate distance from transducer element 104.
  • the distance may be the distance from line element 102 to the object being imaged.
  • the angle may be the angle from line element 102 centreline of the Field of View to the object being imaged. If the endocardial surface 114 is too close to the transducer element 104 there will be parts of the endocardial surface that are between the first and second swath that will not be scanned and vital information on the endocardial surface may be missed. If the endocardial surface 118 is too far from the transducer element 104 there will be overlap between the first and second swaths which is a waste of processing and bandwidth. Therefore, it is appropriate to examine the first scan to determine the ideal angle ⁇ through which to rotate and/or twist catheter 106 to scan a second swath that borders the first swath.
  • line element 102 only is shown in FIG. 3. It is to be understood that any movement of catheter 106 will move both line element 102 and 103. That is, rotation and/or twisting of catheter 106 will effect the same relative movement on line element 103 as it will on line element 102. It is understood that movement may affect one or both of location and orientation of line element 102 and 103.
  • the scan produced by line element 102 allows a bearing to the object to be calculated.
  • interferometric data is obtained and the elevation of a returned signal can be determined.
  • by combining this scan with the scan produced by line element 103 interferometric data is obtained and the elevation of a returned signal can be determined.
  • the further steps of method 220 are step 226 in which the second region of the endocardial surface is scanned to produce the second scan. Then in step 228 an image of the endocardial surface is produced from the first scan and the second scan.
  • the image of the endocardial surface is produced by aligning the first scan with the second scan and displaying the image on, for example, display 112.
  • One particularly advantageous embodiment of the invention is using a robot to move catheter 106 and to control the deflection and positioning of catheter 106.
  • the robot is used to move catheter 106 into a suitable position to obtain the second scan.
  • Suitable robotic catheter manipulation systems include the system available from Stereotaxis, 4320 Forest Park Avenue Suite 100, St. Louis, MO 63108, U.S.A., that uses large external magnets to move the internal catheter and the system available from Hansen, 380 North Bernardo Avenue Mountain View, CA 94043, U.S.A., which uses an electronically controlled sheath to move the catheter.
  • the robot can conduct a controlled sweep such that appropriate coverage of the endocardial surface is achieved. This coverage can be determined by an operator or ideally by a computer system that determines the best path to provide the coverage.
  • the robot can be controlled with either one or more of speech commands, gesture commands and stylus commands.
  • the robot incorporates a localization system to localize the position of a sensor on catheter 106.
  • the invention takes advantage of one of the characteristics of ultrasound which is that position of catheter 106 relative to the heart chamber will be known from the reference frame of the chamber itself i.e. distance of catheter 106 from the surface is known but the precise region of the surface will not be known unless there is an anatomical marker.
  • the localization system is a closed loop control system wherein the robot controlling the catheter tip updates its position based on a location sensor.
  • the location sensor may be located anywhere on the robot or catheter 106 and is preferably at a tip of catheter 106.
  • Suitable location sensors are the Biosense Carto system and the sensor described in US patent 5099845 to Micronix.
  • the Biosense Carto sensor allows the position of catheter 106 and the associated scan planes to be determined from the position of the sensor and the angle of rotation of line element 102, 103.
  • the robot uses open loop control, where there is no position sensor feedback, to determine its own position relative to some starting point. The robot is given commands to move to a certain position so the robot knows where it is at all times based on the original starting position and the movements made. This is only hindered if the catheter is obstructed in its movement. To overcome this issue catheter 106 can have one or more force sensors to detect when it is obstructed.
  • An advantage of open loop control is that it is not necessary to have a location sensor in the catheter.
  • the robot may not be able to autonomously scan the entire region of interest. In such a case some operator intervention can be used to complete the scanning. Within a particular region the imaging ability is improved by feeding back data into the decision where the next scan and orientation of that scan is made.
  • the use of the robot allows the method to be semi-autonomous with operator intervention.
  • FIG. 4 shows only the part of catheter 106 housing line elements 102, 103.
  • Line elements 102, 103 are housed at a known distance from each other in catheter body 107. As discussed above each line element 102, 103 is made up of multiple sub-elements (not shown). Each sub-element is able to form a sonic beam in a plane perpendicular to the line element 102, 103 without the requirement for any computation. As shown in FIG. 4 line elements 102, 103 extend in a direction parallel to the longitudinal axis of body 107. By arranging line elements 102, 103 in this longitudinal manner good use of catheter shape is made and interferometric scans may be obtained by measuring relative phase delay between signals measured on both line elements 102, 103.
  • the ultrasound data obtained by catheter 106 is in a perpendicular direction to that from a linear multi-element array in which transducer elements have vertical extent i.e. perpendicular to the body of the catheter.
  • the ensonification and reception region is in a plane perpendicular to the face of the line elements and in plane with the longitudinal axis of the catheter.
  • catheter 106 Another advantage of catheter 106 is that by having line elements 102, 103 disposed in a horizontal extent the beamwidth has a greater elevation than similarly sized line elements positioned in a vertical extent. Additionally, having more than one beam in a particular direction has the extra advantage of being able to measure gradients of surfaces in that direction within the one scan.
  • Another advantage of multiple sub-elements is that by combining the scans from line elements 102 and 103 and using interferometry both bearing and elevation of a received signal can be discriminated which means volumetric imaging can be obtained.
  • the near field limitation restricts the minimum distance that can be imaged.
  • the near field is given approximately by D ⁇ 2/4 lambda, where D is the aperture size and lambda is the wavelength.
  • D is the aperture size
  • lambda is the wavelength.
  • volumetric data may be obtained by sweeping the catheter to obtain scans of multiple regions of the heart volumetric data. This allows the building of a volumetric image to visualise the endocardial surface and/or objects, such as a thrombus, in front of the surface.
  • the elements are not made up of multiple-sub elements the single element would have high sidelobes which would be a limitation. Shading or aperture apodisation, as described below could be used to reduce the sidelobes. This would however, broaden the main beam.
  • One significant advantage of using only two line elements 102, 103 is that less wires are needed in catheter 106. This simplifies manufacture, decreases cost and reduces the chance of device failure.
  • the first scan can be used in method 220 to determine the position to which catheter 106 must be moved to scan a complementary second region.
  • the second region may be bordering the first region or a desired distance from the first region.
  • the first scan may be used to determine the position and orientation to which catheter 106 must be moved to scan the first region again.
  • a distance between the first region and the second region or an amount of overlap between the first and second regions can be used to determine the position to which catheter 106 must be moved. If a thrombus or potential thrombus is detected it may be advantageous to acquire more scans in the region of the thrombus or potential thrombus. The scans are then combined into a mosaic to build a surface map based on the detection of the endocardial surface. Mosaicing may be simple abutting of adjacent images or more complex image manipulation. In this manner a surface map of the entire interior cardiac chamber can be built. Alternatively only a defined portion of the cardiac chamber may be mapped. The defined portion may be a portion within a given distance from a region of interest.
  • thrombus Of particular interest in treating atrial fibrillation is the region of the pulmonary veins or regions where it is likely that thrombus may form. If a thrombus or pulmonary vein is detected in step 224 a clinician may decide to move catheter 106 to a position where the second scan will give desired information on the thrombus or pulmonary vein. For example, an autonomous or clinician directed second scan bordering the first scan can be taken to determine the size of the thrombus or the size of the pulmonary vein. If the thrombus or pulmonary vein is large this may be an iterative process.
  • the catheter can autonomously scan to take a second scan inside a vein.
  • the first scan can also be used to set the distance from line element 102, 103 to the endocardial surface and/or to set the orientation of line element 102, 103 to the endocardial surface.
  • element 102, 103 can be angled at the optimum angle for observation of the endocardial surface and/or for observation of a feature of the endocardial surface for example, a pulmonary vein.
  • the surface of the endocardium is detected in the scans and the surface is rendered using standard 3-D visualisation techniques to give a 3-D image that can be observed by a clinician.
  • the endocardial surface is rendered as a surface with texture layered on that surface.
  • any dense material for example a thrombus, will be rendered and displayed as a cloud in front of the endocardial surface. Transparency is used to see surfaces behind such dense material. For example, by scanning and/or rescanning the inside surface of a cardiac chamber an image of the surface of the inside of the cardiac chamber can be built up. To build up an image that a clinician can easily equate with the actual cardiac anatomy the cardiac surface can be scanned and/or rescanned which is analogous to painting and repainting the surface and volume of the cardiac surface.
  • the volume data set consists of quantized values of one or more scalar fields that have been sampled at positions throughout a three- dimensional volume.
  • the sampling can be performed on a regular or irregular grid, with data set sizes ranging from kilobytes to gigabytes.
  • volume rendering in which an image is generated directly from the volume data without the generation of an intermediate geometric model. Typically this is done by mapping the data values in the volume to the color and opacity of an imaginary semi- transparent material, and then rendering an image of this material. Data values of interest can be assigned high opacity values and a specific color to highlight their location within the volume while other data values can be assigned low opacity values to reduce their visual importance. It is also possible to render geometric and volumetric primitives together, allowing the inclusion of geometric primitives such as coordinate axes and other reference objects. This technique is useful for displaying relationships between areas of interest that are not well defined in a geometric sense. It is also useful for displaying the volume around areas of geometric interest, such as the volume near an isosurface.
  • scans obtained with catheter 106 can be used in method 220 to monitor any change in the cardiac chamber during a medical procedure.
  • An example of such a change is thrombus formation and/or ablation during RFCA. This will allow any tissue that breaks off, or any thrombus formed during ablation, to be detected and visualized in real time. The change can be detected by identifying a change in the image produced at 228.
  • any suitable approach can be used to align the scans to provide a desired 3-D reconstruction.
  • Any suitable approach can be used to align the scans to provide a desired 3-D reconstruction.
  • an approach that provides position information associated with the orientation of one scan relative to another is used.
  • a manual process may also be involved.
  • aligning scans There is further discussion on aligning scans below. Any method to detect a surface can be used for example, a threshold technique or a surface detection algorithm.
  • the data used to determine the surface can be Doppler data or Doppler energy data.
  • Doppler data is particularly useful in the case of intracardial imaging because as the heart beats the heart wall moves.
  • Continuous Wave (CW) pulse in which the wave has a constant or nearly constant frequency is used and the frequency shift in the returned echo is determined.
  • FM pulses can also be used.
  • frequency is swept from one value to another.
  • FM pulses gives good range resolution and improved detection.
  • Coded pulses may also be used.
  • some code or pattern is used to modulate the transmitted signal. This code or pattern can be removed from the received signal to decompress the signal.
  • Golay codes are examples of coded pulses.
  • CW and FM pulses are used.
  • Separate processing chains can be used in the processing of the echoes returned by each pulse.
  • Image segmentation determines, as accurately as possible, where boundaries lie or which regions in the image are the same or different.
  • a common approach is edge detection which determines the outline of objects at the boundary between different regions in an image.
  • a measure such as the gradient which is the slope of the reflected intensity change is taken between a pixel and its neighbors and then compared to a value called a threshold. If the gradient is above a threshold then an edge point is located at that pixel. The original image is then transformed into an image containing information about edges. Then a visualization method is used to show these values. The larger the intensity of the edge the sharper the edge. As the amount of noise increases the ability to detect edges is reduced. To reduce the effects of noise on finding edges the data processing can include a step of preprocessing.
  • edge detection technique is called mask convolution which involves convolution of the image with a mask function.
  • template matching is another edge detection technique. In this technique rather than convolving a template a matching process determines whether a region matches a set of prescribed templates to be an edge.
  • wavelet analysis can be used to enhance contrast in images.
  • Most edge enhancement strategies involve edge detection and subsequent increase in image crispness
  • texture discrimination Another technique is called texture discrimination. With texture discrimination rather than trying to find the edges in an image regions of an image are characterized based on measures of texture. An edge map is produced by creating a border between regions determined to have different textures.
  • Doppler signal can be used to detect where edges are. This technique takes advantage of moving regions, such as cardiac chambers, having a larger Doppler shift than static regions.
  • edge detection methods can be done in 3D in terms of voxels instead of pixels.
  • an image is obtained based on a quick sweep of the endocardial surface conducted during a single heart beat. This allows an image of the swept area during a particular part of the cardiac cycle to be built up. If close to the surface the return travel time is small and so this is practical.
  • scans at different positions are made during a consistent part of the heart beat. This allows a snap shot of the heart chamber to be built up.
  • the distances from the ultrasound sensor to the heart surface (of the order of cm), are such that the time to measure the distance to the heart endocardial surface and back is much smaller than the heart's beat to beat interval.
  • the return time of flight is approximately 13 ⁇ sec for a 1cm distance compared to a 1 second period for a 60 beats per minute heart rate (period of order 0.1 sec). This means a sweep of a limited defined area can be made with the heart chamber effectively stationary.
  • catheter 106 remains stationary during one full cardiac cycle and then moves to a next position. At each position the full range of heart wall movement can be captured. In this way an image of the beating volume can be built up. This image can be built up by obtaining a suitable number of scans required to cover the endocardial surface over a number of beats. A person of skill in the art can maximise the ping rate and catheter position to obtain the best possible image. The image can also be improved by using image averaging techniques. Additionally, an electrical reference signal can be measured with a surface ECG (electrocardiogram) or from a locally measured electrogram. The scans can then be sorted or aligned with respect to the ECG.
  • ECG electrocardiogram
  • the ultrasound data and scans can be combined with static data such as from computed tomography (CT) or magnetic resonance imaging (MRI).
  • CT computed tomography
  • MRI magnetic resonance imaging
  • a person of skill in the art can readily select an appropriate time for obtaining the static data, such as one day prior to the ultrasound scans.
  • the ultrasound data and static data can be combined by, for example, dynamically registering and displaying them together in real time.
  • the element position can be aligned with the CT and/or MRI image to determine the position of line element 102, 103.
  • the transducer element position can then also be tracked in 3D space as it moves. Further, when an ultrasound scan is acquired and the surface is detected the surface can be matched to the static data.
  • the static image can be manipulated so that its surface is stretched, pushed and/or pulled at the regions where the ultrasound scan is acquired so that the two images match.
  • Such a visualisation will be useful because it allows a clinician to see the whole of the heart chamber and the visualisation can make clear where this chamber is being ensonified as if with a torch light.
  • the surfaces can be matched at these points.
  • combining with a static CT scan will allow the clinician to observe the complex detail of pulmonary veins that are difficult to image with ultrasound.
  • This combined image also allows visualisation of the entire cardiac chamber as well as the ensonified area.
  • only the instantaneous ultrasound scan is displayed in combination with the static scan. This embodiment is like a single slice (or fan shaped field of view) painted onto the static image.
  • a persistence can be implemented in the sonar image to remember the ultrasound image that has previously been scanned.
  • the persistence may be a visual persistence that shows a previously scanned image or images.
  • the currently ensonified area can be made brighter than previously ensonified areas.
  • the use of a persistence on the display will give a sense of where the catheter is sweeping.
  • the static image of the chamber surface may be surface rendered and can be displayed as semi transparent.
  • the surface can be made transparent enough so that it can be easily seen through but opaque enough so that the structure of the chamber can be seen.
  • the view of the CT may also be from the inside of the chamber.
  • the ensonified part of the surface can be displayed so that it is visually distinct from the other displayed elements.
  • a person of skill in the art can readily chose an appropriate distinction such as, displaying the ensonified region as more opaque than the other regions of the surface being displayed or in a different shade or colour.
  • a person of skill in the art is readily able to select appropriate graphical techniques to show echo properties of the surface, for example surface texture and reflectivity.
  • the static image may be warped dynamically to match to the ultrasound detected surface. Because the ultrasound image is real time, the warping may be done in real time. Of great advantage, by matching the real time ultrasound image to the static image any misalignment, such as that which can occur if the patient moves, can be detected. For example, the misalignment could be detected by the real time surface bulging out at certain spots.
  • the real time nature of the invention may allow the surface of the static image to be built up again after a misalignment.
  • the section of the static image that intersects with the beam may be stretched.
  • the regions adjacent may also be stretched so that the surface stays smooth, otherwise the surface graphics may look strange. The stretching would be a gradual process.
  • next region scanned may also be stretched. As the catheter scans, the images may be progressively matched.
  • An electroanatomical map may be constructed by a roving catheter with a position sensor that builds up geometry and one or more calculated electrical properties from the electrograms at each position which may be displayed on the anatomical surface.
  • the invention can obtain and display a 3D field of view.
  • the field of view has an angular extent in orthogonal directions emanating from a central point.
  • intersection of the beam with a surface may be shown on display 112 as a patch.
  • the intersection with the surface is a line, as the beam is swept the surface patch is built up.
  • the patch may show other qualities rather than just delineate the region, for example texture of the surface may be shown based on echo strength.
  • Ultrasound can be used to image the chamber volume and heart wall cross section at each location. This inside wall can be detected.
  • the transmit power of the pings is optimized so that returns are small after a certain distance out from the sensor. This can be done because in imaging the endocardial surface and objects within the intracardial space it is not required to visualize any further than the walls of the heart chamber.
  • the power is also optimized for the dimensions of the actual chamber and for the relative position of the catheter within the chamber.
  • the catheter has a full planar aperture that allows beamforming in 3D and therefore allows true 3D imaging inside the heart chamber.
  • catheter 106 A person of skill in the art is readily able to select suitable materials from which to make catheter 106 and if required suitable materials in which to encase catheter 106.
  • an appropriate maximum size of catheter diameter is 8 French (2.6 mm diameter).
  • the catheter is preferably generally flexible but may contain rigid regions of defined length.
  • Catheter 106 preferably has a length of approximately 7mm, although a person of skill in the art understands that the length of any rigid region of catheter 106, such as that housing the elements 102, 103 is limiting because the rest of catheter 106 is flexible and can curve and bend.
  • a person of skill in the art is readily able to select catheter dimensions based on the application.
  • line elements 102, 103 have a length of about 7 mm and a width of approximately 0.11 mm. These measurements are preferable measurements only and are in no way limiting. A person of skill in the art is readily able to select an appropriate length and width for line elements 102, 103.
  • frequencies for intra-cardiac imaging are 5MHz to 20MHz. These frequencies are able to achieve up to 15 cm depth penetration.
  • transducer Any suitable type of transducer may be used.
  • suitable transducers include, standard piezoelectric ceramics, e.g. PZT; composite transducer technology where piezoelectric elements are in matrix structures with other materials; and PVDF (Polyvinylidene Fluoride) transducers.
  • the 3-D data and image that is obtained can be displayed on either a 2-D computer display or a display that allows approximate or true 3-D display of data.
  • this second catheter may be fitted with a single omni-directional sensor. If this sensor pings and signals are synchronised between the two catheters then catheter 106 can be moved to ping in the direction of the second catheter and localize it relative to catheter 106 and the endocardial surface. This allows more accurate positioning of the second catheter.
  • the sensor on the second catheter is a receiver by measuring the time the ping from catheter 106 arrives at the second catheter the position of the second catheter can be determined. This has the advantage of both signals having the same timebase which makes it possible to measure directly the time delay and hence the distance between the two catheters.
  • the scans are taken with a passive intra-cardiac catheter that has at least two receiving elements and an external ultrasound transmitter.
  • the passive catheter can be simpler and cheaper. This has a cost benefit because catheters can usually only be used once.
  • Another advantage is that the passive catheter does not have to transmit and any heating effects and problems in switching between transmit and receive is overcome. Additionally, a passive catheter does not have to generate the high voltages that are necessary to transmit a sonic beam. This simplifies catheter design and reduces risk of exposing the patient to these voltages.
  • the passive internal catheter and external transmitter will also have a common timebase which can be used to position the beams received by one line element with respect to beams received by another line element.
  • a passive catheter also enables the use of beamform on transmit in which a number of simultaneous transmit beams are produced outside the body and received by the passive internal catheter.
  • Any technique to distinguish the different transmit beams can be used. Suitable techniques are for example, transmitting CW pulses at different centre frequencies and transmitting different orthogonal coded pulses. Additionally, transmitted FM pulses can be discriminated by transmitting up and down in frequency. A person of skill in the art is readily able to choose a suitable technique to distinguish different transmit beams.
  • Modern transducer materials are able to transmit over a wide frequency bandwidth which facilitates the transmission of separable pulses.
  • the transmit element and internal passive receive element may be oriented in orthogonal directions. In this manner a single receive line element can discriminate in both the bearing and elevation directions by filtering and/or decoding the signals received at each sub-element within the line element.
  • Another advantage of a passive internal catheter is that the transmitter is external and can be reused which means the complexity required to be capable of beamform on transmit is not a great barrier.
  • a disadvantage of a passive catheter is the longer travel time from the source to the internal passive catheter.
  • FIG. 5 A second embodiment of a catheter 530 according the invention is shown in FIG. 5
  • Catheter 530 has a first multi-element array 560 that is made up of three line elements 102 and a second multi-element array 570 that is made up of three line elements 103.
  • the two arrays 560, 570 and each of the line elements 102, 103 are housed at a known distance from one another.
  • the use of three line elements 102, 103 allows one line element 102,
  • each multi-element array 560, 570 to transmit and the other two line elements to receive.
  • Having multi-element arrays 560, 570 also gives extra phase information which helps to overcome the ambiguity that occurs when signals return at two angles at the same range simultaneously.
  • Both arrays 560, 570 have multiple line elements 102, 103 and because each line element 102, 103 has multiple sub-elements each array 560, 570 also has multiple sub-elements.
  • line elements 102, 103 that are to be used primarily as transmitters and line elements 102, 103 that are to be used primarily as receivers. It is to be understood that although line element 102, 103 is designated as primarily a transmitter that element 102, 103 may still be used as a receiver. The same is true of an element 102, 103 that is designated as primarily a receiver.
  • a further advantage is that, when sweeping catheter 530 to ping across the endocardial surface larger steps can be made without leaving any gaps in the surface coverage between each ping because there is a wider field of view.
  • the arrays 560, 570 are shown to have three line elements 102, 103 a person of skill in the art is readily able to select an appropriate number of line elements 102, 103 to suit their purposes.
  • the number of line elements 102, 103 in an array 102, 103 could be one, two, three, four, five, six, seven, eight, nine, ten, fifteen, twenty or any other suitable number.
  • An array of only a single line element 102 is still called an array because it is made up of multiple sub-elements.
  • arrays 560, 570 are shown the invention is not so limited.
  • Two arrays 560, 570 is a relatively simple configuration however, a person of skill in the art is readily able to select an appropriate number of arrays to suit their purposes. Increasing the amount of arrays 560, 570 leads to an increase in the maximal possible resolution.
  • the number of arrays 560, 570 could be one, two, three, four, five, six, seven, eight, nine, ten, fifteen, twenty or any other suitable number.
  • the arrays 560, 570 and/or line elements 102, 103 may extend across the entire circumference of the catheter. Having line elements 102, 103 or arrays 560, 570 all the way around a catheter gives extra coverage.
  • An extension of this is a full 2D matrix of line elements 102, 103 which allows a beam to be formed in any direction in 3D space.
  • the extent of the beams that can be formed is determined by the maximum extent of the aperture. In one direction the extent is along the length of the catheter, in the other it is the diameter of the catheter.
  • non-ultrasound data for example, electric potential data
  • the electric potential data can be acquired from a separate probe on the same catheter in an arrangement like the one shown in FIG. 6.
  • lnFIG.6 catheter 630 houses both arrays 560, 570 and an ablation probe 575.
  • the detection of the position of the ablation probe 575 can be facilitated by having an ultrasound transmitting element 576 (not shown) co- located with the ablation probe 575.
  • the ablation probe 575 may be part of a second catheter that is distinct from the ultrasound catheter 106.
  • the angle to the ultrasound transmitting element 576 can be measured in 3D (from time delay in each plane).
  • this is analogous to a transponder.
  • the transmission of the pulse is synched with the ultrasound beam and allows display of remote location in the main image.
  • catheter 106, 530 must have a sufficiently small diameter to pass through the puncture.
  • ultrasound arrays 560, 570 extend around the entire circumference of catheter 630. In this arrangement it is a simple case of selecting the appropriate arrays 560, 570 facing the electrode tip to allow visualisation of the tip with the endocardial surface.
  • FIG. 7 shows a cross-sectional view of catheter 630, through line s-s in FIG. 6, in which multi-element arrays 560, 570, extend around the entire outer surface of the circumference of catheter 630. This arrangement allows scans to be obtained in any direction around catheter 630.
  • FIG. 8 shows another embodiment of a catheter 830 that has three pairs of elements 102, 103 arranged around the outside of catheter 830. Appropriate pairs 102, 103 are chosen to obtain a scan in a desired direction.
  • FIG. 9 shows another embodiment of a catheter 930 in which the multiple sub-elements 942, 952 making up line elements 940, 950 are shown to be spaced apart.
  • the provision of sub-elements 942, 952 throughout the length of line elements 102, 103 allows formation of extra beams laterally.
  • each scan gives truly volumetric data.
  • Line element 942 forms fan shaped beams discriminating in one direction, e.g. bearing.
  • the same is true of line element 952.
  • To discriminate in the other direction e.g. elevation either the data received from another line element can be combined with the data received at line element 942 or signals received from an external transmitter can be filtered and/or decoded. In this manner catheter 930 permits both bearing and elevation discrimination.
  • sub-elements 942, 952 are spaced apart by ⁇ /2 and there are 64 elements in each line element 102, 103.
  • a person of skill in the art is readily able to select an appropriate spacing for sub-elements 942, 952 and an appropriate number of sub-elements 942, 952 for a line element 940, 950.
  • sub-elements 942, 952 may have a length of 0.1mm and may be spaced apart by 1 mm. This size and spacing is in no way limiting. When sub-elements 942, 952 are spaced apart this leads to grating lobes which have the effect that when a reflected signal arrives at a line element 940, 950 it is not possible to determine from which of several angles it arrived at. However, if apertures 944, 954 are filled with each sub-element 942, 952 the response of the individual sub-elements 942, 952 multiplies with the overall pattern. This reduces the off-axis responses and produces a set of unambiguous beams around the centre.
  • sub-elements 942, 952 When the apertures 944, 954 are filled with sub-elements 942, 952 the sub-elements 942, 952 adjoin one another in a continuous manner. In another embodiment sub-elements 942, 952 are spaced further apart than ⁇ /2. Although this leads to grating lobes and ambiguity there are less sub-elements 942, 952 populating the line element 940, 950. This simpler design is cheaper to manufacture and because there are fewer sub- elements 942, 952 there is less chance of device failure.
  • the use of sub-elements 942, 952 allows formation of beams in other directions to the normal (broadside) beam. This results in better coverage of the endocardial surface.
  • Shading and apodisation can be used to reduce sidelobe response. This is done by applying a weighting to each sub- element response prior to beamforming. For example the sensitivity of the sub-elements 942, 952 can be reduced from the central part of line element 940, 950 towards the ends. When sensitivity is adjusted in this manner shading can be applied to the received signal to reduce the sidelobes.
  • Shading can also be achieved by for example, using a specifically shaped line element e.g. a diamond shape and/or by having the spacing between the sub-elements in a line-element increase towards the ends of the line element.
  • a specifically shaped line element e.g. a diamond shape and/or by having the spacing between the sub-elements in a line-element increase towards the ends of the line element.
  • one suitable method is that when the position of element 102, 103 in planes x, y, z is known and the orientation in 3D is given by three angles, then for each scan taken there is a fixed frame of reference. The scans can then be aligned taking into account their relative positions in the fixed frame of reference.
  • Field of View is the region in which targets can be resolved i.e. in range from time delay.
  • targets in the Field of View are in elevation and possibly in bearing when there are multiple elements in each array.
  • the Field of View can be defined by a measure of where response drops off to a certain amount from the Maximum Response Axis (MRA).
  • MRA Maximum Response Axis
  • One measure is the so called 3dB points (half power points).
  • the effective Field of View in elevation (perpendicular to catheter axis) can be calculated. If we have a single beam in bearing (i.e. in the same plane as the line array 102, 103) this will have a certain beam width determined by the length of the line array 102, 103. If we have multiple beams in bearing then beams available furthest from broadside determine the Field of View.
  • the distance from the surface is known from the previous scan. This allows determination of the second region to be ensonified so that this second region lines up with the first.
  • the invention also provides a computer program product that comprises a computer usable medium and computer readable program code embodied on said computer usable medium for obtaining an anatomical ultrasound image.
  • the computer readable code comprises a computer readable program code device configured to cause the computer to analyse a first scan of an anatomical surface to select an appropriate second region of the anatomical surface for a second scan.
  • the computer readable code also comprises a computer readable program code device configured to cause the computer to obtain a second region of the anatomical surface and a computer readable program code device configured to cause the computer to produce an image of the anatomical surface from the first scan and the second scan.
  • FIG. 10 shows a flowchart that illustrates the steps in one example of the method of the invention 1000. As above, this example will be described with reference to endocardial surface imaging, however it is understood that the invention is not so limited.
  • the patient has a static scan, e.g. a CT or MRI scan, in which a 3D surface rendered image of the cardiac chamber is obtained.
  • a static scan e.g. a CT or MRI scan
  • the patient is to have a procedure for mapping and ablation, however it is understood that the invention is not so limited. Either a catheter for mapping and ablation and an ultrasound catheter or alternatively a special catheter with both functions is used.
  • the catheter(s) are located within the frame of reference of the chamber using known methods. One such method is described in US5738096.
  • the static image is co-registered with the image of the chamber obtained during the procedure.
  • a electrical mapping procedure is also carried out to identify potential regions for ablation. Electrical mapping is the measurement of electrograms and calculation of some parameter for example, local activation time with respect to a designated reference time; dominant frequency and cycle length variability. Reference is made to the inventor's earlier patent
  • mapping procedure can be performed alone or partially performed while the sonar image map is obtained.
  • step 1002 the catheter is directed to a region of a cardiac chamber.
  • step 1004 the extent or region to be scanned and/or a scan pattern is specified for autonomous scanning that does not require operator input.
  • the scan pattern may be a predefined scan pattern across a surface for example, up and down or zig-zag.
  • step 1006 scan parameters such as distance to surface from the sensor, angle of centre line of field of view with respect to the surface and location in the ECG (electrocardiogram) cycle are specified.
  • step 1008 the catheter is moved to a position to acquire a first scan.
  • step 1010 a pulse is transmitted and an echo received.
  • step 1012 the first scan is analysed to detect the surface patch and the next position to scan is calculated. This calculation can be based on analyzing the geometry of the surface to predict the position and/or orientation for the catheter to acquire a second scan of a second surface patch.
  • the gradient or normal of the surface can be calculated.
  • the location of the catheter can be chosen by keeping a fixed distance from the surface.
  • the fixed distance may be optimized for a specific catheter for example, optimization for focal distance.
  • the orientation of the catheter can be set so the beam is at some defined angle to the surface.
  • An orthogonal angle may be the best for contrast with the surface.
  • An askance angle may be useful for texture mapping of the surface.
  • the above procedure can be used to get further detail of regions of the image for example, echo properties of the surface; the thickness of the wall in those regions; and/or potential formation of thrombus in the volume.
  • step 1014 a decision is made as to whether the first scan meets prescribed criteria for confidence of detection. The decision may be made by a computer or an operator. If the first scan meets the prescribed criteria step 1016 is performed if not step 1010 is repeated.
  • step 1016 the gradient surface is calculated as built up from consecutive scans.
  • step 1018 the static image is warped or morphed with the real time detected ultrasound surface.
  • step 1020 the graphical display of the current ultrasound image is updated to include a highlight of the ensonified region of the chamber surface.
  • step 1022 a decision is made as to whether the scan of the region is complete. The decision may be made by a computer or by an operator. If the scan is not complete steps 1008-1020 are repeated.
  • step 1024 the catheter is relocated to a next region either manually or by a robot and the method may begin again from step 1002.
  • mapping catheter can then be moved around the chamber to measure various properties to determined where to ablate.
  • the mapping device may have several electrodes.
  • ANALYSIS METHOD AND APPARATUS which discusses measurement of various complex parameters and proposes visual means of displaying them .
  • One example of a parameter that is of interest is the Dominant
  • mapping catheter can be maneuvered into the beam of the ultrasound catheter.
  • the maneuvering may be assisted via the transponder system for localization that is described above.
  • the mapping catheter can then follow the surface geometry in a predefined manner as described above.

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Abstract

La présente invention concerne un procédé pour obtenir une image ultrasonore anatomique comprenant le balayage d'une première région d'une surface anatomique de façon sonique afin de produire un premier balayage, l'analyse du premier balayage afin de sélectionner une seconde région appropriée de la surface anatomique pour un second balayage et le balayage de la seconde région de la surface anatomique de façon sonique afin de produire un second balayage. Le procédé comprend également la production d'une image de la surface anatomique à partir du premier balayage et du second balayage afin d'obtenir ainsi l'image ultrasonore anatomique.
PCT/AU2007/001898 2006-12-08 2007-12-10 Cathéter à ultrasons et procédé Ceased WO2008067617A1 (fr)

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WO2016093848A1 (fr) * 2014-12-11 2016-06-16 Stereotaxis, Inc. Procédé et appareil de commande automatisée et de positionnement multidimensionnel de multiples dispositifs médicaux localisés à l'aide d'un système interventionnel unique de navigation à distance
EP3613351A1 (fr) * 2018-08-22 2020-02-26 Koninklijke Philips N.V. Circulation coronaire faisant appel à un écho intracardiaque

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EP1181893A1 (fr) * 2000-08-18 2002-02-27 Biosense, Inc. Reconstruction tridimensionelle par ultrasons
US20030158477A1 (en) * 2001-11-09 2003-08-21 Dorin Panescu Systems and methods for guiding catheters using registered images
WO2004027712A2 (fr) * 2002-09-19 2004-04-01 Koninklijke Philips Electronics N.V. Procede, logiciel et appareil pour segmenter une serie d'images bidimensionnelles ou tridimensionnelles
WO2005048813A2 (fr) * 2003-11-12 2005-06-02 The Board Of Trustees Of The Leland Stanford Junior University Dispositifs et procedes de formation d'images tridimensionnelles d'un site corporel interieur
US20060241445A1 (en) * 2005-04-26 2006-10-26 Altmann Andres C Three-dimensional cardial imaging using ultrasound contour reconstruction
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Publication number Priority date Publication date Assignee Title
EP1181893A1 (fr) * 2000-08-18 2002-02-27 Biosense, Inc. Reconstruction tridimensionelle par ultrasons
US20030158477A1 (en) * 2001-11-09 2003-08-21 Dorin Panescu Systems and methods for guiding catheters using registered images
WO2004027712A2 (fr) * 2002-09-19 2004-04-01 Koninklijke Philips Electronics N.V. Procede, logiciel et appareil pour segmenter une serie d'images bidimensionnelles ou tridimensionnelles
WO2005048813A2 (fr) * 2003-11-12 2005-06-02 The Board Of Trustees Of The Leland Stanford Junior University Dispositifs et procedes de formation d'images tridimensionnelles d'un site corporel interieur
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WO2016093848A1 (fr) * 2014-12-11 2016-06-16 Stereotaxis, Inc. Procédé et appareil de commande automatisée et de positionnement multidimensionnel de multiples dispositifs médicaux localisés à l'aide d'un système interventionnel unique de navigation à distance
EP3613351A1 (fr) * 2018-08-22 2020-02-26 Koninklijke Philips N.V. Circulation coronaire faisant appel à un écho intracardiaque
WO2020038813A1 (fr) 2018-08-22 2020-02-27 Koninklijke Philips N.V. Circulation coronaire utilisant un écho intra-cardiaque
CN112584772A (zh) * 2018-08-22 2021-03-30 皇家飞利浦有限公司 使用心脏内回波的冠状动脉循环
JP2021534858A (ja) * 2018-08-22 2021-12-16 コーニンクレッカ フィリップス エヌ ヴェKoninklijke Philips N.V. 心臓内エコーを用いる冠循環
JP7133087B2 (ja) 2018-08-22 2022-09-07 コーニンクレッカ フィリップス エヌ ヴェ 心臓内エコーを用いる冠循環

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