SHAPE-SENSING EXPANDABLE MEMBER

• US 20090005674A1
• Filed: 04/24/2008
• Published: 01/01/2009
• Est. Priority Date: 04/25/2007
• Status: Active Grant

• Current Assignee: Nidus Medical LLC
• Original Assignee: Nidus Medical LLC
• Inventors: SAADAT, Vahid, MALCHANO, Zachary J.
• Granted Patent: US 8,463,359 B2
• Time in Patent Office: Days
• US Class Current: 600/424
• CPC Class Codes: A61B 2562/0215 Silver or silver chloride containing
• CPC Class Codes: A61B 2562/046 in a matrix array
• CPC Class Codes: A61B 2562/164 the sensor is mounted in or on a conformable substrate or carrier
• CPC Class Codes: A61B 2562/168 Fluid filled sensor housings
• CPC Class Codes: A61B 5/1076 for measuring dimensions inside body cavities, e.g. using catheters A61B3/1005 takes precedence
• CPC Class Codes: A61B 5/1077 Measuring of profiles
• CPC Class Codes: A61B 5/435 Assessing cervix alteration or dilation

Abstract

An expandable member for characterizing a three-dimensional space within a mammalian body is described. The expandable member is delivered to a target region in a deflated state where it is expanded by inflation of the member. Sensory transducers that contact the member relay sensory information generated when the member is in an expanded state to a microprocessor located outside the body. Using the sensory information, a data-driven picture that characterizes the three-dimensional space within the body is created with a microprocessor. The apparatus is useful in preparation for minimally invasive surgical therapy.

Claims

1. An apparatus for characterization of a three-dimensional space in a target region within a mammalian body comprising:

an expandable member having two or more transducers and a reference sensor,

the expandable member deliverable in a deflated state to the target region having a volume, the member adapted to inflate in the target region to at least partially fill the volume of the target region,

the transducers adapted to sense one or more transducers in the member to obtain sensory information, wherein the sensory information obtained informs the character of the three-dimensional space at the target region.

2. The apparatus of claim 1, wherein the sensory information is relayed to a microprocessor located outside the body.

3. The apparatus of claim 2, the microprocessor having a mechanism for processing captured information selected from creating a shape of the target region, calculating a volume of the target region, display of shape information, display of volume information, display of captured information over time, measuring surface curvature, identifying contour variations, calculating distance, calculating volume, and subtracting an initial data set from a subsequent data set.

4. The apparatus of claim 1, the expandable member adapted to exceed the volume of the target region.

5. The apparatus of claim 1, the transducers capable of an accurate determination of distance between two or more transducers.

6. The apparatus of claim 1, further comprising a through-lumen for adapting the expandable member to slide over a guidewire.

7. The apparatus of claim 1, the expandable member adapted to fit within a steerable catheter in order to deliver the member to the target region.

8. The apparatus of claim 1, further comprising an external control mechanism.

9. The apparatus of claim 8, wherein the control mechanism controls a function selected from steering the member, inflating the member, deflating the member, and adjusting position of the transducers.

10. The apparatus of claim 1, wherein the transducers comprise a sensing mechanism selected from electrical impedance through a conductive medium, ultrasound transmitting through a conductive medium, optical sensing, and low-field electromagnetic sensing.

11. The apparatus of claim 10, the sensing mechanism comprising electrical impedance, the apparatus comprising at least one temperature sensor to monitor temperature in the conductive medium.

12. The apparatus of claim 1, further comprising a calibration mechanism for use as a reference point to calibrate the apparatus before receiving sensory information from the transducers.

13. The apparatus of claim 1, further comprising a control to maintain expanding pressure on the expandable member so that the apparatus can maintain its position within a space that is expanding.

14. The apparatus of claim 10, the sensing mechanism comprising low-field electromagnetic sensing, the transducers comprising internal coils placed in the expandable member relative to a magnetic field generated external to the body.

15. A method of assessing a three-dimensional character of a target region in a mammalian body, comprising:

introducing into the body an expandable member adapted to inflate within the body, the expandable member having two or more transducers and a reference sensor, the expandable member deliverable in a deflated state to the target region having a volume, the member adapted to inflate in the target region to substantially fill the volume of the target region, and the transducers adapted to sense one or more transducers in the member to obtain sensory information, wherein the sensory information obtained informs the character of the three-dimensional space at the target region;

navigating the expandable member to the target region;

inflating the expandable member; and

receiving information from the transducers regarding the three-dimensional character of the target region.

16. The method of claim 15, wherein the target region is selected from a heart, an abdominal aorta, a spinal column, a body orifice and an organ having a tumor.

17. The method of claim 16, the target region comprising the heart, the method adapted to perform a function selected from measuring the shape of a left atrial appendage, measuring the shape and size of a pulmonary vein ostia, and measuring the size and shape of a septal defect in an atrium or ventricle.

18. A system for characterization of a three-dimensional space within a mammalian body comprising:

a delivery sheath comprising a deflated expandable member adapted to expand within a mammalian body,

the expandable member having two or more transducers and a reference sensor,

the expandable member deliverable to a target region having a volume,

the member adapted to inflate in the target region to substantially fill the volume of the target region,

the transducers adapted to sense one or more transducers in the member to obtain sensory information, wherein the sensory information obtained informs the character of the three-dimensional space at the target region, and

a microprocessor located outside the body for receiving the sensory information and processing it.

19. The system of claim 18, further comprising one or more control members for controlling one or more functions selected from delivery of the expandable member, inflation of the member, transducer sensing, and relay of sensory information.

20. The system of claim 18, wherein the expandable member further comprises a through-lumen for a guidewire.

21. The system of claim 18, further comprising a steerable catheter within which the expandable member is deliverable to the target region.

22. The system of claim 18, the microprocessor capable of recording captured information selected from a shape of the target region, a volume of the target region, display of shape information, display of volume information, display of information captured over time, measurement of surface curvature, measurement of distance, measurement of volume, and substracting an initial data set from a subsequent data set.