Anatomical visualization with electrically conductive balloon catheter

Abstract

A balloon catheter for providing a 3-dimensional rendering of the interior of a cavity, the catheter system including a controller, a catheter connected to the controller and a balloon positioned on the catheter. The balloon includes a mesh having members extending longitudinally and circumferentially about the balloon where each member of the mesh has an electrical characteristic that changes as the member is deformed. The controller uses a measurement of the variable electrical characteristic to generate a three-dimensional rendering of an interior surface of the cavity, which can be rotating to different viewing angles.

Claims

1. An imaging system for providing a 3-dimensional image of the interior of a cavity comprising: a balloon catheter; a mesh affixed to the balloon catheter, said mesh having members extending longitudinally and circumferentially about said balloon catheter, said mesh having columns and rows that intersect each other at a node; a controller coupled to the balloon catheter for controlling the inflation of said balloon catheter; wherein each member of said mesh having at least one electrical characteristic that changes as the member is deformed such that, when the member comprises a length (L) a measured electrical characteristic will be different than when the member comprises a length (L.sub.1) where L.sub.1 is greater than L; wherein the controller determines the at least one electrical characteristic from each member and utilizes the measured electrical characteristics to generate a three-dimensional rendering of an interior surface of the cavity.

2. The balloon catheter according to claim 1 wherein each member comprises a radio-opaque material.

3. The balloon catheter according to claim 1 further comprising a display coupled to said controller.

4. The balloon catheter according to claim 1 wherein the three-dimensional rendering is saved on a storage device accessible by said controller.

5. The balloon catheter according to claim 1 wherein said storage device is detachably coupled to said controller.

6. The balloon catheter according to claim 1 further comprising a computer coupled to said controller.

7. The balloon catheter according to claim 6 wherein said computer is coupled to said controller via a network connection.

8. The balloon catheter according to claim 7 wherein the three-dimensional rendering is saved on a storage device accessible by said computer.

9. The balloon catheter according to claim 8 wherein said storage device is detachably coupled to said computer.

10. The balloon catheter according to claim 1 further comprising an input device coupled to said controller for providing input commands to said balloon catheter.

11. The balloon catheter according to claim 10 wherein said input device is selected from the group consisting of: a keyboard, a mouse, a touchpad, a touch screen control, a voice-activated control and combinations thereof.

12. The balloon catheter according to claim 10 wherein said input device is a wireless device.

13. The balloon catheter according to claim 10 wherein the input device allows for a user to rotate the three-dimensional rendering to different viewing angles.

14. The balloon catheter according to claim 1 wherein the balloon catheter comprises a bendable section at a distal end thereof.

15. The balloon catheter according to claim 1 wherein the balloon is comprised of a material selected from the group consisting of: latex, chronoprene, yulex, silicon, polyurethane, C-flex and combinations thereof.

16. The balloon catheter according to claim 1 wherein the electrical characteristic that changes when the mesh is deformed is resistance or impedance.

17. The balloon catheter according to claim 16 wherein the measured electrical characteristic is an applied voltage across a selected column, row or combinations thereof.

18. The balloon catheter according to claim 17 wherein the change in resistance or impedance between each node is used to determine a deformation at a point between each node.

19. The balloon catheter according to claim 17 further comprising an integrated circuit having pins connected to ends of the columns and rows for driving a voltage through each column, row and combinations thereof.

20. The balloon catheter according to claim 19 wherein the pins of the integrated circuit may be driven to either a high voltage state, a low voltage state or a high impedance state.

21. The balloon catheter according to claim 19 wherein said integrated circuit is molded into a tube, which is affixed to the catheter.

22. The balloon catheter according to claim 21 wherein said integrated circuit includes flexible connection leads that extend out through the tube and connect to the ends of the columns and rows.

23. The balloon catheter according to claim 21 wherein said integrated circuit comprises holes such that a balloon inflation medium may pass there through.

24. The balloon catheter according to claim 19 wherein said integrated circuit comprises a timing control and a driver for driving the voltage.

25. The balloon catheter according to claim 24 wherein said integrated circuit further comprises an analog to digital converter and a serializer for converting said measured electrical characteristic to a digital value to be sent to said controller.

26. The balloon catheter according to claim 16 wherein the change in resistance or impedance is calculated by R=f(I).

27. The balloon catheter according to claim 1 wherein said mesh is affixed to an outer surface of said balloon catheter.

28. The balloon catheter according to claim 1 wherein said controller is controlled by an input device selected from the group consisting of: a keyboard, a mouse, a touch screen, a touch pad, a voice-activated control input device and combinations thereof.

29. The balloon catheter according to claim 28 wherein a user may use the input device to append data to the three-dimensional rendering.

30. A method for providing a 3-dimensional image of the interior of a cavity comprising the steps of: coupling a controller to a balloon catheter, the balloon catheter having a mesh having members extending longitudinally and circumferentially about the balloon catheter, the mesh having columns and rows that intersect each other at a node; controlling the inflation of the balloon catheter with the controller; measuring a change of an electrical characteristic of a member as the member is deformed such that, when the member comprises a length (L) a measured electrical characteristic will be different than when the member comprises a length (L.sub.1) where L.sub.1 is greater than L; determining the at least one electrical characteristic from each member and using the measured electrical characteristics to generate a three-dimensional rendering of an interior surface of the cavity.

31. The method according to claim 30 further comprising the step of displaying the three-dimensional rendering on a display.

32. The method according to claim 30 further comprising the step of saving the three-dimensional rendering on a storage device accessible by the controller.

33. The method according to claim 30 further comprising the step of controlling the balloon catheter by inputting a command to the controller via an input device.

34. The method according to claim 33 wherein the input device is selected from the group consisting of: a keyboard, a mouse, a touchpad, a touch screen control, a voice-activated control and combinations thereof.

35. The method according to claim 33 further comprising the step of rotating the three-dimensional rendering to different viewing angles.

36. The method according to claim 30 wherein the electrical characteristic that changes when the member is deformed is resistance or impedance.

37. The method according to claim 36 further comprising the step of applying a voltage across a selected column, row or combinations thereof.

38. The method according to claim 37 further comprising the steps of connecting ends of the columns and rows to pins of an integrated circuit and driving a voltage through each column, row and combinations thereof.

39. The method according to claim 38 further comprising the steps of alternately driving the pins of the integrated circuit to one of: a high voltage state, a low voltage state or a high impedance state.

40. The method according to claim 38 further comprising the steps of molding the integrated circuit into a tube and affixing the tube to the catheter.

41. The method according to claim 40 wherein the integrated circuit includes flexible connection leads and the method further comprises the steps of extending the flexible connection leads out through the tube and connecting the leads to the ends of the columns and rows.

42. The method according to claim 38 further comprising the steps of generating a timing signal with a timing control located in the integrated circuit and driving the voltage with a driver.

43. The method according to claim 42 further comprising the steps of converting the measured electrical characteristic to a digital signal with an analog to digital converter; serializing the digital signal with a serializer; and sending the serialized signal to the controller.

44. The method according to claim 36 wherein the change in resistance or impedance is calculated by R=f(I).

45. The method according to claim 30 further comprising the step of affixing the mesh to an outer surface of the balloon catheter.

46. The method according to claim 30 further comprising the step of controlling the controller with an input device, wherein the input device is selected from the group consisting of: a keyboard, a mouse, a touch screen, a touch pad, a voice-activated control input device and combinations thereof.

47. The method according to claim 30 further comprising the step of appending data to the three-dimensional rendering.

48. The balloon catheter according to claim 1 wherein the node is formed as a knot.

49. The method according to claim 30 wherein the node is formed as a knot.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a block diagram on one advantageous embodiment of the present invention.

(2) FIG. 2 is an illustration of the balloon catheter including the mesh according to FIG. 1.

(3) FIGS. 3A and 3B are illustrations of the balloon catheter of FIG. 2 inserted into a cavity for providing a 3-dimensional rendering of the cavity.

(4) FIG. 4 is a representation of the mesh used in connection with the system of FIG. 1.

(5) FIG. 5 is an illustration of the balloon and module according to the embodiment of FIG. 1.

(6) FIG. 6 is molded module an illustration of the module inserted into the tube according to the embodiment of FIG. 5.

(7) FIG. 7 is an illustration of one embodiment of the mesh construction according to FIG. 1.

(8) FIG. 8 is an integrated circuit block diagram according to the embodiment of FIG. 6.

(9) FIG. 9 is a flow diagram of a method according to the embodiment of FIG. 1.

(10) FIG. 10 is a continuation of the flow diagram according to FIG. 9.

DETAILED DESCRIPTION OF THE INVENTION

(11) Referring now to the drawings, FIG. 1 is a block diagram of an advantageous embodiment of a system 100 for generating a three dimensional image of an interior of a body cavity 150 (FIGS. 3A and 3B).

(12) The system 100 includes a controller 102, which may comprise any type of controller known in the art for controlling the inflating and deflating of a balloon 104 attached thereto by means of a catheter 118 that includes electrical lines 130 to communicate with the controller 102. The controller 102 is coupled to an input device(s) 106 that may comprise virtually any type of interface including, for example but not limited to, a keyboard, a mouse, a touch screen or touch pad, a voice-activated control input device, etc. It is understood that input device 106 may be either wired or wireless, which is illustrated by the use of a dashed line and wireless transmission signal indication in FIG. 1. It is still further contemplated that the input device may comprise a mobile wireless device.

(13) A display 108 is coupled to the controller that may present a visual rendering of the balloon catheter 104 in an inflated state, which may be stored on a storage device 110. A computer 112 (e.g., a personal computer) is also shown coupled to the controller 102 via a network connection 114. It is contemplated that the computer 112, 112, 112 may comprise a single computer or a network of computers (e.g., a plurality of hospital computers and associated storage devices, etc.), or a remote computer (e.g. in the doctor's office or an offsite location) where a rendering generated by the deformation of the balloon catheter 104 may be displayed and stored in a storage 116, 116, 116.

(14) The rendering is a 3-dimensional rendering of the volume of the cavity. In one embodiment, the user may, by means of an input device, rotate the displayed 3-dimensional rendering to obtain different viewing angles. This allows, for example, the physician to get an extremely accurate view of the interior of the cavity. It may be desired to render the interior of the cavity, then, resect material from the cavity and generate a second rendering of the cavity after resection. This process could be performed in numerous stages. However, the system provides the ability to freely rotate the rendering allowing the user to view the volume surface of the cavity from virtually any viewing angle and magnification.

(15) Referring now to FIG. 2, the balloon 104 connected to the controller 102 by means of the catheter 118 is shown in greater detail. The catheter 118, may comprise, for example, a polyethylene material and having an outer diameter of 0.5 mm-2 mm and a length of about 1.2 to 3 meters. The catheter is typically flexible such that it may be inserted into a cavity and may follow the course of the cavity freely without causing harm to the cavity (e.g., freely bendable to follow the course of the cavity, but non-compressible axially so that it may be inserted into the cavity). One example of an elongated body cavity would be insertion into the femoral artery in a patient's thigh, into which the catheter may be inserted to progress toward the patient's heart.

(16) The catheter 118 may further include a bendable section 120 having a length of about 5 to 10 mm at the distal end of the catheter may serve as a safety tip. This is an advantageous feature because, when the catheter is inserted through the available opening of a bodily cavity, it will bend instead of puncturing the walls of the cavity.

(17) A balloon 104 may comprise a compliant material, such as latex, chronoprene, yulex, silicon, polyurethane, C-flex or any other suitable material and is typically positioned near a distal end 122 of the catheter 118 or at an otherwise desirable, predefined distance along the catheter 118. The balloon 104 may come in a variety of lengths and diameters, which can be selected to suit the particular application for which the device is being used. Typically, such balloons 104 will have lengths selected from: 5 mm, 10 mm, 15 mm, 20 mm, 30 mm, 50 mm or greater. Such balloons 104 will also typically have diameters selected from: 2.5 mm, 5 mm, 10 mm, 15 mm, 20 mm, 30 mm, 50 mm or greater. This variety of available balloon sizes allows the balloon 104 to be used in bodily cavities of various diameters and dimensions, such as within articular joints (e.g., knee) or organs (e.g. Bladder) or within large and small bronchial branches, sinuses, and vessels, having different geometries and/or types of tumors and tissues to be treated. The controller 102 (which may include a pump 124, FIG. 1) supplies fluid (e.g. air, etc.) at a pressure ranging from approximately atmosphere to approximately 6 atmospheres in order to be able to inflate the balloon 104 to maximum size, ranging from 2.5 mml to 50 mml. It is understood that the pressure used to inflate the balloon will depend on the application. For example, rendering the interior of a bone cavity may require a higher inflation pressure than rendering the interior cavity of a blood vessel or artery. When soft tissue is rendered, the inflation pressure will be lower so as to avoid deforming the soft tissue.

(18) In certain advantageous embodiments, the balloon 104 may include imaging markers 126, such as radio opaque material or rings, located on the balloon 104. Such markers can be selected and appropriately positioned in order to reflect the relevant waves of various imaging modalities (e.g., x-ray) in order to allow the use of such modalities to provide data so that the system is able to generate a 3-dimensional rendering of the interior of the cavity. It is understood that to generate a 3-dimensional rendering, a plurality of x-ray images from different views would have to be taken and assembled.

(19) The balloon may also be covered with a fiber mesh 126 affixed to the surface 128 (either exterior or interior) of the balloon (or may be integral with the balloon). In certain advantageous embodiments, the surface 128 comprises a textured surface approximately 0.2 mm thick that is an integral part of the balloon 104 and which is incorporated therein during the molding process. In these cases, the surface 128 is made by integrating into the balloon material a fine, fiber mesh 126, which can, in certain embodiments, comprise lycra, polyurethane, composite springs, or other appropriate material.

(20) Referring now to FIGS. 3A and 3B, the balloon 104 and catheter 118 is illustrated inserted into a cavity 150 and expanded to an interior surface 152 of the cavity 150. The mesh 126, 126 is provided such that upon stretching of the balloon 104, the mesh 126, 126 is stretched to conform to the interior surface of the cavity 150. When the mesh 126 comprises a radio opaque material or rings, once inserted and inflated, an imaging device may be used to generate a 3-dimensional rendering of the interior of the cavity. For example, if the imaging device is an x-ray, the radio opaque material will reflect the x-ray wave lengths generating the 3-dimensional view of the interior surface of the cavity.

(21) When the mesh 126 comprises a mesh having variable electrical characteristics (e.g., impedance or resistance), upon expansion of the mesh 126, the variable electrical characteristic(s) will change based on the extent that the mesh 126 stretches to conform to the interior surface 152. Accordingly, as shown in FIGS. 3A and 3B, the mesh will stretch more is some places (both longitudinally and circumferentially) and less in others. The controller 102 will monitor the electrical characteristic(s) change(s) in the mesh 126 and will generate an image 154 rendering of the interior surface of the cavity 150 based upon the change in the measured electrical characteristic(s) of the mesh 126.

(22) It is further understood that an imaging device (not shown) may also be used to generate an image of the expanded balloon 104, which could be used alone or in conjunction with the data generated by the changed electrical characteristic(s) to generate a 3-dimensional rendering of the interior surface 152 of the cavity 150.

(23) FIG. 4 represents the mesh made of elastic conductive material (elastic conductive yarn), which is on an inflated compliant balloon. The resistance of the mesh 126 changes as it is stretched. Thus the stretched material length is a function of its resistance. The function can be linear, exponential, logarithmic, or other. The resistance and change in resistance based upon specified deformation is based on the composition of material, including the amount of conductive fiber (i.e. iron) added thereto. The repeatable function is known in advance.

(24) The rows of the conductive material are illustrated as running circumferential to the balloon 104, while the Columns are the conductive material running lateral on the balloon 104.

(25) Also illustrated in FIG. 4, are resistances designated as Rn, which are shown illustrated as boxes representing each segment of conductive material as equivalent to a known resistance. The resistances are labeled according to the nodes 156 they are connected between. The electrical resistance value of each segment is a function of the amount that the conductive material segment has been stretched and thus the length of the segment.

(26) Each node (represented by, for example, a dot) is a knot 158 (FIG. 7) where the conductive material may intersect. On an inflated balloon 104 (e.g., FIGS. 3A, 3B & 5), the nodes 156 are the only place where the conductive material touch each other and create a closed circuit between columns and rows when the balloon is inflated.

(27) Elastic Conductive Yarns:

(28) Elastic conductive yarns are available from various sources and can be manufactured in many different ways, including coating the elastic yarn with conductive material (polymers or metallics) or adding metal particles to the elastomers. In either case the electrical conductivity or the resistance of unit length of the yarn is a function of the amount of stretched. Resistance can be calculated from the following formula:
R=f(l)Formula 1

(29) This function can be a linear, exponential, logarithmic, etc., but it is known and given the resistance of a segment of yarn, the length of that particular segment may be determined. For example, it is contemplated that a look-up table including the various resistance measurements and associated lengths may be provided in storage 110, 116, 116, 116. Once the resistance of a particular segment is determined, the actual resistance may be used to determine the length of the segment from the look-up table. Alternatively, the length may be calculated each time a resistance measurement is taken. An example of one method for generating an elastic conductive yarn can be seen from the article entitled Woven Electronic Textiles: An Enabling Technology for Health-care Monitoring in Clothing by Christoph Zysset et al., Sep. 29, 2010.

(30) Forming Balloon Sleeve Mesh from Conductive Yarn:

(31) Many techniques can be used to produce the mesh 126 using conductive yarn similar to techniques used in textile manufacturing, including weft, warp circular or flat knitting as well as flat weaving creating a network of resistors. In case of flat techniques the yarn at two horizontal ends can be twisted and brought to the vertical top and bottom terminations. In FIG. 7 each end of the XY matrix that is formed is denote by X X and Y Y.

(32) Integrated Circuit:

(33) Referring now to FIGS. 4 and 8, each end 160 of the elastic conductive yarn is connected to a pin of the integrated circuit 162. Each pin of the integrated circuit 162 is tri-state, such that it can be driven: 1) High: the pin is driven to high voltage (i.e. 5V), source current; 2) Low: the pin is driven to low voltage (i.e. 0V/Gnd), drains current; or 3) High impedance: the input impedance of the pin is at very high value, does not source or drain current).

(34) There are integrated circuits 162 illustrated in FIG. 4. The integrated circuits 162 may include multiplexer(s) and de-multiplexer(s), which may be connected to a computer 112, 112, 112 via serial data in 170, serial data out 172, clock 174, power 176 and ground 178.

(35) The integrated circuit(s) 162 are provided as a very small package suitable to be mounted in a catheter tubing (FIGS. 5 & 6). It is contemplated that the elastic conductive yarn may, in an advantageous embodiment, be connected or coupled to integrated circuit(s) 162 with a conductive glue.

(36) The timing controller 164 receives commands from a computer 112, 112, 112 via serial communication lines 166, 168 connected to the integrated circuit 162 at the proximal end. The timing controller 164 provides timing information for driver 166 and scanner 167.

(37) Based on the data received a driver(s) 166 are enabled and the drive signal (High) is imposed to I/O pin(s), then all other pins are scanned and input to the analog to digital (ND) converter 168.

(38) The digital output of the A/D converter 168 is input into a serializer 170 and sent to the computer 112, 112, 112 in a serial fashion.

(39) Algorithms for Scanning the Mesh Resistor Networks:

(40) Software controlling the drivers 166, may sequentially activate a single line of elastic conductive yarn while holding all other lines at high impedance. Each orthogonal line can, in one embodiment, then be scanned and the voltage measured can then be converted to a digital value.

(41) It should be noted that, while various functions and methods have been described and presented in a sequence of steps, the sequence has been provided merely as an illustration of one advantageous embodiment, and that it is not necessary to perform these functions in the specific order illustrated. It is further contemplated that any of these steps may be moved and/or combined relative to any of the other steps. In addition, it is still further contemplated that it may be advantageous, depending upon the application, to utilize all or any portion of the functions described herein.

(42) For example, when Col. 1 is driven the equivalent circuit for Row R is:
R(12,RR)+R(23,RR)+R(34,RR)+ . . . +R(C-1C-1,RR)(Equation 1)

(43) When Col. 1 is driven the equivalent circuit for Row R-1 is:
R(11,RR-1)+R(12,R-1R-1)+R(23,R-1R-1)+ . . . +R(C-1C,R-1R-1)(Equation 2)
And so on.

(44) When Col. 2 is driven the equivalent circuit for Row R is:
R(23,RR)+R(34,RR)+ . . . +R(C-1C-1,RR)(Equation 3)

(45) When Col. 2 is driven the equivalent circuit for Row R-1 is:
R(22,RR-1)+R(23,R-1R-1)+ . . . +R(C-1C,R-1R-1)(Equation 4)
And so on.

(46) The value of resistor R(12,RR) will be the difference between the equations 1 and 2. Similarly, R(12, R-1 R-1)+R(11, R R-1) will be the difference between the equations 3 and 4.

(47) When scanning is done with the second set of ICs horizontal R(12, R-1 R-1)+R(11, R R-1) is resolved and each resistor value is known (FIG. 4).

(48) It is understood that there are a number of different methods that the mesh resistor network may be scanned to determine or approximate the resistance of each segment. Some of these methods include: utilization of Kirchoff's laws, elimination of segment, transfer matrix, Green's function resistance distance, etc.

(49) Surface Mapping

(50) The following symbols are used for surface mapping (x, y, t): a (x, y) grid at time t R(x, y, t): a measured resistor value at time t G(x, y, t): four R value measured within a grid at time t Diff(x, y, t): G value difference between time t and t1 T(x, y, t): a transformation matrix derived from G(x, y, t) T(x, y, t): error corrected transformation matrix from T G(x, y, t): projected G value from T(x, y, t1) E(x, y, t): difference between G and G at time t

(51) Let R(<x1 x>, <y, y>) denotes measured resister value between point <x1, y> and point <x, y>.

(52) ##STR00001##

(53) Let G(x,y) denotes four resistors value measured among point<x1, y1>, point <x1, y>, point <x, y1> and point <x, y>.

(54) TABLE-US-00001
G(x,y)={R(<x1,x1>,<y1,y>),R(<x1,x>,<y1,y1>),R(<x1,x>,<y,y>),R(<x,x>,<y1,y>)}(Equation 5)

(55) Let G(x, y, t) denotes as G(x, y) measured at the time t. Let Diff(x, y, t) denotes as resisters value difference between G(x, y, t) and G(x, y, t1).
Diff(x,y,t)=SQRT((G(x,y,t)G(x,y,t1))*2)(Equation 6)

(56) Let T(x, y, t) denotes a 55 transformation matrix between G(x, y, t) and G(x, y, t1).
G(x,y,t)=G(x,y,t1)*T(x,y,t)(Equation 7)

(57) Both G(x, y, t) and G(x, y, t1) are known values.
INVERSE(G(x,y,t1))*G(x,y,t)=INVERSE(G(x,y,t1))*G(x,y,t1)*T(x,y,t)(Equation 8)
INVERSE(G(x,y,t1))*G(x,y,t)=I*T(x,y,t)(Equation 9)
T(x,y,t)=INVERSE(G(x,y,t1))*G(x,y,t)(Equation 10)

(58) Surface Mapping Algorithm.

(59) 1. At t=t0 a. save all G(x, y, t0) for [x=1 . . . m] and [y=1 . . . n]

(60) 2. From t=t1 to tn a. for each G(x, y, t) i. Compute Diff(x, y, t); ii. Save the x and y location for the smallest Diff(x, y, t) value to X and Y; iii. Use Simple Value Decomposition (SVD) algorithm or to solve T(x, y t) from:
G(x2,y2,t)G(x1,y2,t)G(x,y2,t)G(x+1,y2,t)G(x+2,y2,t)G(x2,y1,t)G(x1,y1,t)G(x,y2,t)G(x+1,y2,t)G(x+2,y2,t)G(x2,y,t)G(x1,y,t)G(x,y,t)G(x+1,y,t)G(x+2,y,t)G(x2,y+1,t)G(x1,y+1,t)G(x,y+1,t)G(x+1,y+1,t)G(x+2,y+1,t)G(x2,y+2,t)G(x1,y+2,t)G(x,y+2,t)G(x+1,y+2,t)G(x+2,y+2,t) iv. If (t>t1) 1. Compute the projected G(x, y, t) using T(x, y, t1); 2. Compute the difference between G(x y, t) and G(x, y, t) as E(x, y, t); 3. Use Least Square Model Fitting (LSM) algorithm to fit the E(x, y, t) within [x9 . . . x+9, y9 . . . y+9] mesh grids.

(61) 3. At t=t3 to tn a. Using G(x, y, t1) and T(x, y, t1) and E(x, y, t1) to plot the 3D surface as:
G(x,y,t)=G(x,y,t1)*T(x,y,t1)+E(x,y,t1) at the view port.

(62) This is the equation that is used for generating the rendering from different viewing angles.

(63) Flexible Electronic Circuitry and Method of Connecting to Conductive Yarn:

(64) Methods of making flexible electronics 184 (including integrated circuit 162) suitable for interface with textiles, yarn and treads are available. One such method is disclosed in U.S. Pat. No. 6,493,933.

(65) FIGS. 5 & 6 show one method of molding such electronics 184 inside a tubing 180 such that the flexible connection leads 182 extended to the outside of the tubing 180.

(66) Each end 186 of the tubing 180 is then inserted into the catheter tubing before and after the balloon 104 with the mesh sleeve.

(67) It should be noted that the molded structure 188 that the integrated electronic circuit 184 is mounted in has holes 190 such that the balloon inflation medium can pass through.

(68) These flexible connection leads 182 expand and contract as the balloon 104 is inflated and deflated.

(69) The desired elastic yarn member (mesh 126) is attached to the leads 182 by various methods, including stitching, gluing (conductive), mechanical coupling (folding, squeezing, etc.) or combinations thereof.

(70) FIGS. 9 and 10 are a flow diagram illustrating a method for generating a three dimensional rendering of a cavity by measurement of resistor values. At step 200, the system measures resistor values in G(x, y, t) and proceeds to step 202 to determine if t=t0. If t=t0, then the system saves all measured resistor values 204 in memory 206. If tt0, the system determines if t>t1 at step 208. If tt1, then the system calculates the DIFF(x, y, t) from G(x, y, t) and G(x, y, t1) at step 210, and saves <x, y> for the smallest DIFF value at step 212 in memory 206. The system then proceeds to solve T(x, y, t) from G(x, y, t) where [x=x2 to x+2] and [y=y2 to y+2] at step 214, which is also saved in memory 206.

(71) If t>t1 at step 208, then the system proceeds to step 216 to determine if t>t2. It can additionally be seen by reference to FIGS. 9 and 10 that the system will alternatively proceed from step 214 to step 216 to determine if t>t2.

(72) If tt2 at step 216, then the system computes the projected G(x, y, t) using T(x, y, t1) at step 218, which is saved in memory 206. The system then proceeds to compute the difference between G(x, y, t) and G(x, y, t) as E(x, y, t) at step 220. At this point the system uses the Least Square Model Fitting (LSM) algorithm to fit the E(x, y, t) within the mesh window of [x9 . . . x+9, y9 . . . y+9] mesh grids at step 222 and proceeds back to step 210 to calculate the DIFF(x, y, t) from G(x, y, t) and G(x, y, t1).

(73) If t>t2 at step 216, then the system uses G(x, y, t1) and T(x, y, t1) and E(x, y, t1) to plot the 3D surface as G(x, y, t)=G(x, y, t1)*T(x, y, t1)+E(x, y, t1) at the view port at step 224, which is then sent to display 226.

(74) Although the invention has been described with reference to a particular arrangement of parts, features and the like, these are not intended to exhaust all possible arrangements or features, and indeed many other modifications and variations will be ascertainable to those of skill in the art.