AU2002317531B2

AU2002317531B2 - Apparatus and method for selectively positioning a device and manipulating it

Info

Publication number: AU2002317531B2
Application number: AU2002317531A
Authority: AU
Inventors: Jacob Richter
Original assignee: Medinol Ltd
Current assignee: Medinol Ltd
Priority date: 1998-07-31
Filing date: 2002-12-12
Publication date: 2006-05-25
Anticipated expiration: 2019-04-28

Description

-1-

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

Name of Applicant/s: Actual Inventor/s: Address for Service:

CCN:

Zuli Holdings Ltd.

Jacob Richter Baldwin Shelston Waters MARGARET STREET SYDNEY NSW 2000 3710000352 Invention Title: APPARATUS AND METHOD FOR SELECTIVELY POSITIONING A DEVICE AND MANIPULATING IT Details of Original Application No. 24996/99 dated 28 Aprill999 The following statement is a full description of this invention, including the best method of performing it known to me/us:- File: 37046AUP00 IP Australia SZ&Z Documents received on: 1 2 DEC 2002 Batch No: 500092233 1.DOC/5844 la- APPARATUS AND METHOD FOR SELECTIVELY POSITIONING A DEVICE AND MANIPULATING IT FIELD OF THE INVENTION This invention relates generally to an apparatus and method of selectively positioning the apparatus, eg, within a lumen. More particularly, this invention relates to a device and method for pulling a catheter along a wire; a device and method for moving a wire relative to a catheter, a device and method for pulling a catheter relative to a guiding catheter or any larger bore pipeline through which it is inserted; and a device and method for pushing or pulling a device on top of a guide wire or inside a guiding catheter.

BACKGROUND OF THE INVENTION Any discussion of the prior art throughout the specification should in no way be considered as an admission that such prior art is widely known or forms part of common general knowledge in the field.

In many different applications of invasive and minimally invasive medicine there is a need to introduce catheters and other devices into the body, usually through open lumens or closed lumens, utilizing percutaneous entry. Conventional procedures for the introduction of the devices and their controlled motion in the body usually utilize a force, either a manual force or a motorized force, applied from the outside of the patient to "push" the device to the target area. One shortcoming of introducing the device via a "push" operation, even when done on top of a guiding wire, is that this procedure often does not provide optimal trackability into a tortuous anatomy, eg. the coronary arteries.

In contrast, a "pull" operation in which a pulling device precedes the apparatus and "pulls" it into place increases the trackability of the device and reduces the likelihood that the device will get caught in a curve of the lumen or cause trauma to the lumen.

Another problem is the need to push wires through occluded lumen sections that have a great resistance to such penetration. The fact that the wire is pushed from the outside may waste all the pushing energy in accessive loops with very little or none of the pushing energy actually reaching the tip of the wire.

It is an object of the present invention to overcome or ameliorate at least one of the disadvantages of the prior art, or to provide a useful alternative.

-2- SUMMARY OF THE INVENTION According to a first aspect of the present invention there is provided a method comprising using a piezoelectric micro-motor to move a device to a target area in a lumen comprising attaching said micro-motor to a catheter, frictionally engaging a guide wire thatpasses through said catheter with said motor and energizing said motor to bring about relative motion between the wire and catheter.

Unless the context clearly requires otherwise, throughout the description and the claims, the words 'comprise', 'comprising', and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in the sense of"including, but not limited to".

Advantageously, at least in preferred forms, the present invention may provide a device and method for pulling a catheter along a wire.

In other forms a device and method may be provided for pushing a wire relative to a catheter.

In other preferred forms a device and method may be provided for pulling a catheter relative to a guiding catheter or any larger bore pipeline through which it is inserted.

In still further forms, the invention may provide a device and method for pushing or pulling a device on top of a guide wire or inside a guiding catheter.

In yet further forms the invention may provide an apparatus and method for selectively positioning a device, a stent, an Intra Vascular South (IVUS) transducer, an atherectomy device (both rotational and directional), pressure sensors, balloons, and pushing wires to open occlusions, by pulling rather than pushing these devices into place.

According to a second aspect of the invention there is provided an apparatus, comprising: a piezoelectric motor, said motor provided with a motor friction area; and a guide wire biased against said friction area such as to impart friction between said friction area of said motor and said guide wire in an amount sufficient to permit said motor to change position relative to said guide wire by crawling against said guide wire when said motor is energized.

According to a third aspect of the invention there is provided an apparatus, comprising: a piezoelectric motor provided with a friction area; a cylindrical guide tube defining a longitudinal bore, said motor disposed within said bore in such a manner that said friction area presses against an inner surface of said cylindrical guide tube in such a manner as to impart friction between said friction area of said motor and said inner surface in an amount sufficient to permit said motor to change position relative to said guide tube by crawling against said inner surface of said guide tube when said motor is energized.

More generally, embodiments of the present invention employ a piezoelectric micro-motor to move a device to a target area in a lumen. In one embodiment, the motor is attached to a catheter and frictionally engages a guide wire. Energizing the motor brings about relative motion between the wire and catheter. This allows moving the wire to a target area in a lumen with the catheter fixed and/or moving the catheter to the target area while holding the guide wire fixed. The catheter may have a balloon to be expanded in the lumen at the target area. Similarly, the catheter may deliver a stent to the target area where it can be expanded. When there is an obstruction that prevents reaching the target area, the guide wire and motor may be used to clear the obstruction to permit the guide wire and catheter to be moved to the target area.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows an embodiment of the invention in which a cylindrically shaped motor and a guide wire are utilized to dispose a device in the target area of a lumen; FIG. 2 is a cross-sectional end view of the embodiment of the invention shown in FIG. 1; FIG. 3 shows an embodiment of the invention in which a cylindrical motor and a cylindrical guide tube are used to dispose a device in the target area of a lumen; FIG. 4 shows a cross-sectional side view of another embodiment of the invention shown in FIG. 3; FIG. 5 shows the trackability of a catheter that is pulled through a curve in a lumen in accordance with the present invention; FIG. 6 shows the trackability of a catheter that is pushed through a curve in a lumen in a conventional manner; FIG. 7 shows an embodiment of the invention used to dispose a balloon expandable stent in the lumen of a blood vessel; -4- FIGS. 8A to 8D shows an embodiment of the invention used to clear an obstructed lumen; and FIG. 9 shows an alternative embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION Miniature Oscillating Ceramic Motors (OCM) are well known in the art and are disclosed in U.S. patent 5,453,653 to Zumeris the specification of which is incorporated herein by reference. These motors can be made very small and in any shape and they operate by contacting a surface in an amount sufficient to generate sufficient friction to permit the motor to "crawl" along the contacted surface and change its position relative to the contacted surface when the motor is energized. These motors can be adequately insulated to act in aqueous environments. Their small size and low energy level requirements make them especially suitable for use inside living organisms.

FIG. 1 is a lateral perspective of one embodiment of the invention and shows a cylindrical motor 1 having a longitudinal bore therethrough. A guide wire 2 is disposed within the longitudinal bore 5. FIG. 2 is a cross-sectional end view taken on line A-A of FIG. 1 and shows the cylindrical motor 1 having an outer surface 3 and an inner surface 4 defining a longitudinal bore 5. The inner surface 4 defining the longitudinal bore 5 is provided with a friction area 6 adapted to engage the guide wire 2. The longitudinal bore 5 and the guide wire 2 are sized and adapted so that when the motor 1 is energized the motor 1 will crawl along the guide wire 2, thus, changing its position relative to the guide wire 2. The direction of movement is controlled selectively by energizing wires (not shown) connected to the motor 1. In one embodiment, shown in FIG. 2, a biasing means, a leaf spring 7 is utilized to bias the guide wire 2 against the friction area 6 of the motor 1.

FIG. 3 is a cross-sectional side view of another embodiment of the invention and shows a cylindrical motor 8 having an external surface 10 mounted within the guide tube 9 having and outer surface 11 and an inner surface 12. The external surface 10 of the motor 8 and the internal surface 12 of the guide tube 9 are sized and adapted so that the friction area 14 of the motor 8 contacts the inner surface 12 of the guide tube 9 and crawls along the inner surface 12 so as to dispose a device, an Intra Vascular Ultra Sound (IVUS) transducer, atherectomy device, or physiological sensor, (not shown) in the target area of a lumen. In an especially preferred embodiment, shown in FIG. 4, a leaf spring 13 is utilized to bias the friction surface 14 of the motor 8 against the internal surface 12 of the guide tube 9.

In another embodiment of this invention, shown in FIG. 7, a balloon catheter with a micro-motor disposed at the distal end is used to dispose an expandable stent in the target area of a lumen. FIG. 7 shows a catheter 15 having a proximal end 16, a distal end 17, and a longitudinal bore 18 therethrough. An expandable balloon 19 is disposed at the distal end 17. A cylindrically shaped motor 1 is disposed at the distal end 17 of the catheter 15 distal to the balloon 19. The motor I has a longitudinal bore communicating with the longitudinal bore 18 of the catheter 15 and is provided with a motor friction area 6 disposed within the longitudinal bore 5 of the motor 1. A guide wire 2 is disposed within the longitudinal bore 18 of the catheter 15 and the longitudinal bore 5 of the motor 1. The guide wire 2 and the longitudinal bore 5 of the motor 1 are sized and adapted to impart friction between the friction area 6 of the motor 1 and the guide wire 2 in an amount sufficient to permit the motor 1 to change position relative to the guide wire 2 by crawling against the guide wire 2 when the motor 1 is energized.

In operation, an expandable stent 20 is secured to the balloon portion 19 of the catheter 15 and the guide wire 2 is placed into the bore 18 of the catheter 15. The guide wire 2 is then introduced into the lumen to be treated and is advanced by pushing it until it is near the target area. The guide wire 2 is then secured. The micro-motor 1 is then energized so that it crawls along the guide wire 2 which pulls the catheter 15 into the proximity of the target area to be treated. Because the catheter 15 is "pulled" into position as shown in FIG. 5, there is improved trackability and less kinking of the catheter 15, and, thus, reduced risk of trauma to the internal surface of the lumen than when the catheter is "pushed" into place using conventional procedures as shown in FIG.

6. The balloon 19 is then expanded to secure the stent 20 in the target area of the lumen.

The balloon 19 is then deflated and the guide wire 2 and the catheter 15 are pulled out of the lumen using conventional methods.

In another embodiment of this invention shown in FIGS. 8A to 8D, the motor is used to push the guide wire into, and if specific applications dictate through, a constricted area which clears the vessel of the obstruction to permit the catheter to advance beyond the obstruction to the target area. In operation, the catheter 15 is mounted on a guide wire 2 as previously discussed. The guide wire 2 is advanced to the obstruction 21 as shown in FIG. 8A. The provision of the cylindrical motor 1 with a bore through which the guide wire passes, as seen in FIG. 8A, substantially centers the guide wire. The guide wire 2 is secured and the motor is energized causing the catheter to advance towards the obstruction 21. The catheter 15 is advanced until it too is in proximity to the obstruction 21 as shown in FIG. 8B. The catheter 15 is then secured and the motor 1 is activated which causes the guide wire 2 to advance into the obstructed area 21 as shown in FIG. 8C. As can be seen, because of the centering, it advances substantially into the center of the obstruction and any danger of damage to the lumen is reduced.

In some applications, one or more passes may be utilized to clear the obstruction 21. As has been recognized by those skilled in the art, vibrating the guide wire facilitates the wire passing through an obstruction. As explained in US patent 5,453,653 to Zumeris, excitation of the micro-motor of the present invention with an AC voltage is possible. If excited with AC, a vibration in the range of 20-100KHz, depending on the resonant frequency of the material used for the piezoelectric ceramic will result. As further explained, in a pulsed method of operation two electrodes are excited by a positive DC voltage and two electrodes are excited by a negative DC voltage. Under this excitation the left side of piezoelectric ceramic becomes longer than the right side and ceramic moves to the right. When the voltage is removed, the ceramic will move back to its original position. However, if a non-symmetrical voltage pulse is applied to the electrodes, then, during the return to zero, the inertia of body will cause the body not to return the ceramic to the starting position. Thus, when operating in the DC pulsed mode, a vibrating or pulsating motion will occur at a rate dependent on the pulse time, eg. 50 ms, or a pulsating frequency of 20-100 Hz. Stated another way, in each case, an oscillatory motion takes place.

The guide wire 2 is then secured, the motor 1 is energized, and the catheter 15 is advanced through the vessel past the area from which the guide wire 2 has cleared the obstruction 21 from the target area as shown in FIG. 8D. This method may be used to simply clear an obstruction in a lumen as discussed above or may be used in conjunction with other embodiments of the invention, to facilitate the placement of an expandable stent in the target area of a lumen by first clearing the target area of any obstructions.

FIG. 9 shows an alternative embodiment of the invention and shows a slabshaped motor 22 incorporated in a catheter 23.

In the embodiment shown in FIG. 9, the motor 22 is shaped like a slab instead of being cylindrical. The slab-shaped motor 22 is disposed on the inner wall of the catheter 23 and is provided with a friction area 6 sized and adapted to frictionally engage a guide wire 2. The slab-shaped motor 22 is sized and adapted to permit the catheter 23 to be moved relative to the guide wire 2 as previously discussed and as shown in FIG. 9.

While the invention has been described with respect to a limited number of embodiments, it will be appreciated that many variations, modifications, and other applications of the invention may be made.

Claims

1. A method comprising using a piezoelectric micro-motor to move a device to a target area in a lumen comprising attaching said micro-motor to a catheter, frictionally engaging a guide wire that passes through said catheter with said motor and energizing said motor to bring about relative motion between the wire and catheter.

2. A method according to claim 1 comprising: a) inserting the guide wire into a lumen; b) advancing the guide wire to a target area; c) securing the guide wire; and d) energizing the micro-motor so that the micro-motor advances along the guide wire to target area, carrying with it the attached catheter.

3. A method according to claim 2 wherein: a) there is an obstruction in the lumen; and b) the guide wire is advanced to a proximal end of the obstruction; c) the micro-motor is energized so that the micro-motor advances distally along the guide wire, carrying with it the attached catheter, toward the proximal end of the obstruction, and further including: d) securing the catheter; e) energizing the micro-motor so that the guide wire advances distally.

4. The method according to claim 3 wherein said energizing the micro-motor so that the guide wire advances distally comprises energizing in an oscillatory manner.

The method according to claim 3 wherein said step of energizing the motor so that the guide wire advances distally comprises repeatedly, until said guidewire and catheter pass substantially through said obstruction: a) securing the catheter; b) energizing the micro-motor so that the guide wire advances distally; c) securing the guide wire; d) energizing the micro-motor so that the micro-motor advances along the guide wire, carrying with it the attached catheter.

6. The method according to claim 5 wherein said step of energizing the motor so that the guide wire advances distally comprises alternately: a) energizing the motor so that the guide wire advances distally; -9- b) energizing the motor so that the guide wire advances proximally; and c) repeating steps a) and b) a plurality of times.

7. The method according to claim 6 comprising repeating steps a) and b) until the guide wire has substantially cleared the obstruction.

8. The method according to claim 6 or claim 7 wherein said steps a) and b) comprise energizing in an oscillatory manner.

9. The method according to claim 3 wherein said step e) comprises energizing the motor so that the guide wire advances through the obstruction.

The method according to claim 9 wherein said energizing the micro-motor so that the guide wire advances through the obstruction comprises energizing in an oscillatory manner.

11. The method according to claim 1 wherein said relative motion comprises first moving the wire to a target area in a lumen with the catheter fixed and then moving the catheter to the target area while holding the guide wire fixed.

12. The method according to claim 11 and further including delivering a balloon on the end of said catheter to said target area and expanding said balloon at the target area.

13. The method according to claim 11 or claim 12 and further including delivering a stent on the end of said catheter to said target area and expanding said stent at the target area.

14. A method according to claim 1 comprising traversing an obstruction in a lumen by causing the guide wire driven by a piezoelectric micro-motor in a oscillatory manner to advance into the obstruction including moving the catheter to which the micro-motor is attached and the guide wire to the target area using the micro-motor, holding the catheter fixed, and driving said micro-motor to cause said guide wire to advance against said obstruction in an oscillatory manner.

The method of claim 14 wherein said guide wire advances through said obstruction.

16. The method of claim 14 comprising alternately advancing the catheter and the guide wire until the catheter and guide wire are clear of the obstruction.

17. The method according to claim 4, 10 or 16 wherein said micro-motor is a piezoelectric motor and said driving comprises energizing with an AC voltage, thereby introducing a vibration to said guide wire.

18. The method according to claim 17 wherein said AC voltage has a frequency in the range of 20-100kHz.

19. The method according to claim 4, 10 or 16 wherein said micro-motor is a piezoelectric motor and said driving comprises energizing with an pulsed DC voltage thereby imparting a pulsating motion to said guide wire.

The method according to claim 19 wherein said pulsed DC voltage has a frequency in the range of 20-100 Hz.

21. The method according to claim 4, 10 or 16 and further comprising centering said guide wire within a bore in said motor to insure that said guide wire engages substantially the center of said obstruction.

22. The method according to claim 21 wherein said micro-motor is cylindrical with a bore, and said guide wire is substantially centered by passing it through said bore of said micro-motor.

23. The method according to claim 2, 4, 10 or 16 and further including withdrawing the guide wire, motor, and catheter from the lumen.

24. The method according to claim 23 wherein said obstruction is at or proximal to a target area of the lumen and wherein a balloon is disposed on the distal end of the catheter and further including, prior to withdrawing the guide wire, motor, and catheter from the lumen: a) inflating the balloon in the target area of the lumen; and b) deflating the balloon.

The method according to claim 24 wherein the stent is disposed over the balloon and the inflating of the balloon in the target area of the lumen expands the stent to dispose it in the target area.

26. The method according to claim 23 wherein a stent is provided at the distal end of the catheter and further comprising expanding the stent in the target area of the lumen to dispose it in the target area prior to withdrawing the guide wire, motor, and catheter from the lumen.

27. An apparatus, comprising: a piezoelectric motor, said motor provided with a motor friction area; and a guide wire biased against said friction area such as to impart friction between said friction area of said motor and said guide wire in an amount sufficient to -11- permit said motor to change position relative to said guide wire by crawling against said guide wire when said motor is energized.

28. The apparatus according to claim 27 and further including a catheter attached to said motor, said guide wire passing through said catheter.

29. The apparatus according to claim 28 and further including a stent disposed at a distal end of said catheter.

The apparatus according to claim 29 wherein said stent is a balloon expandible stent and further including a balloon at the distal end of said stent over which said stent is disposed.

31. The apparatus according to any one of claims 27 to 30, wherein said guide wire is biased with a leaf spring.

32. The apparatus according to any one of claims 27 to 31, wherein said motor has a bore substantially centering said guide wire.

33. The apparatus according to any one of claims 27 to 32, wherein said motor is adapted to be energized by an AC voltage.

34. The apparatus according to any one of claims 27 to 32, wherein said motor is adapted to be energized by a pulsating DC voltage.

An apparatus, comprising: a piezoelectric motor provided with a friction area; a cylindrical guide tube defining a longitudinal bore, said motor disposed within said bore in such a manner that said friction area presses against an inner surface of said cylindrical guide tube in such a manner as to impart friction between said friction area of said motor and said inner surface in an amount sufficient to permit said motor to change position relative to said guide tube by crawling against said inner surface of said guide tube when said motor is energized.

36. The apparatus of claim 35, further comprising a biasing means to bias said inner surface of said guide tube against said friction area.

37. The apparatus of claim 36, wherein said biasing means is a leaf spring.

38. The apparatus of any one of claims 35 to 37, further comprising a device to be placed in a lumen disposed within said guide tube and contacting said motor.

39. A method according to claim 1, substantially as herein described with reference to any one of the embodiments of the invention illustrated in the accompanying drawings and/or examples. -12- An apparatus according to claim 27 or claim 35, substantially as herein described with reference to any one of the embodiments of the invention illustrated in the accompanying drawings and/or examples. DATED this 8 th day of May 2006 Shelston IP Attorneys for: Zuli Holdings Ltd.