Wheel for robotic catheter system drive mechanism

Abstract

A drive mechanism for a robotic catheter system including a first engagement surface and a second engagement surface is provided. The first engagement surface and second engagement surface are configured to engage a catheter device to allow the drive mechanism to impart motion to the catheter device. The first engagement surface is textured to facilitate gripping between the first engagement surface and the catheter device.

What is claimed is: 
     
         1 . A drive mechanism for a robotic catheter system which imparts both axial and rotational motion comprising:
 a tire of a drive wheel and a tire of an idler wheel which interact with each other, each of which has an engagement surface which interacts with a catheter device to cause it to move along its axis and which is free of any gripping features which run perpendicular to the axis of the catheter device; and   a set of rotational drive assembly wheel tires each of which has an engagement surface which interacts with a catheter device to cause it to rotate about its axis and which has a gripping feature which runs perpendicular to the axis of the catheter device.   
     
     
         2 . The drive mechanism of  claim 1  wherein the engagement surfaces of both of the rotational drive assembly wheel tires has a durometer hardness of no more than about 85 A. 
     
     
         3 . The drive mechanism of  claim 1  wherein the engagement surface of at least one of the rotational drive assembly wheel tires has slits which run perpendicular to the axis of the catheter device. 
     
     
         4 . The drive mechanism of  claim 3  wherein the engagement surface of both of the rotational drive assembly wheel tires of the set has slits which run perpendicular to the axis of the catheter device. 
     
     
         5 . The drive mechanism of  claim 3  wherein the rotational drive assembly wheel tires of the set apply a substantially lighter pinch force to the catheter device than do the drive wheel tire and idler wheel tire. 
     
     
         6 . The drive mechanism of  claim 5  wherein the drive wheel tire and the idler wheel tire apply a pinch force of about 9 pounds to the catheter device and the rotational drive assembly wheel tires apply a pinch force of about 1.25 pounds to the catheter device. 
     
     
         7 . The drive mechanism of  claim 3  wherein there are three sets of rotational drive assembly wheel tires. 
     
     
         8 . The drive mechanism of  claim 1  wherein the engagement surfaces of both the drive wheel tire and the idler wheel tire have a durometer hardness of at least about 95 A. 
     
     
         9 . The drive mechanism of  claim 1  which includes an auxiliary encoder wheel tire with an engagement surface which interacts with the catheter device which has a durometer hardness of no more than about 85 A. 
     
     
         10 . The drive mechanism of  claim 9  wherein the auxiliary encoder wheel tire and an encoder idler wheel tire which interacts with the auxiliary encoder wheel tire apply a substantially lighter pinch force to the catheter device than do the drive wheel tire and idler wheel tire. 
     
     
         11 . The drive mechanism of  claim 10  wherein the drive wheel tire and the idler wheel tire apply a pinch force of about 9 pounds to the catheter device and the auxiliary encoder wheel tire and an encoder idler wheel tire apply a pinch force of about 0.75 pounds to the catheter device. 
     
     
         12 . The drive mechanism of  claim 1  wherein the radial thickness of both the drive wheel tire and the idler wheel tire is between about 0.03 and 0.06 inches. 
     
     
         13 . The drive mechanism of  claim 10  wherein the engagement surface of each the drive wheel tire and the idler wheel tire has a durometer hardness of less than about 50 D. 
     
     
         14 . The drive mechanism of  claim 1  wherein catheter device is a guide catheter or a working catheter which deploys an angioplasty balloon or a stent. 
     
     
         15 . The drive mechanism of  claim 1  wherein the catheter device is a guide wire. 
     
     
         16 . The drive mechanism of  claim 15  wherein the guide wire has a diameter between about 0.014 inches and 0.038 inches. 
     
     
         17 . The drive mechanism of  claim 1  wherein the guide wire has a diameter of about 0.014 inches. 
     
     
         18 . A drive mechanism for a robotic catheter system which imparts both axial and rotational motion comprising:
 a drive wheel tire and an idler wheel tire which interact with each other, each of which has an engagement surface which interacts with a catheter device to cause it to move along its axis; and   a set of rotational drive assembly wheel tires each of which has an engagement surface which interacts with a catheter device to cause it to rotate about its axis;   wherein one or more of the tires has a composite structure in which a material or structure of higher resilience is interposed between its engagement surface and the hub on which it is mounted.   
     
     
         19 . The drive mechanism of  claim 18  wherein the rotational drive assembly wheel tires have the composite structure. 
     
     
         20 . The drive mechanism of  claim 19  wherein interposed material or structure of higher resilience is a pressurized fluid, a high resistance o-ring or a canted coil spring. 
     
     
         21 . The drive mechanism of  claim 18  wherein the engagement surface of at least one of the rotational drive assembly wheel tires has slits which run perpendicular to the axis of the catheter device. 
     
     
         22 . The drive mechanism of  claim 18  wherein the catheter device is a guide wire.