System for neuronavigation registration and robotic trajectory guidance, robotic surgery, and related methods and devices

Abstract

A system for robotic surgery makes use of an end-effector which has been configured so that a drill connected thereto is guided in its trajectory and limited in its advancement into an associated anatomical feature by a drill guide. The drill guide may be adjusted manually to engage a corresponding surface of the drill after its advancement by a pre-selected amount. The drill guide likewise includes features to guide the drill during trajectories having oblique angles relative to the surface of the anatomical feature associated with the medical procedure.

What is claimed is: 
     
         1 . A surgical robot system for surgery on an anatomical feature of a patient, the system comprising:
 a surgical robot;   a robot arm connected to the surgical robot;   an end-effector connected to the robot arm and orientable to oppose the anatomical feature so as to be in operative proximity thereto;   a processor circuit;   a surgical tool comprising a drill selectively connectible to the end-effector;   a memory accessible by the processor circuit and comprising machine readable instructions configured, in response to user input, to determine a drill target and an associated drill trajectory, the instructions further configured, when executed, to cause the end-effector to move to a position corresponding to a determined target and a determined drill trajectory to permit advancement of the drill toward the target;   a drill guide having proximal and distal ends, the drill guide releaseably connected to the end-effector at the distal end and to the drill at the proximal end, wherein the drill guide is configured to stop the advancement of the drill at a pre-selected drill depth associated with the determined target and is further configured to guide the drill along the determined drill trajectory during the advancement of the drill;   wherein the drill includes a chuck having a distal surface and a rotatable, elongated drill bit extending distally from the distal surface of the chuck and terminating in a drill tip capable of engaging the anatomical feature, the drill bit having a first predetermined length corresponding to the distance between the distal surface of the chuck and the drill tip;   wherein the drill guide includes a guide shaft having proximal and distal guide shaft ends, openings at the proximal and distal guide shaft ends, respectively, and a bore extending between the openings and sized to slideably receive the drill bit therethrough, the guide shaft having associated therewith a second, predetermined length;   wherein the drill guide further includes a depth stop having proximal and distal depth stop ends, the depth stop mounted to the proximal end of the guide shaft and selectively slidable longitudinally to vary the second predetermined length to be shorter than the first predetermined length of the drill bit, so that the drill bit when received in the guide shaft may be advanced beyond the distal end of the guide shaft by a preselected amount;   wherein the depth stop has a surface for engaging the distal surface of the chuck of the drill, whereby the depth to which the drill tip is advanceable by the drill is limited by an amount corresponding to the position of the depth stop.   
     
     
         2 . The system of  claim 1 , wherein the drill guide comprises a depth indicator having indicia corresponding to graduated depths of advancement of the drill bit associated with the drill guide. 
     
     
         3 . The system of  claim 2 , wherein the depth stop comprises a longitudinal stem slideably received within the bore of the guide shaft;
 wherein the guide shaft has portions forming a window sized and located to reveal the longitudinal stem received in the guide shaft; wherein the indicia associated with the graduated depths are located on at least one of the stem and the portions adjacent the window to indicate the predetermined drill depth.   
     
     
         4 . The system of  claim 3 , wherein the indicia comprise a pointer and a numerical value scale moveable relative to each other, the pointer disposed on one of the stem and the portions adjacent the window, and the numerical value scale disposed on the other of the stem and the portions adjacent the window. 
     
     
         5 . The system of  claim 1 , wherein the drill guide comprises an engagement mechanism to set the depth stop at one of a plurality of selectable, longitudinal positions corresponding to a desired drill depth. 
     
     
         6 . The system of  claim 5 , wherein the engagement mechanism comprises a ratchet assembly engageable at one of the plurality of longitudinally spaced locations between the proximal and distal ends of the depth stop. 
     
     
         7 . The system of  claim 5 , wherein the drill guide comprises a spring-biased trigger actuatable to disengage the engagement mechanism from a first one of the longitudinal positions and set the engagement mechanism at a second one of the longitudinal positions, the second longitudinal position corresponding to the desired drill depth. 
     
     
         8 . The system of  claim 7 , wherein the trigger comprises a trigger lock operatively connected to the trigger to inhibit the actuation of the trigger and thereby inadvertent disengagement of the engagement mechanism. 
     
     
         9 . The system of  claim 5 , wherein the drill guide comprises a handle operatively connected to the engagement mechanism to manually set the depth stop at the selective one of the longitudinal positions. 
     
     
         10 . The system of  claim 1 , wherein the guide shaft has at least one bushing disposed within the bore and sized to receive the outer longitudinal surface of the drill bit slideably and rotatably therein. 
     
     
         11 . The system of  claim 10 , wherein the guide shaft comprises upper and lower bushings disposed at longitudinally-spaced locations within the bore. 
     
     
         12 . The system of  claim 10 , wherein the bushing has an internal diameter sized to engage the longitudinal surface of the distal end of the drill bit with a force opposing lateral displacement of the drill bit within the guide shaft to reduce deviation of the drill bit from the determined drill trajectory. 
     
     
         13 . A method of guiding a drill during robot-assisted surgery on an anatomical feature of a patient, the method comprising the steps of:
 determining, by computer processing, a drill target and an associated drill trajectory and effectuating movement of an end-effector to a position corresponding to the determined target and the determined drill trajectory;   manually setting a depth stop connected to the end-effector to one of a plurality of selectable positions corresponding to a desired depth of advancement of the drill relative to the anatomical feature, whereby the drill is limited from penetrating the anatomical feature beyond the desired depth.   
     
     
         14 . The method of  claim 13 , wherein the step of setting the depth stop comprises:
 displacing the depth stop relative to visually perceptible indicia, the indicia corresponded to graduated depths of advancement of the drill; and   securing the depth stop at a desire position corresponding to a selected one of the graduated depths.   
     
     
         15 . The method of  claim 14 , wherein the steps of displacing and securing the depth stop comprise:
 actuating a spring-biased trigger to disengage the depth stop from a first position;   longitudinally sliding the depth stop relative to the visually perceptible indicia to a second position, the second position corresponding to the desired position of the depth stop; and   releasing the trigger to re-engage the depth stop at the desired position.