Robotic apparatus

Abstract

A robotic apparatus has eight actuators (M0-M7) and a linkage (LINK 0-LINK 5) that actuates an end effector. Three serial macro freedoms have large ranges of motion and inertias. Four serial micro freedoms have small ranges of motion and inertias. Translation of the end effector in an y direction is actuated by at least one micro joint and at least one macro joint. The apparatus can be part of a master and slave combination, providing force feedback without any explicit force sensors. The slave is controlled with an Inverse Jacobian controller, and the mater with a Jacobian Transpose controller. A slave having more degrees of freedom (DOFs) than the master can be controlled. A removable effector unit actuates its DOFs with cables. Beating heart surgery can be accomplished by commanding the slave to move with a beating heart and cancelling out any such motion in the motions perceived by the master.

Description

CROSS-REFERENCES TO RELATED APPLICATIONS[0001]This application is a divisional of and claims the benefit of priority from U.S. patent application Ser. No. 10 / 893,613 (Attorney Docket No. 017516-005521US), filed Jul. 15, 2004; which is a divisional of application Ser. No. 09 / 508,871 (Attorney Docket No. 017516-005520US), filed Jul. 17, 2000; which is a 35 U.S.C. §371 United States National Stage application of International Patent Application No. PCT / US98 / 19508, filed on Sep. 18, 1998; which claims priority to U.S. Provisional Application No. 60 / 059,395, filed on Sep. 19, 1997; the full disclosures of which are incorporated herein by reference.[0002]The inventions disclosed herein are also somewhat related to inventions by two of the inventors herein (Salisbury and Madhani), described in three U.S. patent applications, all of which are incorporated herein by reference. The three applications were all filed on May 16, 1997, as follows: ARTICULATED SURGICAL INSTRUMENT FOR PERFORMING MI...

AI Technical Summary

Benefits of technology

The invention is a robotic apparatus with a base unit and an effector unit. The base unit has a support and a drivable member that can be controlled by an actuator to move the effector unit. The apparatus has a linkage with multiple joints that provide a wide range of motion for the effector unit. The linkage has both macro and micro joints, with the micro joints being redundant with the macro joints. The actuators are connected to the joints through transmissions, and the linkage has a total of six effector cable tension segments. The apparatus can be controlled using an Inverse Jacobian or a Jacobian Transpose controller. The technical effects of the invention include a wide range of motion for the effector unit, reduced inertia of the macro freedoms, and a cost function to resolve redundancy in control.

Problems solved by technology

However, only about 1,000,000 of the surgeries currently use these techniques, due to limitations in minimally invasive surgical instruments and techniques and the additional training required to master them.

There are many disadvantages of current minimally invasive surgical technology.

The surgeon is deprived of three-dimensional depth cues and may have difficulty correlating hand movements with the motions of the tools displayed on the video image.

Second, the instruments pivot at the point where they penetrate the body wall, causing the tip of the instrument to move in the opposite direction to the surgeon's hand.

Third, existing MIS instruments deny the surgeon the flexibility of tool placement found in open surgery.

Those that include any articulation have only limited maneuverability.

Fourth, the length and construction of many endoscopic instruments reduces the surgeon's ability to feel forces exerted by tissues and organs on the end effector of the tool.

However, despite surgeons' adaptation to the limitations of endoscopic surgery, the technique has brought with it an increase in some complications seldom seen in open surgery, such as bowel perforations due to trocar or cautery injuries.

Moreover, one of the biggest impediments to the expansion of minimally invasive medical practice remains lack of dexterity of the surgical tools and the difficulty of using the tools.

Proposed methods of performing telesurgery using telemanipulators also create many new challenges.

A system's ability to provide force reflection is limited by factors such as friction within the mechanisms, gravity, the inertia of the surgical instrument and the size of forces exerted on the instrument at the surgical incision.

Even when force sensors are used, inertia, friction and compliance between the motors and force sensors decreases the quality of force reflection provided to the surgeon.

Another challenge is that, to enable effective telesurgery, the instrument must be highly responsive and must be able to accurately follow the rapid hand movements that a surgeon may use in performing surgical procedures.

Another challenge is that to enable minimally invasive surgery, the instrument must be small and compact in order to pass through a small incision.

However, the mass and configuration of the effector affects the dynamics and kinematics of the entire system.

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