A Robot for Automated Motion Scaling in Robotic Microsurgery Group 2 Keshav Chintamani Lavie Golenberg Prashanth Mathihalli Group 2 Keshav Chintamani Lavie Golenberg Prashanth Mathihalli

Problem Statement Different surgical tasks require varying motion scales (MS) between the surgeon and the end-effector –E.g. Suturing vs. gross translation have different scale requirements Surgeons currently keep the MS constant due to –Inconvenience and interruptions during procedures –Higher mental workload –Failures in selecting correct scales might lead to fatal errors –May require an additional technician Different surgical tasks require varying motion scales (MS) between the surgeon and the end-effector –E.g. Suturing vs. gross translation have different scale requirements Surgeons currently keep the MS constant due to –Inconvenience and interruptions during procedures –Higher mental workload –Failures in selecting correct scales might lead to fatal errors –May require an additional technician

Currently… A touch screen allows the surgeon or technician to change the motion scale value The scale is a semi circle with a minimum value of 1 and a maximum of 10 Tapping the circumference changes the MS value of the Zeus robot A touch screen allows the surgeon or technician to change the motion scale value The scale is a semi circle with a minimum value of 1 and a maximum of 10 Tapping the circumference changes the MS value of the Zeus robot

Specific Aims Design and construct an Automated Motion Scaling Robot (AMSR) –Hardware –Software Integrate the AMSR with zeus robot system Analysis and validation of the AMSR through an objective human factors study Design and construct an Automated Motion Scaling Robot (AMSR) –Hardware –Software Integrate the AMSR with zeus robot system Analysis and validation of the AMSR through an objective human factors study

The Hypotheses Eliminate the need for a technician Remove pauses during operations Be capable of changing the MS more frequently Deliver MS changes more accurately than a human Not be susceptible to fatigue Create a more responsive system Eliminate the need for a technician Remove pauses during operations Be capable of changing the MS more frequently Deliver MS changes more accurately than a human Not be susceptible to fatigue Create a more responsive system The AMSR will:

Hardware

Design Requirements A two degree-of-freedom (DOF) RP robot arm –One rotational and one prismatic joint –Damping mechanism to prevent damage to the touch screen –Rapid input/output response –Provide accurate responses to inputs from the surgeon –Provide ease of removal during maintenance and repair A two degree-of-freedom (DOF) RP robot arm –One rotational and one prismatic joint –Damping mechanism to prevent damage to the touch screen –Rapid input/output response –Provide accurate responses to inputs from the surgeon –Provide ease of removal during maintenance and repair

Design Requirements, Contd.. Designing the Robot Mount to provide –A high center-center accuracy between the AMSR and the Motion Scale –Variable chassis geometry settings for the AMSR for calibration Designing the Robot Mount to provide –A high center-center accuracy between the AMSR and the Motion Scale –Variable chassis geometry settings for the AMSR for calibration

Design Hurdles Providing motors with sufficient torque Providing a unique design that is –Replaceable –Reliable –Sensitive to pressure Providing motors with sufficient torque Providing a unique design that is –Replaceable –Reliable –Sensitive to pressure

Preliminary Concepts for the Prismatic Joint

Motor Selection A high torque motor was chosen for the base (rotation) –300 deg/sec Angular Velocity –11 Kg/cm Peak Torque A light weight motor for tapping (translational) –24 g net weight –3 Kg/cm Peak Torque –350 deg/sec angular velocity A high torque motor was chosen for the base (rotation) –300 deg/sec Angular Velocity –11 Kg/cm Peak Torque A light weight motor for tapping (translational) –24 g net weight –3 Kg/cm Peak Torque –350 deg/sec angular velocity

SoftwareSoftware

Electronics Robix RCS-6 Controller Controller provides support for –6 servos with 6 sensor inputs –Parallel port data transmission The programming was done in Microsoft Visual C Robix RCS-6 Controller Controller provides support for –6 servos with 6 sensor inputs –Parallel port data transmission The programming was done in Microsoft Visual C++ 6.0

Robot Control Software Fully integrated control functions for –Speed, acceleration and deceleration of servos –Positional feedback –Additional sensor data acquisition capabilities Fully integrated control functions for –Speed, acceleration and deceleration of servos –Positional feedback –Additional sensor data acquisition capabilities

Final Design

Final Design: 2D Views

Final Design: 3D View

A Descriptive Video

The AMSR!

EvaluationEvaluation

Methodology Obtain preliminary data for 3 humans and the AMS Robot performing a tapping task Compare performance between the robot and the subjects Obtain preliminary data for 3 humans and the AMS Robot performing a tapping task Compare performance between the robot and the subjects

Preliminary Human Factors Test Participants were provided with 5 minutes for practice on the MS display They were asked to input 99 values based on verbal prompts from the experimenter Participants were asked to tap values with and without a stylus Values displayed on screen were recorded Participants were provided with 5 minutes for practice on the MS display They were asked to input 99 values based on verbal prompts from the experimenter Participants were asked to tap values with and without a stylus Values displayed on screen were recorded

Analysis A within-subjects factorial design was used The experiment was balanced using a Latin square The data was analyzed for input error A within-subjects factorial design was used The experiment was balanced using a Latin square The data was analyzed for input error

Results, Discussion & Conclusion

Plots Error variation between factors Error variation between AMSR and Human

Overall Plots

Conclusion Human beings are incapable of the level of dexterity that robots possess Hand movements with a stylus improved human performance The AMSR can provide more rapid and accurate cyclic responses than a human These responses are repeatable Human beings are incapable of the level of dexterity that robots possess Hand movements with a stylus improved human performance The AMSR can provide more rapid and accurate cyclic responses than a human These responses are repeatable

Conclusion, contd… With the AMSR, surgeon performance can immensely be enhanced Surgeon fatigue and workload can be reduced Can result in efficient surgeries with reduced time durations With the AMSR, surgeon performance can immensely be enhanced Surgeon fatigue and workload can be reduced Can result in efficient surgeries with reduced time durations

Future Work

Creating a closed loop system Increase the accuracy of the robot Continue subject testing Analyze performance of linear scales over semi-circular scales Provide various forms of input methods Creating a closed loop system Increase the accuracy of the robot Continue subject testing Analyze performance of linear scales over semi-circular scales Provide various forms of input methods

Future Work, contd… Combine AMSR with Automatic Motion Scaling This study can lead to further research into human hand tracking performance Develop display methods/cues for enhancing performance Combine AMSR with Automatic Motion Scaling This study can lead to further research into human hand tracking performance Develop display methods/cues for enhancing performance

Thank you

References S. M. P. M. Sunil M. Prasad MD*, Hersh S. Maniar MD†, Celeste Chu MD*, Richard B. Schuessler PhD* and Ralph J. Damiano, Jr. MD*, Corresponding Author Contact Information, FACS, "Surgical robotics: Impact of motion scaling on task performance," R. D. Ellis, A. Cao, A. Pandya, A. Composto, M. D. Klein, and G. Auner, "Minimizing Movement Time In Surgical Telerobotic Tasks," presented at 49th Annual meeting of the Human Factors and Ergonomics Society Orlando, Florida, J. Accot and S. Zhai, "Scale effects in steering law tasks," CHI, vol. No.3, pp. 1-8, P. M. Fitts, "The Information Capacity of the Human Motor System in Controlling the Amplitude of Movement," Journal of Experimental Psychology, vol. Vol. 121, pp , S. M. P. M. Sunil M. Prasad MD*, Hersh S. Maniar MD†, Celeste Chu MD*, Richard B. Schuessler PhD* and Ralph J. Damiano, Jr. MD*, Corresponding Author Contact Information, FACS, "Surgical robotics: Impact of motion scaling on task performance," R. D. Ellis, A. Cao, A. Pandya, A. Composto, M. D. Klein, and G. Auner, "Minimizing Movement Time In Surgical Telerobotic Tasks," presented at 49th Annual meeting of the Human Factors and Ergonomics Society Orlando, Florida, J. Accot and S. Zhai, "Scale effects in steering law tasks," CHI, vol. No.3, pp. 1-8, P. M. Fitts, "The Information Capacity of the Human Motor System in Controlling the Amplitude of Movement," Journal of Experimental Psychology, vol. Vol. 121, pp , 1954.