Medical Robotics: An Overview

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Medical Robotics An Overview

• Jennifer Brooks
• for Comp 790-072, Robotics An Introduction
• at University of North Carolina, Chapel Hill
• November 9, 2006

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3 Categories

• Biorobotics
• Rehabilitation Robotics
• Robotics for Surgery
• Autonomous Robots
• Computer Assisted Surgery

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Biorobotics

• Modeling and simulating biological systems in
  order to provide a better understanding of human
  physiology
• For example, haptics research to provide
  force-feedback in master-slave systems
• May also lead to a number of practical
  applications for the substitution of organs
  and/or functions of humans
• Examples
• bionic limb prosthesis
• hearing aids and other aids targeted at
  neuromotor recovery
• the possibility of inserting brain chips
• implanting microscopic activators in the heart to
  pump blood
• data and image acquisition microsystems for
  artificial sight
• microchips to detect sound and to substitute the
  auditory nerve
• May be used to aid in investigation of diseases
  or other health-related ailments
• Examples
• inch-worm robot developed in Singapore for colon
  exploration
• intestinal bug developed in the Nanorobotics lab
  at CMU

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Example Biorobotic System DDX

• Rovetta, 2001
• DDX is an experimental biorobotic system designed
  to acquire and provide data about human finger
  movement, applied in analysis of neural
  disturbances with quantitative evaluation of both
  response times and dynamic action of the patient.
  
• The goal is to measure the response parameters of
  a person in front of a soft touch, made by his
  finger in front of a button.
• It is now applied in daily clinical activity to
  diagnose the progression of the Parkinson
  pathology.

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Disease Detector 3 (DD3)

• Rovetta, 2001
• A fuzzy-based control system for detection of
  Parkinson disease
• May be used remotely to monitor a patients
  health at his or her home
• Patient pushes button on a joystick system
  measures response time, speed, fingertip
  pressure, and tremor
• Virtual Movement on a display, the patient is
  asked to follow a virtual image relating to each
  moment of the test. Again, system measures
  response time, speed, fingertip pressure, and
  tremor from the press of a button and grip on a
  joystick.

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Other Biorobots
Six-legged Intestinal Bug with swallowable
camera to allow docs to see inside the
intestine. Image from http//www.post-gazette.com,
May 2005 Article in Health, Science, and
Environment
Metin Sitti, director of CMU's Nanorobotics Lab
A Retina-Like CMOS Sensor for vision Image from
Sadini et al, 2000
Above Medical Telediagnostic System with Tactile
Haptic Interfaces Image from Methil-Sudhakaran
et al, 2005
Biomechanics of Voice Production Goal is to
address questions regarding the etiology and
treatment of common voice pathologies.
http//biorobotics.harvard.edu/research/heather.h
tml
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Other Biorobots (Contd)
A scheme of a fingertip incorporating three
different types of sensors which provide
information on object geometry and material
features comparable to those of the human
fingertip. A close-up of one of the sensors (a
256-element array sensor), which imitates the
space-variant distribution of tactile receptors
in the fingertip skin. Image from Dario et al,
1996
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Rehabilitation Robotics

• Robotics systems for hospitals
• HelpMates
• MELKONG
• Manipulators in rehabilitation
• Wheelchair-mounted arms
• MoVAR the Mobile Vocational Assistant
• URMAD a mobile base that responds to a fixed
  workstation, mainly devised for residential
  applications
• Intelligent wheelchairs
• self-navigating wheelchairs with sensors enabling
  them to avoid obstacles
• Daily life home assistance
• MOVAID a mobile base which fits into different
  activity workstations, built on URMAD technology
• Advanced prosthesis and orthosis
• Functional Electric Simulation (FES)
• Computer-Aided Locomotion by Implanted
  Electro-Stimulation (CALIES)
• Virtual environments for training and
  rehabilitative therapies

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MoVAR (1983-1988)

• Unique and patented 3-wheeled omni-directional
  base
• Mounted PUMA-250 arm with camera to display
  robots activities and surroundings to user
  console
• Desk-high and narrow enough to go through
  interior doorways.
• Wireless digital link for receiving commands and
  sending position and status information.
• Bumper-mounted touch sensor system for obstacle
  avoidance
• Wrist-mounted force sensor and gripper-mounted
  proximity sensors to assist in manipulation
• The robot console had three monitors graphic
  robot motion planning, robot status, and camera
  view. It had keyboard, voice, and head-motion
  inputs for command and cursor control, and voice
  output.
• Funding for it terminated in 1988. The hardware
  and software were transferred to the Intelligent
  Mechanisms Group at the NASA Ames Research Center
  (Mountain View, CA) for use in the development of
  real-time controllers and stereo-based user
  interfaces for semi-autonomous planetary rovers.

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URMAD
Image from Dario, 1996
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Computer-Aided Locomotion by Implanted
Electro-Stimulation (CALIES)

• Probably the most important coordinated effort in
  the world for restoring autonomous locomotion in
  paralyzed persons Dario, 1996
• Investigated the possibility of implanting
  electrodes into lower limb muscles, or nerves,
  which could be stimulated via an external
  computer to produce close to natural walking

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Robotics for Surgery
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A Definition

• Robot - A reprogrammable multifunctional
  manipulator, designed to move material, parts,
  tools or specialized devices through variable
  programmed motions for the performance of a
  variety of tasks
• Robot Institute of America
• A powered computer controlled manipulator with
  artificial sensing that can be reprogrammed to
  move and position tools to carry out a range of
  surgical tasks
• B Davies (2000)
• Robotic systems for surgery are
  computer-integrated surgery (CIS) systems first,
  and medical robots second. In other words, the
  robot itself is just one element of a larger
  system designed to assist a surgeon in carrying
  out a surgical procedure that may include
  preoperative planning, intraoperative
  registration to presurgical plans, use of a
  combination of robotic assist and manually
  controlled tools for carrying out the plan, and
  postoperative verification and follow-up.
• Taylor (2003)

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Robots One Aspect of an Integrated System
Typical stages in robotic knee surgery Davies,
1999
Pre-operative Image patient Edit images and create three-dimensional model of leg Create three-dimensional model of prostheses Superimpose prostheses over three-dimensional model of leg Adjust and optimize location Plan operative procedure
Intraoperative Fix and locate patient on table Fix and locate robot (on floor or on table) Input three-dimensional model of cuts into robot controller Datum robot to patient Carry out robot motion sequence (Monitor for unwanted patient motion)
Post-operative Remove robot from vicinity Release patient Check quality of procedure
If further cuts are necessary Reclamp patient Reposition and datum robot to patient Repeat robotic procedure
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Benefits

• from Davies, 1999
• The ability to move in a predefined and
  reprogrammable complex three-dimensional path,
  both accurately and predictably.
• The ability to actively constrain tools to a
  particular path or location, even against
  externally imposed forces, thus preventing damage
  to vital regions. This can lead to safer
  procedures than those achieved using Computer
  Assisted Surgery (CAS).
• The ability to make repetitive motions, for long
  periods, tirelessly.
• The ability to move to a location and then hold
  tools there for long periods accurately, rigidly
  and without tremor.
• The ability to perform in environments unsafe for
  humans, such as radioactive and fluoroscopic.
• Precise micromotions with prespecified
  microforces.
• Quick and automatic response to sensor signals or
  to changes in commands.
• To be able to perform keyhole minimal access
  surgery, without the aid of vision and without
  forgetting the path or the location.

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Timeline
1985 Kwoh et al used Puma 560a standard industrial robotto hold a fixture next to the patients head to locate a biopsy tool for neurosurgery
1985 Taylor at IBM was developing an industrial robot system (based on an IBM Scara style of robot) for hip surgery. Following laboratory studies, the robot became a veterinarian robot replacing hips of pet dogs under direction of vet Dr. Hap Pal. The IBM robot was replaced by a Scara industrial robot from the Japanese company, whose Sanko-Seiki control system incorporated additional safety structures for surgery.
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Timeline (contd)
1988 First attempt at active motion robot in surgery. The Mechatronics in Medicine Group at Imperial College built onto Puma 560 to perform soft-tissue surgery in transurethral resection of prostate (TURP).
April 1991 First time an active robot was used to automatically remove tissue from patients. This resulted from developments based on the PUMA studies for TURP. Since that time a 2nd-generation prostate robot (called Probot) has been developed at Imperial College.
Late 1991 The modified Sanko Seiki robot system, now called Robodoc was tried clinically on human patients.
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Timeline (contd)
Dec 1993 The AESOP 1000, used for holding an endoscopic camera in minimal invasive laparoscopic surgery, developed by Computer Motion was approved by the FDA.
1997 The da Vinci Surgical System manufactured by Intuitive Surgical Inc., became the first assisting surgical robot to receive FDA approval to help surgeons more easily perform laparoscopic surgery. Jacques Himpens and Guy Cardier in Brussels, Belgium used the da Vinci by Intuitive Surgical Inc. system to perform the first telesurgery gall bladder operation.
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Timeline (contd)
Oct 2001 ZEUS Robotic Surgical System from Computer Motion receives FDA regulatory clearance. (ZEUSs 3rd arm is an AESOP voice-controlled robotic endoscope for visualization Lanfranco et al, 2004.)
Sept 2001 ZEUS robotic system developed by Computer Motion was used in the trans-Atlantic operation. A doctor in New York removed the diseased gallbladder of a 68-year-old patient in Strasbourg, France. See Marescaux, 2002 for details.
There are many more these are just some
highlights to give an idea about how medical
robotics has evolved.
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Robot Trivia

• The word "robot" was first used by Czech writer
  Karl Capek for his 1920 play, R.U.R. Rossum's
  Universal Robots, in which artificial workers
  eventually overthrow their creators. But contrary
  to popular opinion, Karl Capek didn't invent the
  word "robot". He wanted to call the workers
  "labori" but his brother, cubist painter and
  writer Josef Capek, suggested they be called
  "robots". The Czech word "robota" means "forced
  work or labour".

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Timeline

• For another, more extensive timeline, see
  http//biomed.brown.edu/Courses/BI108/BI108_2005_G
  roups/04/timeline.html

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Robotic Surgery How it differs from
Computer-Assisted Surgery (CAS)?

• Davies, 1999 differentiates between the two
• In CAS, the surgeon holds the tools and could
  ignore warnings to the contrary and cut into
  unsafe regions whereas, a robot can be
  programmed to prevent motions into critical
  regions or only allow motions along a specified
  direction
• computers might help in planning and positioning
• In robotic surgery, robots will hold the tools,
  providing greater accuracy and precision
• More recent developments, however, dont fit
  easily into one of these categories based on the
  definitions offered by Davies (and later by Bann
  et al, 2003).
• Consider telesurgery

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Benefits of Computer-Assisted Surgery

• Some systems correct the surgeons tremor
• Higher accuracy
• Minimally Invasive Surgery
• Reduction of radiation exposure for both patient
  and surgeon
• Less time consuming interventions because of
  better planning and simulation Schep et al,
  2001

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Robotic Surgery Current Applications
TABLE 3. Current Applications of Robotic Surgery
From   Lanfranco Ann Surg, Volume
239(1).January 2004.14-21
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2 Main Types of Robotics for Surgery

• Those based on image guidance and
• Those aimed at obtaining minimal invasiveness
  Dario et al, 1996
• For example
• Bone-mounted miniature robot
• Some achieve both
• For example
• da Vinci Surgical System a master-slave system
• Zeus a master-slave system

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MARS A Bone-Mounted Miniature Robot Shoham et
al, 2003

• Reasons given for slow uptake of Surgical Robots
  in the Operating Room
• Contemporary medical robots are voluminous. They
  occupy too much space and raise safety issues.
• Commercial surgical robot systems are expensive
  (300,000 to 1,000,000). Thus, their use is
  limited to the few large research hospitals that
  can afford them.
• The patient anatomy needs to be immobilized by
  fixing it to the operating room table, or
  compensated for by tracking it in real time and
  adjusting the fixed robot position accordingly.

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MARS A Bone-Mounted Miniature Robot Shoham et
al, 2003

• MARS is a cylindrical 5x7 cm3, 200-g,
  six-degree-of-freedom parallel manipulator.
• Authors were developing two clinical applications
  to demonstrate the concept
• surgical tools guiding for spinal pedicle screws
  placement and
• drill guiding for distal locking screws in
  intramedullary nailing.
• In both cases, a tool guide attached to the robot
  is positioned at a planned location with a few
  intraoperative fluoroscopic X-ray images.
• Preliminary in-vitro experiments demonstrated the
  feasibility of this concept.

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MARS A Bone-Mounted Miniature Robot Shoham et
al, 2003

• Design goals
• precise position and orientation of long,
  handheld surgical instruments, such as a drill or
  a needle, with respect to a surgical target
• small work volume enclosing a sphere whose radius
  is several centimeters
• rigid attachment to the bone
• lightweight and compact structure
• lockable structure at given configurations to
  provide rigid guidance
• capable of withstanding lateral forces resulting
  from instrument guidance of up to 10 N
• modular design to allow customization of the bone
  attachment and targeting guide for different
  surgical applications
• repeatedly sterilizable in its entirety or easily
  covered with a sterile sleeve
• quick and easy installation and removal from the
  bone.

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MARS A Bone-Mounted Miniature Robot
The above is not from a MARS operation, but
illustrates how a robot can perform more
precisely than a human surgeon. Image from
Dario, 1996
Images from Shoham et al, 2003
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Image-Guided CAS

• Recall that the robots are one aspect of an
  integrated system that includes
• Pre-operative planning
• Intra-operative Intervention
• Post-operative assessment
• In image-guided CAS
• Pre-operative planning involves processing of
  images such as CT- and MRI-scans. 3-D images are
  often computed at this stage.
• The image data, including the validated
  pre-operative work-up are subsequently loaded on
  an OR workstation
• During the operation, the position of the
  surgical instruments and implants are displayed
  on a computer screen in relation to the patients
  anatomy. For this purpose, position tracking and
  registration are required. Schep et al, 2001

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Image-Guided CAS Instrument and Position Tracking

• Schep et al, 2003
• The system has been compared with a global
  positioning system (GPS)
• car ? surgical instrument
• driver ? surgeon
• In surgical navigation, pre- or intra-operatively
  acquired digital radiographic images act as the
  roadmap.
• Key element is the tracking sensor, which
  identifies the instruments in order to determine
  their position.
• In a GPS, the tracking sensor is a satellite.
• Surgical tracking systems use magnetic, acoustic
  or optical signals for locating a target within
  the operating room.

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Image-Guided CAS Instrument and Position
Tracking (Contd)

• Schep et al, 2003
• Most commonly used technique is tracking by
  (infrared) light emitting diodes (LEDs) or
  passive markers such as retro-reflective spheres
  or disks.
• Shields with typically four or six LEDs/passive
  markers are attached to the instruments and the
  operated bone.
• To allow freedom of movement during surgery, the
  position of the target bone is also tracked.
  Therefore, a frame with LEDs or passive markers
  is attached to the skeleton, the so-called
  dynamic reference frame (DRF).

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Image-Guided CAS Instrument and Position
Tracking (Contd)

• Schep et al, 2003
• The tracking sensor overlooking the surgical
  field receives the signals emitted by the
  LEDs/passive markers of both the DRF and the
  surgical instruments.
• Subsequently, the position of the instruments is
  superimposed on the radiographic images of the
  operated bone.

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Image-Guided CAS Registration of Pre-Operatively
Obtained Images

• Schep et al, 2003
• Registration is required to establish a
  relationship between the anatomy in the operating
  field and the anatomy displayed in pre-operative
  images.
• The procedure can be roughly divided in two
  different kinds of techniques.
• External markers
• Requires additional operation to implant the
  markers
• Each marker on the patient is touched in a
  predefined order with a tracked instrument that
  registers it with a position on the pre-operative
  image
• Anatomic landmarks
• No operation needed to implant markers
• Registration of the landmarks can be done a
  couple of ways
• Paired-point registration a 3D localiser is
  used to touch well-defined anatomic landmarks on
  the bone surface.
• Surface registration a random cluster of points
  is used instead of specific landmarks. The
  computer uses trial and error technique to match
  the touched bone surface area with the
  corresponding 3-D image area

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Image-Guided CAS
Paired-point Registration
Images from Schep, 2003
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Image-Guided CAS Registration (Contd)

• Schep, 2003 also mentions 2 newer types of
  registration which are non-invasive
• Ultrasound
• Laser beams

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the da Vinci System, picture from
IntuitiveSurgical.com
38
the da Vinci System, picture from
IntuitiveSurgical.com
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Da Vinci System in Action

• video-clip
• Recording by students in Brown Medical School
  (http//biomed.brown.edu/Courses/BI108/BI108_2005_
  Groups/04/davinci.html)

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Summary

• Medical Robotics have a bright future.
• Research and practice have shown that Robotic
  Surgery is safe, less invasive, and more accurate
  than surgery performed in the absence of
  robotics.
• It is still in its infancy, however Lanfranco et
  al, 2003 so theres plenty of opportunity.

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Some Current Opportunities in Medical Robotics
Research

• Robots with more autonomy to perform procedures
• Haptics research that will provide force-feedback
  to the surgeon manipulating the tools in
  master-slave systems
• Schep et al, 2003
• Though initial experiences have been promising,
  CAS is still complex and sensitive to failures
  due to pitfalls in registration, tracking and
  instability of software.
• A more sophisticated solution is automated
  registration by intra-operative imaging.
• Flouroscopy based CAS is evolving rapidly (i.e.
  navigation in 3D fluoroscopic images)
• An additional inconvenience is limitation in
  tracking techniques. Optical tracking requires a
  straight line of sight between the LEDs and the
  camera, which could be obstructed by the surgeon.
• More flexible tracking techniques with
  multi-angle detection of signals would allow a
  surgeon greater freedom of movement in OR.

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References

• Bann et al (2003)
• Bann et al, Robotics in Surgery
• Boilot (2002)
• Classification of bacteria responsible for ENT
  and eye infections using the Cyranose system
• Dario et al (1996)
• Robotics for Medical Applications
• Davies (1999)
• A Review of Robotics in Surgery
• Lanfranco (2004)
• Robotic Surgery A Current Perspective
• Marescaux et al (2002)
• Transcontinental Robot-Assisted Remote
  Telesurgery Feasibility and Potential
  Applications
• Methil-Sudhakaran et al (2005)
• Development of a Medical Telediagnostic System
  with Tactile Haptic Interfaces
• Rovetta (2001)
• Biorobotics An Instrument for an Improved
  Quality of Life. An Application for the Analysis
  of Neuromotor Diseases
• Sandini (2000)
• A Retina-Like CMOS Sensor and Its Applications
• Schep et al (2001)