The presentation was designed so as to show the procedure and considerations regarding Medical Robot Design. I hope it is beneficial to everyone. Please do not hesitate to contact me via Email if you have something helpful to me. Let me know, please. Email address is: S.mohammad.zargar@gmail.com

1. Design of Medical Robots
[Ch 5, Ref 12]
Presenter: Seyed Mohammad Zargar
Supervisor: Dr. Sadeghian
Fall 2017
Under the name of the Lord, the Merciful, the Majestic

2. Introduction
• Medical devices is to have close interaction
with a human environment facing
unpredictable behavior.
• A complex system consisting of
 Articulate and motorized mechanical
structure
 Human-machine interface and instruments
 Electronic components
 Software controller

3. Introduction
Constraints
 Easily transportable and quickly removed for intraoperative complications
Limited amount of workspace Safety
Various functionalities needed for
diverse types of operation
Sterilization
Environment crowded by other
medical equipment
Different positioning

4. Introduction
How to achieve a medico-surgical robot ??
The modeling or the characterization of gestures and
interactions
The selection or the design of kinematics and the
actuation adapted to the requirements deriving from
the characterization of gestures
The synthesis of a controller and the definition of the
Human-machine interface

5. 1. From the characterization of gestures to the design of robots
Surface tracking ->
Skin harvesting
Benefits to surgeon: Downscaling the
force and displacement, surgeon’s tremor
filtering
Benefits to the patient: Minimization of
scarring
Kinematic and dynamic
specification
Analysis of the gesture
Kinematic choices
Dermarob
Laboratoire d'Informatique, de Robotique et de Microélectronique de Montpellier (LIRMM)
A dermatome with an electric motor to vibrate the blade and
perform skin incision.
 Requirements: 6 DOF, to 50 N force, Velocity ~ cm/s
 A force sensor + a cable actuated velocity sensor

6. 1. From the characterization of gestures to the design of robots
Conventional Serial Kinematic Manipulator Arms
• Anthropomorphic: 6 DOF, Spherical accessible workspace, Simpler
kinematic
• SCARA: 4 DOF, Cylindrical accessible workspace, Easier
management of collision
Kinematic choices
Anthropomorphic Kinematic SCARA Kinematic

7. 1. From the characterization of gestures to the design of robots
Manipulator Arms with Parallel Architecture
• Easy to design
• Capable of reaching very high velocities and accelerations
• High resolution and accuracy
• Can be implemented for various scales and uses
Kinematic choices
Parallel Kinematic

8. 1. From the characterization of gestures to the design of robots
Kinematic Architecture with a Remote Center of
Motion
• The RCM is imposed by the kinematic structure of the
mechanism or the environment or is virtual and defined by
a combination of sensors, models and control algorithm.
Kinematic choices

9. 1. From the characterization of gestures to the design of robots
Manipulators Arm with Redundant Architecture
• More DOF than the need
• Avoids collision
Kinematic choices
a hybrid serial-parallel hyper-redundant
active structure

10. 2. Design Methodologies
 Different constraints
 Desired level of cooperation between the
operator and the robot
 Multiplicity of possible technical solutions
Thus, No Single Recipe!
1. Concept Selection
Objectives tree method
Mimetic approach

11. 2. Design Methodologies
 Different constraints
 Desired level of cooperation between the
operator and the robot
 Multiplicity of possible technical solutions
Thus, No Single Recipe!
1. Concept Selection
Objectives tree method
Mimetic approach

12. 2. Design Methodologies
2. Optimization of design parameters
 Single-objective synthesis
Considering single objective criterion such as workspace, the
manipulability, the duration of the movement, a safety distance,
etc.
We can use the optimization techniques in this regard like
gradient or simplex or genetic algorithms.
 Multi-objective synthesis
For meeting the objectives that are conflicting such as
transmitting important effort efforts while being small in size
and safe during operation

13. 3. Technological Choices
1. Actuators
 Reversibility
 Stiffness
 Compensation of the tool/tissue interaction force
 Haptic feedback
 Size and type: electric, pneumatic, etc.
2. Sensors
Two classes of problems
1. The measurement of interaction forces directly on the organ or tissue
with the design of miniature force sensors
2. The integration of new vision systems to monitor physiological
movements, intra-cavity ultrasound probes, MRI, CT scanner, etc.
3. Material
Toxicity, Transparency, Not producing artifacts, etc.

14. Security and Dependability
Electromechanical, Electrical and Software safety have to be into consideration
1. Redundancy into perception
and control
More secure but less reliable
2. Applying reliable basic
components
3. Designing intrinsically safe
components
“Harmonic drive” type gears to limit the
velocity of the robot