Introduction to Rehabilitation Robotics Matteo Malosio - - PDF document

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Introduction to Rehabilitation Robotics

Matteo Malosio matteo.malosio@cnr.it

Robotics

• A robot is ‘‘a reprogrammable, multifunctional manipulator

designed to move material, parts, tools, or specialized devices through various programmed motions for the performance of a variety of tasks’’ (Robotic Industries Association)

• The industry's current working definition of a robot has

come to be understood as any piece of equipment that has three or more degrees of freedom.

• In practice, robots are computers with servomechanisms.
• A servomechanism is an automatic device that uses error-

sensing negative feedback to correct the performance of a mechanism.

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Service robotics Surgical robots

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Rehabilitation robotics

Rehabilitation robotics includes:

• Prosthetics

A mechanical device that substitutes for a missing part of the human body

• Orthotics

A mechanism used to assist or support a weak or ineffective joint, muscle, or limb.

• Assistive Robots

Provide greater independence to people with disabilities

Speich J., and Rosen J., “Medical Robotics”, in Encyclopedia of Biomaterials and Biomedical Engineering, 983-993, Marcel Dekker, Inc., 2004

Robotic prosthesis

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The actors in rehabilitation Rehabilitation

Orthopedic Neurological

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Stroke

• Loss of brain function due to a

disturbance in the blood supply to the brain.

• ischemia (lack of blood flow)
• hemorrhage (bleeding of blood vessels)
• The affected brain area cannot

function normally, resulting in:

• inability to move one or more limbs on
• ne side of the body
• failure to understand or formulate speech
• a vision impairment of one side of the

visual field…

CT scan slice of the brain showing a right-hemispheric ischemic stroke.

Neurorehabilitation

• Neurological disorders due to

cerebrovascular diseases is a relevant world problem.

• Rehabilitation has to mitigate negative effects

and prevent societal and work relapses.

• An effective rehabilitation program can help

to:

• maintain a patient’s quality of life,
• maximize the patient’s physical and psychosocial

functions

World Health Organization, Neurological disorders affect millions globally: WHO report, WHO Library Cataloguing-in-Publication (2006)

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Societal impact

• Stroke requires
• therapy intensity shortly after the incident
• continued therapy in the following period
• Stroke events in EU countries (WHO)
• 1.1 million per year (2000) -> more than 1.5 million per year

(2025) (because of the demographic changes).

• Demographic changes
• decrease of medical staff and care personnel availability.
• European stroke cost if about 38G€/year
• (2-3 % of health expenditure for European Union).

R4H Roadmap

Source: EU Robotics for Health Roadmap Robotized and multi-sensory systems are considered the most promising technologiies.

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Neurorehab devices aims

• Relieve therapist’ effort
• Make the patient partially independent
• Objective measures and assessments
• Intensity of treatment

Motor relearning

Cortical activation before treatment Cortical activation after treatment

• Function recovery possible due to brain plasticity
• Neurorehabilitation is “training the brain” on how to

control movement

• Sensory feedbacks enhance the cerebral reorganization

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“Traditional” rehabilitation Orthopedic rehabilitation

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• A programmed motion law is maintained

and controlled by the CPM controller

• The patient’s action is considered a

disturbance

• No feedback from the patient
• Feedback from motor sensors

Continuous Passive Motion

CPM device Controller Target position

Doesn’t involve actively (or involve slightly) the patient Actual robot target motion is not modified by the patient

Patient Actual position

Neurological rehabilitation

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Assist-as-needed Input/Output devices in rehabilitation

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Rehab exercise Patient behaviour Force/Torque signals

Disturbance

Patient in the loop – force feedback

Motion controller Robot Patient

Target position Actual position

Motion planner

Position/Velocitiy signals

• For patients able to generate a muscular stimulus,
• but too weak to perform autonomously a movement.

Patient in the loop – EMG feedback

Rehab exercise Force/Torque signals EMG signals

Motion controller Robot Patient

Target position Actual position

Motion planner

Position/Velocitiy signals Patient behaviour

Disturbance

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• Assistive controllers
• Impedance-based assistance
• Counterbalancing assistance
• EMG-based assistance
• Performance-based adaptation of task parameters
• Challenge-based robotic therapy control algorithms
• Resistive strategies
• Constraint-induced strategies
• Error-amplification strategies

Force feedback control strategies

• L. Marchal-Crespo and D. J. Reinkensmeyer, “Review of control strategies for robotic movement training after

neurologic injury.” Journal of neuroengineering and rehabilitation, vol. 6, no. 1, pp. 20+, Jun. 2009. http://www.biomedcentral.com/content/supplementary/1743-0003-6-20-S1.pdf

Patient in the loop – EEG feedback

Rehab exercise Force/Torque signals EMG signals EEG signals

Disturbance Motion controller Robot Patient

Target position Actual position

Motion planner

Position/Velocitiy signals Patient behaviour

sweating, temperature, heartbeat, breathing, ... are other possible feedback signals to monitor physio – psicological state

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Patient in the loop – multimodal controllers

Rehab exercise Force/Torque signals EMG signals

Motion controller Robot Patient

Position/Velocitiy signals Patient behaviour

VR controller VR FES controller FES Motion planner

Patient in the Loop Psycho-physio-biomechanical loops

König A., "Human-in-the-Loop Control During Robot-Assisted Gait Rehabilitation”, Dissertation ETH No. 19641, Zurich, 2011

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Psycho-Physiological feedback

• Compatible with the range of

motion (ROM) of the human arms

• Torques and motions compatibles

with articulations

• No hazard and discomfort

Design guidelines of an interactive robot

Schiele, A., van der Helm, F.C.T., 2006, ‘Kinematic design to improve ergonomics in human machine interaction’, IEEE Transactions on Neural Systems and Rehabilitation Engineering 14(4): 456–469. Rocon, E. and Ruiz, A. F. and Raya, R. and Schiele, A. and Pons, J. L. and Belda-Lois, J. M. and Poveda, R. and Vivas, M. J. and Moreno, J. C., 2008, Human–Robot Physical Interaction, Wearable Robots, John Wiley & Sons, Ltd: 127–163.

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End-effector / Esoscheletro

End-effector Esoscheletro

Articolazioni di arti superiori e inferiori

Glenohumeral Elbow joint Pronosupination Hip Knee Tibiofibular

Spherical Rotational Rotational Universal

Ankle Wrist

+ + + = 7

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End-effector constraint and motion

• Limbs (and articulations)

result in a self-adapted configuration

• Limbs chains can rotate

around proximal-to-distal articulation axis (joint redundancy)

End-effector constraint and motion

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End-effector – Inmotion (MIT Manus) End-effector - MOTORE

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Cable-driven upper-limb rehabilitation robots

• G. Rosati, P. Gallina, and S. Masiero, “Design, Implementation and Clinical Tests of a Wire-Based Robot for

Neurorehabilitation”, IEEE Transactions on Neural Systems and Rehabilitation Engineering, 15(4):560–569, 2007.

• G. Rosati, P. Gallina, A. Rossi, and S. Masiero, "Wire-based robots for upper-limb rehabilitation", International

Journal of Assistive Robotics and Mechatronics, 7(2):3–10, 2006.

Exoskeletal constraints and motion

Joints movement

• Limbs control and

movements are obtained by exoskeletal joints aligned to human articulations

• Limbs chains poses are

uniquely determined by exoskeleton joints

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Shoulder girdle

The clavicle and the scapula

Source: Pronk, G.M., 1991. The shoulder girdle: analysed and modelled kinematically. In: Ph.D. Thesis, Delft University of Technology, The Netherlands

Shoulder rhythm and humeral ICR displacement

(with the permission of Tobias Nef and Robert Riener, ETH and University of Zurich, Switzerland)

Shoulder complex movement is due to a combination of the shoulder girdle and the gleno- humeral joint movement (Shoulder rhythm). The humeral head ICR translates as function of the upper arm elevation angle.

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Aligned human and robot joints

• The distance between cuffs and joints is constant in

the joint range of motion

• Relative displacement between skin and bone does

not occur

constant

Forces are normal to the bone axis with no axial components

Misaligned human and robot joints

Forces have a component aligned to the bone axis

• The distance between cuffs and joints is not

constant in the joint range of motion

• Relative displacement between skin and bone can
• ccur (soft tissues compliancy) and proper joint

decoupling should be introduced

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Esoscheletri per arto superiore ARMEO Power

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Esoscheletri antigravitari Esoscheletri per le mani

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End-effector arti inferiori – G-EO Esoscheletro arti inferiori - Lokomat

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Esoscheletri «ambulanti» arti inferiori

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49

Human beings created robots…

… robots will help human beings heal.

Thanks