BIOMEDICAL ENGINEERING Technology for Life

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Rehabilitation Technology;. The applicability of Smart materials. Arjan Buis, PhD. .... Translation into Rehabilitation Technology. Prosthetics. &. Orthotics ...

Dr. Arjan Buis

BIOMEDICAL ENGINEERING Technology for Life

Rehabilitation Technology; The applicability of Smart materials Arjan Buis, PhD. Biomedical engineering, University of Strathclyde, Glasgow, Scotland, UK

Overview o Biomedical engineering at Strathclyde o Introduction to Smart materials.

o Transducers, Sensors & Actuators. o Translation into Rehabilitation technology.

Biomedical Engineering

Activity Scope (research)

Rehabilitation Engineering

Introduction to Smart materials o What do we mean by “Smart”

o Definition of Smart Material behaviour. Material that has the intrinsic or extrinsic capabilities to respond to an external stimulus in a functionally useful, reliable, reproducible and usually reversible manner. Smart behaviour is the reaction of a material to stimuli from its environment, no material can be Smart in isolation, it must be a part of a structure or system such as your mobile phone, the coffee mug or a leg prosthesis.

Types of Smart materials o o o o o o o

Chromogenic. Halo-chromic . Shape Memory; Alloys , Polymers. Piezoelectric. Magneto-strictive. Smart fluids. Smart Fabrics.

Chromogenic Materials o Chromogenic materials change colour in response to external stimuli: o Electrical

o Optical (i.e. light intensity) o Thermal changes.

www.slowtwitch.com images5DON186U thermochromic-urinal_zTLKJ_58

Halochromic materials; o Colour change as a result of changing acidity

imagesLDT0P9XX

Shape Memory materials; Alloys Nitinol (Ni-Ti) One-way SME Two-way SME Pseudo-elasticity

Polymers

Ag-Cd 44/49 at.% Cd Au-Cd 46.5/50 at.% Cd Cu-Al-Ni 14/14.5 wt.% Al and 3/4.5 wt.% Ni Cu-Sn approx. 15 at.% Sn Cu-Zn 38.5/41.5 wt.% Zn Cu-Zn-X (X = Si, Al, Sn) Fe-Pt approx. 25 at.% Pt Mn-Cu 5/35 at.% Cu Fe-Mn-Si Pt alloys Co-Ni-Al Co-Ni-Ga Ni-Fe-Ga Ti-Pd in various concentrations Ni-Ti (~55% Ni) Ni-Ti-Nb Ni-Mn-Ga

o Stimuli responsive polymers (plastics) Applications; drug delivery, textiles, artificial muscles etc. Jani, J. M.; Leary, M.; Subic, A.; Gibson, M. A. (2013). "A Review of Shape Memory Alloy Research, Applications and Opportunities". Materials & Design.

Piezoelectric materials; o Produces a voltage when stress is applied

www.youtube.com/watch?v=OPwIKWSiwVU www.youtube.com/watch?v=RydSojhrur8

Magnetostrictive materials o Magnetostrictive materials can convert magnetic energy into kinetic energy, or the reverse, and are used to build actuators and sensors.

Magnetostriction_by_Zureks

Smart fluids o A smart fluid is a fluid whose properties (for example the viscosity) can be changed by applying an magnetic field or a electric field .

www.youtube.com/watch?v=7LArS6tlVNg www.youtube.com/watch?v=yViGgApwrIk

Transducers, Sensors and Actuators Sensor(s) oA sensor is a device, which responds to an input quantity by generating signals proportional to the changing measurand, usually in the form of an electrical or optical signal. Transducer(s) oA transducer is a device that converts energy from one form to another. When a transducer converts a measurable quantity (sound pressure level, optical intensity, magnetic field, etc) to an electrical voltage or an electrical current we call it a sensor. Actuator(s) oWhen the transducer converts an electrical signal into another form of energy, such as sound, mechanical movement, it is called an Actuator. cas.ee.ic.ac.uk‎

Transducers, Sensors and Actuators

www.pi.com linear actuator www3.gehealthcare.com

Transducers, Sensors and Actuators

www.pi.com linear actuator www3.gehealthcare.com

Translation into Rehabilitation Technology

Prosthetics & Orthotics

Prosthetic examples

Orthotic examples

Prosthetics

Prosthetics

Prosthetics & Smart materials Prosthetic components

Otto Bock healthcare gmbh Ossur ltd

Prosthetics Body/device interface; What can smart materials contribute? o Issues: Quantification of socket fit. 

    

Interface pressure and shear Bone movement Activity Temperature Blood flow Volume management

Prosthetics Interface pressure and shear

Boundary shear

Pressure

Shear stress level

Pressure level

Prosthetics Bone movement

Lateral

Lateral

A

P

Medial

Hydro Cast

P

A

Medial

Ischial Containment

Prosthetics o Activity

o Temperature o Blood flow

o Volume management

Future developments Sensor(s)

o Toward ubiquitous mobility solutions for body sensor networks on Healthcare. o Dynamic adaptable prosthetic sockets. o Dynamic adaptable orthotics. o Powered prosthesis/orthosis using artificial muscle concepts. o Self healing components.

Thank you!