medelec100 rehabeng.ppt [相容模式] -...

Rehabilitation EngineeringRehabilitation Engineering

H i L ChHsiao-Lung ChanDept Electrical Engineering

Chang Gung Universitychanhl@mail cgu edu [email protected]

Topics Related to Electrical Engineering and C S iComputer Science

Biomedical Engineering

System Analysis RehabilitationMedical MedicalSystem Analysis and Modeling

Understand Physiological System

Rehabilitation Engineering

Provide Therapeutics and Aids Devices for

Medical Instrumentation

Monitor and Measure Physiological Event

Medical InformaticsBuild Medical

Information and

Signal Processing

Physiological System

Medical Imaging

and Aids Devices for the Disabled

Physiological Event Information and Decision Support

Systems

Bioinformatics Detect, Classify and Analyze Biomedical

Signals

Display Anatomical Details and

Physiological Function

Solve Computational Problems in

Molecular Biology

HL Chan , EE, CGURehabilitation engineering 2

Rehabilitation devicesRehabilitation devices

Sensorial prosthesis Locomotor prosthesis Pacemaker and life-sustaining devices Robot systems and advanced mechanics


Sensorial prosthesesSensorial prostheses

Retinal prosthesis to benefit the visually impaired Hearing rehabilitation


Retinal Prosthesis implant systemRetinal Prosthesis implant system

Wentai Liu et al

http://www.irp.jhu.edu/project/HL Chan , EE, CGU

Rehabilitation engineering 5

Multiple-unit Artificial Retinal Chipset (MARC)Multiple unit Artificial Retinal Chipset (MARC)


Early Visual SystemEarly Visual SystemHyperpolarized by

light flashlight flash

Signal inverted leading to

depolarization

G2 fires while light on, and G1 fires when turn offPeter Dayan and L.F., Theoretical Neuroscience, MIT Press, 2001.


Pathway form retina through LGN of thalamus to primary visual cortex

Peter Dayan and L.F., Theoretical Neuroscience, MIT Press, 2001.HL Chan , EE, CGU

Rehabilitation engineering 8

Implanted MARCImplanted MARC


Retinal prosthesis systemRetinal prosthesis system


Photo-detecting circuit & current pulse generatorPhoto detecting circuit & current pulse generator


MARC system functionalityMARC system functionality


ASK and PWMASK and PWM

Pulse width modulation

Amplitude shiftAmplitude shift key modulation


Hearing rehabilitationHearing rehabilitation

Hearing aid Cochlear implant


How does hearing work?How does hearing work?

1. Outer ear collects sound waves that pass through the air.

2. Sound waves vibrate eardrum2. Sound waves vibrate eardrum and three tiny bones (hammer, anvil, and stirrup) in the middle earmiddle ear.

3. This vibration moves the tiny hairs of the sensory cells in the inner ear or cochlea; sensory cells convert the vibrations to an electrical signal that is sent gto the hearing nerve.

4. The signal travels up the nerve and into the brain where it is http://www advancedbionics com/and into the brain, where it is interpreted as sound

http://www.advancedbionics.com/


Hearing aidHearing aid

Beyond-the-ear aid In-the-ear aid


Principle of hearing aidPrinciple of hearing aid


Programmable hearing aidProgrammable hearing aid


Cochlear implant (Bionic ear)Cochlear implant (Bionic ear)

Provides a sense of sound to a person who is profoundly deaf orprofoundly deaf or severely hard of hearing


Cochlear implant systemCochlear implant system


Multi-electrode cochlear implantMulti electrode cochlear implant


SpeechSpeech

s i gn al


Australian Nucleus cochlear implantAustralian Nucleus cochlear implant


Nucleus implant (cont )Nucleus implant (cont.)


Formants and pitch in speechFormants and pitch in speech

Point process

Glottal excitation

Pit h o p o

Impulse

Pitch

Time-variantvocal tract

Voiced speech

Unvoiced speechgenerator

xfilter system

Random numbergenerator

Amplitudegenerator


Random process

Formant ()Formant ()


French Digisonic cochlear implantFrench Digisonic cochlear implant


Digisonic implant (cont )Digisonic implant (cont.)

Band slelection (exceeding threshold)Band slelection (exceeding threshold)

No need to extract more of less arttifically special features in speech to enhacespecial features in speech to enhace hearing performance


American Clarion cochlear implantAmerican Clarion cochlear implant


Clarion implant (cont )Clarion implant (cont.)


Cochlea structureCochlea structure

CochleaCochlea


Electrode partition along cochlea (Clarion implant )Electrode partition along cochlea (Clarion implant )

A electrode is live and all the others are connected ground.

The live electrode sweeps the electrode array under the control of electronic multiplexingelectronic multiplexing

Electrode pairs are electrically separated.

Information id reduced but indepence is increased.


Locomotor prosthesesLocomotor prostheses

Prosthesis control using myoelectric signal Selective neural activation for motor neural prostheses Sensory feedback for lower limb


Prosthesis control using myoelectric signalg y g(Myoelectric Control System at University of New Brunswick, Canada)


EMG during different movementsg


Mode of operations of myoelectric prosthesis controlMode of operations of myoelectric prosthesis control


Compliant grasp in a myoelectric hand prosthesisCompliant grasp in a myoelectric hand prosthesis

HL Chan , EE, CGURehabilitation engineering 37Okuno et al, IEEE EMB 2005.

Grasp control in myoelectric hand prosthesisGrasp control in myoelectric hand prosthesis


Setup for grasp controlSetup for grasp control

Force and displacement are measured when length perturbation is


o ce a d d sp ace e a e easu ed e e g pe u ba o sapplied to flexor pollicis longus (FPL) muscle during contraction at constant isometric force.

Selective neural activation for motor neural prostheses: functional electrical stimulation (FES)

Nerve-based activationSpinal cord-based

ti ti

M l b d ti ti

Nerve-based activationactivation

Muscle-based activation


Electrode for electrical stimulationElectrode for electrical stimulation

Percutaneous electrode

Transcutaneous electrode

Subcutaneous electrode

Cleveland FES centerCleveland FES center

Standing & transfer Walking


http://fescenter.org/index.php

Sensory feedback for lower limbSensory feedback for lower limb

Floor-based measurement

Foot pressure

In-shoe-based measurement


Central pressure (CP) trajectories in normal walkingCentral pressure (CP) trajectories in normal walking


CP trajectories of prosthetic (left) and natural (right) foot


Tactile sensation for balanceTactile sensation for balance

No sensation Peak sensationPeak sensation

Sensory neurons produce the sense of touch on the sole of the foot. In these cells, signals that are too weak to breach a certain

threshold are not detected by the brain. Stochastic resonance whereby noise strengthens a signal

can help brain sense signal.


Improving sensation at the foot can help people maintain their balance.

Noise-enhanced human sensorimotor functionNoise enhanced human sensorimotor function

HL Chan , EE, CGURehabilitation engineering 47Collins et al, IEEE EMB 2003.

Noise-enhanced sensorimotor function (cont )Noise enhanced sensorimotor function (cont.)

HL Chan , EE, CGURehabilitation engineering 48Collins et al, IEEE EMB 2003.

Pacemakers and life-sustaining devicesPacemakers and life sustaining devices

Diaphragm pacing for chronic respiratory insufficiency Cardiac pacemaker


Diaphragm pacing for chronic respiratory insufficiency


Neural control of respiration

Accessory respiratory muscles


Cardiac pacemakerCardiac pacemaker

Chap 12 pp 253-255 in textbook


Chap 12, pp.253-255 in textbook

Circulatory control systemCirculatory control system

Firing controlled by SA Nodeby SA Node

Rideout, Mathematical and computer modeling of physiological systems, Prentice-Hall, Chap 4, p.109, 1991.


Prentice Hall, Chap 4, p.109, 1991.

Asynchronous cardiac pacemakerAsynchronous cardiac pacemaker

Fixed pacing rate no matter at rest or exercise


Synchronous cardiac pacemakerSynchronous cardiac pacemaker

If SA node normally functions

120 ms

2 ms

HL Chan , EE, CGURehabilitation engineering 55Stimulate purkinje fiber

Physiological cardiac pacemakerPhysiological cardiac pacemaker

Automatically adjust heart rate to match level of activity

HL Chan , EE, CGURehabilitation engineering 56E. Park, St. Jude Medical

Physiological cardiac pacemaker (cont )Physiological cardiac pacemaker (cont.)

When the sensor determines the patient needs rate response, reaction time parameter regulates how quickly rate response is deliveredrate response is delivered

By considering patients age, lifestyle, activities, and how quickly patients would need rate responsequickly patients would need rate response


E. Park, St. Jude Medical

Physiological cardiac pacemaker (cont )Physiological cardiac pacemaker (cont.)

Recovery time determines the minimum time from maximum sensor rate to go back down to programmed based ratebased rate


Sensors for physiologic cardiac pacemakerSensors for physiologic cardiac pacemaker

Activity sensors Accelerometers Vibration sensors

Physiologic sensorsQRS d l i i & QT i l QRS depolarization & QT interval

Peak endocardial accelerationMinute ventilation Minute ventilation

Temperature


Activity sensorsActivity sensors


QRS depolarization and QT intervalQRS depolarization and QT interval

QRS depolarization decreases in area with exercise QT interval shortens with exercise


Endocardial acceleration sensorEndocardial acceleration sensor

Inserted in the tip of pacing lead for chronic measurement of endocardial acceleration (EA)P k EA fl t di t tilit d t b li Peak EA reflects cardiac contractility and metabolic demand


Peak endocardial acceleration (PEA)Peak endocardial acceleration (PEA)


Minute ventilation (MV)Minute ventilation (MV)

Uses low-level electrical signals to measure resistance across the chest

R i t i d i i h li d d d i Resistance increases during inhaling, and decreases during exhaling

Detect respiration rate (RR) and relative change in tidal Detect respiration rate (RR) and relative change in tidal volume (TV) MV = RR x TVMV RR x TV

Related to metabolic


TemperatureTemperature

Related to metabolic


Robot systems and advanced mechanicsRobot systems and advanced mechanics

Obstacle avoidance systems for the blind and visually impairedWh l h i Wheelchairs


Obstacle avoidance systems for the blind and visually impaired: NavBelt

Transferring mobile robotics technology to a portable navigation aid for the blind g


NavBeltNavBelt

Obstacle are detected by ultrasonic sensors

Sonar range readings are projected onto polar histogramhistogram

Acoustic sweep is generated from polar histogram12150 from polar histogram 12150

GuideCaneGuideCane


Intelligent power wheelchairIntelligent power wheelchair

Mazo and SIAMO Project IEEE Robot & Automation 2001


Intelligent power wheelchair (cont )Intelligent power wheelchair (cont.)


Breath-expulsion unitBreath expulsion unit


Guidance by head movementsGuidance by head movements


Guidance by electro-oculography (EOG)Guidance by electro oculography (EOG)

Ocular dipolep


Navigation strategy for wheelchairNavigation strategy for wheelchair

Landmark based absolute positioningLandmark-based absolute positioning


Navigation strategy for wheelchairNavigation strategy for wheelchair

Local mapping-based navigation: self-identifyingenvironment.


E-Motion power-assisted wheelchairE Motion power assisted wheelchair

The wheels assist the user to propel the wheelchair

The batteries are integrated gin the wheel hub.

A sensor registers the propelling movement andpropelling movement and activates the electrical motors


iBOT wheelchairiBOT wheelchair

Self-balancing technology allows the user to

go up and down staircases go up and down staircases navigate difficult terrain stand at eye level with the

b l l d hambulatory people around them

http://www.ibotnow.com/



iBOT (cont )iBOT (cont.)

4-wheel stand balance

Climb up/down stairs



ReferenceReference

Horia-Nicolai Teodorescu, Lakhmi Jain. Intelligent Systems and Technologies in Rehabilitation Engineering, CRC Press, 20012001.

Rory Cooper, Hisaichi Ohnabe, Douglas Hobson. Introduction to Rehabilitation Engineering Taylor &Introduction to Rehabilitation Engineering, Taylor & Francis, 2007.

Wikipedia, the free encyclopedia Wikipedia, the free encyclopedia


medelec100 rehabeng.ppt [相容模式] -...

Documents