PRESENTER : DR M PERTINRIMS,IMPHAL(INDIA)

i-Limb Hand

27/9/2014; 2 pm

1

History of Prosthetics

Oldest known splint: 5th Egyptian Dynasty (2750-2625 B.C.)

500 BC : Earliest known written reference on artificial limb by Herodotus, Greek historian

300 B.C : Artificial limb made of copper and wood leg unearthed at Capri, Italy in 1858

27/9/2014; 2 pm

2

1529, Ambroise Pare, French surgeon introduced amputation – 1st scientific prosthesis

1863, Dubois L Parmelee , New York City : socket

1898 :Dr Vanghetti invented an artificial limb that could move with muscle contraction

1946 : Suction sock for the AK prosthesis at University of California (UC) at Berkeley

27/9/2014; 2 pm

3

History of myoelectric prosthesis

Myoelectric control (1945) : 1st implemented by Reinhold Reiter, physics student at Munich University; prototype demonstrated

1948 : Production stopped due to lack of fundLate 1950s & early 1960s : USSR, United Kingdom,

USA, Europe and Canada, after invention of transistors1964 :1st commercial myo-electric arm; Central

Prosthetic Research Institute, USSR; distributed by the Hangar Limb Factory, UK 

1970s : rapid development; advances in battery and magnet technology; reduction in motor size and weight

27/9/2014; 2 pm

4

Non prehensileNon prehensile PrehensilePrehensile

• Touching, feeling• Pressing down• Tapping• Stirring• Vibrating cords of

instruments• Lifting/pushing with

hand

Precision grips• Palmar pinch• Tip pinch• Lateral or key pinch• Three jaw chuck Power grips• Cylindrical grip• Spherical grip• Hook

Hand functions

27/9/2014; 2 pm

5

Psychosocial roles : Gestures, caressing, communication, and sensation.

Psychosocial roles : Gestures, caressing, communication, and sensation.

Ideal prosthesis

Function - simple, meet user’s need and

dependable

Comfort - fits well, easy to don and doff, light

weightCosmesis - natural look both at rest and

` functional activity Fabrication - easy and widely available

Economics - affordable and worth costProsthetic device that provides the best prehension and functional

movement is an important goal Prosthetic device that provides the best prehension and functional

movement is an important goal

Prosthetic options

Passive prosthesis Body-powered prosthesis Electrically powered prosthesis Hybrid prosthesis Activity-specific prosthesis

27/9/2014; 2 pm

7

Passive prosthesis

Passive : No moving

part/functionCosmesis

27/9/2014; 2 pm

8

Body powered prosthesis

Restriction from harness in ROM and function

Non use of prosthesis

Body powered: Operating force from muscular effort remote from the amputation site

DurableWeigh less than their

electrical counterpartsMechanics depend on proprioceptive

feedback and pull through the harness system

27/9/2014; 2 pm

9

Externally powered prosthesis

Externally powered :• Operating force

from outside the body - Pneumatic

- Hydraulic - Battery

Pectoralis, Deltoid-ant/post, Infraspinatus, Teres major, Biceps, Triceps, Wrist extensors/flexors

Controls : Myo-electrodes Switches slider-type input

devices force-sensing resistors

or touch pads

27/9/2014; 2 pm

10

Hybrid prosthesis

Combination of body and electrically powered types

At or above elbow amputations : Body-powered elbow and electrical terminal device and wrist

27/9/2014; 2 pm

11

Activity specific terminal devices

27/9/2014; 2 pm

12

Terminal devices :Passive : No moving part/function

Cosmesis Passive hand, Mitts

Prehensile :

Hooks – Voluntary opening/closing Hands - Voluntary

opening/closing

27/9/2014; 2 pm

13

i-Limb Hand

Bionic HandFirst commercial active prosthetic3 variants : I-Limb Pulse, Ultra & Ultra

revolutionDeveloped by David Gow of the Scottish

National Health ServiceBuilt by Touch Bionics™Major advance on previous hooked limbs.Became commercially available in 2007

27/9/2014; 2 pm

14

Hand

27/9/2014; 2 pm

15

Wrist

Multiple positions of flexion and extension in set increments

Quick detachment for changing between terminal devices

Flexible mode: Natural movement with progressive resistance with a spring-loaded mechanism that returns the wrist to a neutral position

Rigid mode: Locks the flexion or extension in increments for holding and carrying objects

360-degree rotation, with stops at multiple positions

27/9/2014; 2 pm

16

Processor and electrodesProcessor and electrodes Battery Battery

27/9/2014; 2 pm

17

Basic descriptions

27/9/2014; 2 pm

18

How It Works

Sensors are imbedded in the forearmImpulses from the brain are readA microprocessor controls each finger

individuallyDetermines the amount of force necessary to

grasp an object

27/9/2014; 2 pm

19

How it works

Electrode mounted on residual limb.

User tightens muscles, this generates an electrical impulse.

Impulse sent to computer on board the prosthetic.

Based which muscles are fired the hand will open or close.

Requires some prepositioning of fingers for some actions.

27/9/2014; 2 pm

20

EMG electrodesEMG

amplifier/processors

TMR

Targeted Muscle ReinnervationDeveloped by Dr Todd KuikenLigated nerves rewired to adjacent muscles :

amplification of nerve signalsCreation of new EMG sites:

Transradial – forearm Trans humeral - residual upper arm Shoulder disarticulation- chest

• Controlled by muscle contractionsMuscles serve as biological amplifiers of motor

commands 27/9/2014; 2 pm

21

Features

3 degrees of freedom : Elbow flexion/extension Wrist supination/pronation Terminal device opening/closing

• 5 articulating fingers moving independently at joints similar to natural joints

• Near normal dexterity :• Can hold a single sheet of paper or string• Withstand strain upto 99 kg • Instantaneous action• High degree of proportionality to the muscle activity

27/9/2014; 2 pm

22

Features cont.....

• Silicone cosmetic glove : touch sensitive for touch screen devices

• Grip chips : Bluetooth enabled devices that are stuck to daily and mostly used objects eg. BT keyboard

• Triggers pre-programmed chip configuration when detected by i-limb

• Apps : Biosim,• My i-limb mobile apps – compatible with android

27/9/2014; 2 pm

23

Features cont.....

Vari grip mode : variable digit by digit grip strength

Auto grasp mode : prevents objects from falling

Inactivity : automatically moves to standby resting position

Feeling as part of body

27/9/2014; 2 pm

24

23 Apr 2013

27/9/2014; 2 pm

25

27/9/2014; 2 pm

26

27/9/2014; 2 pm

27

Right candidate ?

• Amputation at the wrist or forearm

• Standard body-powered prosthetic devices are insufficient to meet the functional needs

• Musculature has minimum microvolt threshold to allow operation of a myoelectric prosthetic device

• No neuromuscular disease

• Good cognition

27/9/2014; 2 pm

28

Bionic fingers/i-limb digits

27/9/2014; 2 pm

29

Trans-metacarpal amputations

27/9/2014; 2 pm

30

Positives

Simple to implementNon-invasiveMore range of motionIndividually moving fingers allow for better gripLarger functional area- more ADL independenceMore natural appearanceDust resistantCan reduce phantom painPsychological advantage

27/9/2014; 2 pm

31

Setbacks

Heavy- muscle fatigue and frictionCostAvailabilityMoisture- problem with electronic circuitry if

improper fabricationRequire prepositioning for some actionsFinger control coupled with open/close

function,so not completely independent

No sensory control to control grip strengthPre-programmed grip patterns to learn27/9/2014; 2 pm

32

Future promising areas

Challenge : Limited input to control vast outputsTargeted Sensory Re-innervation (TSR)- sensory

feedbackArtificial muscles(Electroactive polymers)Osteo-integration Mechano-myographic (MMG) feedback: control

of a prosthetic device with cortical and peripheral nerves

Other Bionic Limbs -Shoulders, Wrists, Elbows

27/9/2014; 2 pm

33

Boston digital armBebionic 3 (Terminator hand) : developed by

RSL Steeper Multi-articulating myo-electric hand

Michelangelo hand : Developed by Advanced Arm Dynamics & Otto Bock Features a thumb that electronically moves to

different positions for multiple grip functions

27/9/2014; 2 pm

34

27/9/2014; 2 pm

35

Before your comments and questions......

27/9/2014; 2 pm

36

Cost of an i- limb hand ????

27/9/2014; 2 pm

37

Ans : $ 18,000 - $ 48,000 /-

= Rs 11,02,140 – 29,39,040 /- ( 1 $ = Rs 61.23) ≈ ( 27/09/2014)

27/9/2014; 2 pm

38

Thank you !!

27/9/2014; 2 pm

39

27/9/2014; 2 pm

40

27/9/2014; 2 pm

41