L19 Upper Limb Prothetics Flashcards
Prosthesis
an artificial device to replace a missing or impaired
part of the body
Prosthetics
the field of study or specialty concerned with the design, construction of fitting of prostheses
Prosthetic
Of or relating to a prosthesis or prosthetics
prosthetic limb
Persons with amputations:
- 1.6 million persons with amputation in the United States in 2005.
- 35% with loss or deficiency of the upper extremity.
- Approximatively 2.2 million amputees in 2020.
- 2.4% of all the wounded in the Iraq and Afghanistan (OIF/OEF) conflicts have
had a traumatic amputation - Each year there are 185,000 amputations that have a
cost of over 8.3 billion dollars - Main causes for these amputations are vascular
diseases that take up 54 percent of the amputee
population and 45 percent of the causes are due to trauma. - # of amputations due to diabetes increased by 24%from 1988 to 2009
- Traditional lower limb prostheses: $5,000 to $50,000
- Traditional upper limb prosthesis: $3,000 to $30,000
dollars.
Leading Causes of Upper Extremity Amputations
- Trauma
- Congenital deficiency
- Tumor
- Disease
Amputation Levels
- Transradial amputation: below the elbow: long,
medium, short - Transhumeral amputation: above the elbow – typical length, 50-90% of humeral length
- Shoulder, elbow, or wrist disarticulation
- Finger, partial hand
Successful prosthesis
- Comfortable
- Easy to don/doff
- Lightweight
- Durable
- Cosmetically pleasing
- Functions well
- Reasonable maintenance
- Motivates individual
Components of an Upper Limb Prosthesis
- Suspension
- Socket Design
- Alignment
- Terminal Devices: hooks, hands, specialties
- Wrist units, elbow units, shoulder units
- Control: body-powered, myoelectric, hybrid
Component Selection
- Patient’s Limb: skin, muscle function, tolerance
- Amputation level
- Type of trauma or injury: frostbite, land mines, congenital
- Gender, age
- Developed or developing countries
- Occupation
- Leisure activities
- Cost/Reimbursement
Basic Types of Upper Limb Prostheses
- Body powered prosthesis
- Myoelectric prosthesis
- Hybrid System
- Activity specific
Terminal Devices - Non prehensile
touching feeling, pressing down with fingers, tapping, lifting, pushing
Terminal Devices - Prehensile
precision grip – pincher grip, lateral grip, hook power grip
Terminal Devices - Active
hooks, functional hands, activity specific
Terminal Devices - Passive
cosmetic hands
Body powered
Voluntary Opening (VO):
* Practical
* In closed position, by springs
* User pulls the cable to open
* Prehensile force – from spring
Voluntary Closing (VC):
* Physiological
* In open position
* User pulls the cable to close
* Prehensile force – from patient
* Greater proprioceptive inpu
Myoelectric Prosthetic Hands
Bebionic Hand:
* Ottobock
* 14 different grip patterns
* Individual motors in each finger
* Three wrist options
* Two Sizes
i-Limb Ultra:
* Ossur
* 18 different grips
* Five motors for each finger
* 4 sizes
TrueLimb:
* Unlimited Tomorrow
* Ultralightweight (1-1.5 lbs)
* 30+ sensors: intuitive control
* 3D scan residual limb
* 3D printed
Recent Innovations
- Increased joint movement and power
- Settings, adjustments controlled via Bluetooth
- User change modes, grip patterns
- EMG pattern recognition – may increase the amount of motions user can control
- Targeted Muscle Reinnervation
- Proprioception
Hand Proprioception and Touch Interfaces (HAPTIX)
- DARPA Project
- deliver natural sensation to prosthesis users
- brain and nervous system working together based on intent
Pattern recognition
- Solves problem of a lack of muscles controlling a prosthetic movement at
ounterintuitive joint segments - More natural control and movements
Generation of EMG signals -> Preprocessing to remove obvious interferences -> Windowing of EMG signals -> Feature recognition -> Recognition/Classification
Challenges
- Loss of joints due to amputation: limited DOFs
- Body’s kinematics changed drastically
- Compensatory motion
- More utilization of intact limb
- Overuse syndrome will most likely appear
- High rejection rates of upper limb prostheses
- Lack of training using the prosthesis
- Need for an effective prosthetic training tool
Outcome Measures
Box and Blocks Test
Southampton Assessment Procedure (SHAP)
e-Nable
- Online global community
- Use 3-D printer to make free and low cost prosthetic upper limb devices
- 40,000 volunteers in over 100
countries
