Learning Objectives

By the end of this study guide, you should be able to:

  • Define rehabilitation engineering and its scope
  • Identify key assistive technologies and their applications
  • Understand the principles of prosthetics, orthotics, and wheeled mobility
  • Describe assessment methods and outcome measures in rehabilitation
  • Recognize emerging trends in rehabilitation engineering

1. Overview of Rehabilitation Engineering

Rehabilitation engineering is the application of engineering principles to design, develop, adapt, test, evaluate, apply, and distribute technological solutions to problems faced by individuals with disabilities.

Key Concept: The Rehabilitation Engineering Process

1. Assessment of client needs and abilities
2. Problem identification and formulation
3. Development of design specifications
4. Design and development of solution
5. Implementation and fitting
6. Training and follow-up
7. Evaluation and outcome measurement

Historical Context

Rehabilitation engineering emerged after WWII to address the needs of injured veterans. The field expanded significantly with legislation such as the Rehabilitation Act of 1973 and the Americans with Disabilities Act (ADA) of 1990.

Interdisciplinary Nature

Rehabilitation engineers work closely with:

  • Physical and occupational therapists
  • Physicians (physiatrists, orthopedists)
  • Prosthetists and orthotists
  • Speech-language pathologists
  • Psychologists and social workers

Quick Check: Understanding Scope

Which of the following is NOT typically a focus area of rehabilitation engineering?

  • Prosthetic limb design
  • Wheelchair accessibility
  • Drug development for chronic pain
  • Augmentative communication devices

2. Key Concepts and Definitions

Disability
An impairment that may be cognitive, developmental, intellectual, mental, physical, sensory, or some combination of these that results in restrictions on an individual's ability to participate in what is considered "normal" in their everyday society.
Assistive Technology (AT)
Any item, piece of equipment, software program, or product system that is used to increase, maintain, or improve the functional capabilities of persons with disabilities.
Universal Design
The design of products and environments to be usable by all people, to the greatest extent possible, without the need for adaptation or specialized design.
Activities of Daily Living (ADLs)
Basic self-care tasks such as bathing, dressing, eating, and mobility.
Instrumental Activities of Daily Living (IADLs)
More complex activities such as managing finances, cooking, shopping, and using technology.

The Human Activity Assistive Technology (HAAT) Model

This model describes the interaction between four components:

  1. Human: The person with specific skills, abilities, and needs
  2. Activity: The task to be accomplished
  3. Assistive Technology: The device or system used
  4. Context: The physical, social, cultural, and institutional environment

Matching Exercise

Match the following terms with their definitions:

A. Prosthetics

B. Orthotics

C. Augmentative and Alternative Communication (AAC)

1. Devices that support or align weakened or abnormal joints or limbs

2. Artificial devices that replace missing body parts

3. Methods to help individuals with severe communication disorders

3. Assistive Technology Categories

Mobility Aids

  • Wheelchairs: Manual, power, standing, and sports models
  • Walkers and Canes: Standard and adaptive designs
  • Exoskeletons: Powered devices for gait assistance

Communication Aids

  • Speech Generating Devices (SGDs): For individuals with limited speech
  • Eye-tracking Systems: Allow control through eye movements
  • Brain-Computer Interfaces (BCIs): Direct neural control of devices

Environmental Control Systems

Systems that allow control of lights, appliances, doors, and other environmental features through alternative access methods (switches, voice, etc.)

Sensory Aids

  • Visual: Screen readers, magnification systems, braille displays
  • Auditory: Hearing aids, cochlear implants, alerting devices
  • Tactile: Haptic feedback systems

Technology Spotlight: Cochlear Implants

Cochlear implants are electronic devices that bypass damaged portions of the ear and directly stimulate the auditory nerve. They consist of:

  1. External microphone and speech processor
  2. Transmitter and receiver/stimulator
  3. Electrode array implanted in the cochlea

Unlike hearing aids which amplify sound, cochlear implants convert sound waves to electrical signals.

4. Prosthetics and Orthotics

Prosthetics (Artificial Limbs)

Upper Limb Prostheses:

  • Body-powered: Controlled through cables and harness systems
  • Myoelectric: Use electrical signals from residual muscles
  • Hybrid: Combine body-powered and myoelectric components

Lower Limb Prostheses:

  • Below-knee (transtibial): Socket, pylon, foot assembly
  • Above-knee (transfemoral): Includes knee joint mechanism
  • Dynamic response feet: Store and release energy during gait

Orthotics (Braces and Supports)

Orthotic devices are classified by the body region they support:

  • AFO: Ankle-Foot Orthosis (for foot drop, ankle instability)
  • KAFO: Knee-Ankle-Foot Orthosis (for knee and ankle issues)
  • HKAFO: Hip-Knee-Ankle-Foot Orthosis (for paraplegia)
  • Spinal Orthoses: TLSO (thoracic-lumbar-sacral), cervical collars

Design Consideration: Socket Design

The prosthetic socket is critical for comfort and function. What are the most important considerations in socket design?

  • Weight distribution and pressure relief
  • Aesthetic appearance and color matching
  • Cost and manufacturing time
  • Material strength and durability