Lecture 5 - Orthotics and Wearables Flashcards
Give examples of current solutions for mobility assistance.
- powered wheelchairs
- manual wheelchairs
- elevators, suspensions
- walking aids
- passive orthoses
- powered orthoses
List types of walking aids in order of increasing mobility of the user.
- Parallel bars
- Wheeled walker
- Crutch walker
- Underarm crutches
- Below elbow crutches
- Cane with wide base
- Cane (walking stick)
What are walking crutches usually made of?
Wood or metal
Why would you include rubber at the lower end of crutches?
To avoid slipping and improve shock absorption
What type of patients are walking crutches aimed at?
- mild disabilities
- elderly
What is a white cane used for?
It is a mobile tool for visually impaired persons to detect objects in their pathway
What is a white cane usually made of?
Aluminum or plastic
What is the main difference in terms of the mechanical requirements of a walking cane and a white cane?
A white cane does not need to support high body loads
What is the Guidecane? What makes it special?
- cane that rolls on passive wheels
- servo motor steers the wheels to avoid objects on the path
- 10 ultrasonic sensors to detect obstacles in 120 degree wide sector ahead
- mini-joystick allows user to specify a desired direction of motion
What is the Ultracane? What makes it special?
- emits ultrasonic waves with 2 transducers on the handle
- different ranges of detection from the tip and the handle
- tactile feedback is given through vibrating buttons on the handle, indicating proximity of the object
- it is particularly useful for warning of hazards at head height
What are below elbow crutches usually made of?
Light metal
What is the benefit of below elbow crutches?
Relieve the wrist and increase guidance by the forearm
What type of patients are below elbow crutches aimed at?
Mild to moderate disability
What are the main properties of Flamingo crutches?
- stylish design
- shock absorbing properties
- holding alternatives to divide the pressure in the hand while holding the handle
- soft texture on handle
- adjustable height
What are arthritis crutches made out of?
They are made of a metal pipe combined with a cushioned shell to connect the forearm.
At what angle is the elbow held at for arthritis crutches?
- 90 degrees (adjustable between 15-90)
Explain point of action of forces for someone using arthritic crutches and the benefits of this.
Force acts via elbow joint on the upper arm. Weight load is transferred to forearm, thus reducing pain, discomfort and blistering on hands.
What are underarm (armpit) crutches usually made out of?
Wood or metal
Explain point of action of forces for someone using underarm crutches and the benefits of this.
Gravity force acts mainly on the armpit/shoulder, thus providing relief for elbow and wrist.
Describe a danger of the prolonged use of underarm crutches.
Crutch paralysis: paralysis due to constant pressure o the radial nerve or brachial plexus
What are 4 pt. crutches or crutch walkers usually made of?
Light metal
What are the main properties of 4 pt. crutches, aka. crutch walkers?
- high tilt stability
- 4 feet
What type of patients are 4 pt. crutches, aka. crutch walkers aimed at?
patients with moderate disabilities, e.g. balance problems
What are wheeled walkers or hand trolleys usually made of?
Light metal
Describe the main structure of wheeled walkers or hand trolleys.
2 wheels + 2 rubber feet
or 3 or 4 wheels with hand breaks
What type of patients are wheeled walkers or hand trolleys aimed at?
patients with moderate disabilities
What type of patients is the PAMM - Personal Assistant for Mobility and Monitoring aimed at?
Elderly with mobility difficulty due to physical fragilitz and/or disorientation
What are the main properties of the PAMM - Personal Assistant for Mobility and Monitoring?
- navigation & obstacle-avoidance
- microphone and speakers for voice communication
- contact health-sensors (6 axis force sensor at handle as user interface)
- admittance based controller
- camera for location detection and ultrasonic obstacle detection
What are the main characteristics of EXPOS, Exoskeletal Assistive Device?
- wearable exoskeleton and caster walker
- 4 active joints at exoskeleton
- wire transmission from the walker to the exoskeleton joints
- springs to maintain proper tension (pulley system)
- the handle bar can be lifted during sitting down and standing up motions
List 5 possible passive joint orthoses.
- Hand orthoses
- Back orthoses
- Arm orthoses
- Knee orthoses
- Foot orthoses
Name 2 types of knee orthoses and what they are used for.
- Functional 4 pt. rigid frame orthosis (4 straps = 2 dista + 2 proximal)
- Universal orthosis
- Used for limitation of ROM and joint stabilisation, e.g. after surgery, ACL insufficiency
What is the C-Brace?
The C-Brace is a powered knee ankle foot orthosis by Ottobock that adjusts damping as a function of the gait cycle.
Name 2 types of ankle orthoses and what they are used for.
- Functional ankle orthosis
- Functional 4 pt. rigid frame orthosis
- Used for ankle joint flexion/extension limitation, e.g. after ligament injuries
Give an example of a hand orthosis and what is is used for.
Wrist Joint Fixation orthosis - for patients after surgical interventions or patients with wrist lesions.
Give 3 examples of elbow orthoses and what they are used for.
- Elbow orthosis with flexion and extension limitation - for patients with elbow luxation or after surgery
- Contracture bracing (static progressive orthoses) - orthoses to improve joint passive ROM via stress relaxation, thus preventing or reducing contracture development
- Elbow clasp - compression over the muscles to provide relief at the muscle insertion points
What are back orthoses used for?
- for lesions of the shoulder, vertebrae or thorax
- scoliosis treatment
What are the main technical challenges of powered joint orthoses (exoskeletons)?
- intention detection
- battery power (wearable)
- weight
Why are powered joint orthoses (exoskeletons) more successful in therapy and training versus mobility and daily life assistance?
Because of the possibility of receiving assistance, support and guidance of a trained therapist familiar with the equipment during therapy.
List 4 possible uses for Exoskeletons.
- Therapy and training
- Mobility and assistance
- Industrial and care workers (e.g. heavy lifting)
- Sports (e.g. skiing)
What are the advantages of exosuits over exoskeletons?
- easier to put on/take off
- can be much thinner and lighter
- possibility to sit
How is the line of action of forces different in rigid exoskeletons vs. in soft exosuits?
Rigid exoskeletons - perpendicular forces
Soft exosuits - parallel forces
During which 4 phases of gait could support by an exosuit be particularly useful? Why?
- Terminal stance
- Pre-swing phase
= ankle plantar flexion + hip flexion = accelerating action - Loading response
- Mid-stance phase
= knee extension + hip extension = antigravity action
The Myosuit has 3 layers to provide continuous support against gravity. What are these and what are their functions?
- Garment layer
- Ligament layer
- hip flexion
- knee flexion - Power layer
- hip extension
- knee extension
In the case of the Myosuit, how does the max. torque on the hip joint compare to that on the knee joint and why?
Max. torque on the hip joint is less than that of the knee joint because it is further away from the motor (loss by friction).
