1. Difference between tactile and haptic
· Tactile: Only related to the touch sense of the skin.
· Haptic: Adding proprioception (spatial perception of the posture and movement of own body)
Example: exploring a sculpture by a blind person to get a more
spatial overview/impression
B2, 17
1. Examples for mobile and stationary robots
Stationary
Feeding robots, RAID (Robot to Assist the Integration of the Disabled)
Mobile
iARM, Care-o-Bot
C3, 30
1. Audible Threshold Audiogram
Measurement of hearing threshold (input signal is pure sine wave)
Once via air conduction (normal hearing using earphone) and once with bone conduction (vibrator directly behind the ear on bone)
A2, 17
Why may older persons have issues distinguishing colors?
because cones (color perception) degenerate with time, and because the lenses of their eyes can become yellowish
What is a sensor vicariate?
Replacement of a defaulting sensory organ by proxy, e.g. visual stimuli cannot be perceived with the eyes, so a tactile or haptic interface is used instead.
B1, 8
1. Name 3 different types of Assistive Aids + examples?
augmentative aids ( hearing aids)
inserting aids (cochlea implant)
substituting aids (lip reading instead)
1. Retinitis pigmentosa
· Effect: tunnel vision, night blindness
· Causes: Enzyme disorder; Mostly hereditary, but also caused by infection or intoxication
· Affected part of organ: degeneration of rods
1. Name 4 of the 7 Universal Design Principles with explanation
“The environment, single products or services shall be designed in a way to allow full and equal use for an as large range of persons, including children and disabled or old people, without special effort or adaptation.” – still allows for arbitrary exclusion
· Equitable Use. The design is useful and marketable to people with diverse abilities.
· Flexibility in Use. The design accommodates a wide range of individual preferences and abilities.
· Simple and Intuitive Use. Use of the design is easy to understand, regardless of the user's experience, knowledge, language skills, or current concentration level.
· Perceptible Information. The design communicates necessary information effectively to the user, regardless of ambient conditions or the user's sensory abilities.
· Tolerance for Error. The design minimizes hazards and the adverse consequences of accidental or unintended actions.
· Low Physical Effort. The design can be used efficiently and comfortably and with a minimum of fatigue.
· Size and Space for Approach and Use. Appropriate size and space is provided for approach, reach, manipulation, and use regardless of user's body size, posture, or mobility.
B1, 18
1. Explanation of Conductive hearing loss diagram
· air conduction (x) lies below bone conduction (]) = “air-bone-gap”. Issue exists in the transportation of the sound stimuli within the ear, cannot get through the outer and middle ear.
· Hearing loss starting at a certain frequency: often age-related hearing loss
A3, 82
Speech output aids: Which technical requirements for a) blind people b) people with speech impairment?
· for blind people: pure information source/relay. Synthesizer speaks information to “print disabled” persons, e.g. screenreader; natural voice is nice-to-have, but not necessary.
Unlimited vocabulary High speed of speaking Adjustable voice pitch Fast reaction to commands Speaks punctuation, capitalization, formatting
· for people with speech impairment: Synthesizer speaks “for” the disabled person to another person.
Good understandability for non trained listeners required Prosody (natural human sound) Cosmetic aspects: gendered voice, voice character, age, dialect ...
B2, 11
1. Describe the operating principle of a piezo-electric Braille display + pros/cons
2 strips of piezo ceramic glued together, working principle like bimetal. Elongation and shrinkage depending on the polarity.
· Pros: relatively lightweight, needs less energy than electromagnetic versions
· Cons: high costs, sensitive to dust and dirt, multi-line displays are difficult, still has quite some space requirements
1. Which problems can obstacle mounting heights cause for users of white canes?
· Problems: stumbling over, walking into or brushing obstacles, as well as missing drop-offs
· Problematic range: anything higher than 30 cm above ground in a width range of 60-90cm, depending on the exact technique the cane user applies, and the cane used.
1. Cataract, Macular Degeneration and Glaucoma cause impairments of different parts of an organ. Describe the effect(s)
· Cataract: lens becomes clouded; caused by injury, diabetes, infection in pregnancy, radiation, or simply by age. Solution: remove/replace lens.
· Macular Degeneration: degeneration of the macula (yellow spot) causes “inverse tunnel vision”. Caused by age, Morbus Stargardt or Morbus Best
· Glaucoma: tunnel vision; too high pressure of intraocular liquid damages the optic nerve. Solution: reduce pressure (if damage is not irreversible yet)
1. What is the definition of the Visus and how is it measured?
· Definition:
Visual acuity = the reciprocal of the smallest angle (a in arcminutes) under which two points can be perceived as separated. normal sighted eye can differentiate 2 points if they result in an angle of 1 arcminute (1'). The Visus then is V = 1 / a min = 1 / 1 = 1 (or 100%)
· Measurement: Snellen charts, Landolt rings
1. Give 4 examples of typical accessibility features today’s operating systems and briefly describe the benefit for certain user groups
· keyboard settings: “Einrastfunktion”, “Anschlagverzögerung”
· mouse settings: keyboard mouse, sticky click, near-miss-function, mouse cursor size
· color, contrast, font settings; magnification:
· audio output: screen reader, visualisation of sounds
B2, 43
1. Which problems can interfaces of technical devices cause for persons with epilepsy?
· Problem: flicker can provoke seizures, even with closed eyes.
· Problematic range: 3 Hz to 80 Hz
1. What environment/design requirements do persons in wheelchair have?
· turning circle: radius at least 75cm
· grasping range: 40-130cm from floor level (depends on arm range, height of the wheelchair, size of the person, …)
· placement of control elements: 85cm height, distance from corners 40/50cm, pedestals less than 10cm
keep in mind that access/operation is from below, so place nothing underneath e.g. a light switch or door bell!
1. List human sensor systems (senses) and compare their characteristic properties
· Vision (eye): 10^6 bit/s information bandwith, good spatial performance, relatively low frequency
· Hearing (ear): 10^4 bit/s information bandwith, low spatial resolution, higher frequencies
· Tactile (skin): 10^2 bit/s information bandwith, largest sensory organ; touch, pressure, vibration, heat & cold, pain & itching.
· Smelling (nose): <10^1 bit/s; receptors are “primary” sensory cells; chemical “distant range” sense; high adaptation (longer lasting stimuli are no longer perceived after some time)
· Tasting (tongue): <10^1 bit/s; chemical “close range” sense; high adaptation (longer lasting stimuli are no longer perceived after some time)
1. Describe and/or sketch the dot (Braille) script (system, characters, dimensions)
2 rows with 3 dots (or, extended, 4) dots each. Allows for encoding of 64 (= 2⁶, extended 256 = 2⁸) characters (including space). Fits size and sensitivity of finger pulp. U = A + 3 + 6. Numbers (1 … 0). correspond to first 10 letters of alphabet. W added later. Various shortenings in use.
1. List advantages each of dot (Braille) script and relief (Moon) script
· Braille: Braille can be read AND written by blind people (Moon is embossed in wet paper)
· Moon: Symbols similar to Latin characters (easier to lU+0065arn for late blind persons). Quick reading not possible (the recognition of lines, angles, arcs is difficult), difficult to write by hand (has to be embossed into wet paper)
1. What are important differences of tactile sense and visual sense?
· bandwidth: how much information can be encoded/decoded within how much time/space (10^2 vs 10^6)
· visual includes perspective, shadows, blocking of view;
· visual allows for easier temporal changes.
1. Estimate roughly the amount of disabled people in the population. Why is it often difficult to compare national statistics on disability from different countries?
· Percentage (%) of total population: 10-15%
· Difficulties comparing statistics: definitions vary, counting methods vary. What is a chronic illness, what is a disability, (how) do you count people who live in specialised homes?
1. What is proposed by the “People First” language/principle? Give 2 examples!
· Proposed: paradigm change; from model looking at only deficiencies to one looking at strenghts. BUT risk of making the (socially constructed, structural, wide-spread) disabling invisible or reducing it to the individual.
· Examples: person with ADHD, person with paraplegia
A1, 15
1. How and where are vowels / consonants created when speaking (difference)
· Vowels: Arise from oscillations of the vocal cords. Different vowels do not differ in the base frequency but in the formant frequencies.
· Consonants (voiceless sounds): are noises produced by audible eddies of the air flow due to narrowing of the articulatory tract. (Vocal cords do not oscillate)
- Vokale: Entstehen durch Schwingungen der Stimmbänder. Die verschiedenen Vokale unterscheiden sich nicht in der Grundfrequenz, sondern in den Formantfrequenzen.
- Konsonanten (stimmlose Laute): sind Geräusche, die durch hörbare Wirbel des Luftstroms aufgrund einer Verengung des Artikulationstrakts entstehen. (Die Stimmbänder schwingen nicht)
1. Which body parts are involved in voice formation (phonation)? (at least 3)
· respiratory system (lungs & airways),
· larynx (vocal cords),
· articulatory system (throat, oral cavity, nasal cavity)
1. What causes a Down-Syndrome? What are characteristic symptoms?
· Cause: Chromosomal disorder, at insemination or proliferation (cell division) a third extra chromosome 21 appears in the cells which continues to be reproduced with each proliferation.
· Symptoms: deformations and changes in the habitus, Mental impairment of different grades, Speech disorder,Muscle hypotonia
1. Advantage of an intelligent emergency call system over traditional senior alarms?
Many emergencies are not covered by a usual emergency call system, because the user as result of the incident is unable to act or underestimating the situation.
C4,71
Select 3 types of disability and give an example of a particular functionality of a modern device or app and explain how it helps in the telecommunications field.
· blind people: “be my eyes” apps, text-to-speech
· folks with language/speech disabilities: text to speech, written comms in general
· folks with impaired mobility: find amenities ?
· deaf users: speech to text (incoming), written comms in general, video calls
1. Mark the important elements conveying meaning for visual communication (X)
· Visemes: smallest segment distinguishable at the lip image
· Phonemes: smallest meaningful sounding segment of a language
What is the difference in methods between speech audiometry and audiogram?
· Audiogram: subjective, sine wave via air conduction and bone conduction, determines hearing threshold
· Speech audiometry: numbers, words and sentences at different volumes via earphones, determines speech understanding
1. What are advantages of using mainstream devices instead of assistive devices?
· Reduced costs / better availability
· Reduced stigmatisation associated to use of device
· Increased Self confidence
· Reduced Abandonment
· Higher chance to receive help from sighted people
· One smart phone with several Apps can provide many
· Functionalities
C1, 120
1. What important changes did the ICF implement over ICIDH?
disability -> activities, Handicap->participation - to deal with the in Reality more complex factors of Interaction.
1. For Braille displays theoretically several stimulation principles are possible. Which of them have gained (until now) NO practical importance?
List the 3 goals of Rehabilitation Engineering
1st Goal:
Restoration or improvement of a function affected by Disability
2nd Goal:
Overcoming the effects of a disability without restoring the function
3rd Goal:
Removal of barriers
A1, 24
1. Which aids for using money do you know for blind persons? List two of them!
Mechanical Banknote detector “CashTest”
Electronic banknote detector “Electronic Money Identifier”
Apps for smartphone “Cashreader”
C4,43
How are Disability-Handicap-Impairment defined?
· Impairment = (health) damage
· Disability = ability restriction
· Handicap = (social) impact/restriction
1. Which impairment you can derive from this audiogram? („x“ = air conduction, „ ]“ = bone conduction) Explain your diagnosis.
1. Describe the difference between language impairment and speech impairment!
· Language impairment: difficulties in understanding or using words in context (affecting communication)
· Speech impairment: challenges with the physical act of forming sounds and words.
1. List some usual effects of age on human performance/abilities
· Visual performance
· Accomodation performance
· Need of illumination
· Hearing threshold
· Muscle force
· Smell, taste
Shift from seeing a disability as a problem of a person to seeing it as a complex collection of conditions.
A1, 12
1. Which types of tactile displays are NOT used?
· Electrical irritation – still being researched
· surface texture – still being researched
· heat (thermal irritation) – too inaccurate, too slow
1. What is speech audiometry?
measures speech understanding (every-day relevance!): numbers, monosyllabic words and sentences are applied with different volume via earphones (input signal is speech, not pure sine)
1. What are the environment/design requirements for blind people?
· Vertical space requirements: for safely using white canes
· on floor detection range 70 x (90-150) cm (depends on length of cane, which depends on persons hight)
· freestanding obstacles should be above the floor with max. distance 30 cm
· obstacles above head: at least 220 cm above floor
· Tactile Labelling (raised letters) and additional if possible in Braille
- Vertikaler Platzbedarf: für die sichere Verwendung von weißen Stöcken
- auf dem Boden Erfassungsbereich 70 x (90-150) cm (abhängig von der Länge des Stocks, die wiederum von der Körpergröße abhängt)
- freistehende Hindernisse sollten sich in einem Abstand von max. 30 cm über dem Boden befinden
- Hindernisse über dem Kopf: mindestens 220 cm über dem Boden
- Taktile Beschriftung (erhabene Buchstaben) und zusätzlich wenn möglich in Brailleschrift
How is a Syndrome defined?
A combination of several signs (symptoms) that are characteristic of a disease pattern.
Most often the reason for the disease is coherent (aetiology), but the progression of the disease (pathogenesis) is unknown.
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