TU Wien:Assistive Technologien 1 VO (Panek)/Exam Question Collection

A combined exam question collection for Assistive Technology 1 and 2, as some of the topics (and questions) overlap.

Difference between tactile and haptic

• tactile relates only to touch, e.g. to read Braille
• haptic includes proprioception (spatial perception of posture and movement of one’s own body), e.g. a 3D-print of an image or sculpture to get a more spatial impression of it.

Examples for mobile and stationary robots

• mobile feeding robots (iARM), care-o-bot
• stationary feeding robots, RAID workstation

audible threshold audiogram (Tonschwellenaudiometrie)

• shows the differences in air conduction (via earphone, marked X) and bone conduction (via vibrator behind the ear, marked ]). Can help find the source/cause for hearing loss (i.e. ear structure or nerves)
• uses pure sines, as opposed to speech audiometry; bot are subjective procedures (patient must indicate whether they hear a signal).

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 another, e.g. visual stimuli cannot be perceived with the eyes, so a tactile or haptic interface is used instead.

Name 3 different types of Assistive Aids + examples

• augmentative aid: amplify stimulus or action; e.g. certain hearing aids, spectacles
• inserting aids: forward the stimulus or action to the original organ or nerve; e.g. Cochlea implant
• substituting aids: redirect a stimulus to another sense/organ; e.g. translating black print to Braille; lip reading or sign language instead of hearing

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

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.

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

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 ...

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

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)

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

(not sure about this answer, but only thing I found about this subject)

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.

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)

Describe the operating principle of a piezo-electric Braille display and an advantage and a disadvantage.

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

Describe the operating principle of an electromagnetic Braille display and an advantage and a disadvantage.

each pin is moved by combination of magnet and coil. Systems with locking mechanism exist, provide more resistance and a better legibility (but have other issues)

• pros: Not high tech, rather simple – not too expensive?
• cons: needs a lot of space; high energy consumption; warms up considerably; not a mobile device

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!

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)

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

Give 4 examples of typical accessibility features today’s operating systems (Windows, Android, MacOS, iOS etc.) 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

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

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?

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) dis-abling invisible or reducing it to the individual.
• Example 1: person with ADHD
• Example 2: person with paraplegia

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)

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.

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)

What are important differences of tactile sense and visual sense?

• bandwidth: how much information can be encoded/decoded within how much time/space
• visual includes perspective, shadows, blocking of view;
• visual allows for easier temporal changes.

Cell phones, smartphones and tablets have opened up many new opportunities for people with disabilities. 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

Mark the important elements conveying meaning for visual communication (X).

	Visemes	Phonemes	Characters	Words
Lip Reading	x
Finger Alphabet			x
Cued Speech		x
Manually Coded Language				x

• Visemes: smallest segment distinguishable at the lip image
• Phonemes: smallest meaningful sounding segment of a language

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)

What are main reasons why Braille is now used by fewer blind persons?

because it takes a lot of time to learn; documents are often not available in Braille; and: modern devices provide accessibility without having to use Braille.

What is the Lormen or Lorm Alphabet used for? Describe the method.

• Usage: letter-wise text transmission to a deaf-blind person by touching their palm and fingers.
• Method: encodes letters on parts of fingers and palm, e.g. fingertip or side of the hand

(Vinyl) records were previously used as media for audiobooks (or “talking books”). What more modern media are there today? What are the advantages?

digital audio books – if done according to DAISY standards, there will be chapter marks etc so that the book can be properly navigated. Needs less space (smartphone, laptop, …), no dedicated device necessary, can be bought & downloaded via internet (way faster than ordering, sending, ...).

What is the function of a Screenreader and for which users?

text to speech for blind users.

Describe two ways (devices, procedures etc.) to put Braille on paper?

stylus and slate (from BEHIND); braille typewriter.

When two people communicate, what are (some) purposes of this action?

Passing on of information; understanding; negotiation and emerging of knowledge, stances, opinions, theories, … Food. Reproduction. Trade. Need for Social Interaction. Necessity.

Name different common dot (Braille) script codings for German and describe the essential differences (no details needed)

base, full, shorthand, stenography. Various levels of compression/shortening. Shorthand allows for ~ 30% savings.

List examples of smart phone apps dedicated to blind users or to deaf users and briefly outline the principles the apps are based on.

Blind users: “be my eyes” – contact a seeing person and ask them to describe whatever you’re showing them. Deaf people: Greta (urks, how about just including subtitles in your screenings), DEC 112 (contact emergency numbers via text message)

Writing Braille with slate & stylus and using a Braille typewriter (e.g. Perkins Brailler) are two methods of putting Braille on paper. Describe important differences.

stylus and slate is written in mirror and from behind onto the document. Brailler is operated using 3 fingers of each hand.

Which (undesirable) effects does the use of text prediction often imply (e.g. with regard to additional effort related to time and cognition)? Name and describe briefly.

• cognitive load: extra time for making the right decision; necessary to keep in mind the word(s) that still are in the queue to be written (rest of the sentence/message).
• Additional problem space: in some languages, one stem may be shared by many words (forsch-: er, erin, ende, en, end, …).

List advantages of Semantic Compaction in AAC?

• Method using pictorial language to formulate sentences.
• Only a small number of icons to be learned (40 – 80)
• Icons on the display stay in a fixed location (yay muscle memory)
• Patterns applied to say a word can be used when learning to say new words

How is „AAL“ motivated by the Demographic Change?

People are getting older, less young people “coming after”. AAL allowing older people to stay in their “usual” surroundings for longer, or needing less assistance.

Which principal methods can be tried to overcome a communication handicap of a communication partner?

Depends on the handicap: find first what the issues are; be mindful & patient. As the non-disabled person: adapt to the disabled communication partner’s speed/mode of communication.

Which simple measures can increase the communication rate when using “scanning” (communication with single switches and characters on an on-screen keyboard) – except “predictive typing”? Give short descriptions.

Arrangement of characters on the display: Sort by character frequency; Frequency or probability of occurrence; Put frequent letters at the beginning

To respectfully (was: "(politically) correctly") communicate with and about people with disabilities also means to avoid discriminating terms (Give Examples)

don’t generalize. Ask how people want to be referred to. Do not patronize. Get used to using “behindert” as a label; do not use it as a slur. Use the correct terms, e.g. Trisomie 21, instead of the (unfortunately, well-known) slurs. Try to keep up with the discourse.

signal vs message in communication

signal is how you convey the message (e.g. sound for speaking to someone)

Which possibilities exist to support hearing with hearing aids?

Lots, and mostly depends on what the cause for the hearing loss is. e.g. augmentative vs. insertive aid: former will help with conductive hearing loss (amplify sounds), latter with sensorineural hearing loss (e.g. cochlea implant)

What is „Keystroke Saving Rate”?

Number of stops necessary with conventional input vs Number of stops with predictive input

Name replacements for manual writing

typing; speech to text; speech; Lormen alphabet; magnified overhead projection; symbols/images.

What is „Active / Ambient Assisted Living“?

• Target user group: older people (+ care persons)
• Aim: Supplement / support in everyday life through technology (as a form of augmentative / alternative communication)

List important principles languages can be based on

syntax and phonology, if you mean “principles” according to Chomsky (biological/congenital part of languages)

List the 3 goals of Rehabilitation Engineering

1. Restoration or improvement of a function affected by disability (compensation in same modality)
2. Overcoming the effects of a disability without restoring the function (compensation in alternative modality)
3. Removal of barriers: starting point: design of the environment (e.g. step-less entrances to public buildings)

Which aids for using money do you know for blind persons? List two of them!

• Mechanical banknote detector (insertion up to the stop, value can be read at the first non covered mark)
• Electronic banknote detector: detectors with speech output (better e.g. US dollar notes compared to mech. det. since all sizes are the same)
• Apps for mobile phones to detect banknotes (e.g. Cash Reader)

What causes a Down-Syndrome? What are characteristic symptoms?

Cause: chromosomal disorder: at cell devision a 3rd chromosom 21 appears => hence the name

Symptoms:

• Mental impairment of different grades
• speech disorder
• muscle hypotonia

Advantages of an intelligent emergency call system over traditional senior alarms?

Usual system: user needs to actively press button ore make a phone call

Intelligent systems: can automatically detect an emergency by monitoring health and activity parameters and also other smart home funtions (e.g. myStella; from motor lock over fall sensor/ emergency button to attack button or smoke detector)

Pilot study in USA: smart portrait shows relatives/friends health/ activity parameters of their loved ones

What is the difference in methods between speech audiometry and audiogram?

speech audiometry: speech understanding; measuring? Numbers, monosyllabic words and sentences are applied with different volume vai earphones (=> input signal is speech not pure sine)

audiogram: graph representing a person‘s hearing thresholds at different frequencies (=> input signal is pure-tone)

What are advantages of using mainstream devices instead of assistive devices?

• Reduced cost/ better availability
• reduced stigmatisation associated to use the device
• increased self confidence
• reduced abandonment
• one smartphone -> several apps can provide may functionalities
• easier to get it repaired
• higher chance to receive help from sighted people

Which impairment you can derive from this audiogram? (X = air conduction, ] = bone conduction) Explain your diagnosis.

(There is also a figure in which the air conduction lies below bone conduction) => conductive hearing loss

Describe the difference between language impairment and speech impairment.

Language impairment:

difficulties in understanding or using words in context

Speech impairment:

challenges in the physical production of sounds necessary for verbal communication

List some usual effects of age on human performance/abilities (4)

• Farsightedness (due to reduced elasticity of the lens)
• Age induced hearing loss (typical loss in the area of high frequencis)
• Changes in spectral sensitivity (eye): colours look „washed out“
• Reduction in muscle force -> walking speed decreases; problems with steps/stairs; writing speed
• Longer reaction times

How is Syndrome defined?

Coincidence of several symptoms which are characteristic for a disease pattern.

Most often the reason for the disease is coherent (aetiology), but the progression (pathology) of the disease is unknown.