The topics covered include the following: the need for telerobotics in rehabilitation; barriers to telerobotics technology in rehabilitation and health care; institutional barriers; technical barriers; and a partial view of the future

Leifer, Larry

Michalowski, Stefan

Vanderloos, Machiel

English

NASA Technical Reports Server

N95-14030
TELEROBOTICS IN REHABILITATION: BARRIERS TO A VIRTUAL
EXISTENCE
,3
Larry Leifer, Machiel Van Der Loos, and Stefan Michalowski
Stanford Center for Design Research
Stanford, California
The Need for Telerobotics in Rehabilitation
There are over 67,500 quadriplegics in the United States today, with an estimated 2,400 to 4,000
new injuries occurring each year (Stover et al., 1986). These injuries occur most frequently among
young males between the ages of 16 and 30. Due to advances in medical treatment (antibiotics and
skin care), these individuals now have a relatively normal life expectancy. They are alive, but dra-
maticaUy cut off from most aspects of a normal existence. They live, virtually, through the actions of
others. Perhaps, life would be more fulfilling if they were also offered the opportunity to directly
control their environment through telerobotic tools for independent living. Virtual telerobotic envi-
ronments for the rest of us could bring reality to these individuals.
It is estimated that caring for a quadriplegic, including standard medical treatment, equipment
maintenance and attendant care, costs about $47,000 (1980 dollars) per year. This translates to
approximately 1.9 million dollars over forty years (Kalsbeek et al., 1980). The net direct cost to the
Department of Veterans Affairs will be approximately $5 billion for its current population of service
connected quadriplegics. On the promising side, Young et al (1982) estimated that every dollar spent
for rehabilitation research and development returns $11 in cost benefits to society. In the case of
quadriplegia, the cost of attendant care (nominally $25/hr to the insurer and increasing) can be
reduced by providing personal telerobots (nominally $5/hr and decreasing). Hammel et al. (1989)
demonstrated that telerobots can satisfy the vocational manipulation needs of personal computer
users for periods of over four hours at a time without attendant intervention. Employment makes it
possible to recover some or all of the indirect cost of severe disability.
Barriers to Telerobotics Technology in Rehabifitation and Health Care
If the direct cost of severe disability is so high, and telerobotics technology is available to help
reduce costs, then what have been the barriers to its widespread acceptance and deployment? Clini-
cal experience with telerobots suggests that there are several key barriers:
Social Barriers: As a society, we place little emphasis on restoration of function for persons
with disability, we prefer to "take care of them". Because the economics of cost and ben-
efit are not coupled, we fail to see the opportunity. However, even if we began deploy-
ment today, our society has educated too few persons to support the advanced assistive
devices (i.e., we have enough researchers to create independent living tools, but too few
development and service persons to support clinical and domestic usage). These are the
dominant factors impeding wider adoption of advanced technical aids for persons with
disability.
50
https://ntrs.nasa.gov/search.jsp?R=19950007617 2020-06-16T10:37:09+00:00Z
Institutional Barriers: Government programs are scattered and disjoint. There is no system-
atic vision and considerable inter-agency protectionism. Perhaps most significantly, the
"conflict of interest" witch hunt in government makes it virtually impossible to transfer
laboratory results to the commercial sector in a timely and cost-effective manner. For its
part, the commercial sector does not take the investment risk to develop these devices
because it is not clear that third party reimbursement will be forthcoming.
Technical Barriers: Here, at least, the science and engineering communities do have some
control of the issues, these include:
The human-machine-interface is the dominant technical barrier to widespread use
of telerobots in rehabilitation. Text, voice, graphic and kinematic command-con-
trol interfaces are very cumbersome for robot motion specification, planning and
supervision. This forces the user to be overly dependent on pre-programmed
motions and the technicians who create them. We must work towards
"instructable'" telerobots.
The machine-environment-interface is the second most deficient aspect of teler-
obotics in rehabilitation. The absence of sensor driven grasp and object approach-
avoidance reflexes forces the user to directly control end-effector motion under
difficult observational circumstances and without "natural kinesthetic cues". We
must develop robust sensate end-effectors and the "reflexes" to make them useful.
Force (impedance) control will be a requirement for advanced user support tasks.
Mobility, or the lack of it, defines the telerobot's work space and, in part, its ultimate
utility. One can not reasonably expect general cost-effectiveness when people
must be available to bring work to the telerobot. Raw mobility is, however, not
enough. Remote presence makes much greater demands on the user-interface and
telerobotic sensory capability. A more "intelligent" robot may, in fact, be the
greatest challenge yet to the user-interface designer.
Fault-intolerance is an overriding shortcoming of almost all robots. As program-
mable electro-mechanical systems, they are inherently subject to a very wide
variety of fault modes. Not even the digital controller in current machines take
advantage of computer fault-tolerance architectures (which themselves make no
provision for sensor and actuator failure modes). Widespread personal use of
telerobots will require fundamental progress in design for fault-tolerance (we must
get well beyond just being careful).
51
Telerobotics in Rehabilitation: Once Around the World
A small number of underfinanced telerobotics teams around the world are attempting to over-
come these barriers. The most recent compilation of papers are in the Proceedings of the "First Inter-
national Workshop on Robotic Applications in Medicine and Health Care" (1988). The next edition
will grow out of the International Conference on Rehabilitation Robotics (sponsored by the A. I.
duPont Institute, June, 1990). The following synopses highlight some of the ongoing R&D (see
Table-4 for a technical comparison of the telerobots used.
The Johns Hopkins University Applied Physics Laboratory (JHU/APL) project (Schneider et al.,
198 I) concentrated on the implementation of a workbench-mounted robot intended to perform
activities of daily living (ADL) tasks. The design (initially 4 degrees-of-freedom then extended to 5)
was derived from prosthetic arm technology. Control is accomplished by a head-motion (chin) con-
trolled joystick for joint specific motion. Pre-programmed motions are invoked by menu-selection
and input command via a sip-and-puff switch.
The Tufts-New England Medical Center robotics project (Gilbert and Foulds, 1987; now at the
A I duPont institute) concentrated on the design of a universal robot programming language,
CALVIN, to provide a common interface to the many different manipulators available. Using
CALVIN, they set up a variety of small, low cost, robot work cells (typically 4 and 5 degree-of-
freedom manipulators) in clinical rehabilitation settings for disabled children. The clinical objective
is to foster intellectual development of the child.
The Boeing Company developed a voice-controlled workstation using the Universal Machine
Intelligence RTX (5 degree of freedom) manipulator (Fu, 1986). The distinctive feature of this pro-
ject is that it's user interface is a voice query system for large data bases developed by Boeing. Prab
Command, Inc., began marketing the system in 1988 for vocational applications. There is very little
telerobotic function beyond pre-programmed diskette loading. The internal project at Boeing has
ended and Prab sold the technology to the Zenith-Heath.
From 1980 through 1988, the Veterans Administration sponsored a collaborative effort with
Stanford University (Leifer, 1982; Hammel et al., 1989) to test the hypothesis that industrial manipu-
lators could cost effectively serve the needs of severely impaired spinal cord injury patients. The
project demonstrated that, through voiced commands, the utility and reliability of a high perfor-
mance manipulator (PUMA-260) and control language (VAL-2) can yield attractive cost-to-benefit
performance ratios when the telerobot is able to operate for four hours without attendant interven-
tion. Sensate end-effector, mobility, 3D point designation and natural language studies laid the foun-
dation for further R&D. A desktop vocational assistant robot (DeVAR) version of the system is
available commercially.
Outside the United States, the Canadian Nell Squire Foundation has developed a low-cost
manipulator designed for desktop applications in rehabilitation (Cameron, 1986). The system is
being sold by the foundation. At the Institute for Rehabilitation Research in the Netherlands, Hok
Kwee (previously with the French Spartacus project (Kwee, 1983) and his colleagues have devel-
oped a wheelchair mounted, joystick-controlled, manipulator (MANUS, Kwee, 1987). They are
52
particularlyinterestedin collocationof therobotanduserat all times.Themanipulatorisexpectedto
functionasanarm,not reallyatelerobot.
While humanattendantcareis thenormtoday,andteleroboticstechnologypromisesto release
someattendantimecosteffectively,thereis athird alternative.Capuchinmonkeyshavebeen
trainedto provideattendantservicesfrom feedingto applianceoperation(internalVA program
review, 1988).Monkeytrainingisexpensive,labile, anddoneby methodsobjectionableto theani-
malrightscommunity.Programretention(to amaximumof 12shorttasks)andwillfulnessremain
significantobstaclesto themonkeyassistantconcept.Theapproachis particularlylimited by thefact
thatmonkeyscanonly work one-on-onewith their user.Thedistractionsof institutionalandvoca-
tional settingsrenderthemonkeyineffective.
Table1presentsanextendedcomparisonof thestrengths,capabilitiesandlimitationsof five
approachesto augmentingtheindependenceof severelyimpairedpersons.Supportedby agrowing
bodyof experimentalevidence,thiscomparisonstronglysuggeststhattelerobotscanbecomecost-
effectivepersonalandvocationalassistants.Table2 listsmanyof thefeeding,personalhygiene,
vocational,andrecreationaltasksthathavebeendemonstratedoverthepast8 yearsby four genera-
tionsof theStanford-VARehabilitationR&D Center'sTeleroboticsystems.Table3 identifiesthe
technicalfunctionsrequiredto performthesetasks.
A Partial View of the Future
The operator interface will remain the dominant problem. It is so difficult that most systems
designers prefer to ignore it and focus on "tangible" technical specifications. It is likely to use mul-
tiple-channels in the sense of incorporating a "natural robot instructional language" and bi-direc-
tional pictographic dialog between the operator and the system. Increasingly "autonomous" teler-
obots will actually increase the burden on this interface.
Sensor driven motion planning and autonomous grasp/avoidance reflexes will become common-
place. The rate of introduction of such features will, however, be much slower than expected. In part,
this is due to the fact that system architectures will continue to be "fault-intolerant" such that the
introduction of both sensors and programmed reflexes will bring new reliability problems with them.
Force (impedance) control of telerobots will continue to evolve slowly even thought this capa-
bility is a fundamental requirement for any robot that must work intimately with humans. Physical
therapy by robots is both needed and impossible without force control. These lines of technical evo-
lution will themselves depend on getting more applications feedback from telerobots in the clinic,
home and office. In combination, we see a rather daunting challenge.
Acknowledgment
The following individuals have made important contributions to the reasoning in this paper: Joy
Hammel, David Lees, Dean Chan, Inder Perkash, Lin Liang, David J. Cannon, Charlie Wampler,
Chuck Buckley, John Jameson, Doug Schwandt, and Jim Anderson.
53
References
Cameron, W., Manipulative Appliance Development in Canada in Interactive Robotic Aids - one
option for independent living, World Rehabilitation Fund, New York, 1986
Fu, C., An Independent Vocational Workstation for a Quadriplegic, Proceedings of the 9th Annual
RESNA Conference, Minneapolis, MN, 1986
Gilbert, M., and Foulds, R., Robotics at Tufts-New England Medical Center: a progress report, Pro-
ceedings of the 10th Annual RESNA Conference, San Jose, CA, 1987
Hammel, J., Hall, K., Lees, D., Leifer, L., Van der Loos, M., Perkash, I, and Crigler, R., Clinical
evaluation ofa Desktop Robotic Assistant, Journal of Rehabilitation Research and Develop-
ment, Vol. 26, No.3, 1989
Kalsbeek, W., McLaurin, R., Harris-III, B., and Miller, D., The national head and spinal cord injury
survey: Major Findings, Journal of Neurosurgery, Vol. 53, 1980, pp. S 19-$31
Kwee, H. H., et al., Development of the MANUS Wheelchair-Borne Manipulator: progress report,
Proceedings of the 10th Annual RESNA Conference, San Jose, CA, 1987
Kwee, H. H., First Experimentation with the Spartacus Telethesis in a Clinical Environment, Para-
plegia, vol. 21, 1983
Leifer, L. J., Restoration of Motor Function: a robotics approach, in Uses of Computers in Aiding
the Disabled, Amsterdam: North-Holland Co., 1982
Schneider, W., Schmeisser, G., and Seamone, W., A Computer-Aided Robotic Arm-worktable System
for the High-Level Quadriplegic, IEEE Computer, pp. 41-47, January, 1981
Stover, S. L., Fine, P. R., et al: Spinal Cord Injury: The Facts and Figures, University of Alabama,
1986
Van der Loos, H. F. M, Michalowski, S. J., Hammel, J., Leifer, L. J., and Stassen, H. G., Assessing
the impact of robotics devices for the severely physically disabled, Proceedings of the First
International Workshop on Robotic Applications in Medical and Health Care, Ottawa, Canada,
1988, pp. 1-6
Young, J., Burns, P., Bowen, A., and McCutchen, R., Spinal Cord Injury Statistics, Phoenix,
Arizona, Good Samaritan Medical Center, 1982
Proceedings of the First International Workshop on Robotic Applications in Medical arm Health
Care, Editorial Office Rm. 301, Electrical Engineering, National Research Council, Ottawa,
Canada, K1A 0R8, 1988
54
Table la In-depth Review of the Capabilities, Strengths and Weaknesses of Five Basic Approaches
to the Restoration of Manipulative Function for People with Severe Physical Limitations (none = -,
limited = *, usable = **, good = ***, excellent -- ****).
Environment Controllers
Prosthetics Workstations - Seamone
Monkeys - Willard
Robots - Leifer
People
Human input/Output Factors
COMMAND * ** * *** ****
Substitution errors 5% 5% 10% 10% 1%
Detection errors 10% 10% 25% 15% 2%
Number of commands 10 20 12 100 2000
Syntax options - menu menu program English
User programming - - yes yes
CONTROL
Real-time - yes
Degrees of freedom - 7
Flexible - yes
User programmable - yes
DIALOG * * * *** ****
Feedback modes lights lights noises voice voice
Explanations status unlimited
Inference limited unlimited
Rule based limited general
User adaptive ? limited unlimited
Model based ? sensory general
Machine Input/Output
AUTONOMOUS PLANNING ** ****
Path limited general
.Strategy limited general
Data driven limited general
PROGRAMMABLE REFLEXES * ** ****
Force compliance ** ** ***
• * ****Contour following - -
Proximity sensing - *** -
• ** * ****Collision avoidance
• ** *** ****POSITION/ORIENTATION
Degrees of freedom - 4 9 7 9
Radius of working volume - 40cm 30cm 40cm 55cm
Precision - low low high flexible
Repeatability - 2ram 3mm 0.2ram 3mm
Strength - low low low flexible
Speed low moderate flexible flexible
MOBILITY - *** ** ****
Degrees of freedom - 6 4 6
Range rooms desk room rooms unlimited
Remote control IR link - voice voice voice
Autonomous 7 limited unlimited
GRASP * *** ** ****
Degrees of freedom 1 6 1 6
Grip force lkg 1.5kg 3kg 25kg
Dexterity minimal good minimal excellent
SENSATION **** ** ****
Tactile **** * ****
Forcc **** ** ****
Proximity **
Vision **** - ****
Audition **** - ****
55
Assessment
PERFORMANCE
Task time
Training time
Number of tasks
Commands per task
Precision
Repeatability
Reliability
Accessibility
SAFETY
Intention errors
Intrusion errors
Contact errors
COST
Hardware
Software
Training
Maintenance
Cost/hour of use
Table lb
Environment Controllers
Prosthetics Workstations - Seamone
Monkeys - Willard
Robots - Leifer
seconds minutes minutes minutes
2hrs 30hrs 20hrs 40hrs
10-20 15-30 10-20 20-200
1 1-4 1-4 1-20
- 5mm 2mm 0.2mm
- lmm 3mm 0.2mm
high good fair good
24hrs 24hrs 12hrs 24hrs
5% 10% 5% 10%
0% 4% 5% 5%
0% 2% 4% 2%
low medium medium high
low low high high
low medium high medium
low medium medium low
$1/hi" $4/hr $10/hr $5/hr
People
seconds
4hrs
40-400
1-2
2mm
3mm
fair
8hrs
4%
2%
1%
low
low
low
high
$25/hr
56
Table 2 Meal preparationandservice,vocationalmaterialhandling,personalhygiene,andrecre-
ationaltasksthathavebeenperformedfor andwith disabledindividualsacrossfour generationsof
desktoproboticassistants(DeVARsI, II, III, IV)
Meal preparation and service Vocational material handling Personal hygiene
arrange table setting
open and close microwave door
open and close refrigerator door
manipulate containers
set appliance timer
pour liquids and solids
beat eggs
toss salad
soup preparation and service
heat and serve casseroles
serve pudding
serve fruit
prepare and serve spaghetti
prepare and bake a cake
use knives, forks and spoons
retrieve drinks
mix drinks
lock and unlock cabinet doors
light and extinguish candles
light and extinguish cigarette
open and close storage drawers
room lights
window open and close
write with pen and/or pencil
retrieve books and manuals
set up books for reading
turn book and report pages
turn on-off computer equipment
type on keyboard
adjust keyboard position
operate private and speaker phones
insert and retrieve diskettes
insert and retrieve audio tapes
operate dictation equipment
manipulate printout
voiced control of generic software
load and operate printer
retrieve and serve medication
circuit boards for inspection
operate electronic control units:
door operation
security system
stereo equipment
Recreation
paint and sketch
arrange flowers
hand out flowers
hand out candy and souvenirs
perform one armed ballet
checkers
monopoly
television
operate video games
pac-man
invaders
play board games:
chess
wash and dry face
brush teeth
dispense toothpaste
use electric shaver
retrieve mouthstick
comb and brush hair
blow nose
apply makeup
57
Table 3. Several functional capabilities are needed in a Telerobotic Assistant to achieve utility in the
performance of independent living tasks, not needed (), should have ([]), must have (=)
MAINTENANCE Tasks
Food Preparation i
Food Service I
Personal Hygiene I"
Personal Grooming I
Clothing Management ["
Appliance Usage I
VOCATION Tasks
Storage & Retrieval I
Equipment Operation I
Assembly I
Word Processing I
Computing I
Materials Processing I
RECREATION Tasks
Reading I
Film & Video I
Performing Arts r
Graphic Art.¢ [
Sports [
Social Interaction l"
OMMAND
i )NTROL
n _LOGUE
PLANNING
GRASP
I
] ] C I
] E ,:] I
I i ,_ I
I
I [ ] I
I
i i l i
! [
! _ 121
I O ] I
I C y [! , !
ll'" "
MANIPULATION
_EFLEXES
I II
I II
I []
I II
I II
I II
I II
I II
I II
] [1
I []
] []
I II
I II
I II
I II
] []
I
I
I
I
t
58
o_
0
o II
_ _ __
59


Telerobotics in rehabilitation: Barriers to a virtual existence

Abstract

Similar works

Full text

Available Versions

NASA Technical Reports Server