Tweet
Attached are the replies to my request for information about
systems which allow the imposition of GRF vectors onto video.
Several commercial sources are available (Ariel, Peak, Video
Vector Generator, BITIS) as well as some "in-house" custom software.
Thanks to all who responded.
************************************************** ***********************
Mary Rodgers, PhD, PT (_)
Associate Professor |
Dept. of Physical Therapy /|\
University of Maryland / | \
100 Penn Street / | \
Baltimore, MD 21201 / \
mrodgers@umabnet.ab.umd.edu / \
(410)706-0840 office /_ \_
(410)706-6387 FAX
************************************************** *********************
From: Gideon Ariel
To: Mary Rodgers
Subject: Re: GRF and video
The only sysgtem in the world that will do it for you is at:
http://www.arielnet.com
The price of the whole system for educational institution is around
$10,000. This include computer, VCR, Software, Analog Module etc. (Comple=
te)
************************************************** ****************
From: Gordon Robertson
To: Mary Rodgers
Subject: Re: GRF and video
At U.Ottawa we use both APAS video systems annd cinefilm digitizing. We=20
have a custom built program called IMAGER that can draw two-dimensional=20
stick-figures and can superimpose the ground reaction force vectors. =20
This program can animate the sequences so that the forces are displayed=20
simultaneously with the stick-figures. You can also split the screen to=20
display one person against another or two trial of the same person. The=20
software is available free and will be available on the ISB website shortly=
=2E
Gord Robertson
dger@uottawa.ca
************************************************** *
From: George Miller
To: Mary Rodgers
Subject: Re: GRF and video
Hi Mary,
Your current version of Peak Motus will allow you to display and animate
your force vectors on the stick figure display. All you have to do is chec=
k
the "Add force vector segment to spatial model" checkbox on the Force Plate
Setup dialog when you select which force plate to use. Give us a call if
you have any questions.
George
*************************************
Dear Mary!
Here is a short description of the Vifor System, a system for
superposition of force vectors in real time on video recordings (in the
sagittal and frontal projection simultaneously):
Vifor (Video Force) is a system for analysis of patterns of movement and
loads in the lower extremities during walking. It has primarily been
developed for gait analysis, but can also be used in static situations.
The fundamental function of the system is to mark on video pictures the
ground reaction forces between foot and surface that successively act on
the walking patient. The sequence is automatically recorded by a
computer-controlled video cassette recorder. By studying the tape
recording of the sequence, an idea can be obtained very quickly as to
what forces are acting in the different parts of the leg. In this way it
is possible to study how a leg prosthesis works, and to see, for
example, how the foot is being used during different parts of a step.
The system can also be used to evaluate various changes in the lower
extremities, such as gait changes after surgery and effects of training
programmes.
The system has been developed on the basis of a couple of fundamental
principles:
*=09In order to obtain a correct notion of the load situation in a given
part of a leg, it is necessary to record simultaneously both the pattern
of movement and the external forces acting on the leg.
*=09In order for a system of this kind to truly be a useful tool other
than in pure research projects, it must be designed so that the costs,
time and trouble associated with its use are perceived as reasonable in
relation to the benefits obtained.
=20
Based on these principles, a system has been developed with the
additional requirement that its use shall involve as few manual
operations as possible. The operator shall instead be free to devote
most of his attention to the patient. Because the results are presented
in visual form on a videotape recording, it is also very easy to
understand what is happening, and the patient can participate in
studying the videotape recordings.
The main components in Vifor are a force plate installed in the floor
for measuring the forces between the foot and the surface, video cameras
and a video cassette recorder (VCR) for recording the pattern of
movement, a personal computer for processing the force data, plotting
ground reaction forces in video format and controlling the VCR, and a
video mixer for superimposing information from the video cameras onto
the computer images. In addition, the system includes photocells for
recording the walking speed and a video copier to furnish hard copies of
selected video images.
=20
Technical details
The system consist of a personal computer to which the following items
are connected: a force plate, a video graphics card, 2 video cameras, 2
photo cells, a video mixer, a video hard copy unit, a video cassette
recorder and a video monitor.=20
The key point from a technical point of view is the synchronisation
between force and video data. This is obtained in the Vifor system by
using one of the video cameras (or the video graphics card) as a master
sync source, which controls the second video camera and the force plate
sampling. The force vectors are drawn in real time onto the video images
(both sagittal and frontal planes), and this is useless unless it is
certified that the force data are measured almost simultaneously with
the video image generation. In the present system there is a 13 ms delay
between the force plate sampling and video image generation. A short
delay is necessary, otherwise the force information would not be
available for drawing force vectors onto the video images in real time.
However, if this delay is too long, or if there is no synchronisation
between force plate sampling and video image generation then the body
can move during the time from force data collection to video image
generation. This might result in totally erroneous estimation of the
distance between the force vector and the body joints. Hereby the
calculated joint moments can be quite misleading.
Selected Vifor and related gait analysis literature:
Lanshammar H (Editor)=20
Gait Analysis in Theory and Practice. Proceedings of the 1985 Uppsala
Gait Analysis Meeting. UPTEC 8532 R, Department of Technology, Uppsala,
June 1985.=20
Lanshammar H
Measurement and analysis of displacement. In "Gait Analysis in Theory
and Practice, editor H. Lanshammar, UPTEC 8532 R, Department of
Technology, Uppsala, pp 29-45, June 1985.=20
Lanshammar H and Lindroth T=20
Assessment of tibial osteotomy using gait analysis. Part 1, methods and
genuine three dimensional results presentation. Biomechanics X-A, ed. B
Jonsson, Human Kinetic Publishers, Champain, Illinois, pp 95-101, 1987.=20
Lanshammar H =20
Assessment of human gait - Available techniques versus clinical
usefulness. Presentation at, and included in the proceeding of, the
International Biomechanics Seminar, Chalmers University of Technology,
May 23, 1987. =20
=20
Lanshammar H =20
Estimation of gait cycle duration and stride length from one landmark
kinematic data. 5th Meeting of the European Society of Biomechanics,
Berlin (West), September 1986. In "Biomechanics: Basic and Applied
Research", ed: G Bergmann, R K=F6lbel, A Rohlmann, Martinus Nijhoff
Publishers, pp 129-134, 1987. =20
=20
Lanshammar H =20
VIFOR - A system for force line visualization. In: Biomechanics XI-B,
International Series On Biomechanics, Volume 7-B, ed: G de Groot, P
Hollander, P Huijing, G van Ingen Schenau, Free University Press,
Amsterdam, pp 984-988, 1988.
Lanshammar H and Holmgren R =20
Dynamics of prosthetic ankle joint - Estimation of mecanical parameters
using gait analysis and computer simulation. In: Biomechanics XI-A, ed:
G de Groot, P Hollander, P Huijing, G van Ingen Schenau, International
Series On Biomechanics, Volume 7-A, Free University Press, Amsterdam, pp
312-317, 1988.
Lanshammar H
Metod f=F6r analys av stabiliteten vid sittande med och utan sittskal.
Sammanfattning av f=F6redrag vid "Nordisk Ortopedteknisk Konferens",
H=E4lsoh=F6gskolan, J=F6nk=F6ping, 17 - 20/3, 1988b.
Lanshammar H
VIFOR - Ett system f=F6r g=E5nganalys genom visualisering av st=F6dkraften.
Ortopediskt Magasin, 3, 1988.
Lanshammar H
Variation of medial and lateral plateau loads at the knee joint with
different lever arms of the ground reaction force vector.
Congress Proceedings, XII International Congress of Biomechanics, ed: R
Gregor, R Zernicke, W Whiting, Dept of Kinesiology, University of
California, Los Angeles, June 26-30, 1989.
Lanshammar H
VIFOR - A Clinicians Tool for Load Analysis During Walking. Presentated
at the International Society for Prosthetics and Orthotics VI World
Congress, Kobe, Japan, 12-17 Nov, 1989.
Lanshammar H and Wall M
VIFOR Applications - On the Usefulness of a Clinicians Tool for Load
Analysis During Walking. Presentated at the International Society for
Prosthetics and Orthotics VI World Congress, Kobe, Japan, 12-17 Nov,
1989.
Harms-Ringdahl K, Lanshammar H and Kolehmainen I
A method for assessing cervical spine positions and gravitational force
lever arms during bicycling with different handlebar positions. Clinical
Biomechanics, 4:105-110, 1989.=20
Samneg=E5rd E, Turan I and Lanshammar H
Postoperativ utv=E4rdering av olika operationsmetoder p=E5 foten med hj=E4l=
p
av EMED g=E5nganalyssystem (Post operative evaluation of different
surgical procedures on the foot using the EMED system for gait analysis,
in Swedish). Presented at the 4:th Meeting of the Nordic Society of
Podology, Mariehamn, =C5land (Finland), June 8-9, 1989.
Lanshammar H
Gait Analysis as a Tool for Prosthetic Fitting of the Lower Limb
Amputee. Presented at XI Congresso Internationale Interbor - Roma, April
28 May 1, 1990.
Lanshammar H, Ekstr=F6m L, K=E5gstr=F6m A and Lanshammar K
External knee moments and moment arms of the ground reaction force
during young adult walking. Presented at the First World Congress of
Biomechanics, San Diego, Aug 30-Sept 4, 1990.
Steen M, Radell R, Lanshammar H, Fristedt =C5
The sitting shell - A funcional sitting aid for severely handicapped
children. Presented at the Annual meeting of the American Academy of
Cerebral Palsy and Development Medicine, Orlando Florida, October 3-6,
1990.
Samneg=E5rd E, Turan I, Lanshammar H
Postoperative Pressure under the rheumatic foot. The Journal of Foot
Surgery. Vol 29, No 6, pp 593-594, 1990.
Samneg=E5rd E, Turan I, Lanshammar H
Postoperative Evaluation of Keller's arthroplasty and arthrodesis of the
1st metatarsophalangeal joint using the EMED gait analysis system.
Journal of Foot Surgery. Vol 30, No 4, pp 373-374, 1991.
Steen M, Radell R, Fristedt =C5, Lanshammar H
Sittskalet - Ett hj=E4lpmedel f=F6r gravt r=F6relsehindrade barn och ungdom=
ar.
Sjukgymnasten, No 12, 1991, (Vetenskapligt supplement =C5rg=E5ng 2 nr 2
1991), pp 25-30, 1991.
Lanshammar H
Vifdig - A method for digital analysis of human motion recorded on a
VCR. Book of Abstracts, XIII International Congress of Biomechanics, The
Department of Human Movement Studies, The University of Western
Australia, Perth, (ed: Marshall, R.N. et al), pp 373-375, 1991. Abstract
in J Biomechanics, Vol 25, No 7, p 769, 1992.
Lanshammar H
On the selection of variables for gait characterization. Book of
Abstracts, XIII International Congress of Biomechanics, The Department
of Human Movement Studies, The University of Western Australia, Perth,
(ed: Marshall, R.N. et al), pp 441-443, 1991. Abstract in J
Biomechanics, Vol 25, No 7, p 786, 1992.
Lanshammar, H
VIFOR - A system for load analysis during walking
Technical report, UPTEC 92011R, 1992.
Lanshammar, H
Repeatability and validity of human gait data
Invited lecture at the European Symposium on Clinical Gait Analysis,
ETH, Z=FCrich, Proceedings pp 74-78, April 1-3, 1992.
Wall, M and Lanshammar, H
On shoe sole design and loads at the ankle and knee joint
Proceedings, 7th World Congress of ISPO, (ed: Janet K. Zupko), p 103,
Chicago, Ill., June 28-July 3, 1992.
Lanshammar, H, Turan, I, and Blomgren M
Ground reaction forces and knee joint moments - a correlation study
Proceedings, 7th World Congress of ISPO, (ed: Janet K. Zupko), p 321,
Chicago, Ill., June 28-July 3, 1992.
Lanshammar, H
Reduced Gait Analysis Methods in Prosthetics and Orthotics
(Lecture notes) Instructional course presented at the 7th World Congress
of ISPO, Chicago, Ill, June 28-July 3, 1992.
Lanshammar H
G=E5nganalysmetoder. I "Amputationskirurgi and proteser", ed: Tor Hierton,
Svensk Ortopedisk F=F6renings Skriftserie, nr 5, Mediapro AB, Tomelilla,
1992.
Lanshammar H
On multiple 2D versus full 3D gait analysis. UPTEC 92090R, June 1992.
Lanshammar H, Turan I, Blomgren M
On the repeatability and validity of human gait data. UPTEC 92089R, June
1992.
Lanshammar H, Turan I and Blomgren M
Age and sex related normal gait data for the knee joint. UPTEC 92103R,
August 1992.
Lanshammar H, Turan I and Lindgren U =20
Biomechanical analysis of foot loads during locomotion pre- and =20
postoperatively for hallux valgus and hallux rigidus patients. Clinical
Biomechanics, Vol 8, No 3, pp 135-141, May 1993. =20
Lanshammar H
Force vector visualization versus full 3D gait analysis. Book of
abstracts, XIV International Congress of Biomechanics (ed: S Metral), pp
754-755, 1993
Hansson K, Lanshammar H, Sahl=E9n T
An object oriented approach to musculoskeletal modelling. Book of
abstracts, XIV International Congress of Biomechanics (ed: S Metral), pp
548-549, 1993.
Sahl=E9n T, Lanshammar H, Hansson K
Marker-free estimation of hip joint position. Book of abstracts, XIV
International Congress of Biomechanics (ed: S Metral), pp 1164-1165,
1993.
Norrlin S, Lagerkvist B, Lanshammar H, Rehnberg L
Balanskontroll och g=E5nganalys p=E5 kraftplatta. Vetenskapligt supplement,
Sjukgymnasten, Nr 2, 1993.
Sahlstr=F6m A, Wigren A and Lanshammar H
Ground reaction force and its moment with respect to
the knee joint centre in a total condylar arthroplasty series. Clinical
Biomechanics, Vol 9, pp 125-129, 1994.
Sahlstr=F6m A, Lanshammar H and Adalberth G
Knee joint moments in work related situations. (Ergonomics, in Press).
Lanshammar H, Persson T, Medved V
Comparison between a marker-based and a marker-free method to estimate
centre of rotation using video image analysis. Accepted for presentation
at the Second World Congress of Biomechanics, Amsterdam, July 10-15,
1994.
H. Lanshammar, T. Persson & V. Medved
A marker-free method to estimate hip joint centre of rotation,
compared with radiological determination. Submitted to the World
Congress on Medical Physics and Biomedical Engineering, Rio de Janeiro,
August 21-26, 1994.
Sahlstr=F6m A, Lanshammar H and Adalberth G
Knee joint moments in work-related situations. Ergonomics, Vol 38, No 7,
pp 1352-1359, July 1995.
Hilding, M, Lanshammar H, Ryd, L
A relationship between knee joint moment during gait and tibial
component loosening in knee arthroplasty. EORS (European Orthopaedic
Research Society (Winner of the G=F6ran Selvik Prize), July 1995.
Persson, T, Lanshammar, H, Medved, V
A marker-free method to estimate joint centre of rotation by video image
processing. Computer Methods and Programs in Biomedicine, 46, pp
217-224, 1995.
Hilding, M, Lanshammar, H, Ryd, L
A relationsship between dynamic and static assessment of knee joint
load. Gait analysis and radiography before and after knee replacement in
45 patients. Acta Orthopaedica Scandinavica, 66 (4), pp 317-320, 1995.
Persson, T, Lanshammar, H
Estimation of an obejct=92s position and orientation using model matching.
Presented at the XVth Congress of the International Socitey of
Biomechanics, Juv=E4skyl=E4, Book of Abstracts, pp 724-725, July 1995.
Lanshammar, H, Karlsson, A
Analysis of postural strategies using force plate data and an inverted
pendulum model. Presented at the XVth Congress of the International
Socitey of Biomechanics, Juv=E4skyl=E4, Book of Abstracts, pp 530-531, July
1995.
Hilding, M, Lanshammar, H, Ryd, L
The importance of knee joint moments during gait in tibial component
loosening in knee arthroplasty. Presented at the XVth Congress of the
International Socitey of Biomechanics, Juv=E4skyl=E4, Book of Abstracts, pp
384-385, July 1995.
Hilding, M, Lanshammar, H, Ryd, L
The importance of knee joint load in tibial component loosening.
Combined Orthopaedic Research Societies Meeting, San Diego, California,
November 6-8, 1995.
Hilding, M, Lanshammar H, Ryd, L
Knee joint load and tibial component loosening. Brittish Journal of Bone
and Joint Surgery, Vol. 78-B, No. 1, pp 66-73, January 1996.
Persson, T
Analysis of Joint Loads and Balance - Methods Intended for Routine Use
in Clinical Settings. Licentiate Thesis, Department of Technology,
Uppsala University, UPTEC 96056R, April 1996.
Lanshammar, H
Estimation of knee joint center position using the centroid of an
elastic band. 10th Conference of the European Society of Biomechanics,
Leuven, Book of Abstracts, p 245 August 1996.
Karlsson A, Lanshammar H
Analysis of balance strategies: A comparison between model and marker
based methods. 10th Conference of the European Society of Biomechanics,
Leuven, 1996, Book of Abstracts, p 292, August 1996.
Hansson, K
Object-Oriented Modelling and Simulation of Human Gait. Licentiate
Thesis, Department of Technology, Uppsala University, UPTEC 96120R,
October 1996.
Lanshammar, H
G=E5ngens kinematik och kinetik, Studentlitteratur, 1996 (to appear).
Karlsson, A, Lanshammar H
Analysis of postural sway strategies using an inverted pendulum model
and force plate data. Gait and Posture (Scheduled to appear in Vol 5, No
2, Spring 1997).
=20
I will send you some more information by mail.
Good luck!
H=E5kan Lanshammar
--=20
************************************************** ***
* From: H=E5kan Lanshammar Systems and Control Group *
* hl@SysCon.uu.se Uppsala University *
* Tel: +46-18-18 30 33 P.O. Box 27 *
* Fax: +46-18-50 36 11 S-751 03 Uppsala, SWEDEN *
************************************************** ***
---------- Forwarded message ----------
Dear Mary
I do not know of any systems which produce 3D vector visualisation=20
and I have to say that I would be surpised if someone actually=20
claimed to have managed that feat!
There are systems which correct for the depth of the force plate,=20
using parallelogram templates, but I am sure they all assume =20
orthoganol views of the plate. ORLAU, Robert Jones and Agnes Hunt=20
Orthopaedic Hospital, Oswestry, England did produce=20
a developmental PC-based version of their vector system using this=20
approach, but I am not sure if this facility is in the system which=20
was subsequently produced by MIE Ltd , 6 Worley Moor Road, Leeds,=20
England. I think Ray Wytch, Dept. Biomedical Physics and=20
Bioengineering also has a similar PC-based system but I do not know=20
if it is commercially available.=20
Hope that is helpful.
Jeremy Linskell
Clinical Gait Analysis Service Manager
The Dundee Gait Lab
Dundee Limb Fitting Centre
Dundee, DD5 1AG, Scotland=20
tel +1382-730104, fax +1382-480194
email: j.r.linskell@dth.scot.nhs.uk
---------- Forwarded message ----------
Date: 19 Nov 96 08:36:26 EST
From: "C. Calame, Kistler"
To: Mary Rodgers
Cc: Matthew Randazzo
Subject: Re: GRF and video
Dear Mary
I know of two systems for force vector visualization, one commercially
available, working with a portable Kistler force plate type 9286, the other=
one
a research prototype:
- Commercially available, running with Kistler portable force plates:
Video Vector Generator
MIE Medical Research Ltd.
6 Wortley Moor Road
Leeds LS12 4JF
United Kingdom
Tel: ++44 113 2793710
Fax: ++44 113 2310820
- Research prototype:
A Realtime Ground Reaction Force Vector Visualisation System
Victoria University of Technology
Centre for Rehabilitation, Exercise and Sport Science
Geoff Roberts
Melbourne 3000
Australia
redda@dingo.vut.edu.au
Best Regards
Christian Calame
Product Manager Biomechanics
-----------------------------------------------------------
Kistler Instrumente AG Winterthur, P.O.Box 304,=20
CH-8408 Winterthur, Switzerland
Tel: +41 52 224 11 11, Fax: +41 52 224 14 14
Telex 896 296 KAG CH,=20
E-Mail: 100072.1173@compuserve.com
-----------------------------------------------------------
---------- Forwarded message ----------
Date: Tue, 19 Nov 1996 15:19:59 -0800 (PST)
From: "Jill L. McNitt-Gray"
To: Mary Rodgers
Subject: Re: GRF and video
Mary,
We have developed and refined a real time system that does this.
Jill
Jill L. McNitt-Gray, Ph.D.
Biomechanics Research Laboratory, Director
3560 Watt Way
Dept. of Exercise Science
University of Southern California
Los Angeles, CA 90089-0652
213-740-2492
FAX 213-740-7909
email: mcnitt@usc.edu
---------- Forwarded message ----------
Date: Wed, 20 Nov 1996 02:58:03 -0500
From: FredCei@aol.com
To: Mrodgers@umabnet.ab.umd.edu
Subject: Digivec System for GRF and Video superimposition
Hello there Mary,
My name's Frederik CEI and I'm the US Representative for B|T|S products. I
read your request from Biomech and thought I'd tell you a little about the
DIGIVEC system.
This system allows you to superimpose up to three different video views wit=
h
the GRF coming from a Kistler, AMTI or Bertec platform. The information is
recorded and displayed in REALTIME, and doesn't require a data reduction st=
ep
to obtain the information. The system is great for research due to its quic=
k
turn around of information, and ideal as an educational tool.
I have attached a file describing the system. I included some low resolutio=
n
video images to give you an idea of the three different views that are
possible. This particular example uses a Kistler Force plate with a glass t=
op
to assist in viewing the C.O.P. progression during a gait cycle. Other
application uses are sports related.
You can open the attached document in Word for Windows...
My office number is (310) 473-5994
Fred CEI
B|T|S
---------- Forwarded message ----------
Date: Wed, 20 Nov 1996 08:43:52 +0000
From: David Davis
To: Mary Rodgers
Subject: Re: GRF and video
Dear Mary,
Check out the following paper if you haven't already got a copy:
P.J.Rowe , 1996, Technical notes: Development of a low cost video vector fo=
r
display of ground reaction forces during gait, Med.Eng.Phys.,
Vol.18:No.7
p.591-595
Authors address is: P.J.Rowe, Dept. of Physiotherapy, Queen Margaret
College, Duke St., Leith, Edinburgh, EH6 8HF, United Kingdom.
Hope that helps.
David Davis
---------------------------------------------------------------------------=
-
-----------
Department of Human Sciences
Loughborough University
Leics.
LE11 3TU
UK
Tel: 01509 223086
Fax: 01509 223941
Email: D.Davis@lboro.ac.uk
---------- Forwarded message ----------
Date: Wed, 20 Nov 1996 16:22:45 +0100 (MED)
From: Bart Freriks
To: mrodgers@umabnet.ab.umd.edu
Subject: GRF-vector systems
Being the Research and Development department of a Rehabilitation
Center (het Roessingh, Enschede, the Netherlands) with a special
interest in movement analysis, we have developed a budget-friendly,
real-time ground reaction force (GRF) visualisation system a few
years ago. We use this system daily in our clinical service (e.g.
movement analysis in CP children) as well as in a number of research
projects.
The system superimposes the GRF-vector meausured by a 3D force
platform on the video image which is taken of the subject with an
ordinary commercial available video camera. The resulting picture can
be recorded on video tape which allows frame-by frame replay
afterwards. Since the projection of the GRF vector on the video-image
is done in real-time, the system can also be used in situations in
which direct feedback from the subject is desired (double tasks,
stability in standing, etc.). The system is very easy to operate.
Subjects can be recorded from both lateral and frontal side.
In the beginning of next year, we hope to have the system available
for others via a partner. Then we will introduce it as part of another
system: the VisionPlus system. The VisionPlus system can be regarded
as a multi media (movement analysis) PC. It is a dedicated PC which
contains both the hard and software to realise a number of 'basic'
applications which can be used in (clinical) movement analysis:
The basic applications are:
1. VIVEC II: If a force plate (and amplifier), an ordinary videocamera
and an ordinary VCR and/or television screen will be connected to the
VisionPlus system, it is possible to combine the GRF-vektor with a
video-image as explained above. 2. Myo-vision: If an EMG amplifier, an
ordinary videocamera and an ordinary VCR and/or television screen will
be connected to the VisionPlus system, it is possible to superimpose
muscle activation patterns of (up to 8) muscles on the video image of
a subject. 3. DualView: If 2 videocameras, a VCR and/or a television
screen will be connected to the VisionPlus system, it is possible to
show and record the subject from 2 views (e.g. frontal and lateral)
simultaniously.
Basic applications can be combined into more =91advanced=92 applications
by just connecting the necessary additional equipment (EMG, Force) to
the VisionPlus system. As such it is possible to gradualy extend the
VisionPlus system starting with one of the above explained 'basic'
applications and ending at a VisionPlus system which combines both the
GRF-vector of a subject, his/her (up to 8) muscle activation
patterns, and both the lateral and frontal view in one single video
image simultaniously and store this on a video tape.
Today I will fax you some brochures concerning the VIVEC II
application as well as the muscle activation patterns application.
I hope I have given you the desired information.
Please do not hesitate to call, fax or mail us if you have any
questions. Best regards,
ir. Bart Freriks
Roessingh Research and Development b.v., Enschede, the Netherlands
********************************************
ir. Bart Freriks
Roessingh Research and Development bv
Roessinghsbleekweg 33
7522 AH ENSCHEDE
The Netherlands
Phone: +31-53-4875734
Fax: +31-53-4340849
E-mail: b.freriks@rrd.nl
Internet: http:\\www.introweb.nl\~rrd
systems which allow the imposition of GRF vectors onto video.
Several commercial sources are available (Ariel, Peak, Video
Vector Generator, BITIS) as well as some "in-house" custom software.
Thanks to all who responded.
************************************************** ***********************
Mary Rodgers, PhD, PT (_)
Associate Professor |
Dept. of Physical Therapy /|\
University of Maryland / | \
100 Penn Street / | \
Baltimore, MD 21201 / \
mrodgers@umabnet.ab.umd.edu / \
(410)706-0840 office /_ \_
(410)706-6387 FAX
************************************************** *********************
From: Gideon Ariel
To: Mary Rodgers
Subject: Re: GRF and video
The only sysgtem in the world that will do it for you is at:
http://www.arielnet.com
The price of the whole system for educational institution is around
$10,000. This include computer, VCR, Software, Analog Module etc. (Comple=
te)
************************************************** ****************
From: Gordon Robertson
To: Mary Rodgers
Subject: Re: GRF and video
At U.Ottawa we use both APAS video systems annd cinefilm digitizing. We=20
have a custom built program called IMAGER that can draw two-dimensional=20
stick-figures and can superimpose the ground reaction force vectors. =20
This program can animate the sequences so that the forces are displayed=20
simultaneously with the stick-figures. You can also split the screen to=20
display one person against another or two trial of the same person. The=20
software is available free and will be available on the ISB website shortly=
=2E
Gord Robertson
dger@uottawa.ca
************************************************** *
From: George Miller
To: Mary Rodgers
Subject: Re: GRF and video
Hi Mary,
Your current version of Peak Motus will allow you to display and animate
your force vectors on the stick figure display. All you have to do is chec=
k
the "Add force vector segment to spatial model" checkbox on the Force Plate
Setup dialog when you select which force plate to use. Give us a call if
you have any questions.
George
*************************************
Dear Mary!
Here is a short description of the Vifor System, a system for
superposition of force vectors in real time on video recordings (in the
sagittal and frontal projection simultaneously):
Vifor (Video Force) is a system for analysis of patterns of movement and
loads in the lower extremities during walking. It has primarily been
developed for gait analysis, but can also be used in static situations.
The fundamental function of the system is to mark on video pictures the
ground reaction forces between foot and surface that successively act on
the walking patient. The sequence is automatically recorded by a
computer-controlled video cassette recorder. By studying the tape
recording of the sequence, an idea can be obtained very quickly as to
what forces are acting in the different parts of the leg. In this way it
is possible to study how a leg prosthesis works, and to see, for
example, how the foot is being used during different parts of a step.
The system can also be used to evaluate various changes in the lower
extremities, such as gait changes after surgery and effects of training
programmes.
The system has been developed on the basis of a couple of fundamental
principles:
*=09In order to obtain a correct notion of the load situation in a given
part of a leg, it is necessary to record simultaneously both the pattern
of movement and the external forces acting on the leg.
*=09In order for a system of this kind to truly be a useful tool other
than in pure research projects, it must be designed so that the costs,
time and trouble associated with its use are perceived as reasonable in
relation to the benefits obtained.
=20
Based on these principles, a system has been developed with the
additional requirement that its use shall involve as few manual
operations as possible. The operator shall instead be free to devote
most of his attention to the patient. Because the results are presented
in visual form on a videotape recording, it is also very easy to
understand what is happening, and the patient can participate in
studying the videotape recordings.
The main components in Vifor are a force plate installed in the floor
for measuring the forces between the foot and the surface, video cameras
and a video cassette recorder (VCR) for recording the pattern of
movement, a personal computer for processing the force data, plotting
ground reaction forces in video format and controlling the VCR, and a
video mixer for superimposing information from the video cameras onto
the computer images. In addition, the system includes photocells for
recording the walking speed and a video copier to furnish hard copies of
selected video images.
=20
Technical details
The system consist of a personal computer to which the following items
are connected: a force plate, a video graphics card, 2 video cameras, 2
photo cells, a video mixer, a video hard copy unit, a video cassette
recorder and a video monitor.=20
The key point from a technical point of view is the synchronisation
between force and video data. This is obtained in the Vifor system by
using one of the video cameras (or the video graphics card) as a master
sync source, which controls the second video camera and the force plate
sampling. The force vectors are drawn in real time onto the video images
(both sagittal and frontal planes), and this is useless unless it is
certified that the force data are measured almost simultaneously with
the video image generation. In the present system there is a 13 ms delay
between the force plate sampling and video image generation. A short
delay is necessary, otherwise the force information would not be
available for drawing force vectors onto the video images in real time.
However, if this delay is too long, or if there is no synchronisation
between force plate sampling and video image generation then the body
can move during the time from force data collection to video image
generation. This might result in totally erroneous estimation of the
distance between the force vector and the body joints. Hereby the
calculated joint moments can be quite misleading.
Selected Vifor and related gait analysis literature:
Lanshammar H (Editor)=20
Gait Analysis in Theory and Practice. Proceedings of the 1985 Uppsala
Gait Analysis Meeting. UPTEC 8532 R, Department of Technology, Uppsala,
June 1985.=20
Lanshammar H
Measurement and analysis of displacement. In "Gait Analysis in Theory
and Practice, editor H. Lanshammar, UPTEC 8532 R, Department of
Technology, Uppsala, pp 29-45, June 1985.=20
Lanshammar H and Lindroth T=20
Assessment of tibial osteotomy using gait analysis. Part 1, methods and
genuine three dimensional results presentation. Biomechanics X-A, ed. B
Jonsson, Human Kinetic Publishers, Champain, Illinois, pp 95-101, 1987.=20
Lanshammar H =20
Assessment of human gait - Available techniques versus clinical
usefulness. Presentation at, and included in the proceeding of, the
International Biomechanics Seminar, Chalmers University of Technology,
May 23, 1987. =20
=20
Lanshammar H =20
Estimation of gait cycle duration and stride length from one landmark
kinematic data. 5th Meeting of the European Society of Biomechanics,
Berlin (West), September 1986. In "Biomechanics: Basic and Applied
Research", ed: G Bergmann, R K=F6lbel, A Rohlmann, Martinus Nijhoff
Publishers, pp 129-134, 1987. =20
=20
Lanshammar H =20
VIFOR - A system for force line visualization. In: Biomechanics XI-B,
International Series On Biomechanics, Volume 7-B, ed: G de Groot, P
Hollander, P Huijing, G van Ingen Schenau, Free University Press,
Amsterdam, pp 984-988, 1988.
Lanshammar H and Holmgren R =20
Dynamics of prosthetic ankle joint - Estimation of mecanical parameters
using gait analysis and computer simulation. In: Biomechanics XI-A, ed:
G de Groot, P Hollander, P Huijing, G van Ingen Schenau, International
Series On Biomechanics, Volume 7-A, Free University Press, Amsterdam, pp
312-317, 1988.
Lanshammar H
Metod f=F6r analys av stabiliteten vid sittande med och utan sittskal.
Sammanfattning av f=F6redrag vid "Nordisk Ortopedteknisk Konferens",
H=E4lsoh=F6gskolan, J=F6nk=F6ping, 17 - 20/3, 1988b.
Lanshammar H
VIFOR - Ett system f=F6r g=E5nganalys genom visualisering av st=F6dkraften.
Ortopediskt Magasin, 3, 1988.
Lanshammar H
Variation of medial and lateral plateau loads at the knee joint with
different lever arms of the ground reaction force vector.
Congress Proceedings, XII International Congress of Biomechanics, ed: R
Gregor, R Zernicke, W Whiting, Dept of Kinesiology, University of
California, Los Angeles, June 26-30, 1989.
Lanshammar H
VIFOR - A Clinicians Tool for Load Analysis During Walking. Presentated
at the International Society for Prosthetics and Orthotics VI World
Congress, Kobe, Japan, 12-17 Nov, 1989.
Lanshammar H and Wall M
VIFOR Applications - On the Usefulness of a Clinicians Tool for Load
Analysis During Walking. Presentated at the International Society for
Prosthetics and Orthotics VI World Congress, Kobe, Japan, 12-17 Nov,
1989.
Harms-Ringdahl K, Lanshammar H and Kolehmainen I
A method for assessing cervical spine positions and gravitational force
lever arms during bicycling with different handlebar positions. Clinical
Biomechanics, 4:105-110, 1989.=20
Samneg=E5rd E, Turan I and Lanshammar H
Postoperativ utv=E4rdering av olika operationsmetoder p=E5 foten med hj=E4l=
p
av EMED g=E5nganalyssystem (Post operative evaluation of different
surgical procedures on the foot using the EMED system for gait analysis,
in Swedish). Presented at the 4:th Meeting of the Nordic Society of
Podology, Mariehamn, =C5land (Finland), June 8-9, 1989.
Lanshammar H
Gait Analysis as a Tool for Prosthetic Fitting of the Lower Limb
Amputee. Presented at XI Congresso Internationale Interbor - Roma, April
28 May 1, 1990.
Lanshammar H, Ekstr=F6m L, K=E5gstr=F6m A and Lanshammar K
External knee moments and moment arms of the ground reaction force
during young adult walking. Presented at the First World Congress of
Biomechanics, San Diego, Aug 30-Sept 4, 1990.
Steen M, Radell R, Lanshammar H, Fristedt =C5
The sitting shell - A funcional sitting aid for severely handicapped
children. Presented at the Annual meeting of the American Academy of
Cerebral Palsy and Development Medicine, Orlando Florida, October 3-6,
1990.
Samneg=E5rd E, Turan I, Lanshammar H
Postoperative Pressure under the rheumatic foot. The Journal of Foot
Surgery. Vol 29, No 6, pp 593-594, 1990.
Samneg=E5rd E, Turan I, Lanshammar H
Postoperative Evaluation of Keller's arthroplasty and arthrodesis of the
1st metatarsophalangeal joint using the EMED gait analysis system.
Journal of Foot Surgery. Vol 30, No 4, pp 373-374, 1991.
Steen M, Radell R, Fristedt =C5, Lanshammar H
Sittskalet - Ett hj=E4lpmedel f=F6r gravt r=F6relsehindrade barn och ungdom=
ar.
Sjukgymnasten, No 12, 1991, (Vetenskapligt supplement =C5rg=E5ng 2 nr 2
1991), pp 25-30, 1991.
Lanshammar H
Vifdig - A method for digital analysis of human motion recorded on a
VCR. Book of Abstracts, XIII International Congress of Biomechanics, The
Department of Human Movement Studies, The University of Western
Australia, Perth, (ed: Marshall, R.N. et al), pp 373-375, 1991. Abstract
in J Biomechanics, Vol 25, No 7, p 769, 1992.
Lanshammar H
On the selection of variables for gait characterization. Book of
Abstracts, XIII International Congress of Biomechanics, The Department
of Human Movement Studies, The University of Western Australia, Perth,
(ed: Marshall, R.N. et al), pp 441-443, 1991. Abstract in J
Biomechanics, Vol 25, No 7, p 786, 1992.
Lanshammar, H
VIFOR - A system for load analysis during walking
Technical report, UPTEC 92011R, 1992.
Lanshammar, H
Repeatability and validity of human gait data
Invited lecture at the European Symposium on Clinical Gait Analysis,
ETH, Z=FCrich, Proceedings pp 74-78, April 1-3, 1992.
Wall, M and Lanshammar, H
On shoe sole design and loads at the ankle and knee joint
Proceedings, 7th World Congress of ISPO, (ed: Janet K. Zupko), p 103,
Chicago, Ill., June 28-July 3, 1992.
Lanshammar, H, Turan, I, and Blomgren M
Ground reaction forces and knee joint moments - a correlation study
Proceedings, 7th World Congress of ISPO, (ed: Janet K. Zupko), p 321,
Chicago, Ill., June 28-July 3, 1992.
Lanshammar, H
Reduced Gait Analysis Methods in Prosthetics and Orthotics
(Lecture notes) Instructional course presented at the 7th World Congress
of ISPO, Chicago, Ill, June 28-July 3, 1992.
Lanshammar H
G=E5nganalysmetoder. I "Amputationskirurgi and proteser", ed: Tor Hierton,
Svensk Ortopedisk F=F6renings Skriftserie, nr 5, Mediapro AB, Tomelilla,
1992.
Lanshammar H
On multiple 2D versus full 3D gait analysis. UPTEC 92090R, June 1992.
Lanshammar H, Turan I, Blomgren M
On the repeatability and validity of human gait data. UPTEC 92089R, June
1992.
Lanshammar H, Turan I and Blomgren M
Age and sex related normal gait data for the knee joint. UPTEC 92103R,
August 1992.
Lanshammar H, Turan I and Lindgren U =20
Biomechanical analysis of foot loads during locomotion pre- and =20
postoperatively for hallux valgus and hallux rigidus patients. Clinical
Biomechanics, Vol 8, No 3, pp 135-141, May 1993. =20
Lanshammar H
Force vector visualization versus full 3D gait analysis. Book of
abstracts, XIV International Congress of Biomechanics (ed: S Metral), pp
754-755, 1993
Hansson K, Lanshammar H, Sahl=E9n T
An object oriented approach to musculoskeletal modelling. Book of
abstracts, XIV International Congress of Biomechanics (ed: S Metral), pp
548-549, 1993.
Sahl=E9n T, Lanshammar H, Hansson K
Marker-free estimation of hip joint position. Book of abstracts, XIV
International Congress of Biomechanics (ed: S Metral), pp 1164-1165,
1993.
Norrlin S, Lagerkvist B, Lanshammar H, Rehnberg L
Balanskontroll och g=E5nganalys p=E5 kraftplatta. Vetenskapligt supplement,
Sjukgymnasten, Nr 2, 1993.
Sahlstr=F6m A, Wigren A and Lanshammar H
Ground reaction force and its moment with respect to
the knee joint centre in a total condylar arthroplasty series. Clinical
Biomechanics, Vol 9, pp 125-129, 1994.
Sahlstr=F6m A, Lanshammar H and Adalberth G
Knee joint moments in work related situations. (Ergonomics, in Press).
Lanshammar H, Persson T, Medved V
Comparison between a marker-based and a marker-free method to estimate
centre of rotation using video image analysis. Accepted for presentation
at the Second World Congress of Biomechanics, Amsterdam, July 10-15,
1994.
H. Lanshammar, T. Persson & V. Medved
A marker-free method to estimate hip joint centre of rotation,
compared with radiological determination. Submitted to the World
Congress on Medical Physics and Biomedical Engineering, Rio de Janeiro,
August 21-26, 1994.
Sahlstr=F6m A, Lanshammar H and Adalberth G
Knee joint moments in work-related situations. Ergonomics, Vol 38, No 7,
pp 1352-1359, July 1995.
Hilding, M, Lanshammar H, Ryd, L
A relationship between knee joint moment during gait and tibial
component loosening in knee arthroplasty. EORS (European Orthopaedic
Research Society (Winner of the G=F6ran Selvik Prize), July 1995.
Persson, T, Lanshammar, H, Medved, V
A marker-free method to estimate joint centre of rotation by video image
processing. Computer Methods and Programs in Biomedicine, 46, pp
217-224, 1995.
Hilding, M, Lanshammar, H, Ryd, L
A relationsship between dynamic and static assessment of knee joint
load. Gait analysis and radiography before and after knee replacement in
45 patients. Acta Orthopaedica Scandinavica, 66 (4), pp 317-320, 1995.
Persson, T, Lanshammar, H
Estimation of an obejct=92s position and orientation using model matching.
Presented at the XVth Congress of the International Socitey of
Biomechanics, Juv=E4skyl=E4, Book of Abstracts, pp 724-725, July 1995.
Lanshammar, H, Karlsson, A
Analysis of postural strategies using force plate data and an inverted
pendulum model. Presented at the XVth Congress of the International
Socitey of Biomechanics, Juv=E4skyl=E4, Book of Abstracts, pp 530-531, July
1995.
Hilding, M, Lanshammar, H, Ryd, L
The importance of knee joint moments during gait in tibial component
loosening in knee arthroplasty. Presented at the XVth Congress of the
International Socitey of Biomechanics, Juv=E4skyl=E4, Book of Abstracts, pp
384-385, July 1995.
Hilding, M, Lanshammar, H, Ryd, L
The importance of knee joint load in tibial component loosening.
Combined Orthopaedic Research Societies Meeting, San Diego, California,
November 6-8, 1995.
Hilding, M, Lanshammar H, Ryd, L
Knee joint load and tibial component loosening. Brittish Journal of Bone
and Joint Surgery, Vol. 78-B, No. 1, pp 66-73, January 1996.
Persson, T
Analysis of Joint Loads and Balance - Methods Intended for Routine Use
in Clinical Settings. Licentiate Thesis, Department of Technology,
Uppsala University, UPTEC 96056R, April 1996.
Lanshammar, H
Estimation of knee joint center position using the centroid of an
elastic band. 10th Conference of the European Society of Biomechanics,
Leuven, Book of Abstracts, p 245 August 1996.
Karlsson A, Lanshammar H
Analysis of balance strategies: A comparison between model and marker
based methods. 10th Conference of the European Society of Biomechanics,
Leuven, 1996, Book of Abstracts, p 292, August 1996.
Hansson, K
Object-Oriented Modelling and Simulation of Human Gait. Licentiate
Thesis, Department of Technology, Uppsala University, UPTEC 96120R,
October 1996.
Lanshammar, H
G=E5ngens kinematik och kinetik, Studentlitteratur, 1996 (to appear).
Karlsson, A, Lanshammar H
Analysis of postural sway strategies using an inverted pendulum model
and force plate data. Gait and Posture (Scheduled to appear in Vol 5, No
2, Spring 1997).
=20
I will send you some more information by mail.
Good luck!
H=E5kan Lanshammar
--=20
************************************************** ***
* From: H=E5kan Lanshammar Systems and Control Group *
* hl@SysCon.uu.se Uppsala University *
* Tel: +46-18-18 30 33 P.O. Box 27 *
* Fax: +46-18-50 36 11 S-751 03 Uppsala, SWEDEN *
************************************************** ***
---------- Forwarded message ----------
Dear Mary
I do not know of any systems which produce 3D vector visualisation=20
and I have to say that I would be surpised if someone actually=20
claimed to have managed that feat!
There are systems which correct for the depth of the force plate,=20
using parallelogram templates, but I am sure they all assume =20
orthoganol views of the plate. ORLAU, Robert Jones and Agnes Hunt=20
Orthopaedic Hospital, Oswestry, England did produce=20
a developmental PC-based version of their vector system using this=20
approach, but I am not sure if this facility is in the system which=20
was subsequently produced by MIE Ltd , 6 Worley Moor Road, Leeds,=20
England. I think Ray Wytch, Dept. Biomedical Physics and=20
Bioengineering also has a similar PC-based system but I do not know=20
if it is commercially available.=20
Hope that is helpful.
Jeremy Linskell
Clinical Gait Analysis Service Manager
The Dundee Gait Lab
Dundee Limb Fitting Centre
Dundee, DD5 1AG, Scotland=20
tel +1382-730104, fax +1382-480194
email: j.r.linskell@dth.scot.nhs.uk
---------- Forwarded message ----------
Date: 19 Nov 96 08:36:26 EST
From: "C. Calame, Kistler"
To: Mary Rodgers
Cc: Matthew Randazzo
Subject: Re: GRF and video
Dear Mary
I know of two systems for force vector visualization, one commercially
available, working with a portable Kistler force plate type 9286, the other=
one
a research prototype:
- Commercially available, running with Kistler portable force plates:
Video Vector Generator
MIE Medical Research Ltd.
6 Wortley Moor Road
Leeds LS12 4JF
United Kingdom
Tel: ++44 113 2793710
Fax: ++44 113 2310820
- Research prototype:
A Realtime Ground Reaction Force Vector Visualisation System
Victoria University of Technology
Centre for Rehabilitation, Exercise and Sport Science
Geoff Roberts
Melbourne 3000
Australia
redda@dingo.vut.edu.au
Best Regards
Christian Calame
Product Manager Biomechanics
-----------------------------------------------------------
Kistler Instrumente AG Winterthur, P.O.Box 304,=20
CH-8408 Winterthur, Switzerland
Tel: +41 52 224 11 11, Fax: +41 52 224 14 14
Telex 896 296 KAG CH,=20
E-Mail: 100072.1173@compuserve.com
-----------------------------------------------------------
---------- Forwarded message ----------
Date: Tue, 19 Nov 1996 15:19:59 -0800 (PST)
From: "Jill L. McNitt-Gray"
To: Mary Rodgers
Subject: Re: GRF and video
Mary,
We have developed and refined a real time system that does this.
Jill
Jill L. McNitt-Gray, Ph.D.
Biomechanics Research Laboratory, Director
3560 Watt Way
Dept. of Exercise Science
University of Southern California
Los Angeles, CA 90089-0652
213-740-2492
FAX 213-740-7909
email: mcnitt@usc.edu
---------- Forwarded message ----------
Date: Wed, 20 Nov 1996 02:58:03 -0500
From: FredCei@aol.com
To: Mrodgers@umabnet.ab.umd.edu
Subject: Digivec System for GRF and Video superimposition
Hello there Mary,
My name's Frederik CEI and I'm the US Representative for B|T|S products. I
read your request from Biomech and thought I'd tell you a little about the
DIGIVEC system.
This system allows you to superimpose up to three different video views wit=
h
the GRF coming from a Kistler, AMTI or Bertec platform. The information is
recorded and displayed in REALTIME, and doesn't require a data reduction st=
ep
to obtain the information. The system is great for research due to its quic=
k
turn around of information, and ideal as an educational tool.
I have attached a file describing the system. I included some low resolutio=
n
video images to give you an idea of the three different views that are
possible. This particular example uses a Kistler Force plate with a glass t=
op
to assist in viewing the C.O.P. progression during a gait cycle. Other
application uses are sports related.
You can open the attached document in Word for Windows...
My office number is (310) 473-5994
Fred CEI
B|T|S
---------- Forwarded message ----------
Date: Wed, 20 Nov 1996 08:43:52 +0000
From: David Davis
To: Mary Rodgers
Subject: Re: GRF and video
Dear Mary,
Check out the following paper if you haven't already got a copy:
P.J.Rowe , 1996, Technical notes: Development of a low cost video vector fo=
r
display of ground reaction forces during gait, Med.Eng.Phys.,
Vol.18:No.7
p.591-595Authors address is: P.J.Rowe, Dept. of Physiotherapy, Queen Margaret
College, Duke St., Leith, Edinburgh, EH6 8HF, United Kingdom.
Hope that helps.
David Davis
---------------------------------------------------------------------------=
-
-----------
Department of Human Sciences
Loughborough University
Leics.
LE11 3TU
UK
Tel: 01509 223086
Fax: 01509 223941
Email: D.Davis@lboro.ac.uk
---------- Forwarded message ----------
Date: Wed, 20 Nov 1996 16:22:45 +0100 (MED)
From: Bart Freriks
To: mrodgers@umabnet.ab.umd.edu
Subject: GRF-vector systems
Being the Research and Development department of a Rehabilitation
Center (het Roessingh, Enschede, the Netherlands) with a special
interest in movement analysis, we have developed a budget-friendly,
real-time ground reaction force (GRF) visualisation system a few
years ago. We use this system daily in our clinical service (e.g.
movement analysis in CP children) as well as in a number of research
projects.
The system superimposes the GRF-vector meausured by a 3D force
platform on the video image which is taken of the subject with an
ordinary commercial available video camera. The resulting picture can
be recorded on video tape which allows frame-by frame replay
afterwards. Since the projection of the GRF vector on the video-image
is done in real-time, the system can also be used in situations in
which direct feedback from the subject is desired (double tasks,
stability in standing, etc.). The system is very easy to operate.
Subjects can be recorded from both lateral and frontal side.
In the beginning of next year, we hope to have the system available
for others via a partner. Then we will introduce it as part of another
system: the VisionPlus system. The VisionPlus system can be regarded
as a multi media (movement analysis) PC. It is a dedicated PC which
contains both the hard and software to realise a number of 'basic'
applications which can be used in (clinical) movement analysis:
The basic applications are:
1. VIVEC II: If a force plate (and amplifier), an ordinary videocamera
and an ordinary VCR and/or television screen will be connected to the
VisionPlus system, it is possible to combine the GRF-vektor with a
video-image as explained above. 2. Myo-vision: If an EMG amplifier, an
ordinary videocamera and an ordinary VCR and/or television screen will
be connected to the VisionPlus system, it is possible to superimpose
muscle activation patterns of (up to 8) muscles on the video image of
a subject. 3. DualView: If 2 videocameras, a VCR and/or a television
screen will be connected to the VisionPlus system, it is possible to
show and record the subject from 2 views (e.g. frontal and lateral)
simultaniously.
Basic applications can be combined into more =91advanced=92 applications
by just connecting the necessary additional equipment (EMG, Force) to
the VisionPlus system. As such it is possible to gradualy extend the
VisionPlus system starting with one of the above explained 'basic'
applications and ending at a VisionPlus system which combines both the
GRF-vector of a subject, his/her (up to 8) muscle activation
patterns, and both the lateral and frontal view in one single video
image simultaniously and store this on a video tape.
Today I will fax you some brochures concerning the VIVEC II
application as well as the muscle activation patterns application.
I hope I have given you the desired information.
Please do not hesitate to call, fax or mail us if you have any
questions. Best regards,
ir. Bart Freriks
Roessingh Research and Development b.v., Enschede, the Netherlands
********************************************
ir. Bart Freriks
Roessingh Research and Development bv
Roessinghsbleekweg 33
7522 AH ENSCHEDE
The Netherlands
Phone: +31-53-4875734
Fax: +31-53-4340849
E-mail: b.freriks@rrd.nl
Internet: http:\\www.introweb.nl\~rrd