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Betty Troy
08-04-1997, 03:28 AM
Hello All:

Here is a list of replies I received from my request for information on
goniometers last month. We are still in the process of researching
possibilities.

THANK YOU so much for your helpful input!

-- Betty

Original message sent on 7/10/97:
>Hello All:
>
>We are searching for goniometers to be used to measure hip, knee, and ankle
>angles during gait and functional tasks (along with video motion analysis
>and accelerometry). Can anyone offer me any advice or experiences (ie,
>accuracy, ease of attachment, how it was chosen?) with particular
>goniometric systems which are commercially available in measurement of
>joint angles in the lower limb?
>
>I have browsed the BIOMCH-L archives. Many listings were on the Penny &
>Giles flexible goniometers & I've received information from the company.
>Experiences of others with the system are still welcome.
>
>Also, any advice on attatchment methods/innovative adaptations of
>goniometers would be appreciated as well.
>
>Betty Troy, MSBME
>Biomedical Engineer
>
>troy@roses.stanford.edu
>Dept. of Veterans Affairs Health Care System
>RR&D Center
>Palo Alto, CA
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Replies:
Try cantacting MIE Medical research this sound right up there street.
you can contact Dr. Malcolm Ellis on +44-113-2793710 I think they can
be found on the net but I don't know where.

Yours
Dr. Robert Levi
(Slovakian Biomechanics Research Centre)
R-Levi@usa.net
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Betty,

We're using Penny and Giles goniometers to measure
dorsiflexion/plantarflexion and knee flexion/extension in children (with
CP). We've used pretty much the P&G Laboratory system interfacing to a
laptop PC through a PCMCIA data acquisition card and developed our own
software to control data capture and storage. I am very pleased with the
system we've ended up with.

The inherent accuracy of the measuring equipment appears to be in the range
of +/-2 degrees within the range of movements we wish to measure at the knee
and ankle (primarily in a single plane). This accuracy is degraded if there
are large movements out of this plane and I would want to do careful tests
if for example I was measuring hip flexion in the presence of significant
ab/adduction or internal/external rotation.

We asked P&G to modify the goniometer by turning the fixed endblock through
90 degrees so that it is perpendicular to the sensitive element for the
ankle goniometers. This means they can be mounted laterally with the distal
end along the lateral aspect of the calcaneus and the proximal end along a
line from lateral malleolus to fibular head.

I was also not very happy with P&G's normal approach of applying the
goniometers to a fairly loose protocol and zeroing them whilst on the
patient with the joint held in a predefined position. Particularly at the
ankle I was concerned as to how repeatable this reference postion could be
obtained. We have therefore chosen to zero the goniometers accurately before
applying them and then apply them in accordance with a well specified protocol.

The goniometers are attached with double sided sticky tape which generally
works well although we tend to reinforced this with a paper surgical tape.

We have found some small technical problems with the instrumentation (odd
MHz frequency noise on output from signal amplifiers, significant 50Hz noise
probably arising from earth compatability problems when using the laptop on
the mains supply, a batch of goniometers which drifted significantly over a
patient test session). P&G have been most obliging in helping us rectify
these. Having spent six months developing the system now I feel I understand
the equipment well and would be happy to give you any more specific advice
you might require.

Richard Baker
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Hi Betty,

Before you do anything you should have a look at Polhemus products. I have
experience with one of their triaxial magneitc goniometers, the ISOTRAK II.
Depending on your application, this may be the best bet. The FASTRAK is a
good system. It consists of a transmitter which emits three magnetic fields
orthogonally, and four receivers. You can place the receivers on the desired
body segment, and the transmitter somewhere convenient (with a cheaper
system you have to mount in on the body, but a more expensive option - the
long ranger, allows the transmitter to be in a location in tha lab.)
Position and orientation of the sensors relative to the source is recorded
at 120hz with one sensor. It reduces to 30Hz with 4 sensors (I think these
figures are correct).

Disadvantages are the umbilical cables, and you can't use it near metal due
to interference. I have used it for triaxial tracking of subtalar joint
motion and found it excellent. The word excellent reflects price, too - you
could buy the system for about 7000 pounds. Software from Polhemus I think
is very expensive (but is very impressive, from what I have seen), but a
decent programmer could use MATLAB to devise suitable software. When I was
using it the latter option was taken, and it only cost a few thousand pounds
I think.

If you want to pursue this, the address is:
Polhemus
One Hercules Drive
Colchester
Vermont
05446-0560

If you need any further info. let me know.
Hope this helps
Ian Mathieson
University of Wales Institute,
Western Avenue
CARDIFF
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
We manufacture both electrogoniometers and motion analysis equipment.

Please have a look at our web site and if you would like any further
information
then please do not hesitate to contact me at M.Ellis@mie-uk.com

Web Site address. http://www.mie-uk.com

Best Regards,
Malcolm.
Tel: +44 (0)113 2793 710
Fax: +44 (0)113 2310 820
www: http://www.mie-uk.com/index.htm
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
From: "Gregory S. Klopp"
Subject: goniometers
To: troy@roses.stanford.edu
Date: Fri, 11 Jul 1997 15:16:02 -0400 (EDT)
MIME-Version: 1.0

Dear Ms. Troy,

Our experience with the Penny and Giles product is that there is a lot
of cross-axis sensitivity. It is also easily damaged. We have had better
luck with angular rate sensors (Applied Technology Associates, Albequerque,
NM) which measure angular velocity directly. It requires some effort to
develop competency but the results have been satisfactory.
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Betty,

Hi. Thanks for forwarding the information that you found on goniometers.

I've encountered some of the products that were mentioned in the email
messages that you forwarded.

MIE Medical Research makes a wireless gait analysis system that might
interest you; perhaps you've already visited their website.

I've had direct experience with Polhemus sensors in my work and the sensors
I used are not terribly impressive. They have what I consider a very
limited spatial range, and their performance degrades (i.e. it becomes
noisier) as the receiver approaches the limit of its useful range. They
are also adversely affected by local metallic objects and any device that
emits emi.

Finally, I've spoken with a sales rep from Penny & Giles (in Santa Monica,
I believe), and found that their sensor amplification add-on hardware options
were somewhat unsatisfactory (for my application). For example, you can
buy a "table-top" amplifier to which the sensors are physically connected
by wire. The amplifier interfaces to a PC, but it is not portable. The
only other option of which I am aware is a "data logger" that can accept
only 4 channels of data (e.g. 4 one-degree-of-freedom measurements or 2
two-degree-of-freedom measurements). It can store data and is
portable, but, as far as I know, it can't talk to a PC in real time.
(This is not sufficient for my application.)

There's a company called Noraxon that uses P&G goniometers, but has attached
a proprietary wireless interface to them. The basic system cost is $8500,
but the telemetry hardware costs extra. You can reach them at 1-800-364-8985
or email them at info@noraxon.com.

Below are references to a few WWW sites that might be of interest to you.

Eric
>>>>
http://www.peakperform.com/peakres.htm
Peak Performance Technologies, Inc. Other Resources

WWW Sites
* 3-D Analysis of Human Movement
* American Academy of Orthopaedic Surgeons
* American Physical Therapy Association
* BIOMCH-L Search Page
* Biomechanics World Wide
Web Resources
* British Columbia Institute of Technology,
Health Applied Research and Development Program
*
Clinical
Gait Analysis Website
* Dalhousie University Kinesiology and Ergonomics
* Human Kinetics, Information Leader in
Physical Activity
* International Society of Biomechanics (ISB)
* The National Centre for Prosthetics and
Orthotics, La Trobe University, Melbourne
* Sport Information Resource Centre
----------------

News Groups
* BIOMECH_L (an electronic mail discussion forum for biomechanics and
movement science). To subscribe, e-mail: LISTSERV@nic.surfnet.nl
Syntax in message: SUBSCRIBE BIOMCH-L firstname lastname (city, state,
and/or institution)
* CGA (an electronic mail discussion forum for Clinical Gait Analysis). To
subscribe, e-mail: listproc@info.curtin.edu.au
Syntax in message: subscribe CGA "your name"
* SPORTSCI (an electronic mail discussion forum for sports science). To
subscribe, e-mail: majordomo@stonebow.otago.ac.nz
Syntax in message: subscribe sportsci
----------------

Conferences
* American Academy of Physical Medicine and Rehab, October 10-13, 1996,
Chicago, IL
* 1996 Intersociety Conference: The Integrative Biology of Exercise,
October 16-19, 1996, Vancouver, BC
* 20th American Society of
Biomechanics, October 17-19, Atlanta, GA
* Pedorthic Footwear Association, November 11-14, 1996, San Antonio, TX
* Society for Neuroscience 1996, November 16-21, 1996, Washington, DC
* Society fo Intergrative and Comparitive Biology, December 26-30, 1996,
Albuquerque, NM
* American Physical Therapy Association's Combined Sections, February
13-15, 1997, Albuquerque, NM Peak will be exhibiting at or attending all
of the above conferences. For more information or if you have comments,
questions, or ideas, please send us an e-mail message.
----------------
Return to Peak Performance Technologies, Inc. Home Page
-----
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Dear Betty Troy,

I have made very good experiences with bioviosion here in Germany.
Also B.Nigg from Calgary is using their equipemnt as far as I have
received information from there.
The products are priced very moderate, so you can afford those things
you need. Mr Hanno Ernst is also a very trained man on the subject of
biomechanics - he is in the field of biomech. since I think about 25
years. He has also always some very good tricks in attaching sensor,
etc. to the body !
You could contact them under email biovision.ernst@t-online.de.
Try them I would suggest.

Yours sincerely,

Dr. med. Oskar Schmid
Director MOTION LAB
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I came across your posting in the BIOMECHANICS newsgroup, and thought that
I would introduce myself - I work for Virtual Technologies, Inc., a company
that you might already be familiar with (particularly since the majority of
our staff comes from Stanford!). We have undertaken a great deal of
research and development in areas that appear relevant to your research.
Indeed, we are poised to release our CyberSuit, a full body wireless motion
capture suit at the upcoming SIGGRAPH 97 (Press Release attached). You may
also want to check with Steve Kautz and Machiel Van der Loos at the VA,
since they recently worked with us to evaluate an initial prototype
lower-extremity assembly (LEA)portion of our CyberSuit.

I hope that this information helps.
Best
John


Virtual Technologies, Inc. Premieres the CyberGraspSYMBOL 212 \f "Symbol"
Haptic Feedback Glove and
the CyberSuitSYMBOL 212 \f "Symbol" Wireless Full-Body Motion-Capture
Suit at SIGGRAPH 1997

FOR IMMEDIATE RELEASE
PALO ALTO, Calif. (July 3, 1997) - Virtual Technologies, Inc., creator of
the award-winning CyberGlove∆ instrumented glove, announced today that it
will be unveiling its new CyberGraspSYMBOL 212 \f "Symbol" haptic
feedback glove, along with its CyberSuitSYMBOL 212 \f "Symbol" wireless
full-body motion-capture suit at SIGGRAPH 97, the computer graphics
conference and exhibition being held August 3 - 8, 1997, in Los Angeles,
California. Demonstrations will be conducted at Virtual TechnologiesŪ
booth (#539) during regular exhibit hours from August 5 - 7. Show
attendees will have the opportunity to experience žfirst handÓ
computer-generated virtual objects using the CyberGraspSYMBOL 212 \f
"Symbol" system, and view the world premiere of the CyberSuitSYMBOL 212
\f "Symbol" body-measurement suit.
CyberGraspSYMBOL 212 \f "Symbol" is a compact, lightweight
force-reflecting handmaster option for the CyberGlove∆ instrumented glove
which adds resistive force feedback to each finger. This innovative
grasp-force feedback device allows an application developer to individually
program the movement-impeding force applied to each fingertip of the
CyberGlove∆ wearer. The CyberGraspSYMBOL 212 \f "Symbol" system enables
an intuitive žreach in and grab itÓ interface, allowing users to literally
žfeelÓ virtual and tele-manipulated objects.

The CyberSuitSYMBOL 212 \f "Symbol" is a wireless full-body
motion-capture system employing Virtual TechnologiesŪ proprietary
bend-sensor technology to measure the movement of the entire human body.
Developed under NASA contract for use on space missions, the
CyberSuitSYMBOL 212 \f "Symbol" records the position of the ankle, knee,
hip, back, neck, shoulder, elbow, forearm, wrist and hand. The joint
sensors are low profile and unencumbering, allowing fluid, natural
movements and a wide range of dynamic activity. During operation, the
CyberSuitSYMBOL 212 \f "Symbol" is fully untethered, requires no external
reference sensors, has no line-of-sight limitations, and is unaffected by
the presence of metallic objects in the surrounding environment. A moving
graphical body model may be displayed in real-time since no post-processing
of the sensor data is required.
žOur CyberGraspSYMBOL 212 \f "Symbol" force-feedback system adds a
powerful new 5-finger haptic dimension to 3D human-computer interface
design,Ó announced Dr. James F. Kramer, President and Founder of Virtual
Technologies. žSimilarly, our CyberSuitSYMBOL 212 \f "Symbol" represents
a breakthrough in untethered body sensing for real-time production,
animation, test and measurement, and biomechanical applications.Ó
The CyberGraspSYMBOL 212 \f "Symbol" haptic-feedback option and the
CyberSuitSYMBOL 212 \f "Symbol" full-body wireless motion-capture suit
are the newest offerings in Virtual TechnologiesŪ expanding product lines.
Since its founding in 1990, Virtual Technologies, Inc. has been a
recognized leader within the realm of body-sensing and haptic feedback.
Other Virtual Technologies products include the CyberGlove∆ 18-sensor and
22-sensor instrumented gloves, the award-winning CyberTouchSYMBOL 212 \f
"Symbol" vibrotactile feedback option for the CyberGlove∆, the
VirtualHand∆ Toolkit graphical hand software, and the GesturePlusSYMBOL
212 \f "Symbol" hand-gesture recognition system.
For more information, contact:
John H. Doffing
Marketing Director
Virtual Technologies, Inc., 2175 Park Boulevard, Palo Alto, CA 94306, USA
Tel: 1-415-321-4900 Fax: 1-415-321-4912
doffing@virtex.com http://www.virtex.com
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Dear Betty

I noticed your mail on the BIOMCH-L b/board and your request for any
attachment methods/adaptations of gonios. Apart from the standard
information you have, we can develop different types of gonios which may be
easier to attach to a subject, given we know what you are trying to measure
(e.g. we have developed right/left angle goniometers to aid the attachment
to CP victims and also gonios with very small end blocks to afix to small
joints on infants)

If you have anything specific you are looking for but do not see it in our
literature, please let us know as we may be able to help you.

Kind regards
Mary Wilding
Biometrics Ltd (formally Penny & Giles Biometrics ltd) - UK
Tel: +44 1495 200800
Fax: +44 1495 200806
Date: 14 July 1997
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Dear Betty Troy:
Our company is manufacturing 3-axial digital goniometers for recording
motion at hip, knee and ankle joints while walking and different motion
tests. The system is called "BIOMECHANIKA". The recoding timing of
walking cycle, reaction of force, EMG is also available.
Our software is build for WINDOWS-95. The date of investigation have
an export function to a different format.
If you will interesting to get more information just let me know by:

address:
MBN company
109180, Russia,
Moscow, B. Ykimanka St. 27-17

tel/fax (095) 238-3773

e-mail mbn@mbn.msk.su

Yours,
Dmitri Skvortsov
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Dear Ms. Troy-
I work for the National Highway Traffic Safety Administration (biomechanics
R&D). We are measuring ankle rotation during dynamic impacts to the foot usi
ng angular rate sensors (Applied Technologies Associates, magneto hydrodynamic
angular rate sensors). We attach a three axis angular rate sensor assembly t
o the tibia and another at the heel. We then pass the data through an algorit
hm (using incremental euler angles) to compute the rotation at the ankle.
We had looked at the Penny & Giles goniometers four years ago but found cons
iderable cross-axis sensitivity. Hence, we went for the MHD sensors.
We have heard that new goniometers are now available along with algorithms
for cross-axis sensitivity compensations. We are therefore very interested in
the replies you have received to your question. Would you please keep us pos
ted on this. Thank you in advance.

Shashi Kuppa
Senior Research Engineer
Conrad Technologies Inc.
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