I hope that the readers of BIOMCH-L and their associates and
students will find the following useful in their research.
Dwight Meglan
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Software for the Analysis and Display of Human Locomotion
PC DOS Version, January 1994
by Dwight Meglan
The Anz/Telio/Show3d package is a set of computer programs for use
in the research as well as the clinical evaluation of human
locomotion. Together, these allow the analysis, plotting, and
graphical display in 3 dimensions of body segment kinematics and
kinetics. The software, originally developed for VAX/VMS in
FORTRAN at The Ohio State University Gait Analysis Lab and now
running under DOS on IBM PC 386 and higher compatible computers, is
being made available in source code and executable form to
facilitate researchers and clinicians in the development of their
own locomotion analysis software. The previous release of this
software in the Fall of 1991, though only for VAX computers at that
time, is being used by a number of groups.
ANZ
Anz uses measured marker trajectories to produce estimates of
spatial limb kinematics, absolute and relative, including
translational and rotational velocities and accelerations. These
can be combined with force plate data to evaluate net joint
resultant loads and joint power transfers. The majority of the
analysis methods are based upon segmental local coordinate systems
that are marker system independent. Several marker sets are
currently supported including clinical full body marker sets
(Helen Hayes, Ohio State, and Cleveland Clinic), a research full
body marker set developed at Mayo Clinic, an upper extremity
marker set, and a detailed foot kinematics marker set . Many
general kinematics and kinetics procedures are included as well as
a number of gait specific evaluations. In a number of evaluations,
several methods are provided to do the same calculation to provide
checking of algorithm validity. Muscle EMG data may also be
processed with digital filtering. The program is command line
based and can be operated interactively for exploratory analysis
can be used repeatedly via command or batch files to yield a
production environment for clinical gait evaluation. The results
of an analysis are stored in a single binary format file
constructed to be transportable between different computers. The
contents of this file can be examined with Telio to produce
graphs, Show3d to produce 3D figures, or exported from Anz in text
format for further processing. The commands used to produce the
analysis results are stored in the Anz binary file providing a
history of the calculation process.
TELIO
Telio is a command line driven program to graphically display the
results of ANZ analyses. It can also read several data file formats
native to the VICON marker tracking system. The program has a
flexible display format so that screen displays and/or printouts
can be produced using either time series or crossplotting of data.
Data may be read from multiple files and a number of graphs
generated at one time. A macro facility has been included to
simplify generating complex displays. Combined with a command or
batch file, printouts of data can be produced without any user
interaction. Thus, the program functions as both an exploratory and
a production display tool. A number of gait specific features are
included to produce clinically useful gait displays. The VOGLE
graphics subroutine library is used to provide device independent
graphics capabilities. On the PC the program can display on a
number of graphics adapters and produce print files in several
formats including postscript.
SHOW3D
Show3d generates 3D views of marker trajectories and body segments
as analyzed by Anz to allow visualization of motion from any
direction. Body segments are represented by parallelapipeds to
emphasize nonsagittal plane motions. Segments may be represented
with hidden lines removed. A number of customization options are
available including the display of the images on screen and/or via
printed form. This program also uses the VOGLE graphics package.
The program produces nice animations when used on a fast 486 PC.
SOURCE CODE
The source code uses VAX extensions to FORTRAN but no system
specific routines, so it should be possible to use any FORTRAN
compiler supporting VAX extensions. The PC versions of
ANZ/TELIO/SHOW3D have been developed with the WATCOM 32bit FORTRAN
compiler. In addition, the VOGLE graphics library has been
customized for use with the WATCOM 32bit C compiler. Use of other
compilers will surely require at least changes in the makefiles if
not the source code of the programs.
Presently, the software supports VICON and AMASS video and analog
data files as well as Motion Analysis Corporation video and analog
data files.
The source code is rather large, totaling about 2.5 MBytes. The
software is copyrighted and has been placed in the public domain as
a research and instructional tool only and as such is UNSUPPORTED.
The source code may be freely modified and redistributed for
nonprofit purposes as long as the changes are clearly marked and
the origin of the software, Dwight Meglan and The Ohio State
University Gait Analysis Laboratory, is mentioned.
Further details regarding the distribution of ANZ/TELIO/SHOW3D can
be found on the ftp archives in the file legalise.txt
REQUIREMENTS
ANZ/TELIO/SHOW3D use a DOS extender so they must be run on 386 or
better PC compatible computers. They are very disk and memory
intensive- a legacy of their VAX origins. The executables are quite
large- around 6 to 9 Megabytes and when running require at least
16MBytes of free disk space for a virtual memory swap file. They
also require a math coprocessor. The graphics programs, TELIO and
SHOW3D, should work on EGA or better adapters though I recommend at
least a VGA (SVGA is supported).
The programs were developed on a 66MHz 486 with 16M RAM and run
quite well on it. They have not been tested on other configurations.
AVAILABILITY
Source code and DOS executables of these programs as well as sample
data and documentation are available in PKZIP archive files. These
are available via anonymous FTP from:
magnus.acs.ohio-state.edu in directory /pub/gaitlab
Copies of hand written notes of the derivations of the kinematics
and kinetics algorithms within ANZ (~50 pages) are available from
the program author for $10 US (to cover duplication and shipping).
If FTP access is not available, the PC archives with derivation
notes can be obtained from the author for $20 US.
All requests for derivation notes or copies of the software should
be sent prepaid in US currency to:
Dwight Meglan 626 Sheridan Rd. #2 Evanston, IL 60202 USA
Inquires: dmeglan@merle.acns.nwu.edu
HISTORY
ANZ/TELIO/SHOW3D came about because the gait analysis lab at Ohio
State needed to replace their locomotion analysis software. That
package was originally written in Pascal under RSX on a PDP
computer. It was brought from Boston when Dr. Sheldon Simon moved
the gait lab from Brigham and Women's Hospital to Ohio State.
I sought to create a program that would allow the analysis of much
more than locomotion and would be transportable to other computers.
At the time the computer language I was most familiar with was
FORTRAN and this was the only compiler we had on the VAX which was
the target platform. The graphics display programs were created to
allow exploration and automation of the presentation of the results
of gait analyses. SHOW3D was created because I thought that 3D
pictures with solid shapes for the segments were more effective in
conveying the data than the stick figures largely in use by other
labs at the time. The DI3000 graphics package was originally used
because we got it for free through a campus wide license. During
this time, I also put together a version of ANZ for the Macintosh
using Language Systems FORTRAN. This version, which was created
for my convenience since I was working at home a lot on my
dissertation, no longer exists.
When the programs were released in the fall of 1991, I had numerous
requests for a PC version. At that time, I had finished my
doctorate at Ohio State and was at the Mayo Clinic Orthopaedic
Biomechanics Lab doing a post-doc. We used a VAX there which happen
to have DI3000 on it, so I was not inclined to go through the
effort of converting the programs. I added a number of new
analyses to ANZ while at Mayo- some for studies in the lab, some
for my own exploration. These were not in the 1991 release.
After finishing at Mayo, I needed to do additional work to get my
doctoral work published, which required ANZ, TELIO, and SHOW3D.
Since I do not have a VAX at home and developing the Macintosh
version left me with unpleasant memories and I was continuing to
get requests for a PC version, I opted to port the software to DOS.
The current release and all future releases (if there are anymore)
will be for DOS. The FORTRAN has been adapted to the WATCOM 32bit
FORTRAN compiler. The graphics were converted from DI3000 to a nice
3D public domain graphics package called VOGLE. VOGLE is written in
C, so it was adapted to the 32bit WATCOM C compiler (mainly the
screen drivers were changed) and an interlanguage call interface
added. So after ten months of on again, off again work, there are
PC versions of all three programs.
They work well for me. Hopefully they will for others. If they
don't, change them so they do- everything is here so you can.
FINAL NOTE
This code is UNSUPPORTED. It has been used extensively in both
clinical and research contexts and I have tried to validate all
the calculations, but with something this large there are bound to
be some latent problems. I am interested in hearing about uses of
the code by others, improvements, or problems identified. I cannot
help with debugging or teaching others about what is in here. This
is intended to be used as a teaching tool for those interested in
studying human locomotion kinematics and kinetics primarily, not
as a finished clinical product. In reality it is being used as such
and I am confident that it carries out this role well, but I do not
have the time or desire to support this set of programs as would be
required for a clinical product.
Comments can be sent to: Dwight Meglan, dmeglan@merle.acns.nwu.edu
This address should be valid until at least Summer 1993. I would
prefer email contact because of the potential for people calling
me inspite of all the disclaimers above.
This software package was developed to meet the clinical and
research needs of the gait analysis lab at Ohio State University,
and later at the Mayo Orthopaedic Biomechancs Lab, and to be used
as part of the my doctoral research. The dissertation focuses upon
several new techniques of human locomotion analysis and as such
goes beyond the areas covered by the ANZ/TELIO/SHOW3D software. In
most cases, the results of gait analyses done with ANZ were used
as the starting point for these other analyses. Details of these
other methods can be found the dissertation:
Enhanced Analysis of Human Locomotion by Dwight A. Meglan, 1991
Department of Mechanical Engineering, The Ohio State University
It can be obtained from University Microfilms Inc. (phone #
800-521-0600) in book form for approximately $35 US and I believe
that credit cards may be used as payment. The identification number
of the dissertation is 92-01716. This work does not describe ANZ,
TELIO, or SHOW3D in any depth. You will need to look at the
derivation notes for details of the algorithms in the software.
Hopefully, all the programs described in the dissertation will
eventually be made available in the same way that ANZ/TELIO/SHOW3D
are being made available.