General Questions
Technical Questions
GENERAL QUESTIONS
What is SIMM? Who uses it?
SIMM is a software package used by health care professionals, scientists, engineers, and animators to construct, model, animate, and analyze three-dimensional musculoskeletal systems. Unlike traditional animation and mechanical CAD packages, the SIMM software suite- SIMM, Gait Module, and the Dynamics Pipeline- is specifically designed to work with systems that consist of bones, muscles, ligaments, and tendons.
In SIMM, a musculoskeletal model consists of a set of body segments that are connected by joints. The joints are modeled
using detailed, accurate kinematic functions, or as simple pin or ball-and-socket joints. The model includes muscle-tendon
actuators that span the joints and develop force, thus generating moments about the joints.
How do I get SIMM pricing or place a SIMM order?
- Call Motion Analysis Corporation at 707.579.6500, and ask for a SIMM sales representative.
- Email us - at info@motionanalysis.com.
- Fax us- 707.526.0629, to the attention of the sales department.
In your request, please include your name, company, phone and fax numbers, and email address if you have one. Please also indicate whether you would like the SGI or Windows version (if SGI, include the machine ID of your SGI workstation). If you have a purchase order number, please include that too.
What kind of workstation can SIMM be run on?
SIMM runs on IBM-compatible PCs running Windows 95, Windows 98, or Windows NT 4.0. SIMM also runs on Silicon Graphics workstations running IRIX 5.3 or higher.
Can I run SIMM from a remote location (using X-windows, for example)?
You cannot run SIMM on any computer other than the machine it is assigned to, not even another SGI on your network. SIMM is
password protected, and this password is assigned to one specific machine.
What is the Dynamics Pipeline?
We offer the Dynamics Pipeline software as an add-on option to the SIMM base package. Dynamics Pipeline connects SIMM to SD/FAST (please see the next question for more details about SD/FAST) to simulate the dynamics of rigid-body systems. The Pipeline is a general-purpose software package that enables users to perform forward and inverse dynamics simulations on musculoskeletal models. For forward dynamics, the user specifies the on/off times of muscles- the Pipeline computes the resulting motions of the body segments. For inverse dynamics, the user specifies the time histories of the joint angles during some activity- the Pipeline calculates the torques required to generate that motion.
What other software components are required to run Dynamics Pipeline?
To use the Dynamics Pipeline, you must also (separately) purchase SD/FAST, an analysis package by Symbolic Dynamics. Symbolic Dynamics can be contacted by e-mail or phone at 650.960.1532.
Is the Order(N) option of SD/FAST required? What does it add?
The SD/FAST Order(N) option is not required. It would provide a performance boost if the model size is more than 15 or 20 degrees of freedom, but is otherwise the same as the default formulation. MusculoGraphics customers typically do not
purchase the Order(N) option.
What motion files are compatible with the Gait Module?
SIMM currently works with .htr,.anb, and .xls files.
Do SIMM or the Dynamics Pipeline take advantage of multi processor workstations or of the SGI's texture mapping capability?
SIMM will not take advantage of the 2nd processor in a 2 processor Octane, nor will it make use of its texture mapping capabilities. Simulations created with the Dynamics Pipeline will run more quickly on the 2 processor Octane.
TECHNICAL QUESTIONS
How do I get the "machine ID" of my Silicon Graphics workstation?
You have to install and run SIMM to get the "machine ID" of your system. If you do not have a password yet, or if it has expired, an error message will appear on the screen. In that message will be the machine ID. It is a series of 8 characters and is a combination of both numbers and letters. (Often it will start with 690....., or 0.......)
How do I make and include 3-D bone models?
- Digitize it by hand.
- Scan it.
- Download it.
- License models from us.
- License models from others.
Our customers digitize bone models by "hand" and then import them into SIMM. The digitizing strategies range from physically touching the bone with a digitizing probe (perhaps using an Immersion probe), recording the 3D data, or in a more automated fashion using a Cyberware 3D scanner. Others will use a CT scanner and trace the bone contours using 3D reconstruction software that is available from several sources.
For "standard" anatomies, some SIMM customers have licensed models from companies that sell 3D models (e.g., Viewpoint Datalabs or Visible Productions).
Can a 3-D image created by a CT system be loaded into SIMM and animated?
Custom bone models, created from CT or MRI data, can be put into SIMM and animated, but this process has some time-consuming steps. SIMM does not have any utilities to create a polygonal surface model of a bone from medical image data, so you will need to find some other program to do this. (There are several vendors who sell this type of product.) After creating the surface model, you need to convert the file into a format that SIMM can read (the utility program 'norm,' which comes with SIMM will do this for you). Once you load the bone into SIMM, you still need to define how it moves relative to the other bones. This involves creating joints and specifying the translations and rotations between the new bone and the old ones. It can take anywhere from one day to a few weeks to do this for a musculoskeletal model with 3 or 4 body segments.
How do I create an image from a SIMM model?
For SGI/IRIX SIMM users:
- In SIMM, manipulate the model until the desired image is obtained.
- Using snapshot, set the picture frame over the desired region and take a picture of the image.
- Using imgworks convert the image into .gif format (or .tiff or .jpeg).
How do I create an animated GIF from a SIMM model?
SIMM 2.0 contains a new utility for saving TIFF images of the model window. This utility can save either a single image or a sequence of them (e.g., to capture an entire motion sequence). Once you have the set of TIFF images, you can use a third-party application to assemble them into an MPEG or Quicktime movie, or an animated GIF.
For SGI/IRIX SIMM users using versions prior to 2.0:
- In SIMM, manipulate the model until the desired starting point is obtained.
- Determine the number of frames that you wish to work with. From this number, choose a reasonable angle increment value.
- Using snapshot, set up the picture frame over the desired region. Take a
picture of the starting point.
- Move the model by one increment, then take another picture of the image.Repeat this step until the animation is complete.
- Change the images to .gif format using imgworks.
- Using imgworks convert each image into .gif format.
- Open Gif Construction Set (a PC-based shareware program) or a similar program and choose animation wizard.
- Follow the directions to finish the animated GIF. The animation will be saved like a normal GIF file...filename.gif.
How do I make a videotape of a SIMM animation?
There are two ways of doing this.
- Low-resolution/low-budget... videotape straight from the screen.
- Mid-resolution/mid-budget... download an inexpensive screen capture software such as Camtasia ($150) or Hypercam ($30)
- Hi-resolution/higher-budget... dump SGI output straight to a VCR (this assumes that you have
a video out available on your SGI).
