The biomechanics facilities at The Johns Hopkins University are situated on the second floor of the Ross Research Building on the Johns Hopkins medical campus. The facility has specific functions related to biomechanics and biomaterial research. The Ross Research Building laboratory occupies approximately 2,500 square feet and is used for material and implant testing, simulations of joint function and loading, pre-operative computer simulation and analysis of joint stability and contact pressure. This facility is also used to conduct animal experiments and tissue histomorphometric analysis. Close cooperation exists between various clinical services in different affiliated hospitals of The Johns Hopkins School of Medicine and the biomechanics laboratory facilities. These afford the biomechanics laboratories access to biological specimens for use in testing and validation studies, as well as databases required for clinical studies. These databases include archives of patient radiographs and other images, as well as motion and EMG data from gait evaluations. Most of the computational and graphics capabilities are provided by Silicon Graphics computer workstations, consisting of an Onyx 2 machine, an Indigo model for the web server, and a Windows NT-based Visual Workstation. The total on-line storage capacity on these stations, including attached auxiliary disk drives is more than 18 Gigabytes. Large storage capacity and powerful graphics capabilities are essential for processing the large image datasets. Other long-term storage and backup capability is provided by a 2 GB optical disk drive and two DAT format tape drives. Multimedia input and output options are available from four HP Laserjet 4 laser printers, a dedicated PC based CCD image acquisition system, a Polaroid digital slide-maker and a Sony LVR video frame recorder (for generating animations). Additional video equipment includes a Panasonic S-VHS recorder and JVC large-screen monitor. In addition to the workstations, the lab is equipped with eight Macintosh and ten PC-compatible computers connected by a high-bandwidth fiber-optic data line that allows file and resource sharing to be transparent. Three-dimensional image reconstruction and segmentation is performed using ANALYZE (Biodynamics Research Unit, Mayo Clinic, Rochester, MN), which is made available to us by a research sharing agreement. Software has been written in-house for contour digitization and mesh triangulation, allowing construction of solid models of biological structures. We use the VisLab (TM) software from Engineering Animation Incorporated for visualization of solid models and joint kinematics. The Patran 3 software, from PDA engineering, combined with Abaqus is used for finite element mesh generation and solution. Numerous other proprietary programs have been developed in the laboratory for joint and muscle force prediction, contact pressure analysis, and image processing purposes. In addition to the computer equipment, the following items are located in the laboratory: - A three-controller joint functional simulator developed and fabricated in close collaboration with MTS (MTS Systems, Inc., Eden Prairie, Minnesota). The kinematics of an anatomical or prosthetic joint can be tested in one to five degrees of freedom. All displacements in rotation and translation at the joint and its proximal and distal anatomic connections can be recorded by potentiometers and linear displacement transducers. Up to three muscle contractions can be simulated using floating hydraulic actuators. This simulator was designed to study dynamic joint contact pressure distribution and joint kinematics in intact and surgically altered knee specimens. It can be easily modified to study other joints, such as the hip, ankle and shoulder.
- Histomorphologic analysis equipment and image analyzer
- 'A Flock Of Birds' (© Ascension Technologies Inc.) for three-dimensional rigid body motion measurement. This is a 3 sensor system.
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