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Injury Analysis & Prevention LabEquipmentBALDER (BALance DisturbER)The BALDER system consist of a horizontal movable platform which can be moved and accelerated in X and Y direction independently of each other. A force plate integrated into the Balder platform registers any pressure of an item pressing against it. The force signals are transmitted to a Data Acquisition Processor (DAP) card which calculates the Center of Pressure Position (CPP) on the force plate. Because of BALDER being able to read just about any external signal it is possible to simulate a large variety of situations. Balders large XY-table can accelerate in any direction in the horizontal plane with up to 18 m/s2 (2g). Instead of slipping the table accelerates and thereby induces perturbation. What makes BALDER unique is the combination of high acceleration and that perturbations can be made in any direction. BALDER is designed to be integrated with a video based motion analysis system (APAS) and an electromagnetic motion tracking system (Motionstar). Additionally, a 50 feet long walkway can be attached to BALDER.
The most visual part of Balder is the platform itself. It is a 86x86x5" platform of wood, on top of an aluminum frame. The platform is movable in any XY direction in the horizontal plane. Mounted on to the aluminum frame are two AC motors that move Balder. The whole system is extensively shielded to reduce electromagnetic interference with the EMG electrodes and the electromagnetic motion tracking system. An AMTI force plate is mounted in the center of the platform. The device senses force and momentum in three orthogonal directions (X,Y,Z). From this information the Center of Pressure can be calculated. The high-end Microstar data acquisition card (DAP3200) with an onboard i486DX4-100 processor and 8 MB of RAM running its own 32-bit operating system called DAPL 2000 works as a real-time acquisition and control system in a host PC. The PC features a custom graphical user interface controlling the operation modes of BALDER and the data acquisition from the motion tracking and EMG recording systems. MotionStarTurn-key motion-capture tracker for character animation. Captures the motions of up to 120 receivers simultaneously over long range without metallic distortion. Each receiver is tracked up to 144 times per second to capture and filter fast complex motions with instantaneous feedback. Utilizes a single rack-mounted chassis for each set of 20 receivers. High-speed Ethernet or serial interface. Supported by all major animation software packages, including Alias/Wavefront, Softimage, 3D Studio, Lambsoft, Protozoa and others.
Ariel Performance Analysis System (APAS)
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Copyright © 2002 NeuroMuscular Research Center. All rights
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Balder
contains of five hardware components, he platform itself, a motor control
unit, a force plate, a DAP card, and a PC as user interface.
The
Ariel Performance Analysis System (APAS) is the most advanced
computer-based system for the measurement, analysis, and presentation of
movement performance. The study of the motion of living things is known as
"Biomechanics" and it has evolved from a fusion of the classic
disciplines of anatomy, physiology, physics, and engineering.
Biomechanical quantification are based on Newtonian equations and the APAS
analytic technique models the human body as a mechanical system of moving
segments upon which muscular, gravitational, inertial, and reaction forces
are applied. Although the system has primarily been used for
quantification of human activities, it has had some industrial, non-human
applications. The computerized hardware/software technique provides a
means to objectively quantify the dynamic components of movement and
replaces mere observation and supposition.