Previous and Ongoing Projects

Project Title: Wireless Accelerometer Node Project Date: 2006-2007 Project Description: A wireless accelerometer node was developed that logs data to on board memory at 1000Hz. The developed sensor platform supports accelerometers from +/-2g to +/-250g. Both single and dual axis accelerometers have been tested. The sensor board is light weight (less than 15grams) and is powered by either one or two 3V coin cell battery Conclusion: The accelerometer node has been tested by measuring: The impact accelerations during vertical jumping, and correlating the results with ground reaction forces measured by a force plate. Accelerations that develop upon impact during an egg drop contest. (The miniature sensor node was placed in a toy plastic egg.)

Wireless accelerometer sensor node. Note the node's size compared to a toy chicken egg.

Project Title: Smart Hip Project Granted by: Confidential Inc. USA. Project Date: 2001 Project Description: Self-powered strain sensor was attached to two very rigid (Titanium and Stainless Steel) Hip Implants. Instron biomechanical tests were performed. Piezoelectric material picked up the strains, converted the strain into electrical power, and powered a transmitter. The transmitter sent out a signal to a remote receiver wirelessly (1meter away). Signals were processed on a PC attached to the receiver in real time. Conclusion: Enough power generated to activate the telemetry unit even in these ultra stiff implants. Loading magnitude could be determined in real time.

Hip implant showing attached PVDF sensor/ generator for monitoring Torsional Loading.

Project Title: XFixMonitor Project Granted by: Confidential Inc. Switzerland Project Date: 2001 to present Project Description: The aim was to monitor the load on an external fixation device in real time. These external devices (3d structural frames) are indicated for patients with long bone trauma. Conventional strain gauges were applied to the bars of these implants. The signals were electronically conditioned, and 5 channels of data were telemetered from the patient to a receiver 10 meters away. The data was acquired at 120samples/second. The receiver was attached to a PC that processed, computed and displayed the data to the surgeon and patient in real time. Patient activity could be monitored, as well as the progress of healing. Conclusion: Telemetry system was functional even when the transmitter was not in direct line of sight of the receiver. Patient activity could be assessed accurately in real time. The device is awaiting clinical trials in Europe.

Remote unit: instrumented external rod with telemetry unit clamped on, separate power pack and flexible cord. Bench-top loading of the frame and remote unit.

Project Title: 3D Analyses and Dynamic Simulation Project Granted by: Confidential Ltd, South Africa Project Date: 2004 Project Description: The aim was to perform three dimensional computer analyses of a stacker and tripper machine. This machine is used in conveyor systems to stack material in piles. The machine runs along rails; the conveyor belt is "tripped" and elevated; the material falls onto the boom stacker; the conveyor on the stacker moves the material and the material falls off the stacker onto a pile stack. Proprietary software sweet, Frame3D was used. Three sets of analyses were conducted, all in 3D: static analysis, modal analysis to extract the first 6 natural frequencies, and a transient dynamic simulation. The movie included here shows the structural behavior as the conveyed material starts to run onto the machine. Conclusion: 3D Static, Modal and Dynamic analyses conducted. Stacker boom more flexible than the tripper. Dynamic transient deflections are not critical.

Movie of 3D Dynamic Simulation: Conveyor material starts to run onto the structure. Proprietary software Frame3D was used.

Project Title: QStroke Project Granted by: Greg Ruckman, US Olympic Rower Project Date: 2001 Project Description: The aim was to monitor the loading in two oars and to display the time history of the strain in oars to the rowers in real time. Piezoelectric strain sensors were applied to the oars of two US Olympic level rowers. The signals were filtered/ processed and a graph of the strain magnitude was displayed on a miniature lap-top for the rowers to observe in real time. (The lap-top was housed in the scull’s cock-pit). Conclusion: Piezoelectric film was an effective and robust strain gauge in wet (rowing) applications. Real time strains in oars can synchronize rower’s power input, and the real time display gives them bio-feedback. Project was tested successfully on the Charles River, MA during four rowing sessions.

Greg Ruckman winning the Olympic Rowing Trial (2004).

Project Title: Smart Distal Locator Project Granted by: Confidential Inc., Germany. Project Date: 2001 to present. Project Description: The aim was to find blind holes in implants without the use of radiography (x-rays). The device is a type of robot. The sensors are mounted on a moveable arm that searches and locates on magnetic fields. The magnetic fields emanate from a magnetic probe. An acquisition system collects the 3 channels of data. A microprocessor performs calculations, and controls the output display. The surgeon follows the output signals (audible and visual). Conclusion: Sensitive magnetometers used successfully. Sophisticated assembler language programming of the microprocessor carried out. Blind holes located in matter of seconds. Product was tested successfully in several cadaver tests. Prototype is awaiting clinical trials

Smart Distal Locator used in finding blind holes in implants.