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Full-Text Articles in Biomedical Engineering and Bioengineering

Mems Capacitive Strain Sensing Elements For Integrated Total Knee Arthroplasty Prosthesis Monitoring, Boyd Mccutchen Evans Iii Dec 2007

Mems Capacitive Strain Sensing Elements For Integrated Total Knee Arthroplasty Prosthesis Monitoring, Boyd Mccutchen Evans Iii

Doctoral Dissertations

Measuring the in vivo load state of Total Knee Arthroplasty (TKA) components is required to understand the structural environment and wear characteristics of the devices. The ability to acquire this information gives tremendous insight into the mechanics of the joint replacement prosthesis. Data corresponding to normal loads, in-plane loads, shear loads, load center, contact area, and the rate of loading is needed to fully understand the kinematics and kinetics of the orthopedic implant. In this research, a novel sensing system has been developed which is capable of fully characterizing three-dimensional strain and stress at a single location.

Capacitance-based sensors were …


Design And Evaluation Of A Non-Intrusive Corn Population Sensor, Haizhou Li Aug 2007

Design And Evaluation Of A Non-Intrusive Corn Population Sensor, Haizhou Li

Doctoral Dissertations

Specific objectives of this study were to develop, prototype, and test a corn population sensor. Both intrusive mechanical and non-intrusive capacitive techniques have been used to develop the stalk population sensors in previous research. However, neither could generate consistent performance. The mechanical method required high maintenance and resulted in significant underestimations of stalk counts. The performance of capacitive systems was limited by inadequate sensing distance, especially at low stalk moisture levels.

In this research, the sensitivity of the capacitive sensor was optimized for corn stalks. This system utilized a single-sided capacitive sensor, Wien bridge oscillator, phase-locked loop, and an operational …