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Full-Text Articles in Engineering

A Low-Field P-31 Nmr Spectrometer To Measure Bone Mineral In The Human Wrist, Joseph Battocletti, Thomas Meyers, Robert Scheidt Mar 2015

A Low-Field P-31 Nmr Spectrometer To Measure Bone Mineral In The Human Wrist, Joseph Battocletti, Thomas Meyers, Robert Scheidt

Robert Scheidt

Nuclear magnetic resonance phosphorus spectroscopy (NMRS) is a method of measuring the mineral content of bone as a diagnostic tool for osteoporosis. A description is given of the design and construction of a low-field spectrometer for the human wrist. It uses a small-size permanent magnet of neodymium-iron-boron. The questions of whether a low-field spectrometer is sensitive enough to measure the phosphorus mineral content of bone and to what extent the phosphorus in soft tissue affects the measurement of bone mass are discussed


Visuomotor Learning Enhanced By Augmenting Instantaneous Trajectory Error Feedback During Reaching, James Patton, John Yejun, Preeti Bajaj, Robert Scheidt Aug 2014

Visuomotor Learning Enhanced By Augmenting Instantaneous Trajectory Error Feedback During Reaching, James Patton, John Yejun, Preeti Bajaj, Robert Scheidt

Robert Scheidt

We studied reach adaptation to a 30u visuomotor rotation to determine whether augmented error feedback can promote faster and more complete motor learning. Four groups of healthy adults reached with their unseen arm to visual targets surrounding a central starting point. A manipulandum tracked hand motion and projected a cursor onto a display immediately above the horizontal plane of movement. For one group, deviations from the ideal movement were amplified with a gain of 2 whereas another group experienced a gain of 3.1. The third group experienced an offset equal to the average error seen in the initial perturbations, while …


Visuo-Proprioceptive Interactions During Adaptation Of The Human Reach, Timothy Judkins, Robert Scheidt Aug 2014

Visuo-Proprioceptive Interactions During Adaptation Of The Human Reach, Timothy Judkins, Robert Scheidt

Robert Scheidt

We examined whether visual and proprioceptive estimates of transient (mid-reach) target capture errors contribute to motor adaptation according to the probabilistic rules of information integration used for perception. Healthy adult humans grasped and moved a robotic handle between targets in the horizontal plane while the robot generated spring-like loads that varied unpredictably from trial-to-trial. For some trials, a visual cursor faithfully tracked hand motion. In others, the handle's position was locked and subjects viewed motion of a point-mass cursor driven by hand forces. In yet other trials, cursor feedback was dissociated from hand motion or altogether eliminated. We used time- …