Brett F. BuSha

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The quantification of respiratory variability may provide insight into the integrative control of breathing. To test the hypothesis that sleep and/or increased chemical drive modifies respiratory variability, six male adult Sprague-Dawley rats were instrumented with diaphragm electromyographic (EMG) electrodes and exposed to 0, 2.5, and 5.0% CO2 with a(More)
During sleep, patients with obstructive sleep apnea (OSA) have repetitive episodes of upper airway collapse, which are terminated by increased activity of upper airway dilator muscles. The repetitive activation of the genioglossus (GG) may result in muscle remodeling. We hypothesized that OSA patients have an altered length-force relationship, increased(More)
STUDY OBJECTIVES The objectives of the study were to characterize spontaneous arousals during NREM sleep in piglets and to compare two methods of identifying these events: a "visual" technique using spectral analysis and an automated technique using wavelets. Our goal was to understand the benefits and limits of these methods when applied to sleep in human(More)
Over 450,000 Americans suffer from debilitative disorders resulting in the loss of proper hand function. A lightweight, non-cumbrous, orthotic hand exoskeleton was designed to restore normal pinching and grasping finger motions. Three functional digit mechanisms were designed: a thumb, index, and grouped third digit, comprised of the middle, ring, and small(More)
Evidence of the Hering-Breuer reflex has been found in humans during anesthesia and sleep but not during wakefulness. Cortical influences, present during wakefulness, may mask the effects of this reflex in awake humans. We hypothesized that, if lung volume were increased in awake subjects unaware of the stimulus, vagal feedback would modulate breathing on a(More)
Imperceptible levels of proportional assist ventilation applied throughout inspiration reduced inspiratory time (TI) in awake humans. More recently, the reduction in TI was associated with flow assist, but flow assist also reaches a maximum value early during inspiration. To test the separate effects of flow assist and timing of assist, we applied a(More)
Cardiorespiratory variability is the product of the integration of centrally generated rhythms with feedback from central and peripheral sensors. To quantify the effect of increased central drive on scaling patterns of cardiorespiratory activity, breath-to-breath interval (BBI) and heartbeat-to-heartbeat interval (RRI) were recorded from 17 female and 17(More)
  • Brett F. BuSha
  • Conference proceedings : ... Annual International…
  • 2010
The effect of filtering and data set length on the accuracy of the quantification of fractal characteristics of cardiorespiratory activity remains unclear. Breath-to-breath interval (BBI) and heartbeat-to-heartbeat interval (RRI) were recorded from 8 healthy human subjects during a quiet seated posture. Movement artifact was filtered from the raw(More)
Every year, thousands of Americans suffer from pathological and traumatic events that result in loss of dexterity and strength of the hand. Although many supportive devices have been designed to restore functional hand movement, most are very complex and expensive. The goal of this project was to design and implement a cost-effective, electrically powered(More)
We investigated the role of V(T) and V(T)/T(I) modulation of breathing in awake human subjects. We applied a PRBS of volume (incrementing ramp) or flow (decrementing wave) assist at levels below the perceptual threshold in order to stimulate respiratory feedback. We modeled the PRBS data with linear difference equations to obtain impulse-response profiles(More)