Medical & biological engineering & computing
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Med Biol Eng Comput · Jul 2011
Predicted effects of pulse width programming in spinal cord stimulation: a mathematical modeling study.
To understand the theoretical effects of pulse width (PW) programming in spinal cord stimulation (SCS), we implemented a mathematical model of electrical fields and neural activation in SCS to gain insight into the effects of PW programming. The computational model was composed of a finite element model for structure and electrical properties, coupled with a nonlinear double-cable axon model to predict nerve excitation for different myelinated fiber sizes. ⋯ Thus, variable PW programming in SCS appears to have theoretical value, demonstrated by the ability to increase and even 'steer' spatial selectivity of dorsal column fiber recruitment. It is concluded that the computational SCS model is a valuable tool to understand basic mechanisms of nerve fiber excitation modulated by stimulation parameters such as PW and electric fields.
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Med Biol Eng Comput · Jul 2011
EditorialEffectiveness of medical equipment donations to improve health systems: how much medical equipment is broken in the developing world?
It is often said that most of the medical equipment in the developing world is broken with estimates ranging up to 96% out of service. But there is little documented evidence to support these statements. We wanted to quantify the amount of medical equipment that was out of service in resource poor health settings and identify possible causes. ⋯ An average of 38.3% (42,925, range across countries: 0.83-47%) in developing countries was out of service. The three main causes were lack of training, health technology management, and infrastructure. We hope that the findings will help biomedical engineers with their efforts toward effective designs for the developing world and NGO's with efforts to design effective healthcare interventions.