Abstract: Apparatus and associated methods for a wound valve assembly provide an annular space extending radially around a central portion of a valve, which valve acts to substantially relieve pressure build up in a thoracic cavity when applied to a thoracic wound. In an illustrative example, the valve assembly may form an annular space that extends radially in all directions around a check valve. In some examples, gasses and exudates may flow substantially radially and/or parallel to the patient's local body. Various embodiments may advantageously provide open fluid communication for the gasses and exudates escaping from the wound when the valve assembly is partially covered (e.g., body armor, clothing, blankets), or when the patient may be laying down on the side of the body with the wound, for example.

Abstract: Methods and apparatus to provide low harmonic distortion AC power for distribution by converting energy from natural or renewable sources into electrical form, and constructing a current waveform on a primary winding of a transformer by recapturing inductive energy previously stored in the transformer so as to transform the converted electrical energy into substantially sinusoidal AC voltage at a secondary winding of the transformer. For example, AC power may be supplied to a utility power grid from raw electrical energy from renewable energy sources (e.g., solar cells). An inverter may construct the primary winding current waveform using two unidirectional switches. On each half cycle, one of the switches first applies energy previously recaptured from primary winding inductance, and then applies the raw energy to the transformer primary winding at the utility power grid frequency. Accordingly, the constructed primary winding current may exhibit substantially improved total harmonic distortion.

Abstract: Apparatus and associated systems and methods may relate to a process for supplying unidirectional current to a load, controlling a reverse electromotive force (REMF), capturing inductive energy from the load, and supplying the captured inductive energy to the load. In an illustrative example, an operating cycle may include a sequence of operations. First, inductive energy captured from the load on a previous cycle may be supplied to the load. Second, energy may be supplied to the load from an external power source. Third, a REMF voltage may be substantially controlled upon disconnecting the power source from the load. Fourth, the load current may be brought to zero by capturing the inductive energy for use on a subsequent cycle. In some embodiments, a single power stage may supply a DC inductive load, or a pair of power stages may be operated to supply bidirectional current to an AC load.