The present invention relates to neck-mount powered respirators and methods of use. The respirators comprise an air handler, a temple rail, and a shoulder rail that fits around the back of the neck and over the shoulders of the wearer. The air handler is either positioned behind the neck of the wearer or integrated into a hollow shoulder rail. The temple rail is hollow and sized to fit snugly around the back of the head and contact with the temples of the wearer. A neck conduit is hollow and interconnects the shoulder rail and the temple rail forming an airflow channel. A face shield includes an elastic band that covers the temple rail temple vents, and the eyes, nose, and mouth of the wearer. Purified filtered air inflates the region between the face shield and the face of the wearer allowing the wearer to breathe the purified filtered air.

A stator assembly has coils in a distributed winding configuration. A poly-phase switched reluctance motor assembly may include a stator assembly with multiple coils in a distributed winding configuration. The stator assembly may have a central bore into which a rotor assembly having multiple poles is received and configured to rotate. A method of controlling a switched reluctance motor may include at least three phases wherein during each conduction period a first phase is energized with negative direction current, a second phase is energized with positive current and there is at least one non-energized phase. During each commutation period either the first phase or second phase switches off to a non-energized state and one of the non-energized phases switches on to an energized state with the same direction current as the first or second phase that was switched off. The switched reluctance motor may include a distributed winding configuration.

A neck strap, a crown strap assembly and a headgear for a breathing mask. The neck strap for a headgear includes a one-piece main body adapted to engage a patient's neck, first and second lower connection portions adapted to connect to first and second lower mask connection straps, and first and second upper connection portions adapted to connect to respective first and second lateral crown straps.

A neck strap, a crown strap assembly and a headgear for a breathing mask. The neck strap for a headgear includes a one-piece main body adapted to engage a patient's neck, first and second lower connection portions adapted to connect to first and second lower mask connection straps, and first and second upper connection portions adapted to connect to respective first and second lateral crown straps.

A method of manufacturing a cushion for a respiratory mask includes providing a mold with at least two mold halves and at least one core therein, closing the mold, and injecting a first material into the mold to form the cushion. The at least one core is enclosed by the cushion thereby forming at least one cavity. The method also includes opening the mold, removing the at least one core from the cushion to provide the at least one cavity within the cushion, and sealing the cavity. The cushion includes a support plane configured to be supported on the patient's face in use. The at least one core is arranged in the cushion with a C-shape on a plane substantially parallel to the support plane.

A method of manufacturing a cushion for a respiratory mask includes providing a mold with at least two mold halves and at least one core therein, closing the mold, and injecting a first material into the mold to form the cushion. The at least one core is enclosed by the cushion thereby forming at least one cavity. The method also includes opening the mold, removing the at least one core from the cushion to provide the at least one cavity within the cushion, and sealing the cavity. The cushion includes a support plane configured to be supported on the patient's face in use. The at least one core is arranged in the cushion with a C-shape on a plane substantially parallel to the support plane.

A safety breathing apparatus has a sensor for measuring the difference in pressure between two point 1a, 1b in the gas delivered to a head unit 9. The sensor is used to measure the difference in the pressure of the gas supplied through the apparatus between the two points in the gas flow, and the pressure difference is then used to calculate the gas flow rate.

A safety breathing apparatus has a sensor for measuring the difference in pressure between two point 1a, 1b in the gas delivered to a head unit 9. The sensor is used to measure the difference in the pressure of the gas supplied through the apparatus between the two points in the gas flow, and the pressure difference is then used to calculate the gas flow rate.

A stimulation device may include a tube, where the tube defines a lumen therein and a gas outlet. The gas outlet may be configured to allow gas to pass from the lumen to an exterior of the tube. The stimulation device may also include one or more first electrodes associated with the tube, one or more second electrodes, and a nasal cavity interface proximal of the gas outlet and the one or more first electrodes.

A system for determining an optimal hardness of a patient interface device includes a fit score determination unit structured to receive a 3-D model of the patient interface device and a 3-D model of a patient's face and to determine a fit score between the patient interface device and the patient's face based on the 3-D model of the patient interface device and the 3-D model of the patient's face, and a hardness determination unit structured to determine a hardness value of the patient interface device based on the determined fit score.