There is provided a method of controlling a powered air purifying respirator blower system to deliver a substantially uniform volumetric airflow to a user, the system comprising a fan powered by a variable speed electric motor, the motor is controlled by an electronic control unit for delivering a forced flow of air through at least one filter to a user, comprising the steps of: (a) monitoring system loading; and (b) decreasing a speed of the electric motor when system loading reaches a predetermined value. There is also provided an air purifying respirator blower system using such a method.

A system is disclosed. The system includes a reservoir for containing a fluidic medium, the reservoir including a front surface, a resilient cylindrical flexure portion connected to the front surface, the resilient cylindrical flexure portion comprising an accordion-like structure that is able to expand and contract to change an interior volume within the resilient cylindrical flexure portion, a central passageway within the resilient cylindrical flexure, and a collection chamber connected to the central passageway. Also, a system including a reservoir, a plunger head located within the reservoir, a plunger arm connected to the plunger head, a driving shaft connected to the plunger arm, and a motor connected to the driving shaft, the motor controllable to move the drive shaft in a first motion and a second motion so as to move the advance plunger head and retract the plunger head within the reservoir.

A needleless injection system is provided to deliver therapeutic fluids to an internal treatment site in a patient, where the system is pressurized and is capable of compensating for differences in injection media viscosity and mechanical system characteristics. In one aspect, a needleless therapeutic fluid injection system is provided that includes modular, interchangeable components. In particular, the system includes a console that generally includes the electronic and/or hydraulic control components for the system, an injection chamber, and a shaft or catheter tube.

The disclosed subject matter relates to extracorporeal blood processing or other processing of fluids. Volumetric fluid balance, a required element of many such processes, may be achieved with multiple pumps or other proportioning or balancing devices which are to some extent independent of each other. This need may arise in treatments that involve multiple fluids. Safe and secure mechanisms to ensure fluid balance in such systems are described.

A fluid injector system for delivering a multi-phase fluid injection to a patient and methods of fluid delivery is disclosed. Methods of creating and using a multi-aspect fluid path impedance model of the injector system are used. Modeling and adjustment of factors that affect impedance and prevent or reduce backflow, reduce the likelihood of fluid flow rate spikes and provide more accurate flow rates and mixing ratios of fluids may be repeated or happen essentially continuously during an injection. The adjustments may be determined before the injection or determined and/or adjusted during the injection. The determination may include sensor feedback commonly used in injectors such as pressure and position feedback as well as other sensors. In all cases, the user can be notified of adjustments through on-screen notices and/or through the recordation of the injection data by a control device of the injector at the conclusion of the injection.

A mechanical ventilation system comprises a mechanical ventilator configured to deliver ventilation to a patient. An electronic controller is programmed to control the mechanical ventilator to perform a mechanical insufflation-exsufflation (MI-E) therapy method including performing a MI-E cycle including: (i) during an insufflation cycle, delivering pressure to the patient at a positive insufflation gauge pressure; (ii) during an exsufflation cycle following step (i), delivering pressure to the patient at a negative exsufflation gauge pressure and detecting whether an upper airway collapse occurs; and (iii) reducing a magnitude of the negative exsufflation gauge pressure if an upper airway collapse is detected in step (ii).

Provided is an oxygen concentration device which, as an oxygen concentration device having a reduced difference in flow rates of gas which flows through a pressure equalization valve of a pressure equalization path during a purge step and a pressure equalization step, is provided at at least one end side of the pressure equalization valve with a pressure control member having a difference in pressure loss due to the direction of gas flow so that pressure loss of the gas which flows through the pressure equalization path in one direction becomes nearly equal to that of the gas which flows therethrough in the opposite direction.

A device for delivering medicament into skin of a patient, the device having a housing, which includes a reservoir for housing the medicament, a first internal region that is sealed from fluid ingress and includes one or more components, and a second internal region that is not sealed from fluid ingress and includes one or more components. The housing also has a barrier that separates the first internal region and the second internal region, a delivery cannula that delivers the medicament into the skin of the patient, and a base including a bottom surface for orienting toward the skin of the patient. The bottom surface of the base has one or more fluid channels disposed therein and at least one of the fluid channels is in fluid communication with the delivery cannula.

A pressure switch for controlling application of negative pressure to dressing disposed adjacent a tissue site is disclosed. The pressure switch comprises a body having a base, sidewalls extending from the base to an open end, and an inlet coupled to the dressing and forming a passage through the body. The pressure switch further comprises a diaphragm closing the open end of the sidewalls and forming a vacuum chamber with the body, wherein the inlet fluidly couples the vacuum chamber and the dressing. The pressure switch further comprises a valve disposed in the passage and configured to restrict the flow of gas through the passage so that a switch pressure developed in the vacuum chamber as a result of the application of negative pressure to the dressing lags a wound pressure at the tissue site to delay, wherein the diaphragm is adapted to be operatively responsive to the switch pressure to move between a relaxed position and a compressed position as the negative pressure increases and decreases. This pressure switch further comprises a switching element coupled to the diaphragm to turn on the negative pressure in the relaxed position and turn off the negative pressure in the compressed position. In another example, a method for controlling application of negative pressure to dressing disposed adjacent a tissue site using a pressure switch is disclosed. In another example, a system for applying negative pressure to a tissue site using a pressure switch is disclosed.

A pressure indicator for a respiratory treatment device, the pressure indicator including an instrument for measuring pressures, a conduit configured to transmit a pressure within the respiratory treatment device to the instrument, and a pressure stabilizer orifice positioned within the conduit.