Invacare Corporation

Other

Gregory A Michaels

Homayoun Birangi

David D Polacsek

David D Polaseck

A rotary valve assembly for use in a process provides fluid communication and enables variable conduit interconnection and flow passage. Process cycle time is variable by means of rotational speed of through one or more apertures of a third valve member and respective alignment with one or more apertures of a first valve member and one or more apertures of a second valve member. Process step time is variable by means of adjustable position and variable alignment of aperture(s) of the first valve member and the second valve member. The rotary valve assembly provides for gradual transition and flow passage between process steps, flow metering, mixing, reversal, or any combination thereof. Process systems including the rotary valve include an adsorption process, humidity control process, heat pump process and/or water purification process among others.

Rotary valve assembly

An acoustic oxygen sensor is provided which can be used in the output lines leading from the sieve beds. This sensor can be used in communication with a microprocessor to control the production and evacuation cycles of the sieve beds, i.e., for example to determine the period for which a bed is supplied with compressed air and communicates with the reservoir as well as to determine the pressure of the compressed air and to determine the amount of time that the product gas is fed through the flow equalization path to supply an aliquot of purging gas to a used bed. In the feedback loop, the microprocessor utilizes the measured oxygen concentration and flow rate to optimize the settings necessary to achieve maximum oxygen concentration and flow rate efficiency. Since the microprocessor has the ability to make incremental changes and compare relative values, the optimum values can be determined empirically eliminating the need to perform complex theoretical calculations.

Gas concentration sensor and control for oxygen concentrator utilizing

An oxygen concentrator is provided which has a first molecular sieve bed connected to a four-way valve (i.e., a cross-over valve) which either joins the sieve bed to a pressurized air source (compressed air) or alternatively vents it to atmosphere. A second molecular sieve bed is also joined to the four-way valve in a corresponding manner. The sieve beds are joined at the outlet end to a product reservoir. The sieve beds are also in fluid communication at the outlet end by a pressure equalization flow path. A concentration equalization valve regulates the flow in the pressure equalization flow path. In accordance with the present invention, the microprocessor uses a closed-loop feedback circuit to evaluate the amount of time that the output product gas is allowed to flow into the used sieve bed. Specifically, an incremental step advance is used assuming a peak value of the time of flow one direction as compared to the time of flow in the second direction. Thus, so long as the measured oxygen output to the patient keeps increasing, the control will direct incremental advances in the valve setting in the same direction. When the measured value decreases, the control steps back to the previous setting (i.e., the penultimate setting). In a second embodiment, control is based on a variable residence time range and variable pressure set point.

Closed-loop feedback control for oxygen concentrator

A filled envelope for use with a shaped tray in a wheelchair comprises upper and lower elastomeric elements. The elements have seals about their edges to create a finite volume. The volume is filled with a fill material which comprises petrolatum and hollow glass spheres. The volume of petrolatum comprising the fill material is not substantially greater than the volume of the interstitial spaces of a quantity of hollow glass spheres alone. The envelope also has additional seals which separate the envelope into quadrants to improve the stability of the cushion to the user.

Seat cushion for wheelchairs

An oxygen concentration system for producing oxygen from air comprises an electrochemical oxygen generator mounted within an inner housing. The generator has an outer surface and is adapted to extract oxygen from air by an electrochemical reaction. The oxygen generator fits within a inner housing having the form of an annulus. The inner housing is insulated and is spaced from the outer surface of the oxygen generator to create a first passageway. Air in the first passageway is heated by the generator and rises upwardly out of the passageway by means of convection.

Method of assembling tubular electrochemical oxygen generators

An oxygen concentration system for producing oxygen from air comprises an electrochemical oxygen generator mounted within an inner housing. The generator has an outer surface and is adapted to extract oxygen from air by means of an electrochemical reaction. The oxygen generator fits within an inner housing having the form of an annulus. The inner housing is insulated and is spaced from the outer surface of the oxygen generator to create a first passageway. Air in the first passageway is heated by the generator and rises upwardly out of the passageway by means of convection.

Oxygen concentrator utilizing electrochemical cell

An oxygen concentration system for producing oxygen from pressurized air comprises an electrochemical oxygen generator which selectively extracts oxygen from air by an electrochemical reaction. The oxygen concentration system includes first, second, and third concentric enclosures. The three enclosures produce three annuli formed between the enclosures. Air enters the top of the outermost enclosure, travels downwardly through the outermost annulus, crosses over the second annulus to the oxygen generators via ports, travels upwardly through the oxygen generators and back downwardly through the second annulus. By orienting the downward flow of the oxygen-depleted air next to the downward flow of the cooler incoming air, the incoming air is heated by the outgoing hot air, thereby increasing comfort to the user and reducing energy requirements.

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Seven Hills, OH, United States of America

Gregory A Michaels