Oxygen enriched reciprocating piston respirator
AssigneeLifecare Services, Inc.
InventorsRaymond D. Chu, Anthony C. Rubner, Marc A. Bergman
Life of this patent
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Abstract
A variable flow reciprocating piston respirator system which is capable of providing a substantially constant oxygen enrichment over an entire inspiration stroke of a variable flow respirator output. A proportional control valve is used to deliver oxygen from an oxygen supply tank to the output of a reciprocation piston pump. A microprocessor controls the magnitude of opening of the proportional valve to insure that a proper overall volume of the output is produced with the proper percentage of enrichment of oxygen.
Claims17
A variable flow reciprocating piston respirator system which is capable of providing a substantially constant supply gas enrichment of a reciprocating piston gas produced by said reciprocating piston respirator throughout an inspiratory stroke of said reciprocating piston respirator comprising:
- reciprocating piston respirator means for producing a variable flow output of said reciprocating piston gas;
- supply gas reservoir means for providing a source of said supply gas to be admixed with said reciprocating piston gas;
- control valve means for regulating flow of said supply gas from said supply gas reservoir means;
- means for combining said flow of said supply gas from said control valve means with said variable flow output of said reciprocating piston gas downstream from said reciprocating piston respirator means;
- and,
- airway means for inducing turbulence sufficient to substantially mix said supply gas with said variable flow output of said reciprocating piston gas from said reciprocating piston respirator means;
- logic means for generating a control signal for regulating said control valve means such that said flow of said supply gas from said control valve means produces said substantially constant supply gas enrichments.
A system for providing a substantially constant oxygen enrichment in a variable flow reciprocating piston respirator comprising:
- piston pump means for producing a variable flow output;
- oxygen supply means for providing a flow of oxygen at a supply pressure substantially higher than pressures of said variable flow output produced by said piston pump means for combination with said variable flow output downstream from said piston pump means;
- control valve means for regulating said flow of oxygen from said oxygen supply means;
- and,
- microprocessor means for generating a instantaneous oxygen flow signal to control operation of said control valve means such that said control valve means produces an instantaneous flow of oxygen resulting in a variable flow respirator output having an oxygen enrichment which remains substantially constant for an inspiratory stroke and a flow profile and volume corresponding to a preselected flow profile and volume.
A method of producing a substantially constant oxygen enrichment in a reciprocating piston respirator which uses a piston pump to produce a variable flow output comprising the steps of:
- determining an instantaneous flow of oxygen to produce said substantially constant oxygen enrichment;
- controlling operation of a control valve to deliver said instantaneous flow of oxygen;
- combining said oxygen delivered by said control valve downstream from said piston pump;
- inducing turbulence in an airway for delivering said variable flow output and said oxygen to a patient to substantially mix said oxygen with said variable flow output.
A method of producing a proportionally substantially constant preselected percentage of oxygen in a variable flow reciprocating piston respirator system comprising the steps of:
- computing a pump volume (VP) to be delivered by said variable flow reciprocating piston respirator system using a total preselected volume (VT) to be delivered and said substantially constant preselected percentage of oxygen considering oxygen present in said pump volume (VP);
- computing a volume of oxygen (VO) to be delivered by an oxygen supply by subtracting said pump volume (VP) from said total preselected volume (VT);
- computing a differential locational position value for a next segment by subtracting a locational position value for a next segment time from a locational position value for a current segment time;
- computing a ratio term (RT) by dividing said differential position value by a total number of locational position valves for an entire stroke;
- computing a ratio term for oxygen (RT.sub.O.sbsb.2) by multiplying said ratio term (RT) by the quotient of VO divided by VT;
- computing an instantaneous flow of oxygen (F.sub.O.sbsb.2) by multiplying said ratio term for oxygen (RT.sub.O.sbsb.2)by an instantaneous total flow (F);
- generating a control signal for opening a control valve to deliver oxygen at a flow rate substantially equal to F.sub.O.sbsb.2 by computing an opening magnitude from a stored performance table for said control valve.
The method of claim 13 further comprising the steps of:
- reducing said control signal during expiratory strokes to close said control valve;
- detecting an oxygen content output signal from an oxygen content detector while said valve is closed;
- increasing said control signal during said expiratory strokes until said oxygen content detector indicates a flow of oxygen to produce an oxygen control valve turn-on value;
- storing said oxygen control valve turn-on value for use in said stored performance table.
Dependencies are inferred from the claim text.