Patient controlled analgesia apparatus
First Claim
1. Apparatus for dispensing a sequence of quantities of liquid with an interval of time between said dispensing of each of said quantities in sequence, said interval having a duration, said apparatus comprising:
- a body having a first bore which is a reservoir,a pump, installed in said body and having a stroke motion and a full stroke and comprising at least two check valves,means for operating said pump,a fill fitting,a dispensing fitting,a second bore in said body and a slide valve installed in said second bore being adjustable to a plurality of settings and slideable in said second bore and having a cylindrical surface and a groove in said surface,means for adjusting said valve to said settings so that at each of said settings said groove in said surface indexes with one of said plurality of grooves,a first passage in said body from said pump to said dispensing fitting,a first of said check valves of said pump in said first passage,a second passage in said body extending from said reservoir toa plurality of passages in said body from said second passage to said plurality of grooves,a third passage in said body from said plurality of grooves to said pump,a second of said check valves of said pump in said third passage,whereby setting said slide valve so that said groove in said cylindrical surface indexes with one of said plurality of said grooves around said bore provides a flow path from said reservoir to said pump via the one of said plurality of passages leading to said one of said plurality of said grooves, said apparatus further comprising;
means of limiting said stroke motion of said pump to any of a plurality of stroke portions in correlation with said means for adjusting said valve,whereby said stroke portions are correlated with flow to said pump from said reservoir through the passage of said plurality of passages to which said groove on said cylindrical surface of said valve is indexed.
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Accused Products
Abstract
The subject patient controlled analgesia (PCA) apparatus is mechanical/hydraulic and comprises a reservoir and a pump operable by the patient for dispensing medicine from the reservoir unto the patient'"'"'s IV system in incremental doses. The pump capacity per stroke may be adjustable, thereby adjusting the size of each dose dispensed. Timing apparatus assures that a specific interval of time (the lockout interval) must pass between sequential dosage dispensations. Check valves in the passages for pumping the medicine and filling the apparatus are double in series to reduce chances of malfunction or misuse due to valve failure. The quantity of medicine in the reservoir is indicated.
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Citations
12 Claims
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1. Apparatus for dispensing a sequence of quantities of liquid with an interval of time between said dispensing of each of said quantities in sequence, said interval having a duration, said apparatus comprising:
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a body having a first bore which is a reservoir, a pump, installed in said body and having a stroke motion and a full stroke and comprising at least two check valves, means for operating said pump, a fill fitting, a dispensing fitting, a second bore in said body and a slide valve installed in said second bore being adjustable to a plurality of settings and slideable in said second bore and having a cylindrical surface and a groove in said surface, means for adjusting said valve to said settings so that at each of said settings said groove in said surface indexes with one of said plurality of grooves, a first passage in said body from said pump to said dispensing fitting, a first of said check valves of said pump in said first passage, a second passage in said body extending from said reservoir to a plurality of passages in said body from said second passage to said plurality of grooves, a third passage in said body from said plurality of grooves to said pump, a second of said check valves of said pump in said third passage, whereby setting said slide valve so that said groove in said cylindrical surface indexes with one of said plurality of said grooves around said bore provides a flow path from said reservoir to said pump via the one of said plurality of passages leading to said one of said plurality of said grooves, said apparatus further comprising; means of limiting said stroke motion of said pump to any of a plurality of stroke portions in correlation with said means for adjusting said valve, whereby said stroke portions are correlated with flow to said pump from said reservoir through the passage of said plurality of passages to which said groove on said cylindrical surface of said valve is indexed. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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Specification