Patient controlled infusion apparatus and method
US5084021A · kind A · utility
Inventor
Key dates
| Filing date | Nov 2, 1990 |
| Grant date | Jan 28, 1992 |
| Priority date | — |
| Expiry date | Nov 2, 2010 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61M2005/1405
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
Patient controlled analgesic (PCA) infusion apparatus and method are disclosed, in which a liquid desired to be self-infused into a patient is controllably supplied from a positively pressurized supply reservoir to a lower pressure dose chamber of a patient operable syringe from which the patient may expel the liquid and infuse such into a suitable infusion site, as through a cannula inserted into the patient, the supply of liquid from the reservoir to the dose chamber being controlled by a flow control metering tube assembly, including a connecting tube with a flow-restricting metering rod disposed therein and of a selected effective length such that the combined flow impedance of the flow path formed by the overall flow metering tube and rod provide a selected flow rate for a reference fluid and reference pressure differential. The flow control metering tube assembly may be suitably constructed by empirical testing and sizing of individual flow control tube/rod assemblies to achieve a desired flow impedance. A suction, preferrably forming a vacuum-induced void, is automatically effected in the dose chamber by a return spring acting on a piston forming a rear wall of the dose cham…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.