Autopriming a micro-cassette while minimizing the formation of air bubbles in a pumping chamber
US6475178B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 10, 2000 |
| Grant date | Nov 5, 2002 |
| Priority date | — |
| Expiry date | Sep 28, 2020 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61M2205/12
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A pump used to infuse a medical liquid into a patient is autoprimed under the control of a microprocessor that monitors and adjusts a priming sequence to minimize the accumulation of small air bubbles within a pumping chamber of the cassette. Small air bubbles can be created by the agitation of liquid and air within the cassette during priming, and as a result of changing pressure conditions within the cassette. Adherence of the air bubbles on the walls of the pumping chamber can negatively affect performance of the pump. The microprocessor controls the flow of liquid into the pump cassette from a liquid supply to establish a layer of liquid at the bottom of the air trap, thereby preventing air bubbles within the air trap from moving into the pumping chamber. The layer of liquid acts as a one-way valve, allowing air to rise up from the pumping chamber and pass through the liquid layer into the air trap, but preventing air from passing through the liquid layer and down into the pumping chamber. The microprocessor then back primes the cassette until air is removed from the proximal liquid line connecting the liquid supply to the cassette. At that point, liquid is pumped from the liqu…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.