Method for compensating for pressure differences across valves in cassette type IV pump
US6497680B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 17, 1999 |
| Grant date | Dec 24, 2002 |
| Priority date | — |
| Expiry date | Dec 17, 2019 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61M2205/50
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A pump used to infuse a fluid into a patient is controlled in accordance with an algorithm that enables a microprocessor to monitor and adjust each pump cycle to compensate for a differential pressure between the pump's inlet and outlet. The algorithm defines a fluid delivery protocol that is applied in controlling the operation of the pump to achieve a desired rate, volume, and timing of the fluid infusion. Fluid is delivered by the pump when a plunger compresses an elastomeric membrane overlying a fluid chamber. Due to the small volume of the chamber, an incremental change in the plunger position before the delivery stroke produces a significant change in the delivery pressure. At the beginning of a pump cycle, the microprocessor determines the differential pressure between the inlet and outlet of the pump, and adjusts the plunger position before the delivery stroke to compensate for the differential pressure. A retraction of the plunger from the home position decreases the delivery pressure of the fluid, and an advancement of the plunger increases it. After the position of the plunger is adjusted to compensate for the differential pressure, the pump cycle proceeds. Following the…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.