Flow monitoring device
US4627840A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 28, 1985 |
| Grant date | Dec 9, 1986 |
| Priority date | — |
| Expiry date | Jan 28, 2005 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61M5/16886
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
The flow monitoring device is used with a pump casing on an outflow tube having a passageway therethrough with a wall thereabout. A solenoid pump communicates with the passageway for providing pulsatile liquid flow therethrough. A reduced-in-thickness area along the wall of the casing or outflow tubing has an outside surface establishing a site to measure pulsatile flow along an adjacent inside surface. A thermistor is mounted on the outside surface of the wall area for sensing the temperature thereof in response to pulsatile flow therebeneath. The thermistor is electrically energized at a predetermined level. A control circuit regulates the input of electrical energy to the thermistor for predetermined time periods. The control circuit includes a sample and hold circuit and a reset switching circuit responsive to the pump activation for supplying thermistor power after pumping begins. An amplifier in the control circuit compares differences in the input power to the thermistor during a selected time interval to measure the pulsatile flow rate through the passageway.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.