Apparatus and method for taking the derivative of a slowly varying electrical signal
US3978414A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 25, 1975 |
| Grant date | Aug 31, 1976 |
| Priority date | — |
| Expiry date | Mar 25, 1995 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06G7/184
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
An electrical circuit for operating upon a slowly varying input signal (on the order of one volt per minute) to provide an output signal representative of the input signal derivative. The circuitry employs at least two feedback loops, one of which is constructed similar to an integrator amplifier. One particularly useful electro-medical application of this apparatus and method lies in the measurement of osmotic fragility of red blood cells, where percentage hemolysis of the blood slowly varies as a function of tonicity of suspension of the medium in which the blood sample is suspended. In this measurement the exact point of maximum slope is important and is provided by the present invention.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.