Sensitivity setting devices and electrocardiographs including the sensitivity setting devices
US5873838A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 7, 1997 |
| Grant date | Feb 23, 1999 |
| Priority date | — |
| Expiry date | Apr 7, 2017 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S128/901
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A sensitivity setting device and an electrocardiograph which includes the sensitivity setting device include a differential amplifier whose amplification factor is changed by a CPU and a CR differentiator connected to the differential amplifier for providing an appropriate electrocardiogram waveform. The CR differentiator includes capacitor and two parallel resistors connected with the capacitor with one of the resistors being connected to an analog switch which is switched on/off by the CPU. If there is an input electrocardiogram waveform from a pair of electrodes attached to a patient's body directly after the measurement of the electrocardiogram waveform, the electrocardiogram waveform is amplified with an initial set amplification factor by the differential amplifier and the resulting signal is inputted to the CR differentiator. When the analog switch is switched on to reduce the CR time constant of the CR differentiator, an accurate electrocardiogram waveform is picked up and an appropriate sensitivity is obtained from the amplitude of the picked-up electrocardiogram waveform. A corresponding amplification factor is then set in differential amplifier, the analog switch is swit…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.