Apparatus and method for solid state storage of episodic signals
US4920489A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 14, 1987 |
| Grant date | Apr 24, 1990 |
| Priority date | — |
| Expiry date | Aug 14, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG16H40/63
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A method and apparatus for digitally storing episodic signals, such as, electrocardiogram signals is disclosed. In a preferred embodiment, the apparatus includes, for each signal channel, an input amplifier, an analog-to-digital converter, and a double data buffer. The incoming signal on each channel is converted to a multibit digital number a fixed sampling rate. Each multibit digital number is stored in a location in the double data buffer. When a fixed amount of data is stored in the buffer, a processor examines the data to determine the periods during which the signal is undergoing the most rapid rate of change. For these periods, both an indicator of the period, and a first number of data samples per unit time is stored in a bulk solid state memory. Preferably, the data stored is a number relating to the difference between the value of the sample and a number related to the value of the last sample. For other periods, having rates of data change high, but not as high as those of the first period, a smaller number of samples per unit time is stored. These samples are chosen to faithfully reproduce the minima and maxima of the waveform. For all other waveform periods, every Rth …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.