Audiometer
US4667683A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 11, 1985 |
| Grant date | May 26, 1987 |
| Priority date | — |
| Expiry date | Jun 11, 2005 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61F11/04
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
Audiometer apparatus comprises an electrostatic transducer having insulated electrodes for application to the skin on the head of a patient and driven by an ultrasonic frequency carrier signal generated in a series resonant circuit including the impedance of the body tissues between the electrodes, the carrier frequency being determined by the series resonant circuit. The amplitude of the carrier is modulated at an audio frequency, and operating parameters such as the magnitude of the current fed to the electrodes and the modulation frequency are controlled automatically in response to preselected values preset therein. Current and modulation frequency values are preset stepwise into a manually adjustable preselectors having detents formed by cooperating magnetic elements establishing successive rest positions corresponding to steps to which the preselector may be set. The preselector is formed with spaced apart segments disposed to cooperate with a pair of optointerruptors to cause the latter to generate stepping pulses and pulses indicating the direction of adjustment of the preselector.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.