Stethoscope
US6438238B1 · kind B1 · utility
Inventor
Key dates
| Filing date | Jul 14, 2000 |
| Grant date | Aug 20, 2002 |
| Priority date | — |
| Expiry date | Jul 14, 2020 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61B2562/0204
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A chest piece for a stethoscope has a housing with a cavity. The cavity has a cavity surface which is paraboloid in shape, having an apex, an axis, and a focal point. The cavity terminates at the apex and an opening, and the focal point resides in the cavity. A transducer is positioned at the focal point. The parabolic shape of the cavity surface acts to reflect sound waves transmitted normal to the opening to the transducer, while reflecting other sound waves. A mechanical wave guide with a series of parallel passages preferably extends across the opening. Preferably, a membrane with a convex surface covers the opening. The cavity is preferably filled with a liquid or gel having physical characteristics similar to human flesh. To reduce noise from motion of the chest piece across the skin, the stethoscope can be activated by a pressure switch responsive to fluid pressure inside the cavity.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.