US 7,593,534 B2
Transducer for bioacoustic signals
Bjoern Knud Andersen, Struer (Denmark)
Assigned to Bang & Olufsen Medicom A/S, Struer (Denmark)
Appl. No. 10/518,588
PCT Filed Jun. 23, 2003, PCT No. PCT/DK03/00427
§ 371(c)(1), (2), (4) Date Dec. 21, 2004,
PCT Pub. No. WO04/002191, PCT Pub. Date Dec. 31, 2003.
Prior Publication US 2005/0232434 A1, Oct. 20, 2005
Int. Cl. A61B 7/04 (2006.01)
U.S. Cl. 381—67  [181/131; 181/132] 12 Claims
OG exemplary drawing
 
1. A transducer assembly for transducing bioacoustic signals, comprising:
a transducer element having a front side and a rear side;
a housing, the housing subject to ambient noise and comprising a surface surrounding the front side of the transducer element, the transducer element and the surrounding surface of the housing situated to establish intimate coupling with a surface of a body part during use, the body part surface defining a source of the bioacoustic signals; and communicating an ambient noise through an opening in the housing and to the rear side of the transducer element and receiving ambient noise at the front side of the transducer element when the housing establishes intimate coupling with the body part surface during use; and thereby reducing ambient noise and
an ambient noise suppression arrangement comprising a selected area ratio of an effective area of the transducer element sd relative to an area of the surrounding surface of the housing sh, wherein the effective area of the transducer element sd is less than 50% of the surrounding surface area sh and the selected area ratio provides for increased ambient noise suppression within a frequency range associated with the bioacoustic signals.