Attributes of a human or animal body are detected by the generation and detection of an electric field. A laminated membrane (202), connected to a control circuit, is placed over an electrically conductive ground-plane (201). An upper-mattress (203) is placed above this for supporting a human or animal body. To improve the response of the detector, a response-enhancement-layer (204) of a substantially electrically non-conducting compressible-material containing electrically-conductive-particles, such as carbon particles, is located between the laminated-membrane (202) and the upper-mattress (203).
