The invention relates to a force or pressure sensor and a method for applying the same. The pressure sensor comprises a substantially rigid, mechanical-load resistant frame (1), a flexible diaphragm (2) secured over its peripheral rim to the frame (1), and a piezoelectric sensor diaphragm (3) applied to the surface of the flexible diaphragm (2). The sensor diaphragm (3) loading element comprises a substantially rigid, mechanical-load resistant cover (4), having its protrusion or shoulder (4a) bearing against a middle section of the flexible diaphragm (2) and thereby prestressing the flexible diaphragm (2) and the piezoelectric sensor diaphragm (3) attached thereto. The frame (1) and the cover (4) define therebetween a closed, hermetically sealed housing chamber, the flexible diaphragm (2) and the piezoelectric sensor diaphragm (3) being located thereinside. The placement of one or more responsive, yet load-resistant sensors in contact with a bed enables measuring a sleeping or lying person for his or her heart rate and respiratory amplitude, as well as frequency.