Patent attributes
A wrist-worn apparatus capable of sensing pulsation of blood in the blood tubes of a user's wrist with high accuracy. The apparatus comprises a body of the apparatus, a band to be used to wear the body of the apparatus on the user's wrist, and a fluid-containing pulsation-sensing fluid chamber provided on the user's wrist side of the case. A part of an outer wall that defines the fluid chamber comprises an elastically deformable member that is elastically deformed depending on pulsation of blood transmitted from the band to thereby change the fluid pressure within the fluid chamber. A deformation preventing member is bonded by vulcanization to a part of a side of the deformable member that will come into contact with the user's wrist for preventing the part of the deformable member from being elastically deformed.