Abstract: A wearable blood pressure meter includes a semi-conformable bladder, serving as a reservoir for an incompressible fluid, and a pressure sensor. The semi-conformable bladder includes a rigid housing defining a cavity within which the incompressible fluid is rigidly constrained and an elastic membrane for elastically constraining the incompressible fluid. The elastic membrane extends across an aperture into the cavity through the rigid housing. The elastic membrane conforms to a body part at the aperture when pressed against the body part. The pressure sensor mechanically couples to the incompressible fluid to measure pressure signals emanating from an artery within the body part and which propagate through the conformable membrane and the incompressible fluid to the pressure sensor.