A device for monitoring blood pressure in a body member having a blood vessel using a tissue adjacent to the blood vessel, the device comprising: a device body configured to extend at least partially about the body member, the device body having an interior surface adapted to be positioned adjacent or in contact with a surface of the body member; a tissue movement detecting assembly positioned on or in the device body, the tissue movement detecting-assembly comprising a strain device; and a contact member formed as a single piece and comprising a perimeter region and a central region , the contact member adjacent to the device body and positioned to engage a surface of the tissue, where the central region of the contact member forms a tissue engaging surface protruding beyond the perimeter region of the contact member such that when the device body is positioned adjacent to tissue, the perimeter region and the central region contact the tissue to compress the tissue, the contact member also having a strain inducing surface extended from a surface opposite to the tissue engaging surface and adjacent to the tissue movement detecting assembly; wherein a compliance of the perimeter region differs from a compliance of the central region to cause the central region to transmit displacement of the contact member to a greater degree than the perimeter region such that, when the tissue engaging surface engages the tissue, displacement of tissue in a radial direction relative to the tissue caused by a change in a pressure in the blood vessel also displaces the tissue engaging surface causing displacement of the central region of the contact member in the radial direction so that the strain inducing surface alters a strain in the strain device to produce a change in an electrical property of the strain device. a device body configured to extend at least partially about the body member, the device body having an interior surface adapted to be positioned adjacent or in contact with a surface of the body member; a tissue movement detecting assembly positioned on or in the device body, the tissue movement detecting-assembly comprising a strain device; and a contact member formed as a single piece and comprising a perimeter region and a central region , the contact member adjacent to the device body and positioned to engage a surface of the tissue, where the central region of the contact member forms a tissue engaging surface protruding beyond the perimeter region of the contact member such that when the device body is positioned adjacent to tissue, the perimeter region and the central region contact the tissue to compress the tissue, the contact member also having a strain inducing surface extended from a surface opposite to the tissue engaging surface and adjacent to the tissue movement detecting assembly; wherein a compliance of the perimeter region differs from a compliance of the central region to cause the central region to transmit displacement of the contact member to a greater degree than the perimeter region such that, when the tissue engaging surface engages the tissue, displacement of tissue in a radial direction relative to the tissue caused by a change in a pressure in the blood vessel also displaces the tissue engaging surface causing displacement of the central region of the contact member in the radial direction so that the strain inducing surface alters a strain in the strain device to produce a change in an electrical property of the strain device. <EOS>