A multiple-axis accelerometer for use with a blood pressure monitor or a blood pressure measuring device (BPM) to determine an inclination associated with the point of fixture. The accelerometer is attached to a substrate that is structured and arranged in a vertical or substantially vertical plane. The accelerometer includes a first accelerometer portion that is adapted to generate a first output based on acceleration in a first direction in the vertical plane (Ax); and a second accelerometer portion that is adapted to generate a second output based on acceleration in a second direction, orthogonal to the first direction, in the vertical plane (Ay). The first and second outputs provide a measure of the inclination about an axis that is orthogonal or substantially orthogonal to the vertical plane. The measured inclination is a roll angle (γ) is given by the formula: γ=arctan(Ay/Ax). The polarity of the roll angle determines dynamically whether the point of fixture is to the right or the left appendage or extremity.