The discovery that a person’s ‘pulse wave velocity’ is closely linked to blood pressure has lead to the development of a unique way of measuring this.

Instead of the traditional cuff, pump, stepthoscope or electronics commonly associated with taking a person’s blood pressure, consumer electronics company Philips has discovered that sensors sewn into the wasitband of a person’s underpants can measure the rate of this wave, the rate at which the pulse pressure wave passes through the blood circulatory system.

Each sensor continually measures the electrical impedance of the tissue beneath it. This property continuously changes as the pulse wave passes by, and so a pair of sensors is used to calculate the speed of the pulse wave by timing how long it takes to travel from one sensor to the other.

Once calibrated with a more conventional blood-pressure reading, the electrodes can provide accurate blood-pressure readings.