Integrated Flexible Sensor for Blood Pressure Measurements

A blood pressure measurement device, comprising:

• a cuff operative to wrap around a limb of a user;
• a bladder coupled to the cuff and operative to compress the limb of the user when inflated;
• a piezoelectric sensor coupled to the cuff, and operative to detect blood flow through the limb of the user;
• and
• a processor operative to:
• receive a signal from the piezoelectric sensor that is indicative of the blood flow through the limb;
• and
• filter the signal to:
• identify a first sound that corresponds to a change in the blood flow due to a partial collapse of a blood vessel within the limb;
• and
• identify a second sound that corresponds to a stoppage of the blood flow in the blood vessel within the limb;
• and
• determine a blood pressure of the user at least partially based on the identified first and second sounds.

A method for measuring blood pressure of a user, the method comprising:

• inflating a bladder of a cuff to increase a pressure within the bladder to compress a blood vessel of the user;
• detecting, using a piezoelectric sensor, changes in blood flow through the blood vessel, the changes corresponding to collapse of the blood vessel;
• outputting a first signal indicative of the changes in the blood flow;
• detecting, using a pressure sensors, the pressure within the bladder;
• outputting a second signal indicative of the pressure;
• and
• filtering the first signal to:
• identify a first sound that corresponds to a change in blood flow through the blood vessel due to partial collapse of the blood vessel;
• and
• identify a second sound that corresponds to a stoppage of blood flow in the blood vessel;
• operating a processor to:
• receive the first and second signals;
• determine, using the first and second signals, a first pressure in the bladder corresponding to an occurrence of the first sound;
• determine, using the first and second signals, a second pressure in the bladder corresponding to an occurrence of the second sound;
• and
• estimate a blood pressure of the user using the first pressure and the second pressure.