Method and apparatus for monitoring respiration using signals from a piezoelectric sensor mounted on a substrate

A respiration sensor comprising:

• a substrate having a first sensing region and a second sensing region, wherein at least one of the first and second sensing regions has a trapezoidal shape;
• a first piezoelectric film mounted on the substrate adjacent the first sensing region so that force applied to the first sensing region in response to respiration generates a charge on the first piezoelectric film;
• and
• a second piezoelectric film mounted on the substrate adjacent the second sensing region so that force applied to the second sensing region in response to respiration generates a charge on the second piezoelectric film.

A patient monitoring apparatus comprising:

• a flexible substrate including a backing layer and a circuit layer having exposed metal contacts, said flexible substrate including:
• a first sensing region having:
• a rigid base ring mounted on the substrate;
• a convex foam material layer mounted on the substrate within the base ring;
• a contact ear connected to the flexible substrate via substrate hinges and being folded over at the hinges so as to rest on the rigid base ring;
• and a film ear connected to the flexible substrate via substrate hinges and being folded over at the hinges so as to rest on the contact ear, the film ear including a first piezoelectric film layer mounted on the film ear;
• a second sensing region including:
• a rigid base ring mounted on the substrate;
• a convex foam material layer mounted on the substrate within the base ring;
• a contact ear connected to the flexible substrate via substrate hinges and being folded over at the hinges so as to rest on the rigid base ring;
• and a film ear connected to the flexible substrate via substrate hinges and being folded over at the hinges so as to rest on the contact ear, the film ear including a first piezoelectric film layer mounted on the film ear;
• a patient monitor interface connecting the first and second sensing regions and having electrically conductive contacts for providing an electrical connection between the piezoelectric films and a patient monitor.

A patient monitor comprising:

• a piezoelectric signal acquisition unit;
• and
• a respiration sensor connected to the signal acquisition unit, wherein the respiration sensor includes a sensing region having:
• a base portion;
• a film ear;
• and
• a contact ear.

A method of monitoring the respiration of a patient, said method comprising the acts of:

• placing a piezoelectric sensor on the patient, wherein the piezoelectric sensor includes a piezoelectric film and a foam material with a convex radius for transforming acoustical vibrations perpendicular to the piezoelectric film into longitudinal acoustical vibrations;
• monitoring acoustical vibrations generated by respiration of the patient;
• and
• providing a value correlating to respiratory activity of the patient based on the acoustical vibrations.

A method of diagnosing respiratory conditions in a patient, said method comprising the acts of:

• placing a piezoelectric sensor on the patient, wherein the piezoelectric sensor includes a piezoelectric film and a foam material with a convex radius for transforming acoustical vibrations perpendicular to the piezoelectric film into longitudinal acoustical vibrations;
• monitoring acoustical vibrations generated by respiration of the patient using the piezoelectric sensor;
• generating a value correlating to respiratory activity of said patient based on the acoustical vibrations;
• and
• comparing the value correlating to the respiratory activity of the patient with known values corresponding to known respiratory conditions.