Acoustic sensor assembly
An acoustic sensor is configured to provide accurate and robust measurement of bodily sounds under a variety of conditions, such as in noisy environments or in situations in which stress, strain, or movement may be imparted onto a sensor with respect to a patient. Embodiments of the sensor provide a conformable electrical shielding, as well as improved acoustic and mechanical coupling between the sensor and the measurement site.
1. An acoustic sensor assembly comprising:
a sensor sub-assembly comprising:
a frame,
a sensing element stretched in tension across an open cavity of the frame and configured to generate a signal responsive to acoustic vibrations, wherein the sensing element comprises a piezoelectric material, and
an acoustic coupler supported by the frame, wherein the acoustic coupler extends into the open cavity and is positioned to apply pressure to the sensing element to push at least a section of the sensing element into the open cavity; and
a patient attachment portion attached to a top portion of the sensor sub-assembly that is opposite a portion of the sensor sub-assembly configured to be placed against a tissue site of a medical patient, wherein the patient attachment portion comprises:
an elastic portion; and
an attachment layer comprising a first side including an adhesive surface and a second side opposite the first side, wherein:
the attachment layer extends between an inner periphery of the attachment layer proximate the sensor sub-assembly and an outer periphery of the attachment layer distal the sensor sub-assembly,
the elastic portion attaches to the top portion of the sensor sub-assembly and extends to the second side of the attachment layer,
the elastic portion is attached to the attachment layer on the second side of the attachment layer and at a point between the inner periphery and the outer periphery of the attachment layer,
the patient attachment portion is configured to enable attachment of the acoustic sensor assembly to the medical patient via user attachment of the adhesive surface to the tissue site of the medical patient, and
the frame, the adhesive surface, and the elastic portion are arranged with respect to one another such that attachment of the adhesive surface to the tissue site of the medical patient causes deformation of the elastic portion and a resulting force to press the sensor sub-assembly against the tissue site of the medical patient.
2. The acoustic sensor assembly of claim 1 , wherein the acoustic coupler is configured to transmit acoustic vibrations to the sensing element through the acoustic coupler when the acoustic sensor assembly is attached to the medical patient.
3. The acoustic sensor assembly of claim 2 , wherein the force is determined based at least in part upon an elasticity of the elastic portion.
4. The acoustic sensor assembly of claim 3 , wherein, when the acoustic sensor assembly is attached to the patient, the elastic portion is in a state of deformation and inclined with respect to the attachment layer.
5. The acoustic sensor assembly of claim 4 , wherein the elastic portion at least partially surrounds the sensor sub-assembly.
6. The acoustic sensor assembly of claim 5 , wherein the acoustic coupler further includes an outer protrusion disposed on an outside surface of the acoustic coupler.
7. The acoustic sensor assembly of claim 6 , wherein the acoustic coupler is configured to substantially evenly distribute pressure on the sensing element.
8. The acoustic sensor assembly of claim 7 , wherein the acoustic coupler electrically isolates the sensing element from the medical patient when the acoustic sensor assembly is attached to the medical patient.
9. The acoustic sensor assembly of claim 8 , wherein the acoustic coupler comprises an elastomer.
10. The acoustic sensor assembly of claim 8 , wherein the signal comprises an electrical signal.
11. The acoustic sensor assembly of claim 8 further comprising:
a cable in communication with the sensing element and configured to communicate the signal to an acoustic monitor.
12. The acoustic sensor assembly of claim 1 , wherein the adhesive surface extends from the inner periphery to the outer periphery of the attachment layer.
13. The acoustic sensor assembly of claim 1 , wherein, when the acoustic sensor assembly is not attached to the patient, the elastic portion is in a state of relaxation and substantially parallel to the attachment layer.
14. A method comprising:
detecting, by an acoustic sensor assembly according to claim 1 , acoustic vibrations, wherein the acoustic vibrations are transmitted to the sensing element via the acoustic coupler;
converting, by the sensing element, the acoustic vibrations into an electrical signal; and
outputting the electrical signal.
15. The method of claim 14 further comprising:
processing the electrical signal by an acoustic monitor to determine one or more physiological parameter measurements of the patient.
16. The method of claim 15 further comprising:
wherein the one or more physiological parameter measurements include at least one of: heart rate, heart sounds, respiratory rate, expiratory flow, tidal volume, minute volume, apnea duration, breath sounds, riles, rhonchi, stridor, or changes in breath sounds such as decreased volume or change in airflow.