Monitoring a condition of a subject
Apparatus for monitoring a clinical condition of a subject is described. A motion sensor senses motion of the subject without contacting or viewing the subject, and generates a sensed motion signal responsive to the sensed motion. A signal analyzer is adapted to analyze the motion signal to identify a cough in the subject. Other applications are also described.
1. Apparatus for detecting a cough in a subject, the apparatus comprising:
a motion sensor adapted to sense a motion of the subject without contacting or viewing the subject, and to generate a motion signal corresponding to the sensed motion; and
a signal analyzer adapted to analyze the motion signal to identify a cough.
2. The apparatus according to claim 1 , wherein the signal analyzer is configured to register body movements of the subject by filtering the motion signal using a low frequency passband that has a higher end cutoff frequency of up to 10 Hz.
3. The apparatus according to claim 2 , wherein the low frequency passband has a higher end cutoff frequency of 1-10 Hz.
4. The apparatus according to claim 3 , wherein the low frequency passband has a lower end cutoff frequency of 0.03-0.2 Hz.
5. The apparatus according to claim 1 , wherein the signal analyzer is further configured to register acoustic sound by filtering the motion signal using a high frequency passband.
6. The apparatus according to claim 5 , wherein the high frequency passband includes 50 Hz.
7. The apparatus according to claim 6 , wherein the high frequency passband includes 8 kHz.
8. The apparatus according to claim 5 , wherein the high frequency passband includes 150 Hz.
9. The apparatus according to claim 8 , wherein the high frequency passband includes 1 kHz.
10. The apparatus according to claim 5 , wherein the high frequency passband has a lower end cutoff frequency that is at least 50 Hz.
11. The apparatus according to claim 1 , wherein the signal analyzer is configured to:
(a) register body movements by filtering the motion signal using a low frequency passband having a higher end cutoff frequency of up to 10 Hz,
(b) register acoustic sound by filtering the motion signal using a high frequency passband, and
(c) identify a cough in response to identifying an event that is present in both the low frequency passband and the high frequency passband of the motion signal.
12. The apparatus according to claim 11 , wherein the low frequency passband has a higher end cutoff frequency of 1-10 Hz.
13. The apparatus according to claim 11 , wherein the high frequency passband has a lower end cutoff frequency that is at least 50 Hz.
14. The apparatus according to claim 1 , further comprising an acoustic sensor adapted to sense a sound of a subject and generate an acoustic signal corresponding to the sensed sound.
15. The apparatus according to claim 14 , wherein the signal analyzer is adapted to correlate the acoustic signal and the motion signal, and to identify a cough in response to identifying an event that is present in both the acoustic signal and the motion signal.
16. The apparatus according to claim 14 , wherein the acoustic sensor is a first acoustic sensor, and wherein the apparatus further comprises a second acoustic sensor configured to be disposed at a separate respective location from the first acoustic sensor, and adapted to provide a second acoustic signal to the signal analyzer, and wherein the signal analyzer is adapted to (a) correlate the acoustic signals from the first and second acoustic sensors and (b) reject an identification of an acoustic signal source of the acoustic signals as being a cough if the first and second acoustic sensors have not sensed the same sound.
17. The apparatus according to claim 14 , wherein the motion sensor comprises a pressure gauge, and the acoustic sensor and the pressure gauge are integrated into a single sensor.
18. The apparatus according to claim 1 , wherein the signal analyzer is adapted to identify a characteristic of the motion signal and compare the characteristic to a criterion associated with a condition selected from the group consisting of: the subject having fluid in the lungs, and the subject being a smoker.