Apnea detector and system
An apnea detector is disclosed. A detector unit in communication with a capacitive type sensor is adapted to receive an electrical signal which is indicative of variable capacitance resulting from movement of a subject and to emit an alert signal when the received electrical signal is indicative of symptoms of apnea. In one embodiment, a detector unit is in communication with a curvature sensor adapted to detect a variable curvature of a subject body surface resulting from breathing patterns of a subject. The detector unit is attached to an article of clothing of the subject.
1. A method of detecting apnea of a human subject using one or more capacitor plates, the method comprising at a time when at least one of the capacitor plates is mechanically coupled to an article of clothing worn by the human subject:
a) capacitively sensing a distance(s) between:
i) the mechanically coupled capacitor plate and;
ii) an outer surface of the human subject's body, to generate a sensor-output electrical signal, said distance traversing a thickness of the article of clothing;
b) analyzing time variations in the sensor-output electrical signal to determine if the time variations are indicative of a symptom of apnea in the subject; and
c) generating an apnea alert signal that is contingent on the results of the apnea determining.
2. The method of claim 1 wherein the capacitance sensing occurs within a circuit comprising the following serially-connecting circuit elements:
i) a first of the capacitor plates;
ii) the subjects body; and
iii) a second of the capacitor plates.
3. The method of claim 1 wherein there are at least two capacitor plates and each capacitor plate is coupled to the article of clothing such that the capacitor plates are next to each other separated by an insulating portion of the article of clothing.
4. The method of claim 1 wherein at least one of the capacitor plates is releasably attachable to the article of clothing.
5. The method of claim 1 wherein at least one of the capacitor plates is embedded within the article of clothing.
6. A system for detecting apnea of a human subject, the system comprising:
a) an article of clothing wearable by the human subject; and
b) a capacitance-sensor configured to capacitively sense a distance(s) between: i) at least one article of clothing associated capacitor plate that is mechanically coupled to the article of clothing and that is part of the capacitance sensor; and ii) an outer surface of the human subject's body when the article of clothing is worn by the human subject, thereby generating a capacitance output signal, said distance traversing a thickness of the article of clothing;
c) a detector unit in communication with the at least one article of clothing coupled capacitor plate, the detector unit configured to analyze time variations of the capacitance output signal to determine if the time variations are indicative of a symptom of apnea in the human subject, and contingent on the results of the apnea determining, to generate an alert signal.
7. The system of claim 6 , wherein the detector unit is configured to emit acoustical information, and further comprising a stationary unit disposed within an audible range of the detector unit, the stationary unit configured to receive the acoustical information and to send a wireless signal to a portable unit indicative of an apnea status of the subject.
8. The system of claim 6 , wherein the article of clothing is a diaper.
9. The system of claim 6 , wherein the capacitance-sensor is configured to capacitively sense the distance independent of any pressure exerted on the capacitance-sensor.