INFANT MONITOR

• US 20080183095A1
• Filed: 01/29/2008
• Published: 07/31/2008
• Est. Priority Date: 01/29/2007
• Status: Abandoned Application

• Current Assignee: Idaho State University
• Original Assignee: Idaho State University
• Inventors: Semmler, Bart, Wells, Richard B., Austin, Colby R., Cornwall, Laila, Otto, Jeff L., Curtis, Chris E., Hasenoehrl, Jennifer L., Daugherty, Lloyd C.
• Application Number:
  US12/022,088
• Publication Number:
  US 20080183095A1
• Time in Patent Office: Days
• US Class Current: 600/534
• CPC Class Codes: A61B 5/0002 Remote monitoring of patients using telemetry, e.g. transmission of vital signals via a communication network A61B5/07 takes precedence; transmission systems for measured values G08C; transmission H04B; transmission of digital information H04L; wireless communication networks H04W
• CPC Class Codes: A61B 5/053 Measuring electrical impedance or conductance of a portion of the body
• CPC Class Codes: A61B 5/0809 by impedance pneumography
• CPC Class Codes: A61B 5/113 occurring during breathing

Abstract

A breathing monitor and method for monitoring respiration, such as for detecting apnea events and/or preventing Sudden Infant Death Syndrome includes one or more variable inductance sensors that are configured to stretch and contract in response to breathing movements. Stretching and contraction are associated with an inductance change in the sensors, which are configured to alter a frequency of an oscillator circuit. The breathing monitor may also comprise a transmitter circuit coupled to a microcontroller or other processor that analyzes the frequency changes and sounds an alarm in the event that breathing ceases for a predetermined time period. The breathing monitor and associated sensor circuitry can be secured to a garment to be worn by an infant or other subject to be monitored.

Claims

1. A breathing monitor comprising:

a garment;

at least one impedance sensor configured to be secured to the garment and situated on the garment so as to be responsive to breathing; and

a breathing detector removably attached to the garment and configured to provide a breathing status indication based on an impedance of the at least one sensor.

2. The breathing monitor of claim 1, further comprising at least one snap fastener configured to removably attach the breathing detector to the garment, wherein the snaps are configured to electrically connect the breathing detector and the at least one impedance sensor.

3. The breathing monitor of claim 1, wherein the breathing detector comprises a sensor oscillator configured to be coupled to the at least one impedance sensor and to provide a sensor oscillator signal at a sensor frequency associated with an impedance of the at least one impedance sensor, a reference oscillator configured to produce a reference oscillator signal at a reference frequency, and a frequency comparator configured to produce a frequency comparator signal associated with a difference between the sensor frequency and the reference frequency, and a processor configured to produce a breathing status indication based on the difference.

4. The breathing monitor of claim 3, wherein the sensor oscillator comprises a modified Colpitts oscillator that includes a transistor having an emitter and a fixed inductor and a resistor placed in series between the emitter and a ground connection.

5. The breathing monitor of claim 3, where the at least one sensor is a variable inductance sensor.

6. The breathing monitor of claim 2, wherein the breathing detector is housed in a flexible plastic protective enclosure.

7. The breathing monitor of claim 1, wherein the garment is selected from the group consisting of an infant undergarment and an infant pajama.

8. The breathing monitor of claim 3, wherein the garment comprises a stabilizer fabric and a fabric overlayer, and the variable inductance sensor is located between the stabilizer fabric and the overlayer.

9. The breathing monitor of claim 5, wherein the at least one variable inductance sensor comprises first, second, third, and fourth variable inductance sensors.

10. The breathing monitor of claim 9, wherein the garment has a midline extending vertically along the length of the garment as situated upright and the first and second variable inductance sensors are positioned on the garment to the right of the midline, and the third and fourth variable inductance sensors are symmetrically positioned on the garment to the left of the midline.

11. The breathing monitor of claim 10, wherein the first and second variable inductance sensors are connected in series, and the third and fourth inductance sensors are connected in series.

12. The breathing monitor of claim 11, wherein the first and second variable inductance sensors are connected in parallel with the third and fourth variable inductance sensors.

13. The breathing monitor of claim 10, wherein the first, second, third, and fourth variable inductance sensors are each positioned substantially horizontally with reference to the vertical midline of the garment.

14. A variable inductance sensor, comprising:

an elastic core; and

an inductor comprising first and second ends configured for coupling to a breathing monitor, first and second anchor portions secured to the elastic core, and a coil about the elastic core situated between the first and second anchor portions.

15. The variable inductance sensor of claim 14, further comprising stitched regions configured to secure the first and second anchor portions to the elastic core.

16. A garment comprising:

at least four variable inductance sensors;

an inner chest panel;

an outer chest panel; and

a breathing detector positioned between the inner and outer chest panel.

17. The garment of claim 16, further comprising at least one French seam configured to secure the at least four variable inductance sensors.

18. A method for monitoring respiration in a subject, comprising:

securing one or more variable inductance sensors and a breathing detector to a garment;

electrically connecting the one or more variable inductance sensors and the breathing detector;

detecting a change in frequency associated with a change in inductance of the one or more variable inductance sensors; and

analyzing the detected frequency and providing an indication of subject respiration based on the detected frequency change.

19. The method of claim 18, further comprising displaying a signal indicative of subject respiration.

20. The method of claim 19, further comprising sounding an audible alarm in response to the indication.

21. A method for monitoring respiration in a subject, comprising:

positioning first, second, third, and fourth inductive coils substantially perpendicular to a subject vertical midline extending across a chest of the subject such that the first and second inductive coils are positioned near an upper chest region of the subject and are symmetrical situated about the vertical midline, and the third and fourth inductive coils are positioned near a diaphragm region of the subject and are symmetrically situated about the midline;

detecting an inductance change in at least one of the inductive coils in response to breathing movements of the subject; and

transmitting a respiration indication in response to a detected inductance change.