Method and system of monitoring respiratory signal by radio

• US 20080300503A1
• Filed: 07/19/2007
• Published: 12/04/2008
• Est. Priority Date: 06/04/2007
• Status: Active Grant

• Current Assignee: Chungbuk National University Industry Academic Cooperation Foundation (Chungbuk National University)
• Original Assignee: Chungbuk National University Industry Academic Cooperation Foundation (Chungbuk National University)
• Inventors: Cha, Eun Jong, Kim, Kyung Ah, Lee, In Kwang
• Granted Patent: US 7,828,742 B2
• Time in Patent Office: Days
• US Class Current: 600/534
• CPC Class Codes: A61B 5/002 Monitoring the patient using a local or closed circuit, e.g. in a room or building A61B5/0017 takes precedence
• CPC Class Codes: A61B 5/1135 by monitoring thoracic expansion
• CPC Class Codes: A61B 5/6804 Garments; Clothes

Abstract

A method and system is provided for monitoring a respiratory signal by radio. The method includes the steps of: converting a change in electric resistance, which is caused by a change in abdominal circumference measured through a rubber waistband that is made of conductive rubber and is mounted on a lower garment of a testee during respiration, into a voltage signal, performing A/D conversion on the voltage signal, and transmitting the converted digital signal to a short distance by radio using a wireless communication protocol for ZigBee; and receiving the respiratory signal transmitted by radio, transmitting it to a computer unit by wire through an RS-232 port that is a serial communication port, and enabling a tester to monitor the respiratory signal through a screen.

Claims

1. A method of monitoring a respiratory signal by radio, the method comprising:

a respiratory signal measuring and transmitting step of converting a change in electric resistance, which is caused by a change in abdominal circumference measured through a rubber waistband that is made of conductive rubber and is mounted on a lower garment of a testee during respiration, into a voltage signal, performing analog/digital (A/D) conversion on the voltage signal, and transmitting the converted digital signal to a short distance by radio using a wireless communication protocol for ZigBee; and

a respiratory signal receiving and monitoring step of receiving the respiratory signal transmitted by radio, transmitting it to a computer unit by wire through an RS-232 port that is a serial communication port, and enabling a tester to monitor the respiratory signal through a screen.

2. The method as claimed in claim 1, wherein the rubber waistband is produced by mixing conductive particles into rubber so as to have the electric resistance from tens of Ω

to several kΩ

.

3. The method as claimed in claim 1, wherein the rubber waistband in the respiratory signal measuring and transmitting step is operated by one of four resistors constituting a Wheatstone bridge circuit, and undergoes the conversion of the electric resistance change thereof into the voltage signal.

4. The method as claimed in claim 1, wherein the voltage signal converted by the electric resistance change of the rubber waistband corresponds to the respiratory signal that is amplified through a differential amplifier circuit and minimizes high-band noise through a low pass filter circuit.

5. The method as claimed in claim 1, wherein, prior to the respiratory signal receiving and monitoring step, a calibration procedure of performing a CO₂ inhalation test on each testee once, analyzing correlation between an abdominal respiratory signal and a tidal volume of the testee to calculate a regression line, and substituting the abdominal respiratory signal, measured in the respiratory signal measuring and transmitting step, into the regression line to measure the lung volume is performed.

6. A system of monitoring a respiratory signal by radio, the system comprising:

a connector that is connected to opposite ends of a rubber waistband, the rubber waistband being mounted on a lower garment of a testee and being made of rubber including conductive particles;

a radio transmitter that is electrically connected with the connector, converts a change in electric resistance, which is caused by a change in abdominal circumference measured through the rubber waistband during respiration, into a voltage signal, performs analog/digital (A/D) conversion on the voltage signal, and transmits the converted digital signal to a short distance by radio using a wireless communication protocol for ZigBee; and

a radio receiver that receives the respiratory signal, transmitted by radio using the ZigBee wireless communication protocol, through a reception antenna, converts the respiratory signal into serial information, and outputs the converted serial information through a RS-232 port,

wherein the respiratory signal is monitored by calculating the input respiratory signal and checkup parameters at the radio receiver, and outputting the calculated result to a monitor screen.

7. The system as claimed in claim 6, wherein the radio transmitter comprises:

a Wheatstone bridge circuit, one resistor of which operates the rubber waistband to convert a change in electric resistance of the rubber waistband into a voltage signal;

a differential amplifier circuit that amplifies and outputs a difference between the voltage signals output from the Weston bridge circuit to one voltage signal;

a low-pass filter circuit that extracts a voltage signal corresponding to the respiratory signal, from which high-band noise is minimized by allowing only a low-band signal to pass therethrough, from the voltage signal amplified through the differential amplifier;

an analog/digital (A/D) converter circuit that converts the respiratory signal output from the low-pass filter circuit into a digital signal; and

a ZigBee transmission circuit that transmits the digital signal output from the A/D converter circuit through a reception antenna by radio to a short distance using a ZigBee wireless communication protocol.

8. The system as claimed in claim 6, wherein the radio transmitter is carried in a pocket of a lower or upper garment of the testee.

9. The system as claimed in claim 6, wherein the A/D converter circuit and ZigBee transmission circuit of the radio transmitter make use of a semiconductor ship.