# US 11,432,744 B2 · Lung condition monitoring device

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- Number: US 11,432,744 B2
- Document ID: US11432744B2
- Status: Granted
- Kind: B2
- Application number: 16/080,021
- Filed: 2017-08-29
- Published: 2020-05-28
- Granted: 2022-09-06
- Earliest claimed: 2016-09-28
- Assignees: Indian Institute of Technology, Guwahati
- Applicants: Indian Institute of Technology, Guwahati
- Inventors: Mitradip Bhattacharjee; Dipankar Bandyopadhyay; Harshal B. Nemade
- Web page: https://patentgrep.com/patent/US11432744B2

## CPC

- A61B 5/0871: {Peak expiratory flowmeters}
- A61B 5/085: Measuring impedance of respiratory organs or lung elasticity
- A61B 5/097: Devices for facilitating collection of breath or for directing breath into or through measuring devices
- G01N 33/497: of gaseous biological material, e.g. breath
- A61B 5/082: {Evaluation by breath analysis, e.g. determination of the chemical composition of exhaled breath (A61B5/083, A61B5/091 take precedence)}
- A61B 2562/0271: Thermal or temperature sensors
- A61B 2562/029: Humidity sensors
- G01N 27/121: {for determining moisture content, e.g. humidity, of the fluid (moisture content of the tested material G01N27/048)}
- G01N 27/126: {comprising organic polymers}
- A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D)
- G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q)

## Abstract

The present invention discloses a Lung condition monitoring device for performing ultrafast detection of humidity level in exhaled air while breathing out and therefrom detect condition of the human lungs in real time. The Lung 5 condition monitoring device comprises a mouthpiece for forcibly exhaling air there through, one or more humidity sensor to measure the variable electrical resistance based on level of adsorption of water molecules thereon of the humidity content of exhaled air and real time monitoring unit operatively connected to said humidity sensor and having correlating means for correlating 10 the change in humidity level and related variation in the electrical resistance due to exhalation to peak flow rate of the exhaled air for monitoring lung condition. The Lung condition monitoring device is also capable of wireless data transfer to any peripheral computing device such as mobile phone via wireless connectivity and show the test results on the mobile phone display with the help of a 15 proprietary application embodied in the phones operating system. The mobile interface increases the portability, data monitoring, and user friendliness of the device. Further, the mobile interface helps in storage and analysis of big time data for prognosis, diagnosis, and therapeutic purposes.

## Claims

### Claim 1

A lung condition monitoring device comprising:
a mouthpiece for forcibly exhaling air therethrough;
a humidity sensor configured to output variable electrical resistance based on a level of adsorption of water molecules thereon of humidity of the exhaled air;
a real time monitoring unit operatively connected to said humidity sensor and configured for correlating a change in humidity level and related variation in the electrical resistance due to exhalation to a peak flow rate of the exhaled air for monitoring lung condition; and
a heating element for rapid desorption of the water molecules from the humidity sensor and recovery of the humidity sensor for subsequent detection of the humidity level.

### Claim 2 (depends on 1)

The lung condition monitoring device as claimed in claim 1, further comprising a humidity sensor unit exposed to a rapid decrease in the electrical resistance of the humidity sensor due to the adsorption of the water molecules from the exhaled breathing air during forced exhalation; wherein:
said mouthpiece includes an open area to receive exhaled breathing air from a user, wherein said mouthpiece, at a remote end, is operatively connected to said humidity sensor in the humidity sensor unit;
said heating element cooperates with said humidity sensor to increase temperature of the humidity sensor post adsorption of the water molecules for rapid desorption of the water molecule from the humidity sensor and recovery of the humidity sensor for subsequent detection of the humidity level; and
said real time monitoring unit is configured to detect a lung condition and lung function parameters by detecting a maximum change in the electrical resistance across the humidity sensor and correlating the same with the peak flow rate of exhalations from lung.

### Claim 3 (depends on 2)

The lung condition monitoring device as claimed in claim 2, wherein the humidity sensor unit comprises:
at least one opening slot to allows the exhaled breathing air to flow in;
one or more holes on a sidewall of humidity sensor unit's housing to operate as outlets of the air from the humidity sensor unit; and
sensor supporting structure to hold the humidity sensor in the humidity sensor unit.

### Claim 4 (depends on 3)

The lung condition monitoring device as claimed in claim 3, wherein the humidity sensor includes:
one or more films of porous cadmium sulfide (CdS) nanoparticles, each of said films of porous CdS nanoparticles comprising
i. a thermally conductive paper substrate having gold (Au) nanoparticles embedded thereon, and
ii. the porous CdS nanoparticles on said Au nanoparticles embedded thermally conductive paper substrate to constitute a nanoparticle surface for rapid adsorption of the water molecules; and
silver electrodes for operatively connecting said nanoparticle surfaces with the real time monitoring unit.

### Claim 5 (depends on 4)

The lung condition monitoring device as claimed in claim 4, wherein the heating element is placed between the humidity sensors and the sensor supporting structure.

### Claim 6 (depends on 5)

The lung condition monitoring device as claimed in claim 5, wherein the heating element comprises:
a metallic wire in coil form embedded in a polymer matrix or substrate; and
two electrodes for connecting a power source with the coil to operate the heating element and generate heat.

### Claim 7 (depends on 5)

The lung condition monitoring device as claimed in claim 5, further comprising a thermistor positioned between the sensor supporting structure and the heating element to sense temperature of the heating element and act as a negative feedback to control the temperature.

### Claim 8 (depends on 6)

The lung condition monitoring device as claimed in claim 6, wherein the heating element includes copper wire of diameter 180 μm coiled in a 1 centimeter square area having 80 turns fixed in an adhesive paper substrate to keep the structure intact.

### Claim 9 (depends on 2)

The lung condition monitoring device as claimed in claim 2, wherein the real time monitoring unit includes:
a small cabinet for housing a control assembly and the power source;
a plurality of indicator LEDs on housing of the real time monitoring unit for indicating status of the lung; and
a power switch operatively connected with the power source to activate/deactivate the device and ON-OFF indicator LED to display activation of the device.

### Claim 10 (depends on 9)

The lung condition monitoring device as claimed in claim 9, wherein the control assembly includes:
a heating element control module comprising a square pulse generator to operate and maintain the heating element's temperature;
a sensor unit control module having said humidity sensor and configured to connect the humidity sensor with the indicator LED control module via associated resistive network; and
an indicator LED control module having a resistive network operatively connecting the indicator LEDs with the humidity sensor to activate one or more of the indicator LEDs depending on the condition of the lung of the user.

### Claim 11 (depends on 10)

The lung condition monitoring device as claimed in claim 10,
wherein the indicator LED control module is configured to activate one or more of the indicator LEDs depending on the change in the electrical resistance of the humidity sensor and correlating the same with the peak flow rate of exhalations from lung;
wherein the peak flow rate of exhalations from the lung is an indicator of degree of obstruction in airways of bronchi and linearly vary with the change in the electrical resistance of the humidity sensor due to the adsorption of the water molecules from the exhaled breathing air during forced exhalation; and
wherein higher value of the peak flow rate of exhalations indicates healthy lungs and lower values indicate the diseased state of the lungs.

### Claim 12 (depends on 11)

The lung condition monitoring device as claimed in claim 11, wherein the indicator LED control module is configured to activate any one or more of three indicator LEDs for indicating status of the lung and includes the resistive network adapted to drive current through the LEDs for
activating all the LEDs when resistance of the sensor unit after adsorption of the water molecules from the exhaled breathing air corresponds to the peak flow rate of exhalations from a healthy lung;
activating only two LEDs when resistance of the sensor unit after adsorption of the water molecules from the exhaled breathing air corresponds to the peak flow rate of exhalations from a lung in condition of COPD; and
activating only one LED when resistance of the sensor unit after adsorption of the water molecules from the exhaled breathing air corresponds to the peak flow rate of exhalations from a lung in need of emergency medical attention.

### Claim 13 (depends on 6)

The lung condition monitoring device as claimed in claim 6, further comprising a voltage regulator connected to the power source to maintain the stable output voltage to all components of the device.

### Claim 14 (depends on 1)

The lung condition monitoring device as claimed in claim 1, further comprising a wireless communication interface having wireless data exchange connectivity with a peripheral computing device to facilitate wireless data transfer from the humidity sensor to the peripheral computing deivce and display the same on the peripheral computing device screen;
wherein the connected periphal computing device facilitates storage and analysis of big time data for prognosis, diagnosis, and therapeutic purposes and also increases portability, data monitoring, and user friendliness of the device.

### Claim 15 (depends on 14)

The lung condition monitoring device as claimed in the claim 14, further including an open standard mobile application for the peripheral computing device operating system configured for integrating with the present lung condition monitoring device and the wireless communication interface to enable monitoring of the lung function on the screen of the peripheral computing device through wireless data exchange.