Unconstrained Sleep Measuring Device for Breathing Movement

非穿戴式睡眠呼吸運動量測裝置

Presenter: Kun-Han Jhan

Advisor: Dr. Chun-Ju Hou

Date:2013/12/25

OutlineOutline

Problems and RationalePurpose and Specific AimsBackground and Literatures ReviewMaterials and MethodsPreliminary ResultsReferences

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Problems and RationaleProblems and Rationale

Insomnia ratio: 19.3 %◦Taiwan Society of Sleep Medicine (2013)

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Problems and RationaleProblems and Rationale

Sleep disorders◦Arousal and sleep fragmentation ◦Much movement during sleep◦Restless legs syndrome during sleep◦Periodic limb movements during sleep◦Sleep apnea

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Problems and RationaleProblems and Rationale

Sleep apnea features◦Snoring◦Fatigue◦Sleep deficit◦Duration of breathe pause:10s~90s

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Problems and RationaleProblems and Rationale

Technologies for the evaluation of sleep problems◦Evaluating the quality of sleep

Sleep diary, questionnaire Polysomnography (PSG), actigraph

◦Preventing pressure sore and falling Air mattress, image monitor, pressure sensing mattress

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Problems and RationaleProblems and Rationale

Disadvantage of current techniques in evaluating the quality of sleep◦Subjective evaluation◦Need to memorize sleeping status after waking up◦Need to wear multiple sensors on body◦Limitation of manpower in clinical care◦The privacy problem

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Purpose and Specific AimsPurpose and Specific Aims

Design an unconstrained sleep measuring device for breathing movement.◦Analog and digital circuits design◦System calibration and experimental

verification

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Background and Literatures ReviewBackground and Literatures Review

Validation of Unobtrusive Pressure Sensor Array for Central Sleep Apnea Screening

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Daphne Townsend, Student Member, Rafik Goubran, Fellow, Frank Knoefel, and Judith Leech

IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT, VOL. 61, NO. 7, JULY 2012

Identifying body movement

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Background and Literatures ReviewBackground and Literatures Review

Background and Literatures ReviewBackground and Literatures Review

Pressure Sensor Array v.s PSG

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Background and Literatures ReviewBackground and Literatures Review

Detection of Sleep Disordered Breathing with Pressure Bed Sensor

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Guillermina Guerrero, Juha M. Kortelainen,Elvia Palacios, Anna M. Bianchi,Giulia Tachino, Mirja Tenhunen, Martin O. Méndez,and Mark van Gils

35th Annual International Conference of the IEEE EMBS,Osaka, Japan, 3 - 7 July, 2013

Background and Literatures ReviewBackground and Literatures Review

The eight different Pressure Bed Sensor respiration signals

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Materials and MethodsMaterials and Methods

System architecture

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PressureSensor

Mattress

Analogy Circuit Module

Digital Circuit Module

Analogy and DigitalCircuits

Bluetooth Module

Computer

Digital Signal

Process

Display Pressure Signal

Materials and MethodsMaterials and Methods

System architecture

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PressureSensor

Mattress

Constant Voltage Source

Constant Voltage Source

Constant Voltage Source

Constant Voltage Source

Constant Voltage Source

Constant Voltage Source

Constant Voltage Source

Bridge circuit

Bridge circuit

Bridge circuit

Bridge circuit

Bridge circuit

Bridge circuit

Bridge circuit

AD623

AD623

AD623

AD623

AD623

AD623

AD623

Multi-channel measurement

module

Sensor1~7

Sensor8~14

Sensor15~21

Sensor22~28

Sensor29~35

Sensor36~42

Sensor43~49

7 –Channel analog signal

Materials and MethodsMaterials and Methods

Pressure Sensor◦Force sensing resistors (FSR)

Flexible

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Materials and MethodsMaterials and Methods

Design of sensor pad◦Size: 70cm × 70cm◦No. of sensor: 7 × 7 FSRs

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Materials and MethodsMaterials and Methods

Bridge circuit◦Can detect small resistance changes◦Adjust the lower limit of measurement

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𝐕𝐏𝐐= 𝐕𝐫𝐞𝐟ቆ 𝐑𝟑𝐑𝟐 + 𝐑𝟑− 𝐑(𝐓)𝐑𝟏 + 𝐑(𝐓)ቇ

Materials and MethodsMaterials and Methods

Instrumentation Amplifier◦ AD623◦ Frequency response

800kHz at gain:1◦ CMRR: 90dB

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Materials and MethodsMaterials and MethodsMulti-channel measurement module

◦7 Multiplexer ◦1 Decoder

Multiplexer

Multiplexer

Multiplexer

Multiplexer

Multiplexer

Multiplexer

Multiplexer

3-8 decoder

Digital circuits

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3

7-Channel analog signal

7-Channel analog signal

7-Channel analog signal

7-Channel analog signal

7-Channel analog signal

7-Channel analog signal

7-Channel analog signal

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Materials and MethodsMaterials and MethodsMSP430F5438A

◦Low Supply Voltage Range 2.2V to 3.6V

◦Ultralow Power Consumption◦A/D converter with 12-bit,and 16-channel

input ◦4 USCI◦16K RAM◦256 KB Flash Memory◦Shortest cycle instruction execution 125ns◦I/O pins:87

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Materials and MethodsMaterials and Methods

Bluetooth Mode◦BTD43x◦Low cost◦Low power◦Serial Port Profile ◦HyperTerminal Settings◦Transmission distance:100m

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Materials and MethodsMaterials and Methods

System Caliration◦FSR calibration◦System calibration

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Materials and MethodsMaterials and Methods

FSR calibration

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Different Force input

(20 g to 500 g)Pressure sensor

Multi-meter(K ohm)

Materials and MethodsMaterials and Methods

Calibration of analog circuit

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different input resistance

Analog circuit(49 channel)

Multi-meter(V)

Input resistance1)150k Ω2)7k3)3k4)2k5)1k6)0.5k

Preliminary ResultsPreliminary Results

FSR calibration

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Preliminary ResultsPreliminary Results

Digital circuit calibration

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Preliminary ResultsPreliminary Results

Pressure distribution

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Aspiratory Aspirated

Preliminary ResultsPreliminary Results

Pressure distribution

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Aspiratory Aspirated

Preliminary ResultsPreliminary Results

Pressure distribution

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Aspiratory Aspirated

Preliminary ResultsPreliminary Results

Pressure distribution

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Aspiratory Aspirated

ReferencesReferences台灣睡眠醫學學會 http://www.tssm.org.tw/Daphne Townsend, Student Member, IEEE, Rafik

Goubran, Fellow, IEEE, Frank Knoefel, and Judith Leech(2012), Validation of Unobtrusive Pressure Sensor Array for Central Sleep Apnea Screening,IEEE

Guillermina Guerrero, Juha M. Kortelainen,Elvia Palacios, Anna M. Bianchi, Member,. IEEE,Giulia Tachino, Mirja Tenhunen, Martin O. Méndez,and Mark van Gils, Member, IEEE (2013) "Detection of Sleep-Disorbered Breathing with Pressure Bed Sensor",IEEE, vol. 35, pp. 1342 - 1345

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Thanks for Your Attention