Photo-Plethysmograph EEET0470 Biomedical Electronics Rev.13.01 Photo-Plethysmograph & Heart Rate Monitor

วัตถุประสงค์ ศึกษาเกี่ยวกับการวัดสัญญาณชีพจร Copyright © S.Witthayapradit.2009 ศึกษาเกี่ยวกับการวัดสัญญาณชีพจร เรียนรู้เกี่ยวกับการวัดอัตราการเต้นของหัวใจ ออกแบบวงจรอิเล็กทรอนิกส์กับการวัดทางแพทย์

หัวข้อบรรยาย Plethysmography Heart Rate Monitor Copyright © S.Witthayapradit.2009 Plethysmography Strain gate Plethysmography Impedance Plethysmography Photo Plethysmography Heart Rate Monitor Timer & Counter Microcontroller Radiation

Strain gate Plethysmography Impedance Plethysmography Plethysmogram Copyright © S.Witthayapradit.2009 Strain gate Plethysmography Impedance Plethysmography

Photo Plethysmography Photo - Plethysmogram Copyright © S.Witthayapradit.2009 Photo Plethysmography TCRT1000 CTR 2.5% VF = 1.25V @ IF = 50mA VCE(sat) = 0.3V

Photo - Plethysmogram DC Coupling AC Coupling Noise Ch.1 Ch.2 Copyright © S.Witthayapradit.2009 DC Coupling AC Coupling Noise Ch.1 DC Coupling Ch.2 AC Coupling

Design : Amplifier & Filter Copyright © S.Witthayapradit.2009 R2 22Meg C1 10uF C2 1nF R1 220K -3V Vin 1Vac 0Vdc +3V U1 MAX4124EUK 4 3 2 5 1 - + V- V+ OUT VDB non-Inverting Amplifier ; AV = 100 v/v fCL = 0.1Hz & fCH = 5Hz Frequency 10mHz 100mHz 1.0Hz 10Hz 100Hz VDB(U1:OUT) 20 30 40

Photo - Plethysmogram Time 0s 4s 8s 12s V(C2:2) 0V 1.0V -1.5V Copyright © S.Witthayapradit.2009 Time 0s 4s 8s 12s V(C2:2) 0V 1.0V -1.5V SEL>> V(U1:+) 300mV 325mV 350mV C2 1nF R1 R2 +3V V 220K 22Meg 5 C1 U1 10uF 4 - V+ 1 OUT 3 + V- MAX4124EUK/MXM V 2 VPPG ppg12.txt -3V V2 0.325

ECG & PPG Monitor Copyright © S.Witthayapradit.2009

Pulse PPG Hysteresis Comparator Amplifier & Filter Time 0s 4s 8s 12s Copyright © S.Witthayapradit.2009 Hysteresis Comparator Time 0s 4s 8s 12s V(R5:2) V(R3:2) 0V 2.0V -1.0V 3.0V Amplifier & Filter

Heart Rate Monitor Copyright © S.Witthayapradit.2009

Heart Rate Monitor Timer & Counter Preview Copyright © S.Witthayapradit.2009 Timer & Counter Preview

Heart Rate Monitor Time 0s 2s 4s 6s 8s 10s 12s V(start) V(U4:OUTPUT) Copyright © S.Witthayapradit.2009 Count V2 hyst.txt start V1 start.txt R1 9.1K +5V C1 10nF R3 1k V C 270nF R4 910K U3 555B 1 2 3 4 5 6 7 8 GND TRIGGER OUTPUT RESET CONTROL THRESHOLD DISCHARGE VCC Cext 390nF C3 10uF C2 C4 R 2Meg U1 555C U4 R2 180K Time 0s 2s 4s 6s 8s 10s 12s V(start) V(U4:OUTPUT) 0V 2.5V 5.0V

Heart Rate Monitor Time 0s 2s 4s 6s 8s 10s 12s V(U3:OUTPUT) V(Count) Copyright © S.Witthayapradit.2009 Count V2 hyst.txt start V1 start.txt R1 9.1K +5V C1 10nF R3 1k V C 270nF R4 910K U3 555B 1 2 3 4 5 6 7 8 GND TRIGGER OUTPUT RESET CONTROL THRESHOLD DISCHARGE VCC Cext 390nF C3 10uF C2 C4 R 2Meg U1 555C U4 R2 180K Time 0s 2s 4s 6s 8s 10s 12s V(U3:OUTPUT) V(Count) 0V 2.5V 5.0V

Heart Rate Monitor Time Copyright © S.Witthayapradit.2009 0s 2s 4s 6s V(COUNT) V(U3:OUTPUT) 0V 2.5V 5.0V SEL>> V(start) V(U4:OUTPUT)

Heart Rate Monitor Copyright © S.Witthayapradit.2009 Microcontroller

Heart Rate Monitor Copyright © S.Witthayapradit.2009

Heart Rate Monitor Copyright © S.Witthayapradit.2009 Microcontroller

Heart Rate Monitor Copyright © S.Witthayapradit.2009 Radiation

Heart Rate Monitor Radiation 5kHz Resonator Copyright © S.Witthayapradit.2009 Radiation 5kHz Resonator

Heart Rate Monitor Frequency Copyright © S.Witthayapradit.2009 100Hz 10KHz 1.0MHz 10Hz VDB(C3:1) VDB(U2:OUT) VDB(U3:OUT) -50 50 100

Exercise Copyright © S.Witthayapradit.2009 ออกแบบค่าตัวเก็บประจุของวงจรเรโซแนนซ์ที่ความถี่ 5kHz เมื่อ L = 6.8mH L = 6.8mH C = _______ คำนวณหาอัตราขยายและความถี่ตัดด้านต่ำกับด้านสูงของวงจร AV = _______ fCL = _________ Hz fCH = __________ Hz

Reference Copyright © S.Witthayapradit.2009 [1] Sergio Franco , “Design with Operational Amplifiers and Analog Integrated Circuits” , Third edition , McGraw-Hill , 2002. [2] James W.Nilsson , Susan A.Riedel , “Electric Circuits” , 8th Edition , Prentice Hall , 2008. [3] Thomas L.Floyd , “Electronic Devices” , 7th Edition , Prentice Hall Inc. , 2005. [4] http://rick.mollprojects.com/ [5] http://pdfserv.maxim-ic.com/en/an/AN3845.pdf

Photo-Plethysmograph EEET0470 Biomedical Electronics Rev.13.01 Photo-Plethysmograph & Heart Rate Monitor The End Q & A