university of tehran school of electrical and computer engineering
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University of Tehran School of Electrical and Computer Engineering . ISSCC 2013 Intra-Cardiac Signal-Processing IC. Spring 2013. - PowerPoint PPT PresentationTRANSCRIPT
University of TehranSchool of Electrical and Computer
Engineering
ISSCC 2013
Intra-Cardiac Signal-Processing IC
Spring 2013
by:Yasser Rezaeiyan
Sunyoung Kim et al, "A 20µW intra-cardiac signal-processing IC with 82dB bio-impedance measurement dynamic range and analog feature extraction for ventricular fibrillation detection," Solid-State Circuits Conference Digest of Technical Papers (ISSCC), 2013 IEEE International , vol., no., pp.302,303, 17-21 Feb. 2013
Cardiac biologic system
8006004002000-6
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0
2
4
6
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Time, ms
Volta
ge, m
V
S–T elevation
ECG
Intracardiac electrogram
J.G. Webster,”Design of Cardiac Pacemaker” , IEEE PRESS 1998. 1/12
Importance of Intra-Cardiac SPThe accurate recognition of multiple intra-
cardiac signals is becoming more and more important for:Cardiac Resynchronization Therapy (CRT)the analysis of the intra-thoracic fluid status
But for Cardiac pacemakerRobust and accurate heart rate (HR) at the
right/left ventricles and right atriumBut for the intra-cardiac rhythm analysis
accurate motion sensorthoracic impedance measurement Sunyoung Kim et al, "A 20µW intra-cardiac signal-processing IC with 82dB bio-impedance measurement dynamic range
and analog feature extraction for ventricular fibrillation detection," Solid-State Circuits Conference Digest of Technical Papers (ISSCC), 2013 IEEE International , vol., no., pp.302,303, 17-21 Feb. 2013J.G. Webster,”Design of Cardiac Pacemaker” , IEEE PRESS 1998. 2/12
Cardiac PacemakerMemory
AV interval timer
Pacing interval timer
Microprocessor
Telemetry Atrial stimulus generator
Atrial sense
Ventricular sense
Ventricular stimulus generator
Data bus
To heart
Implantable Cardiac pacemaker Requirement:Ultra Low Power 7-10 years life timeHigh Accuracy intra cardiac Signal AnalysisSmall System delay < 10 msSmall Size
Sunyoung Kim et al, "A 20µW intra-cardiac signal-processing IC with 82dB bio-impedance measurement dynamic range and analog feature extraction for ventricular fibrillation detection," Solid-State Circuits Conference Digest of Technical Papers (ISSCC), 2013 IEEE International , vol., no., pp.302,303, 17-21 Feb. 2013J.G. Webster,”Design of Cardiac Pacemaker” , IEEE PRESS 1998. 3/12
Analog signal processing IC
It consists of: 3 power-efficient intra-cardiac signal readout channels An ultra-low-power readout circuit for an external accelerometer(RA) Two quadrature bio-impedance readout channels
Digitized sinusoidal current generator
Accurate Wide dynamic range
Sunyoung Kim et al, "A 20µW intra-cardiac signal-processing IC with 82dB bio-impedance measurement dynamic range and analog feature extraction for ventricular fibrillation detection," Solid-State Circuits Conference Digest of Technical Papers (ISSCC), 2013 IEEE International , vol., no., pp.302,303, 17-21 Feb. 2013 4/12
Intra-thoracic fluid analysis requirespurely sinusoidal current source
Resolve bio-impedance down to a mΩ-range change (AC) superimposed on up to a kΩ-range average (DC) impedance
This approach consumes many mWs of powerμW-range power consumption can be
achieved by square-wave current combined with
quadrature demodulation intolerable measurement errors as high as 23%
Sunyoung Kim et al, "A 20µW intra-cardiac signal-processing IC with 82dB bio-impedance measurement dynamic range and analog feature extraction for ventricular fibrillation detection," Solid-State Circuits Conference Digest of Technical Papers (ISSCC), 2013 IEEE International , vol., no., pp.302,303, 17-21 Feb. 2013
5/12
Current Generator16-level quantized-sinusoidal current source
Suppresses all harmonics’ power below the 63rd
harmonic: High resolution with high THD
Low power consumptionBenefits of this approach:
Maximize the power efficiency Mitigate the AC current mismatch Simply adjust the current magnitude (10–
40μAp-p)
Sunyoung Kim et al, "A 20µW intra-cardiac signal-processing IC with 82dB bio-impedance measurement dynamic range and analog feature extraction for ventricular fibrillation detection," Solid-State Circuits Conference Digest of Technical Papers (ISSCC), 2013 IEEE International , vol., no., pp.302,303, 17-21 Feb. 2013 6/12
Bio-impedance readout channel Quadrature demodulation Extract both DC and AC bio-impedance Offset of the QIRC may affect the
accuracy of the DC bio-impedance calculation that resolve with Multi-Purpose Chopper
These offset values are calibrated in the DSP
97% accuracy (THD < 3%)
Sunyoung Kim et al, "A 20µW intra-cardiac signal-processing IC with 82dB bio-impedance measurement dynamic range and analog feature extraction for ventricular fibrillation detection," Solid-State Circuits Conference Digest of Technical Papers (ISSCC), 2013 IEEE International , vol., no., pp.302,303, 17-21 Feb. 2013 7/12
Programmable QRS extraction Consumes only 426nA
Sunyoung Kim et al, "A 20µW intra-cardiac signal-processing IC with 82dB bio-impedance measurement dynamic range and analog feature extraction for ventricular fibrillation detection," Solid-State Circuits Conference Digest of Technical Papers (ISSCC), 2013 IEEE International , vol., no., pp.302,303, 17-21 Feb. 2013 8/12
ConclusionASP IC for
emerging CRT:achieve accuracy-
delay optimization for HR monitoring
programmable QRS feature extractor
Highly accurate ultra-low-power
(only 20μW when all channel are active)
Sunyoung Kim et al, "A 20µW intra-cardiac signal-processing IC with 82dB bio-impedance measurement dynamic range and analog feature extraction for ventricular fibrillation detection," Solid-State Circuits Conference Digest of Technical Papers (ISSCC), 2013 IEEE International , vol., no., pp.302,303, 17-21 Feb. 2013 9/12
Trend Pacemakers Leadless Pacemakers
www.medtronic.com10/12
Refrences Sunyoung Kim et al, "A 20µW intra-cardiac signal-processing IC with 82dB
bio-impedance measurement dynamic range and analog feature extraction for ventricular fibrillation detection," Solid-State Circuits Conference Digest of Technical Papers (ISSCC), 2013 IEEE International , vol., no., pp.302,303, 17-21 Feb. 2013
J.G. Webster,”Design of Cardiac Pacemaker” , IEEE PRESS 1998. www.medtronic.com
11/12
Thanks for your attention
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