Continuous Cuff-less Blood Pressure Monitoring and Measurement 8 th - - PowerPoint PPT Presentation

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Continuous Cuff-less Blood Pressure Monitoring and Measurement 8 th - - PowerPoint PPT Presentation

Continuous Cuff-less Blood Pressure Monitoring and Measurement 8 th East Asian Consortium on Biomedical Engineering Dated : March 12, 2014 1,2,3 , Chen Nanguang 1,3 , Yong Lian 1,2 Koushik Kumar Nundy 1) NUS Graduate School for Integrative


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SLIDE 1

Continuous Cuff-less Blood Pressure Monitoring and Measurement

8th East Asian Consortium on Biomedical Engineering

Dated : March 12, 2014

Koushik Kumar Nundy

1,2,3 , Chen Nanguang 1,3 , Yong Lian 1,2

1) NUS Graduate School for Integrative Sciences and Engineering 2) Bioelectronics Laboratory, National University of Singapore 3) Optical Bioimaging Laboratory, National University of Singapore

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SLIDE 2

Design of a low power, low noise amplifier

Blood Pressure – Why should we care?

  • Hypertension is the cause and/or effect of several diseases, including

– coronary heart disease – congestive cardiac failure

  • Endocrinal disorders

– Diabetes – Hyper/Hypo-thyroidism

..etc

  • Marker for several non-cardiovascular diseases and disorders, like

– PCOS – Sleep Apnea

… and the list goes on.

kknundy@ieee.org 12/03/2014

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SLIDE 3

Design of a low power, low noise amplifier

Blood Pressure – Why should we care?

In fact, WHO data suggests that cardiovascular diseases, many of whom are associated with atypical BP values, result in up to 30% of all deaths.

– Hypertensive heart disease

alone directly causes about 1.6% deaths.

kknundy@ieee.org 12/03/2014

Image from Wikimedia Commons

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SLIDE 4

Design of a low power, low noise amplifier

Current Approaches to BP measurement

  • Cuff based

– Manual Sphygmomanometers – Electronic Sphygmomanometers

  • Optical (NIR)

– PPG – Pulse oximetry

  • Electrical

– ECG

  • Ultrasound

– Blood-flow

kknundy@ieee.org 12/03/2014

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SLIDE 5

Design of a low power, low noise amplifier

kknundy@ieee.org 12/03/2014

Continuous Cuff-less Blood Pressure Monitoring and Measurement

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SLIDE 6

Design of a low power, low noise amplifier

kknundy@ieee.org 12/03/2014

Continuous Cuff-less Blood Pressure Monitoring and Measurement

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Design of a low power, low noise amplifier

BP measurement

  • Continuous

– To look out for (and predict) sudden anomalies – Check for patterns in blood pressure variation – Pre-emptive healthcare and diagnostics

  • Cuff-less

– Simplified process – No professional required – Doesn't affect blood pressure values – Less invasive

kknundy@ieee.org 12/03/2014

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SLIDE 8

Design of a low power, low noise amplifier

Current Approaches to BP measurement

  • Cuff based

– Manual Sphygmomanometers – Electronic Sphygmomanometers

  • Optical (NIR)

– PPG – Pulse oximetry

  • Electrical

– ECG

  • Ultrasound

– Blood-flow

kknundy@ieee.org 12/03/2014

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SLIDE 9

Design of a low power, low noise amplifier

ECG and PPG based solutions

There have been several attempts to utilize Electrocardiogram (ECG) data and Photoplethysmogram (PPG) data to calculate the expected Blood pressure in the subject at a given time. Some of the more accurate approaches use this data to calculate the Pulse Transit Time (PTT) which has been shown to have some correlation with the Average Blood Pressure (BP)

  • f a subject.

kknundy@ieee.org 12/03/2014

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Design of a low power, low noise amplifier

ECG - PPG models used for BP modelling

  • MIT
  • Chinese University of Hong Kong

P= 1 ζ (ln( 2Rρ L

2

h E0 )−2ln (PTT ))=k1ln (PTT)+k 2 P= 1 ζ (( 2 RρL

2

h E0 )( 1 PTT

2)−1)=

A PTT

2+B

P=α.PTT +β

kknundy@ieee.org 12/03/2014

McCombie et. al., Conf. IEEE-EMBS, 2007. Banet et. al. WO Patent 2 011 082 341, 2011.

  • Y. M. Yong, PhD thesis CUHK, 2008.
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SLIDE 11

Design of a low power, low noise amplifier

ECG - PPG models used for BP modelling

  • MIT
  • Chinese University of Hong Kong

P=1 ζ( ln( 2 RρL

2

h E0 )−2ln( PTT ))=k1ln(PTT )+k 2 P=1 ζ(( 2 RρL

2

h E0 )( 1 PTT

2)−1)=

A PTT

2 +B

P=α . PTT +β

Logarithmic Inverse square Linear kknundy@ieee.org 12/03/2014

McCombie et. al., Conf. IEEE-EMBS, 2007. Banet et. al. WO Patent 2 011 082 341, 2011.

  • Y. M. Yong, PhD thesis CUHK, 2008.
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Design of a low power, low noise amplifier

Current Progress

  • Development of biological understanding
  • Evaluation of equipment and parameter options
  • Framework design for model validation and testing
  • Simulation and testing of previous and novel models using the

following parameters

– Blood Pressure – ECG – PPG

kknundy@ieee.org 12/03/2014

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Design of a low power, low noise amplifier

Setup

kknundy@ieee.org 12/03/2014

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Design of a low power, low noise amplifier

Setup

  • To ensure robustness of model, we can use industrial ECG as well as

in-house ECG solutions developed in our laboratory.

kknundy@ieee.org 12/03/2014

Early lab prototype of ECG on chip [1] 3rd party ECG solution [1] D. L. T. Wong and Y. Lian, “A wearable wireless ECG sensor with real-time QRS detection for continuous cardiac monitoring,” in 2012 IEEE Biomedical Circuits and Systems Conference (BioCAS), 2012, pp. 112–115.

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SLIDE 15

Design of a low power, low noise amplifier

Setup

  • Record ECG-PPG signals over a continuous period of time
  • Measure corresponding Blood Pressure at regular intervals over the

same period

  • Evaluate parameters, such as Pulse Transit Time (PTT) from acquired

data

Data from :

  • A. L. Goldberger, L. A. N. Amaral, L. Glass, J. M. Hausdorff, P. C. Ivanov, R. G. Mark, J. E. Mietus, G. B.

Moody, C.-K. K. Peng, and H. E. Stanley, “PhysioBank, PhysioToolkit, and PhysioNet: Components of a new research resource for complex physiologic signals,” Circulation, vol. 101, no. 23, pp. e215–e220, 2000.

kknundy@ieee.org 12/03/2014

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Design of a low power, low noise amplifier

Results

  • PTT and BP variation with time

kknundy@ieee.org 12/03/2014

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SLIDE 17

Design of a low power, low noise amplifier

Results

  • PTT variation with BP

kknundy@ieee.org 12/03/2014

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Design of a low power, low noise amplifier

Models

  • Linear

kknundy@ieee.org 12/03/2014

  • Inverse
  • Log
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Design of a low power, low noise amplifier

Earlier Data

  • Linear

kknundy@ieee.org 12/03/2014

  • L. Junwei, L. C. Yen, and W. Hanjie, “The Development of Wireless Cuff-less Blood Pressure Sensor for Chronic

Disease Management,” in IEEE Region 10 Student Activities Committee Paper Contest, 2013.

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SLIDE 20

Design of a low power, low noise amplifier

Intended solution

kknundy@ieee.org 12/03/2014

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Design of a low power, low noise amplifier

Current issues & Future Possibilities

  • Data backhaul

– Bandwidth – Processing power (for compression/analysis) – Electrical power (to run the system) – security

  • Compression algorithms

– Lossy vs lossless

  • Accuracy
  • Motion artefacts

– PPG signal highly sensitive to movement

kknundy@ieee.org 12/03/2014

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SLIDE 22

Design of a low power, low noise amplifier

Acknowledgements

  • Bioelectronics Laboratory, NUS

– David Wong – Li Yongfu – Lin Junwei, Lam Cheng Yen, Wang Hanjie

  • School of Public Health, NUS

– Dr Mueller-Riemenschneider Falk – Dr Lim Wei Yen

  • Global COE Program, Tohoku University

for their kind support in funding the conference travel

kknundy@ieee.org 12/03/2014

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SLIDE 23

Design of a low power, low noise amplifier

Questions?

“Blood is a juice of rarest quality” ~ Goethe's Faust

kknundy@ieee.org 12/03/2014

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Design of a low power, low noise amplifier

Thank you

kknundy@ieee.org 12/03/2014

Contact Information :

Koushik Kumar Nundy Bioelectronics Laboratory Department of ECE National University of Singapore

kknundy@ieee.org http://kknundy.net

Paper : http://www.kknundy.net/publications/8EABME_2014.pdf