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 Sciences and Engineering 2) Bioelectronics Laboratory, National University of Singapore 3) Optical Bioimaging Laboratory, National University of Singapore

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

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. Image from Wikimedia Commons kknundy@ieee.org 12/03/2014

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

Design of a low power, low noise amplifier Continuous Cuff-less Blood Pressure Monitoring and Measurement kknundy@ieee.org 12/03/2014

Design of a low power, low noise amplifier Continuous Cuff-less Blood Pressure Monitoring and Measurement kknundy@ieee.org 12/03/2014

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

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

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) of a subject. kknundy@ieee.org 12/03/2014

Design of a low power, low noise amplifier ECG - PPG models used for BP modelling ● MIT ζ ( ln ( h E 0 ) − 2ln ( PTT ) ) = k 1 ln ( PTT )+ k 2 2 2 R ρ L P = 1 McCombie et. al., Conf. IEEE-EMBS , 2007. P =α .PTT +β Banet et. al. WO Patent 2 011 082 341 , 2011. ● Chinese University of Hong Kong ζ ( ( 2 ) − 1 ) = h E 0 ) ( 2 2 R ρ L P = 1 1 A 2 + B PTT PTT Y. M. Yong, PhD thesis CUHK , 2008. kknundy@ieee.org 12/03/2014

Design of a low power, low noise amplifier ECG - PPG models used for BP modelling ● MIT ζ ( ln ( h E 0 ) − 2ln ( PTT ) ) = k 1 ln ( PTT )+ k 2 2 P = 1 2 R ρ L Logarithmic McCombie et. al., Conf. IEEE-EMBS , 2007. P =α . PTT +β Linear Banet et. al. WO Patent 2 011 082 341 , 2011. ● Chinese University of Hong Kong ζ ( ( 2 ) − 1 ) = h E 0 ) ( 2 P = 1 2 R ρ L 1 A 2 + B Inverse square PTT PTT Y. M. Yong, PhD thesis CUHK , 2008. kknundy@ieee.org 12/03/2014

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

Design of a low power, low noise amplifier Setup kknundy@ieee.org 12/03/2014

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. Early lab prototype of ECG on chip [1] 3 rd 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. kknundy@ieee.org 12/03/2014

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

Design of a low power, low noise amplifier Results ● PTT and BP variation with time kknundy@ieee.org 12/03/2014

Design of a low power, low noise amplifier Results ● PTT variation with BP kknundy@ieee.org 12/03/2014

Design of a low power, low noise amplifier Models ● Inverse ● Linear ● Log kknundy@ieee.org 12/03/2014

Design of a low power, low noise amplifier Earlier Data ● Linear 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. kknundy@ieee.org 12/03/2014

Design of a low power, low noise amplifier Intended solution kknundy@ieee.org 12/03/2014

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

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

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

Design of a low power, low noise amplifier Thank you 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 kknundy@ieee.org 12/03/2014