Non-Invasive Pulse Monitor for Assessing Hypertension

PI: Dr. John K-J. Li

Junhyeok Choi, Samson Huang, Olivia Ko, Richard Shen, Hana Hamdi

Why Hypertension?

http://www.cdc.gov/bloodpressure/infographic.htm

http://www.cdc.gov/bloodpressure/infographic.htm

Medical CostsCost of

Cardiologist per visit

Catheterization

$350

$2,700

Problem: Terminal hypertension patients require invasive surgical procedures in order to accurately diagnose the cause of hypertension.

Need: A noninvasive pulse pressure device that enables health providers to monitor and diagnose the cause hypertension in the clinical setting.

Objective

Omron blood pressure monitor

Catheterization SphygmaCor J-Li Monitor

Price $2,700 (procedure) $17,000 ~$50

Diagnosis• Direct diagnoses

of the heart (i.e. BP, blood flow)

• Blood Press.• PWV• HRV

• Blood Pressure

• PWV• HRV

User-Friendly Specialized Cardiologist Expert Patient

Accuracy High High High

Size - Textbook Size Wireless Router Size

Current Technology

Current Technology

SphygmaCor

J-Li Monitor

Text book sized

Wireless router sized

Prototyping Using a tonometer

Pulse pressure waveforms Piezoelectric

transducer(MPX5010DP) Power source (~5V) Small $12.83 on Digi-key AirPositive

Pressure

Clean Signal

Diaph

GainFilter

Prototyping Building the device

Sensitivity Higher gain (1000x) Improve filtering (0.05-0.25hz) Diaphragm & Rubber tubing

Prototyping

DiaphramAir

Positive Pressure

4mm (inner)Gain & Filter

Prototyping

Arduino UNO

USB Cable

J-LI Monitor

Pulse Pressure Pulse waveform of a 25-year old

Dr. Ting Choon Meng (December 2009). Pulse Wave, CASP, and the BPro Device. Retrieved from https://www.youtube.com/watch?v=i3UQ7oTIlfQ.

Arterial Stiffness 47-year old

Stiff Fast

80-year old Even Stiffer Faster

Dr. Ting Choon Meng. ”47-year old pulse wave." Youtube. 11 December 2009. Photograph. 20 April 2014.

Dr. Ting Choon Meng. "80-year old pulse wave." Youtube. 11 December 2009. Photograph. 20 April 2014.

Application

• Pulse Transit Time• Arterial Compliance

• Carotid artery• Radial artery• ECG

• BIOPAC• BSL Analysis

BIOPACCollect Pulse

PressureExtract Data

Preliminary Results Valsalva Maneuver

Normal arterial pressure response during the Valsalva Maneuver Characterized by a sinusoidal pattern

Strain caused by slowly breathing out

mV

mV

Time (s)Start of Valsalva

Peak Detection

Calculating PTT

Preliminary Results Finding Pulse Transit Time (PTT)

ECG

ECG

Pulse Pressure(carotid artery)

Pulse Pressure(radial artery)

.165s

.270s

PTT = 0.105 s

mV

mV

mV

mV

Time (s)

Time (s)

Male Female Male (std) Female (std)SBP (mmHg) 126 124 117.8 ±9.2 110.8 ±8.7**DBP (mmHg) 82 82 79.1 ±7.6 74.3 ±7.7**Pulse Pressure(mmHg)

44 42 38.7 36.5

PTT (s) 0.103 0.90 0.117 ±0.024

0.103 ±0.031**

Compliance (mL/mmHg)SV = 75mL

1.85 1.88 2.0 (avg) 2.0 (avg)

Preliminary Results Sample Physiological Values

113 men and 153 women; age 18–78 years

Zhang et al [8]

Conclusion & Future Work Future Iterations

Housing PCB circuit board User-friendly interface Clinical trials

Hypertensive vs Normal Patients

Commercial Potential Routine screening Preventative treatment

Thank You!

Special thanks to our faculty mentor, Dr. Li Any Questions?

References1. Li, J. K-J. Dynamics of the Vascular System. World Scientific, 2004.

2. García, Manuel Ignacio Monge, Anselmo Gil Cano, and Juan Carlos Díaz Monrové. "Arterial Pressure Changes during the Valsalva Maneuver to Predict Fluid Responsiveness in Spontaneously Breathing Patients." Intensive Care Medicine 35.1 (2009): 77-84. Print.

3. Chemla, Denis, Jean-Louis Hébert, Catherine Coirault, Karen Zamani, Isabelle Suard, Patrice Colin, and Yves Lecarpentier. "Total Arterial Compliance Estimated by Stroke Volume-to-aortic Pulse Pressure Ratio in Humans." American Journal of Physiology-Heart and Circulatory Physiology 274 (1998): H500-505.

4. "Coronary CT Imaging Can Predict Need For Invasive Heart Catheterization." Coronary CT Imaging Can Predict Need For Invasive Heart Catheterization. Web. 25 Jan. 2014.

5. "Global Burden of Disease Profile: United States." Institute for Health Metrics and Evaluation. 2010. Web. 05 Mar. 2014.

6. "High Blood Pressure Facts." Centers for Disease Control and Prevention. Centers for Disease Control and Prevention, n.d. Web. 26 Feb. 2014.

7. Liu, Z. R., C. T. Ting, S. X. Zhu, and F. C. Yin. "Aortic Compliance in Human Hypertension." Hypertension 14.2 (1989): 129-36.

8. Zhang Y, Zheng Y, Ma Z, Sun Y. Radial pulse transit time is an index of arterial stiffness. Hypertension Research: Official Journal Of The Japanese Society Of Hypertension [serial online]. July 2011;34(7):884-887. Available from: MEDLINE, Ipswich, MA. Accessed April 16, 2014.