Blood Pressure Monitor Re-CalibrationLei Qu1, Ross Hamilton1,David Lee1, Haniff Mohd Nor2

Advisor: Dr. Andre Churchwell3 , Dr. Paul King1

Acknowledgments

References

Proposed Circuit Design

Future Directions

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1Biomedical Engineering, Vanderbilt University, 2Mechanical Engineering , Vanderbilt University, 3 Vanderbilt Medical Center Cardiology Department

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Results

• Test our re-calibration device

• Adjust aesthetic and technical qualities to make it more compact and desirable

• Reduce production costs with efficiency improvements

• Optimize the circuit diagram and continue testing for improvements

We would like to thank Dr. Andre Churchwell for being our primary sponsor and advisor providing essential insight to our design process! Dr. Paul King also played a huge role as our secondary sponsor in all aspects of the project. Lastly, we would like to thank the VUMC Clinical Engineering Department and Jonathan Whitfield for their special assistance.

Figure 4. Schematic diagram of the proposed circuit design

Results and Proposed Design

Introduction

• Monitoring the blood pressure of a hypertension patient is one of the most effective ways to treat hypertension

• Traditional method - Mercury Sphygmomanometer:

• Advantage: Accurate reading of an individual’s blood pressure

• Disadvantage: Training and certain skill set required; it is also hard to determine blood pressure since it is done through listening.

• Omron Digital Blood Pressure:

• Advantage: Convenience/easy to use

• Disadvantage: Lack of a method to re-calibrate the device

Objectives

• Verify that the variation between the digital blood pressure monitor and mercury sphygmomanometer is significant in terms of determining the stage of hypertension

• Investigate the causes of the variation between digital blood pressure monitors and mercury sphygmomanometers

• Design a calibration method for the observed variation in this project

Table above shows the measurements of blood pressure we took with the artificial arm (mmHg) • Normal blood pressure on the arm is set for 120/80 mmHg

• Hypertension condition is set for 150/100 mmHg

• P-values are all below 0.05

Table above shows the measurements of blood pressure we took with the artificial arm with flatten arm band method applied (mmHg) • Normal blood pressure on the arm is set for 120/80 mmHg

• P-value for systolic pressure is above 0.05 but for diastolic is below 0.05• Human error can be attributed in this difference

• Difference is smaller than 2 mmHg, normally ignored in clinical practice

Figure 1. Experimental setup for Omron Figure 2. Experimental setup for sphygmomanometer

Figure 3. Proposed schematic design

• Portable Digital Blood Pressure Monitor by Woradon Wattanapanitch and Warut Suampun http://instruct1.cit.cornell.edu/courses/ee476/FinalProjects/s2005/ww56_ws62/Final%20Project%20Web/index.html

• McManus RJ, Mant J, Hull MR, Hobbs FD. Does changing from mercury to electronic blood pressure measurement influence recorded blood pressure? An observational study. Br J Gen Pract. 2003 Dec;53(497):953-6.

• Heinemann M, Sellick K, Rickard C, Reynolds P, McGrail M. Automated versus manual blood pressure measurement: a randomized crossover trial. Int J Nurs Pract. 2008 Aug;14(4):296-302.