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Hypertension Detector for Developing Countries

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Presentation on theme: "Hypertension Detector for Developing Countries"— Presentation transcript:

1 Hypertension Detector for Developing Countries
Matthew Trachtenberg

2 Leading Causes of Deaths, by Country Income Level
See how death rates differ for different incomes Matthew Trachtenberg 2010 "Global Health Risks: Selected Figures and Tables." (2004).

3 What are the biggest contributors to global mortality – Risk Factors
13.5% of Deaths Worldwide Risk factors Matthew Trachtenberg 2010 Lopez, AD, CD Mathers, and M Ezzati. Global Burden of Disease and Risk Factors. Oxford University Press, USA, Print.

4 Costs of Hypertension Suboptimal blood pressure costs $370 Billion globally Treatment may cost up to $1 Trillion in health spending Indirect costs could be as high as $3.6 Trillion annually Gaziano, T. , Bitton, A. , Anand, S. , Weinstein, M. , , . (2009). The Global Cost of Nonoptimal Blood Pressure. Journal of Hypertension, 27(7), Matthew Trachtenberg 2010

5 Need 1: Detect Hypertension
Reliably detect hypertension (systolic BP > 140mmHg, diastolic BP > 90mmHg) False Positives versus False Negatives Matthew Trachtenberg 2010

6 Births Attended by Skilled Health Personnel
See where birth may be more risky Matthew Trachtenberg 2010 "World Health Statistics." (2009). <http://www.who.int/whosis/whostat/en/>.

7 Need 2: User-Friendly Easy to use – user may not be able to read or understand numbers Minimal training required Matthew Trachtenberg 2010

8 Preeclampsia Preeclampsia/eclampsia is a severe complication of pregnancy classically diagnosed by severe hypertension and protein in urine Preeclampsia/eclampsia is currently the 2nd leading cause of maternal mortality in developing countries; partly due to low detection rates Of the small fraction of women who receive prenatal care, only half of them are estimated to have had their blood pressures monitored Treatment (injectable magnesium sulfate) is cheap and effective but relies on accurate and early diagnosis Pre-eclampsia is a severe complication of pregnancy classically marked by severe hypertension and protein in the urine after the 20th week of pregnancy. It can be a rapidly progressing disease leading to multiple organ failure, eclamptic seizures, and even death of both mother and fetus if not appropriately diagnosed and treated. Treatment for preeclampsia is fortunately cheap and effective with injectable magnesium sulfate. Unfortunately, preeclampsia/eclampsia remains the second highest direct cause of maternal mortality in developing countries, second only to hemorrhage. This is in part due to the low detection rate of preeclampsia in developing countries. It is estimated that of the 50% of women in developing countries who receive prenatal care, only half of them receive blood pressure measurements. We propose a blood pressure measuring device suitable for use in developing countries by non literate community volunteers who would visit homes to screen for diastolic blood pressures above 90. Our device would be robust, cheap, crank-powered, utilize a culturally-sensitive wrist cuff, and have a binary audiovisual signal indicating the presence or absence of a high diastolic blood pressure. We hope that this device will improve screening for preeclampsia/eclampsia, and increase the detection rate for this disease such that it can be treated before the mother and baby suffer irreversible injury.  Matthew Trachtenberg 2010

9 Preeclampsia Matthew Trachtenberg 2010
(A) Size of territory drawn according to its land area. (B) Size of territory drawn according to its population. Specifically - Preeclampsia (C) Size of territory drawn according to the proportion of maternal deaths that occur there Matthew Trachtenberg 2010 Duley, Lelia. "The Global Impact of Pre-Eclampsia and Eclampsia." Seminars in Perinatology 33 3 (2009): Print.

10 Need 3: Respect the Culture
Women in deeply conservative societies will not expose their upper arm to a volunteer for a typical blood pressure cuff. Matthew Trachtenberg 2010

11 Public Spending on Health
Per Person: Dorling, Newman, et. al. World Mapper (2005). <http://www.worldmapper.org/textindex/text_health.html>. Matthew Trachtenberg 2010

12 Need 4: Usable in Developing Countries
Inexpensive to manufacture (<$10) Devices that can be recharged/powered by alternative power sources. Robust in wide temperature ranges and in extreme dry and wet areas. Survive water and drops Matthew Trachtenberg 2010

13 Hypertension Detector - Preeclampsia
Purpose: Detect all preeclampsia conditions by testing in a community done by semi-literate volunteers who will visit house to house to check the blood pressure of pregnant women on a regular basis. Specifications: Reliably detect hypertension (systolic BP > 140mmHg, diastolic BP > 90mmHg) Easy to use– user may not be able to read or understand numbers Minimal training needed. Easy to accurately calibrate in the field Culturally compatible e.g. women in deeply conservative societies will not expose their upper arm for a typical blood pressure cuff. Inexpensive to manufacture (<$10) Power that can be recharged/generated by alternative power sources. Robust in wide temperature ranges and in extreme dry and wet areas. As Requested by JHPIEGO Matthew Trachtenberg 2010

14 Technologies Available for Preeclampsia Diagnosis
Intra-arterial Measurement Highly Accurate Highly Invasive Extensive Training Required Expensive Recording Equipment Necessary Matthew Trachtenberg 2010

15 Key technologies needed for Preeclampsia Diagnosis
Korotkoff Sounds No power source Extensive Training Required Sphygmomanometer Cuff inflated above arterial pressure (obliteration of pulse) Cuff is gradually deflated Korotkoff sounds appear and disappear at the systolic and diastolic pressure respectively Necessary to interpret numbers/results correctly Perloff, D, et al. "Human Blood Pressure Determination by Sphygmomanometry." Circulation 88 5 (1993): Print. Matthew Trachtenberg 2010

16 Key technologies needed for Preeclampsia Diagnosis
Complete Care Blood Pressure System - $129 Two cuff sizes Reports systolic and diastolic blood pressure, pulse, time, and date Has hypertension indicator Has irregular heartbeat detector Stores and averages readings Runs on 4 AAA batteries Detect proteinuria/hypertension Matthew Trachtenberg 2010

17 Key technologies needed for Preeclampsia Diagnosis
Gitway Inc Blood Pressure Monitor - $20 Worn on the wrist Shows your pulse and systolic/diastolic pressures Memory recall stores 60 previous readings Requires two AA batteries (not included) Detect proteinuria/hypertension Matthew Trachtenberg 2010

18 Key technologies needed for Preeclampsia Diagnosis
Microlife 3AS1-2 ~$30 Semi-automated upper arm device Memory of 60 readings with averaging ability Blood pressure and pulse measurement Detect proteinuria/hypertension Matthew Trachtenberg 2010 de Greeff, A., et al., Development of an accurate oscillometric blood pressure device for low resource settings. Blood Pressure Monitoring, (6): p. 342.

19 Key technologies needed for Preeclampsia Diagnosis
Clinitek 100 Ames - $700 Configured to read MULTISTIX 10 SG Reagent Strips ( ~ $0.35 each) A reflectance photometer that analyzes the color and intensity of the light reflected from the reagent area and displays the results in clinically meaningful units. Detect proteinuria/hypertension Matthew Trachtenberg 2010

20 Dipsticks for Proteinuria
Key technologies needed for Preeclampsia Diagnosis Dipsticks for Proteinuria In the absence of protein, the dipstick panel is yellow. Proteins in solution interfere with the dye-buffer combination, causing the panel to turn green. Indicate early renal damage. Carroll, MF, and JL Temte. "Proteinuria in Adults: A Diagnostic Approach." American family physician 62 6 (2000): Print. Matthew Trachtenberg 2010

21 Complete Care BP System Preeclampsia Dipsticks
How the Devices Add Up Device Detect Hypertension User-Friendly Respect Culture Developing Countries Price New Design yes yes - gives binary result and user only needs to inflate cuff yes - used on the wrist yes - crank power less than $10 Intra-Arterial no - requires extensive training no no - requires sterility due to invasiveness and an outlet for the measurement device expensive Korotkoff Sounds yes - no power required $15 for a kit Complete Care BP System yes - has hypertension indicator no - battery-powered over $100 Microlife no - user has to interpret results yes - solar power charger is being developed $30 Gitway Inc BP Monitor $20 Preeclampsia Dipsticks yes - color coded Around $1 each Matthew Trachtenberg 2010

22 My First Prototype < $20
Photoplethysmography Matthew Trachtenberg 2010

23 Modular and Alternative Power Sources
Honors Instrumentation Project Fall 2009 – Trachtenberg, Stark Matthew Trachtenberg 2010

24 Design – Gowri Jayaram and Shin Rong Lee
Automatic pump to inflate Solenoid valve to deflate Used parts and packaging from a disassembled wrist BP cuff on the market Battery Powered (9v) Honors Instrumentation Project Fall 2009 Matthew Trachtenberg 2010

25 Oscillometric Method Matthew Trachtenberg 2010
Matthew Trachtenberg 2010

26 New Design/Project Proposal
Cost < $10 Interchangeable with any standard cuff Has hypertension indicator (initially measures just diastolic pressure but eventually both) Visual LED (red/green) feedback means there is no need for an LCD screen Crank-powered. ~20 seconds of cranking per use Manual pump to inflate and a leaky valve to deflate Worn on the wrist Matthew Trachtenberg 2010

27 New Design/Project Proposal
Matthew Trachtenberg 2010

28 Is this just a cheap version of other devices?
A crank utilized to charge a super-capacitor will eliminate costs from batteries and their replacements. A super-capacitor can withstand the charging and discharging over the entire life of the device without a replacement needed. Instead of an LCD screen outputting specific numbers, the microcontroller will interpret what they mean and diagnose the person as hypertensive or healthy. This will save LCD screen costs and make the device more user-friendly. The device is designed to be modular so that donated cuffs can be used with the device and replaced by new ones as needed. Matthew Trachtenberg 2010

29 Acknowledgements JHPIEGO
Dr. Acharya and Dr. Thakor for their guidance and assistance Mr. Christopher Browne and Mr. Martin Pearson for his advice, and materials Heather Benz, Nasir Bhanpuri , Mehdi Rahman, Bejan Darbandi, Natan Davidovics for their advice, and input

30 Questions/Feedback Matthew Trachtenberg 2010

31 Blood Pressure Detection Algorithm
Pump to 180mmHg Light Green LED Deflate Cuff ~(2mmHg/s) Detect Max Pulse Amplitude and 2/3 Pulse Amplitude Yes No Read Pressure >90mmHg <90mmHg Light Yellow Crank device for power Light Red Go down below 60.. Not detect anything. Matthew Trachtenberg 2010

32 Circuit Diagram Matthew Trachtenberg 2010

33 Cost Analysis Wrist Cuff with Air Bladder, Bulb, Tubing $ 0.50
Pressure Sensor $ 6.89 Circuit components $ 6.00 Hand Crank Power Generator $ 2.00 TOTAL COST $15.39 Cuff with Bladder - $1.00 Air pump w/ pressure senor and solenoid valve - $7:50 PIC - $6.00 5V $3 Solenoid Valve - Matthew Trachtenberg 2010

34 System Circuit Matthew Trachtenberg 2010


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