Hypertension Detector for Developing Countries Matthew Trachtenberg.

Hypertension Detector for Developing Countries

Matthew Trachtenberg

Leading Causes of Deaths, by Country Income Level

"Global Health Risks: Selected Figures and Tables." (2004). http://www.who.int/entity/healthinfo/global_burden_disease/global_health_risks_report_figures.ppt.

Matthew Trachtenberg 2010

http://www.who.int/entity/healthinfo/global_burden_disease/global_health_risks_report_figures.ppt

What are the biggest contributors to global mortality– Risk Factors

Lopez, AD, CD Mathers, and M Ezzati. Global Burden of Disease and Risk Factors. Oxford University Press, USA, 2006. Print.Matthew Trachtenberg 2010

13.5% of Deaths Worldwide

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), 1472-1477.

http://www.rd.com/living-healthy/high-blood-pressure-causes/article118951.html


Need 1: Detect Hypertension

• Reliably detect hypertension (systolic BP > 140mmHg, diastolic BP > 90mmHg)– False Positives versus False Negatives


Births Attended by Skilled Health Personnel

At-tende

d46%

54%

Africa

Attended92%

8%

North and South America

At-tended

48%52%

Southeast Asia Region

Attended96%

4%

Europe

Attended59%

41%

Eastern Mediterranean Region

Attended92%

8%

Western Pacific Region

"World Health Statistics." (2009). <http://www.who.int/whosis/whostat/en/>.Matthew Trachtenberg 2010

Need 2: User-Friendly

• Easy to use – user may not be able to read or understand numbers

• Minimal training required


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

http://www.jhpiego.org/quarterly/winter09/Nepal.htmMatthew Trachtenberg 2010

Preeclampsia

Duley, Lelia. "The Global Impact of Pre-Eclampsia and Eclampsia." Seminars in Perinatology 33 3 (2009): 130-37. Print.

(A) Size of territory drawn according to its land area.

(B) Size of territory drawn according to its population.

(C) Size of territory drawn according to the proportion of maternal deaths that occur there


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.


Public Spending on Health

Dorling, Newman, et. al. World Mapper (2005). <http://www.worldmapper.org/textindex/text_health.html>.Matthew Trachtenberg 2010

Per Person:

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


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.

Matthew Trachtenberg 2010As Requested by JHPIEGO

Intra-arterial Measurement• Highly Accurate• Highly Invasive• Extensive Training

Required• Expensive Recording

Equipment Necessary

Technologies Available for Preeclampsia Diagnosis

http://www.medtek.ki.se/medicaldevices/album/Ch%206%20Measurement%20methods%20&%20values/slides/F%206-11b%20Intra-arterial%20blood%20pressure%20measurent.html


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

Key technologies needed for Preeclampsia Diagnosis

http://www.topnews.in/usa/files/Blood%20Pressure.jpg


Perloff, D, et al. "Human Blood Pressure Determination by Sphygmomanometry." Circulation 88 5 (1993): 2460. Print.


http://www.seventhavenue.com/catalog/product.jsp?productId=45496

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



http://www.amazon.com/Get-Organized-JB5237-PRESSURE-MONITOR/dp/B0013J9LYS

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)



de Greeff, A., et al., Development of an accurate oscillometric blood pressure device for low resource settings. Blood Pressure Monitoring, 2008. 13(6): p. 342.

Microlife 3AS1-2 ~$30

• Semi-automated upper arm device• Memory of 60 readings with averaging ability• Blood pressure and pulse measurement




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.

http://www.dotmed.com/listing/512737

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): 1333-42. Print.Matthew Trachtenberg 2010


How the Devices Add UpDevice Detect

Hypertension User-Friendly Respect Culture

Developing Countries Price

New Design yesyes - gives binary result and

user only needs to inflate cuff

yes - used on the wrist yes - crank power less than $10

Intra-Arterial yes no - requires extensive training no

no - requires sterility due to invasiveness

and an outlet for the measurement device

expensive

Korotkoff Sounds yes no - requires extensive

training no yes - no power required $15 for a kit

Complete Care BP System yes yes - has hypertension

indicator no no - battery-powered over $100

Microlife yes no - user has to interpret results no

yes - solar power charger is being

developed$30

Gitway Inc BP Monitor yes no - user has to interpret

resultsyes - used

on the wrist no - battery-powered $20

Preeclampsia Dipsticks yes yes - color coded yes yes - no power

requiredAround $1

each


My First Prototype < $20


Photoplethysmography

Modular and Alternative Power Sources

Matthew Trachtenberg 2010Honors Instrumentation Project Fall 2009 – Trachtenberg, Stark

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)

Matthew Trachtenberg 2010Honors Instrumentation Project Fall 2009

Oscillometric Method

Matthew Trachtenberg 2010http://www.blood-pressure-hypertension.com/how-to-measure/measure-blood-pressure-8.shtml

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


New Design/Project Proposal


Is this just a cheap version of other devices?


No.• 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.

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

Questions/Feedback


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

LED

Crank device for

power

Yes

No

Light RedLED

Light RedLED

Light Green

LED

Circuit Diagram


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


System Circuit


Hypertension Detector for Developing Countries Matthew Trachtenberg.

Documents

severe hypertension

typical blood pressure

hypertension systolic

journal of hypertension

mmhg easy

blood pressures

diastolic bp

health dorling