Hypertension Detector for Developing Countries Matthew Trachtenberg Leading
Hypertension Detector for Developing Countries Matthew Trachtenberg
Leading Causes of Deaths, by Country Income Level Matthew Trachtenberg 2010 "Global Health Risks: Selected Figures and Tables. " (2004). 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 13. 5% of Deaths Worldwide Matthew Trachtenberg 2010 Lopez, AD, CD Mathers, and M Ezzati. Global Burden of Disease and Risk Factors. Oxford University Press, USA, 2006. Print.
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 Gaziano, T. , Bitton, A. , Anand, S. , Weinstein, M. , , . (2009). The Global Cost of annually Nonoptimal Blood Pressure. Journal of Hypertension, 27(7), 1472 -1477. http: //www. rd. com/living-healthy/high-blood-pressure-causes/article 118951. html Matthew Trachtenberg 2010
Need 1: Detect Hypertension • Reliably detect hypertension (systolic BP > 140 mm. Hg, diastolic BP > 90 mm. Hg) – False Positives versus False Negatives Matthew Trachtenberg 2010
Births Attended by Skilled Health Personnel Africa North and South America Southeast Asia Region 2 8% Attended 46% 2 54% Europe 2 4% Attended 92% Eastern Mediterranean Region Attended 48% 2 52% Western Pacific Region 2 8% 2 41% Attended 96% Matthew Trachtenberg 2010 Attende d 59% Attended 92% "World Health Statistics. " (2009). <http: //www. who. int/whosis/whostat/en/>
Need 2: User-Friendly • Easy to use – user may not be able to read or understand numbers • Minimal training required Matthew Trachtenberg 2010
Preeclampsia • Preeclampsia/eclampsia is a severe complication of pregnancy classically diagnosed by severe hypertension and protein in urine • Preeclampsia/eclampsia is currently the 2 nd 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 Matthew Trachtenberg 2010 http: //www. jhpiego. org/quarterly/winter 09/Nepal. htm
Preeclampsia (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 Matthew Trachtenberg 2010 Duley, Lelia. "The Global Impact of Pre-Eclampsia and Eclampsia. " Seminars in Perinatology 33 3 (2009): 130 -37. Print.
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
Public Spending on Health Person: Matthew Trachtenberg 2010 Dorling, Newman, et. al. World Mapper (2005). <http: //www. worldmapper. org/textindex/text_health. html>.
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
Hypertension Detector - Preeclampsia • Purpose: Detect all preeclampsia conditions by testing in a community done by semi-literate volunteers who will visit house to check the blood pressure of pregnant women on a regular basis. Specifications: • Reliably detect hypertension (systolic BP > 140 mm. Hg, diastolic BP > 90 mm. Hg) • 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 2010 As Requested by JHPIEGO
Technologies Available for Preeclampsia Diagnosis Intra-arterial Measurement • Highly Accurate • Highly Invasive • Extensive Training Required • Expensive Recording Equipment Necessary Matthew Trachtenberg 2010 http: //www. medtek. ki. se/medicaldevices/album/Ch%206%20 Mea surement%20 methods%20&%20 values/slides/F%206 -11 b%20 Intra -arterial%20 blood%20 pressure%20 measurent. html
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): 2460. Print. Matthew Trachtenberg 2010 http: //www. topnews. in/usa/files/Blood%20 Pressure. jpg
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 Matthew Trachtenberg 2010 http: //www. seventhavenue. com/catalog/product. jsp? product. Id=45496
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) Matthew Trachtenberg 2010 http: //www. amazon. com/Get-Organized-JB 5237 -PRESSURE-MONITOR/dp/B 0013 J 9 LYS
Key technologies needed for Preeclampsia Diagnosis Microlife 3 AS 1 -2 ~$30 • Semi-automated upper arm device • Memory of 60 readings with averaging ability • Blood pressure and pulse measurement Matthew Trachtenberg 2010 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.
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. Matthew Trachtenberg 2010 http: //www. dotmed. com/listing/512737
Key technologies needed for Preeclampsia Diagnosis Dipsticks for Proteinuria Matthew Trachtenberg 2010 • In the absence of protein, the dipstick panel is yellow. • Proteins in solution interfere with the dyebuffer 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.
How the Devices Add Up Device New Design Intra-Arterial Korotkoff Sounds Complete Care BP System Detect Hypertension yes User-Friendly Respect Culture yes - gives binary result and yes - used user only needs to inflate on the wrist cuff no - requires extensive training yes - has hypertension indicator yes no no Developing Countries Price yes - crank power less than $10 no - requires sterility due to invasiveness and an outlet for the measurement device yes - no power required no - battery-powered over $100 no yes - solar power charger is being developed $30 Microlife yes Gitway Inc BP Monitor yes no - user has to interpret yes - used no - battery-powered results on the wrist Preeclampsia Dipsticks yes Matthew Trachtenberg 2010 $15 for a kit no no - user has to interpret results yes - color coded expensive yes - no power required $20 Around $1 each
My First Prototype < $20 Photoplethysmography Matthew Trachtenberg 2010
Modular and Alternative Power Sources Matthew Trachtenberg 2010 Honors 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 (9 v) Honors Instrumentation Project Matthew Trachtenberg 2010 Fall 2009
Oscillometric Method Matthew Trachtenberg 2010 http: //www. blood-pressure-hypertension. com/how-to-measure/measureblood-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 Matthew Trachtenberg 2010
New Design/Project Proposal Matthew Trachtenberg 2010
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. Matthew Trachtenberg 2010
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 Matthew Trachtenberg 2010
Blood Pressure Detection Algorithm >90 mm Hg Ye s Light Green LED Crank device for power No Pump to 180 mm. Hg No Light Red LED Matthew Trachtenberg 2010 Light Yellow LED Deflate Cuff ~(2 mm. Hg/s) Detect Max Pulse Amplitude and 2/3 Pulse Amplitude Light Red LED Read Pressure <90 m m. Hg Light Green LED
Circuit Diagram Matthew Trachtenberg 2010
Cost Analysis -Wrist Cuff with Air Bladder, Bulb, Tubing $ 0. 50 -Pressure Sensor $ 6. 89 -Circuit components $ 6. 00 -Hand Crank Power Generator TOTAL COST Matthew Trachtenberg 2010 $ 2. 00 $15. 39
System Circuit Matthew Trachtenberg 2010
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