Presentation on theme: "Hypertension Detector for Developing Countries"— Presentation transcript:
1Hypertension Detector for Developing Countries Matthew Trachtenberg
2Leading Causes of Deaths, by Country Income Level See how death rates differ for different incomesMatthew Trachtenberg 2010"Global Health Risks: Selected Figures and Tables." (2004).
3What are the biggest contributors to global mortality – Risk Factors 13.5% of Deaths WorldwideRisk factorsMatthew Trachtenberg 2010Lopez, AD, CD Mathers, and M Ezzati. Global Burden of Disease and Risk Factors. Oxford University Press, USA, Print.
4Costs of HypertensionSuboptimal blood pressure costs $370 Billion globallyTreatment may cost up to $1 Trillion in health spendingIndirect costs could be as high as $3.6 Trillion annuallyGaziano, T. , Bitton, A. , Anand, S. , Weinstein, M. , , . (2009). The Global Cost of Nonoptimal Blood Pressure. Journal of Hypertension, 27(7),Matthew Trachtenberg 2010
5Need 1: Detect Hypertension Reliably detect hypertension (systolic BP > 140mmHg, diastolic BP > 90mmHg)False Positives versus False NegativesMatthew Trachtenberg 2010
6Births Attended by Skilled Health Personnel See where birth may be more riskyMatthew Trachtenberg 2010"World Health Statistics." (2009). <http://www.who.int/whosis/whostat/en/>.
7Need 2: User-FriendlyEasy to use – user may not be able to read or understand numbersMinimal training requiredMatthew Trachtenberg 2010
8PreeclampsiaPreeclampsia/eclampsia is a severe complication of pregnancy classically diagnosed by severe hypertension and protein in urinePreeclampsia/eclampsia is currently the 2nd leading cause of maternal mortality in developing countries; partly due to low detection ratesOf the small fraction of women who receive prenatal care, only half of them are estimated to have had their blood pressures monitoredTreatment (injectable magnesium sulfate) is cheap and effective but relies on accurate and early diagnosisPre-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
9Preeclampsia 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 thereMatthew Trachtenberg 2010Duley, Lelia. "The Global Impact of Pre-Eclampsia and Eclampsia." Seminars in Perinatology 33 3 (2009): Print.
10Need 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
11Public Spending on Health Per Person:Dorling, Newman, et. al. World Mapper (2005). <http://www.worldmapper.org/textindex/text_health.html>.Matthew Trachtenberg 2010
12Need 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 dropsMatthew Trachtenberg 2010
13Hypertension 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 numbersMinimal training needed.Easy to accurately calibrate in the fieldCulturally 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 JHPIEGOMatthew Trachtenberg 2010
14Technologies Available for Preeclampsia Diagnosis Intra-arterial MeasurementHighly AccurateHighly InvasiveExtensive Training RequiredExpensive Recording Equipment NecessaryMatthew Trachtenberg 2010
15Key technologies needed for Preeclampsia Diagnosis Korotkoff SoundsNo power sourceExtensive Training RequiredSphygmomanometerCuff inflated above arterial pressure (obliteration of pulse)Cuff is gradually deflatedKorotkoff sounds appear and disappear at the systolic and diastolic pressure respectivelyNecessary to interpret numbers/results correctlyPerloff, D, et al. "Human Blood Pressure Determination by Sphygmomanometry." Circulation 88 5 (1993): Print.Matthew Trachtenberg 2010
16Key technologies needed for Preeclampsia Diagnosis Complete Care Blood Pressure System - $129Two cuff sizesReports systolic and diastolic blood pressure, pulse, time, and dateHas hypertension indicatorHas irregular heartbeat detectorStores and averages readingsRuns on 4 AAA batteriesDetect proteinuria/hypertensionMatthew Trachtenberg 2010
17Key technologies needed for Preeclampsia Diagnosis Gitway Inc Blood Pressure Monitor - $20Worn on the wristShows your pulse and systolic/diastolic pressuresMemory recall stores 60 previous readingsRequires two AA batteries (not included)Detect proteinuria/hypertensionMatthew Trachtenberg 2010
18Key technologies needed for Preeclampsia Diagnosis Microlife 3AS1-2 ~$30Semi-automated upper arm deviceMemory of 60 readings with averaging abilityBlood pressure and pulse measurementDetect proteinuria/hypertensionMatthew Trachtenberg 2010de Greeff, A., et al., Development of an accurate oscillometric blood pressure device for low resource settings. Blood Pressure Monitoring, (6): p. 342.
19Key technologies needed for Preeclampsia Diagnosis Clinitek 100 Ames - $700Configured 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/hypertensionMatthew Trachtenberg 2010
20Dipsticks for Proteinuria Key technologies needed for Preeclampsia DiagnosisDipsticks for ProteinuriaIn 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
21Complete Care BP System Preeclampsia Dipsticks How the Devices Add UpDeviceDetect HypertensionUser-FriendlyRespect CultureDeveloping CountriesPriceNew Designyesyes - gives binary result and user only needs to inflate cuffyes - used on the wristyes - crank powerless than $10Intra-Arterialno - requires extensive trainingnono - requires sterility due to invasiveness and an outlet for the measurement deviceexpensiveKorotkoff Soundsyes - no power required$15 for a kitComplete Care BP Systemyes - has hypertension indicatorno - battery-poweredover $100Microlifeno - user has to interpret resultsyes - solar power charger is being developed$30Gitway Inc BP Monitor$20Preeclampsia Dipsticksyes - color codedAround $1 eachMatthew Trachtenberg 2010
22My First Prototype < $20 PhotoplethysmographyMatthew Trachtenberg 2010
23Modular and Alternative Power Sources Honors Instrumentation Project Fall 2009 – Trachtenberg, StarkMatthew Trachtenberg 2010
24Design – Gowri Jayaram and Shin Rong Lee Automatic pump to inflateSolenoid valve to deflateUsed parts and packaging from a disassembled wrist BP cuff on the marketBattery Powered (9v)Honors Instrumentation Project Fall 2009Matthew Trachtenberg 2010
25Oscillometric Method Matthew Trachtenberg 2010 Matthew Trachtenberg 2010
26New Design/Project Proposal Cost < $10Interchangeable with any standard cuffHas hypertension indicator (initially measures just diastolic pressure but eventually both)Visual LED (red/green) feedback means there is no need for an LCD screenCrank-powered. ~20 seconds of cranking per useManual pump to inflate and a leaky valve to deflateWorn on the wristMatthew Trachtenberg 2010
27New Design/Project Proposal Matthew Trachtenberg 2010
28Is 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
29Acknowledgements JHPIEGO Dr. Acharya and Dr. Thakor for their guidance and assistanceMr. Christopher Browne and Mr. Martin Pearson for his advice, and materialsHeather Benz, Nasir Bhanpuri , Mehdi Rahman, Bejan Darbandi, Natan Davidovics for their advice, and input
31Blood Pressure Detection Algorithm Pump to 180mmHgLight GreenLEDDeflate Cuff ~(2mmHg/s)Detect Max Pulse Amplitude and 2/3 Pulse AmplitudeYesNoRead Pressure>90mmHg<90mmHgLight YellowCrank device for powerLightRedGo down below 60.. Not detect anything.Matthew Trachtenberg 2010