Blood Pressure Measurement in Low-Resource Settings Group 38 Members: Satish Chandrasekhar, Karthik Krishnan, Matt Everett Client: Dr. Donald Elbert September 22, 2014 Background and Need for Blood Pressure Measurement Blood Pressure Classification Systolic BP (mmHg) Diastolic BP (mmHg) Need Both/Either? Hypotension <90 <60 Either Normal (Normotension) 90-120 60-80 Both Prehypertension 120-139 80-89 Either Stage 1 Hypertension 140-159 90-99 Either Stage 2 Hypertension >159 >99 Either Table 1. NIH Guidelines for Hypotension and Hypertension Diagnosis Problems with Hypertension/Hypotension • Hypertension is a precursor to cardiac disease • Myocardial Infarction • Stroke • Chronic Heart Failure • Hypotension •Dizziness • Fainting Demographics of Hypertension Country Adults w/ hypertension (%) USA 33 India (urban, 30% of population) 40.6 India (rural, 70% of population) 17 India (total) 25 • 2009 – Contributed to 348,000 deaths • 170 million cases in India • 77.9 million cases in the United States Need for Blood Pressure Measurement • Approximately 20% of adults with hypertension in US unaware that they have disorder • 16% of all adults in India undiagnosed • Limitations: • Cost • Training Measurement Techniques and Existing Technologies Auscultatory Method • Widely used in clinic by doctors • Inflate and deflate cuff while listening to sounds in sphygmomanometer Use of Korotkoff sounds in BP measurement. Shaded region of curve represents region in which sounds can be distinguished  . Aneroid Sphygmomanometer • Used in conjunction with stethoscope • Uses auscultatory method • Cost: $10 - $60 • Accuracy within 0.4kPa (3 mm Hg) •Measured by trained clinicians • Medical training required to distinguish sounds Aneroid sphygmomanometer  Oscillometric Method • Measures pressure waves • Can measure mean arterial pressure accurately • Not as good of estimates for systolic and diastolic pressure http://tensoval.com/oscillometric-measurement-devices.php Wrist Monitors • Uses oscillometric method • Requires little to no training to use • Cost: $30 - $90 • Susceptible to changes in body position Omron Wrist Monitor  LionsGate Mobile BP Monitor • Also uses oscillometric method • Outputs results to mobile smartphone • Currently not on market for sale Pulse Wave Velocity • Measure pulse at two points on body, and amount of time needed for pulse to reach each point • Velocity = Distance/Time • Not as accurate • Susceptible to motion artifacts and variations due to body position • Needs to be calibrated with other BP measurement technique http://content.onlinejacc.org/article.aspx?articleid=1144323 SOMNOtouch by SOMNOmedics • Uses Pulse Wave Velocity Method • Outputs data to wrist monitor • Also not available for sale in US, pending FDA approval Invasive Cannulation • Insert cannula into artery to measure blood pressure changes • Most accurate method • Drawbacks: • Invasive/inconvenient • Training required to perform procedure Cannulation of Radial Artery  Patents • Patch Sensor • Optical Methods •Emission, reflection, sensing •Calibrate using BP measurements Patch Sensor Project Scope and Design Specifications Design Specifications Parameter Specification Cost Less than $25 (Rs. 1500) Training Required to Operate Literate individuals with no medical training Rapid Results within 30 seconds of set-up Accurate Within 0.67kPa (5 mmHg) of current methods Reusable All components must be reusable Safe Must not cause harm to user Measurement Non-continuous, as a screening tool Non-invasive Must not require surgical procedure to measure Preliminary Design Schedule and Team Responsibilities Tentative Design Schedule Team Responsibilities • All 3 members have input in all parts of design process • Would also collaborate to learn unfamiliar material • Strengths/Focus: • Matt – Software • Satish & Karthik – Electronics/Circuits • All 3 members will work to schedule meetings with client (Dr. Elbert) and mentors Questions? References 1. Ogedegbe, Gbenga, and Thomas Pickering. "Principles and Techniques of Blood Pressure Measurement." Cardiology Clinics 28.4 (2010): 571-86. Web. 2. Pickering, T. G. "Recommendations for Blood Pressure Measurement in Humans and Experimental Animals: Part 1: Blood Pressure Measurement in Humans: A Statement for Professionals From the Subcommittee of Professional and Public Education of the American Heart Association Council on High Blood Pressure Research."Circulation 111.5 (2005): 697-716. Web. 3. Gesche, Heiko, Detlef Grosskurth, Gert Küchler, and Andreas Patzak. "Continuous Blood Pressure Measurement by Using the Pulse Transit Time: Comparison to a Cuff-based Method." European Journal of Applied Physiology 112.1 (2012): 309-15. Web. 4. Ward, Matthew, and Jeremy A. Langton. "Blood Pressure Measurement."Continuing Education in Anaesthesia, Critical Care, and Pain 7.4 (2007): 122-26. Medscape. Web. <http://www.medscape.com/viewarticle/563819_5>. 5. Keenan, Nora L., and Kimberly A. Rosendorf. "Prevalence of Hypertension and Controlled Hypertension --- United States, 2005--2008." Centers for Disease Control and Prevention. Centers for Disease Control and Prevention, 14 Jan. 2011. Web. 19 Sept. 2014. 6. Go, A. S., D. Mozaffarian, V. L. Roger, E. J. Benjamin, J. D. Berry, W. B. Borden, D. M. Bravata, S. Dai, E. S. Ford, C. S. Fox, S. Franco, H. J. Fullerton, C. Gillespie, S. M. Hailpern, J. A. Heit, V. J. Howard, M. D. Huffman, B. M. Kissela, S. J. Kittner, D. T. Lackland, J. H. Lichtman, L. D. Lisabeth, D. Magid, G. M. Marcus, A. Marelli, D. B. Matchar, D. K. Mcguire, E. R. Mohler, C. S. Moy, M. E. Mussolino, G. Nichol, N. P. Paynter, P. J. Schreiner, P. D. Sorlie, J. Stein, T. N. Turan, S. S. Virani, N. D. Wong, D. Woo, and M. B. Turner. "Heart Disease and Stroke Statistics--2013 Update: A Report From the American Heart Association." Circulation 127.1 (2013): E6-E245. High Blood Pressure. American Heart Association. Web. 7. Yoon, Sung S., Vicki Burt, Tatiana Louis, and Margaret D. Carroll. "Hypertension Among Adults in the United States, 2009–2010."Centers for Disease Control and Prevention. Centers for Disease Control and Prevention, 02 Oct. 2012. Web. 19 Sept. 2014. 8. NIH. "What Is High Blood Pressure?" What Is High Blood Pressure?NHLBI, NIH, 2 Aug. 2012. Web. 19 Sept. 2014. 9. Midha, Tanu, et. al. "Prevalence of Hypertension in India: A Meta-analysis." World Journal of Meta-Analysis 1.2 (2013): 83-89. Web. 10. Gupta, R. "Trends in Hypertension Epidemiology in India." Journal of Human Hypertension 18.2 (2004): 73-78. Web. 11. Moser, Kath A., Sutapa Agrawal, George Davey Smith, and Shah Ebrahim. "Socio-Demographic Inequalities in the Prevalence, Diagnosis and Management of Hypertension in India: Analysis of Nationally-Representative Survey Data." Ed. Yiru Guo. PLoS ONE 9.1 (2014): E86043. Web. 12. Mayo Clinic. "Low Blood Pressure (hypotension)." Diseases and Conditions: Hypotension. Mayo Clinic, n.d. Web. 21 Sept. 2014. <http://www.mayoclinic.org/diseases-conditions/low-blood-pressure/basics/definition/con-20032298>. References 13. Joshi, Shashank R., Banshi Saboo, et. al. "Prevalence of Diagnosed and Undiagnosed Diabetes and Hypertension in India—Results from the Screening India's Twin Epidemic (SITE) Study." Diabetes Technology & Therapeutics 14.1 (2012): 8-15. Web. 14. Janusz Kaczorowski, PhD, Martin Dawes, MB, BS, MD, FRCGP, Mark Gelfer, MD. Measurement of blood pressure: New developments and challenges. BCMJ, Vol. 54, No. 8, October, 2012, page(s) 399-403 — Articles. 15. Sphygmomanometer Measurements. Digital image. N.p., n.d. Web. <http://galileo.phys.virginia.edu/classes/304/bp2a.gif>. 16. Aneroid Sphygmomanometer. Digital image. N.p., n.d. Web. <http://www.smlhygiene.co.uk/images/Aneroid%20Sphygmomanometer.jpg>. 17. Ancillare. "BpTRU - BPM-100 Clinical Blood Pressure Monitors." BpTRU - BPM-100 Clinical Blood Pressure Monitors. Ancillare, 2011. Web. 19 Sept. 2014. <http://ancillare.com/bptru/products.html#bpm_100>. 18. QuickMedical. "Aneroid Sphygmomanometers." Aneroid Sphygmomanometers. QuickMedical, n.d. Web. 19 Sept. 2014. <http://www.quickmedical.com/bloodpressure/professional/aneroid/>. 19. ADC. "E-sphyg." E-sphyg Digital Pocket Aneroid Sphyg. American Diagnostic Corporation, n.d. Web. 19 Sept. 2014. <http://adctoday.com/products/7002>. 20. "CMS CONTEC Ambulatory Blood Pressure Monitor." CMS CONTEC Ambulatory Blood Pressure Monitor. ClinicalGuard, n.d. Web. 19 Sept. 2014. <http://www.clinicalguard.com/id/cms-contec-ambulatory-blood-pressure-monitor--p630.html?gclid=CjwKEAjwheqgBRD5vOfR45az5AESJABy4m8-vntnPg4JVia_8JlXnoHUZyCmBO6ShGhP0Z-snim2phoC2kPw_wcB>. 21. Sheps, Sheldon G. "High Blood Pressure (hypertension)." Wrist Blood Pressure Monitors: Are They Accurate? Mayo Clinic, 20 July 2012. Web. 19 Sept. 2014. <http://www.mayoclinic.org/diseases-conditions/high-blood-pressure/expert-answers/wrist-blood-pressuremonitors/faq-20057802>. 22. LionsGate Technologies. N.p.: LionsGate Technologies, n.d. Mobile Vital Signs Monitoring. LionsGate Technologies, Mar. 2013. Web. <http://www2.lgtmedical.com/LGT_WHITEPAPER.pdf>. 23. SOMNOmedics GmbH. "More Information." SOMNOtouch NIBP: SOMNOmedics. SOMNOmedics, n.d. Web. 19 Sept. 2014. <http://somnomedics-diagnostics.com/products/new-somnotouch/somnotouch-nibp/>. References 24. Berman, Robert A. Inflatable Blood Pressure Cuff. Medical Plastics Inc, assignee. Patent US2981251 A. 25 Apr. 1961. Print. 25. Jankov, Vladimir, and Harry L. Platt. Transtelephonic Blood Pressure Monitor. Vladimir Jankov, assignee. Patent WO2001026544 A1. 19 Apr. 2001. Print. 26. Banet, Matthew. Patch Sensor for Measuring Blood Pressure without a Cuff. Triage Wireless, Inc., assignee. Patent US20050228299 A1. 13 Oct. 2005. Print. 27. Khair, Mohammed, Salvador Lopez, Richard Ng, Sanjar Ghaem, and William Olson. Optical Noninvasive Blood Pressure Sensor and Method. Motorola Inc., assignee. Patent US6533729 B1. 18 Mar. 2003. Print. 28. Riobo Aboy, Pedro Mateo. Blood Pressure Algorithm. Tiba Medical, Inc., assignee. Patent US7927283 B2. 19 Apr. 2011. Print. 29. Jones, Paul H., and Wei-Min Wang. Method of Measuring Blood Pressure with a Photoplethysmograph. Spacelabs, Inc., assignee. Patent US5140990 A. 25 Aug. 1992. Print. 30. McCombie, Devin B., Andrew T. Reisner, Haruhiko H. Asada, and Phillip Shaltis. Wearable Pulse Wave Velocity Blood Pressure Sensor and Methods of Calibration Thereof. Massachusetts Institute Of Technology, assignee. Patent US20080039731. 9 Mar. 2010. Print. 31. Mohler, Sailor. Piezoelectric Sensor for Blood Pressure Measurement. Sailor Mohler, assignee. Patent WO1998026716 A1. 25 June 1998. Print. 32. Khair, Mohammed, Salvador Lopez, Richard Ng, Sanjar Ghaem, and William Olson. Method for Obtaining Blood Pressure Data from Optical Sensor. Motorola Inc., assignee. Patent US 6475153 B1. 10 May 2000. Print. 33. Sorensen, Jodi. "How to Create a Gantt Chart in Excel." Online Project Management Software. Smartsheet, 8 July 2013. Web. 19 Sept. 2014. <http://www.smartsheet.com/blog/gantt-chart-excel>. 34. Churchill Livingstone. "Chapter 30: Direct Measurement of Arterial Blood Pressure." Chapter 30: Direct Measurement of Arterial Blood Pressure. N.p., 2000. Web. 19 Sept. 2014. <http://web.squ.edu.om/med-Lib/MED_CD/E_CDs/anesthesia/site/content/v03/030258r00.htm>. 35. Omron 7 Series Wrist Blood Pressure Monitor. Digital image. N.p., n.d. Web. 18 Sept. 2014. <http://ecx.imagesamazon.com/images/I/819CUp5IvML._SX425_.jpg>. 36. Babbs, Charles F. "Oscillometric Measurement of Systolic and Diastolic Blood Pressures Validated in a Physiologic Mathematical Model."BioMedical Engineering OnLine 11.1 (2012): 56. Web. 37. "Vascular Distensibility and Functions of the Arterial and Venous Systems."Guyton and Hall Textbook of Medical Physiology. Inkling, n.d. Web. 21 Sept. 2014. <https://www.inkling.com/read/guyton-hall-textbook-of-medical-physiology-12th/chapter-15/vascular-distensibility>.