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The eyeHeme : A Novel Approach to Anemia Diagnosis. Team Dx, D-lab Health Arianne Jong Seema Kacker Kristin Kuhn Spring 2010. Motivation Background Strategy Design Parameters Proposal Progress Demonstration! Future directions Prototype development Product development Pricing
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The eyeHeme: A Novel Approach to Anemia Diagnosis Team Dx, D-lab Health Arianne Jong Seema Kacker Kristin Kuhn Spring 2010
Motivation • Background • Strategy • Design Parameters • Proposal • Progress • Demonstration! • Future directions • Prototype development • Product development • Pricing • Manufacturing • Regulatory pathway • Potential impact Overview
Anemia is a primary contributor to the global burden of disease • 2 billion people worldwide • impaired development, reduced productivity • increased infection risk • more rapid disease progression • 42% of all pregnant women • 20% of maternal deaths (>120,000 per year) • birth complications, infant mortality (>134,000 per year) • 40-50% of preschool children in the developing world are anemic • $50 Billion in GDP lost each year Motivation – Impact of Anemia Global Health Risks Report: Mortality and burden of disease attributable to selected major risks. WHO, 2009. Prevalence estimates from WHO Global Database on Anaemia, 2008.
Nine out of 10 anemics live in the developing world, but anemia affects all countries and demographics Motivation
Anemia • Definition: inability of red blood cells to carry enough oxygen to the tissues of the body • measured by hemoglobin concentration • Causes: nutritional and due to infection • Iron-deficiency: >50% of cases • Infection (malaria, hookworms, etc.) • Other nutritional deficiencies • Challenge • Treatment is known, but anemia is under-diagnosed and undertreated Background
Diagnostic Methods: Invasive Methods Limitations Painful Risk of infection Training required Costly Result may not be immediately available • Complete blood count • [Hb] • Hematocrit - volume occupied by RBCs in plasma • Mean Corpuscular Volume: average size of RBCs • Alternative in-vitro methods • HemoCue www.hubpages.com
Diagnostic Methods: Non-Invasive Methods • Few widely available devices • Mostly qualitative analysis of obvious clinical signs • Eyelid, tongue, palmar and nailbed observation, patient interview • Sensitive only to severe anemia • Subjective • Requires training/experience Karnath, 2004
Subcutaneous Absorbance: Modified Pulse-Oximeter Concept Challenges • Sensitivity • Impure sample (multiple species of Hb, blood, tissue, etc.) • Beer-Lambert Law: • Attenuation: • Measure variation in path length with sonomicrometer Aldrich et al., 2002
Occlusion Spectroscopy - OrSense Concept Concept • Occlusion of blood flow causes low signal-noise ratio • Measures transmittance using multiple wavelengths • Cost issues • Appropriate? Challenges Amir et al., 2007
Reflectance Spectroscopy Nadeau et al., 2001 http://www.nrc-cnrc.gc.ca/eng/projects/ibd/diffuse-reflectance.html
Orthogonal Polarization Spectral Imaging Concept Most polarized light retains polarization Deep-penetrating light (to blood vessels) becomes depolarized • Sublingual mucosa • Hemoscan, Cytoscan Nadeau et al., 2001
Optical Diagnosis via the Eye Method • Reflectance obtained from blood vessels in the eye • Fundus, Conjunctiva • Obtain/view reflected signal • Modified ophthalmoscope? Jay et al., 2007
Strategy: Goals for Appropriate Design • Safety • Accuracy • Sensitivity • Specificity • Robustness • Cost-effectiveness • Ease of maintenance • Portability • Results available quickly • User-friendly -> Initial screening device -> Quantitative, but specific numeric output not required
- Use: palpebral conjunctiva -Why? -Clinical signs -Mucosal tissue - Via: reflectance - How? -filter with photodiode Proposal
7.3 g/dL (Anemic) 12.7 g/dL (Mildly Anemic) Proposal 14.0 g/dL (Non-Anemic) 14.5 g/dL (Non-Anemic)
Anemic and Non-Anemic Blood The Concept: Reflectance
Tissue and Hemoglobin The Concept: Reflectance
Prototype Development Increase sensitivity and precision • multiple wavelengths • alternative surfaces (mouth, nostril, e.g.) • multimodal (combine absorbance, reflectance, fluorescence) Nathan Cooke, 2010
Prototype Development • Determine best light source • Test using Intralipid, blood
Product Development • Patient testing • Pilot study: small NGO, health care provider • Comparison to blood tests • Deployment • Integration into health system • Two-tiered pricing system Sensor Light Nathan Cooke, 2010
510(k) Predicate Devices Orsense's absorbance-based hemoglobin sensor Ophthalmoscope SPO Medical's reflectance-based pulse oximeter
Impact on Global Health Better statistics More awareness More funding (fortified rice, iron supplements, etc.)