A Novel Approach to Lactate Sensing

1. A Novel Approach to Lactate Sensing Christine Zhang, Stephanie Wu, Joseph Sun, Wern Ong, Toby Li

2. Objectives • Problem • Market Potential • Background • Requirements • Design • Verification and Validation • Current Status • Questions

3. Problem Statement Fill the market void for a Type II Diabetes prescreening tool Elevated lactate levels are highly correlated with type 2 diabetes onset

4. Diabetes Chronic illness characterized by high blood sugar Insulin is a hormone produced by the pancreas to control blood sugar Type II diabetes is caused by insufficient insulin levels, most often because the body has become resistant to insulin

5. Symptoms Death Coronary artery disease Diabetic retinopathy Erection problems Hypertension Infections of the skin, female urinary tract, and urinary tract Peripheral vascular disease resulting in gangrene, amputations Stroke

6. Diabetes & Lactate Diabetes causes decreased lactate threshold LT is a point during exhaustive, all-out exercise at which lactic acid builds up in the blood stream faster than the body can remove it

7. Market Potential • Type II Diabetes • 170 million worldwide, 20.8 million US • 300 million by 2025 – WHO prediction • Diabetes is a $15 billion dollar industry

8. Current Testing Methods • Fasting Blood Glucose Test • Fast overnight • Go into clinic • Take blood glucose measurement • Drink a 75g sugar beverage • Take blood glucose measurement 2 hours later • Common Complaints • Nausea • Pain • Long wait time

9. Background Information

10. Lactate • What is lactate? • Byproduct of anaerobic metabolism - little O2 in environment

11. Saliva and Blood Lactate Levels • Saliva and blood lactate levels show high correlation

12. Hydrogel Mechanism

13. Hydrogel • pH sensitive hydrogels coupled with lactate oxidase • 2-hydroxyethyl methacrylate (HEMA) • N,N,dimethylaminoethylmethacrylate (DMAEMA) • Tetraethylene glycol dimethacrylate (TEGDMA) • Crosslinking agent

14. Design

15. Performance Criteria • According to the CDC and WHO, there is a need for a: • Cheap • Uniform • Reliable • Accurate • Easy-to-use …predictor for prediabetics

16. Design Goals Hygienic Non-invasive Inexpensive Easy to use Accurate Disposable

17. Lactate Sensor • Directional swelling • Thermometer-like device • Physical Change • Colorimetric Assay • Color change • pH sensitive indicator • Internal Control

18. Performance Metrics • Lactate sensing • 0.1 mmol resolution – if digital • Range 0.15 – 0.3mmol • 0.2mmol indicator level

19. Testing & Verification • How much Saliva? • Interaction Time? • Exact specification of Hydrogel Preparation

20. Solution Overview Hydrogel filled capillary detects lactate levels in saliva Directional Swelling/Colorimetric Assay indicates lactate concentrations Indicate probability of type II diabetes

21. Current Status • Initial Hydrogel Preparation Testing • Hydrogel Preparation Specifications • Lactate Oxidase Concentration

22. In the Future… • Testing • Colorimetric Assay coupled to specific lactate levels • Establishment of Testing Standards/Protocols • Testing varying lactate concentrations under different situations • Fabrication • Calibration of Sensor

23. Website http://www.bme.vanderbilt.edu/srdesign/2010/group11/

24. Questions?