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

2. Objectives Problem Statement Market Potential Background Design
What is lactate?
Why is it important signal?
Design
Goals
Challenges
Current Status
Start with motivation, then background, then design options and current progress
Why is lactate important signal?

3. Problem Statement According to the CDC and WHO, there is a need for a:
Cheap
Uniform
Reliable
Accurate
Easy-to-use
…predictor for prediabetics
Imagine you’ve been training for the ironman 70.3 austin, sweating, and working hard for months so you can really own the competition…. During that training, your anaerobic threshold is critical b/c it determines how intensely you can work out before you cause nasty side effects.
Highly correlated with anaerobic threshold, sensitive predictor of type ii diabetes and indicator of disease progression

4. 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

5. 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
There are nearly 1 million sports enthusiasts who don’t have the financial resources of professional athletes… selling an inexpensive unit at a reasonable $30/unit would lead to $30 million. fabrication of sensor depending on location would be less than a $1. profit margin is huge! Not to mention potential to expand into emergency care by providing paramedics and er doctors with method to easily measure ischemia due to stroke

6. Background What is lactate? Why is it important?
Byproduct of anaerobic metabolism - little O2 in environment
Commonly thought to cause muscle soreness
Why is it important?
Indicates oxidative capacity
what???
Can occur during intense exertion, ischemia (when tissue is not getting enough oxygen)

7. Simply put…
Oxidative capacity is the ability of tissue to produce energy efficiently from available oxygen
Anaerobic threshold gives the critical lactate levels when production >> removal and buildup in blood occurs

8. Correlation Between Lactate and Diabetes
Lactate levels are a predictor of type 2 diabetes

9. Saliva and Blood Lactate Levels
Saliva and blood lactate levels show high correlation
Current performance evaluation systems only give athletes option of blood lactate sensing in clinical environment
Expensive – techs, healthcare professionals
Comfort - Cumbersome equipment, painful
Literature search has revealed that blood lactate and saliva lactate levels are highly correlated with short lag times, if any
Curves highly correlated in figure. Red-blood, blue – lactate
Though peaks are different, its really 2nd derivative curve we’re most interested in (rate of change in slope)
Mouthguards are commonly used in high impact sports and would be convenient platform to host sensing equipment
Embed lactate microfluidic sensor in molded plastic
Sensor captures pooled saliva, uses lactate dehydrogenase enzyme to convert to concentration of lactate to electrical current
Current measured and read out by some adc unit

10. Design Lactate thermometer like device – Lactometer
Hydrogel that changes color based on lactate levels
Readable for the user

11. Design Goals Hygienic Non-invasive Inexpensive Easy to use Accurate
Produce a novel method for monitoring lactate anaerobic threshold in exercise situations that is…

12. Performance Metrics Lactate sensing $1.00 per test
0.1 mmol resolution – if digital
Range 0.15 – 0.3mmol
0.2mmol indicator level
$1.00 per test
Blood lactate levels range from 1-2mmol resting, up to 20 mmol during intense exertion

13. Market Competition Accutrend Plus System Roche Diagnostics $190
Measures glucose, cholesterol, triglyceride and lactate

14. Solution Overview
Hydrogel filled capillary detects lactate levels in saliva
Hydrogel swelling indicates lactate concentrations
Prediabetics confirm presence of type II diabetes or probability of type II diabetes

15. Current Status
Currently testing pH sensitive hydrogels coupled with lactate oxidase
2-hydroxyethyl methacrylate (HEMA)
N,N,dimethylaminoethylmethacrylate (DMAEMA)
Tetraethylene glycol dimethacrylate (TEGDMA)
Crosslinking agent
Lactate oxidase

16. Website http://www.bme.vanderbilt.edu/srdesign/2010/group11/
I encourage everyone to visit our site… I wrote part of the code myself

17. Questions?