A Novel Approach to Lactate Sensing

Christine Zhang, Stephanie Wu, Joseph Sun, Wern Ong, Toby Li

Problem Market Potential Background Requirements Design Verification and Validation Current Status Questions

Objectives

Fill the market void for a Type II Diabetes prescreening tool

Elevated lactate levels are highly correlated with type 2 diabetes onset

Problem Statement

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

Diabetes

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

Symptoms

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

Diabetes & Lactate

Type II Diabetes 170 million

worldwide, 20.8 million US

300 million by 2025 – WHO prediction

Diabetes is a $15 billion dollar industry

Market Potential

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

Current Testing Methods

Background Information

What is lactate? Byproduct of anaerobic

metabolism - little O2 in environment

Lactate

Saliva and Blood Lactate Levels

Saliva and blood lactate levels show high correlation

Hydrogel Mechanism

pH sensitive hydrogels coupled with lactate oxidase 2-hydroxyethyl methacrylate (HEMA) N,N,dimethylaminoethylmethacrylate

(DMAEMA) Tetraethylene glycol dimethacrylate (TEGDMA)

Crosslinking agent

Hydrogel

Design

According to the CDC and WHO, there is a need for a: Cheap Uniform Reliable Accurate Easy-to-use

…predictor for prediabetics

Performance Criteria

Hygienic Non-invasive Inexpensive Easy to use Accurate Disposable

Design Goals

Directional swelling Thermometer-like

device Physical Change

Colorimetric Assay Color change pH sensitive indicator

Internal Control

Lactate Sensor

Lactate sensing 0.1 mmol resolution – if

digital Range 0.15 – 0.3mmol 0.2mmol indicator level

Performance Metrics

How much Saliva?

Interaction Time?

Exact specification of Hydrogel Preparation

Testing & Verification

Hydrogel filled capillary detects lactate levels in saliva

Directional Swelling/Colorimetric Assay indicates lactate concentrations

Indicate probability of type II diabetes

Solution Overview

Initial Hydrogel Preparation Testing Hydrogel Preparation Specifications Lactate Oxidase Concentration

Current Status

Testing Colorimetric Assay coupled to specific lactate

levels Establishment of Testing Standards/Protocols Testing varying lactate concentrations under

different situations Fabrication

Calibration of Sensor

In the Future…

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

Website

Questions?