Continuous Lactate Sensing

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

Problem Statement

Athletes need a means to non-invasively continuously monitor lactate anaerobic threshold for use in training

Current systems are expensive and cumbersome and require a laboratory environment

Performance Criteria

Non-invasive Low cost Easy to use/simplistic Continuous monitoring Real-time feedback

Primary Objective

Continuous monitoring Performance Evaluation Training Exercises

Potential Users Athletes & Professional Sports▪ 400,000 college athletes

Sport Enthusiasts ▪ 467,000 marathon runners in U.S. 2009

Goals

Produce a novel method for monitoring lactate anaerobic threshold in exercise situations that is… Hygienic Easy to use Noninvasive Accurate Inexpensive

Performance Metrics

Lactate anaerobic threshold sensing 1 mmol resolution

80% users surveyed agree that device is Comfortable

Less than 2 minute lag time

Less than $30 per unit Reusable up to 10

times

Solution Description

Sensor detects lactate levels in saliva

Lactate level transduced into electrical signal

Electrical signal triggers notification mechanism

Athlete modifies training accordingly

Design 1

•Saliva and blood lactate levels show high correlation

•Embed microfluidic lactate sensor in mouth guard

sensor & processor

Design Problem

•Wires running from mouth guard would be cumbersome

•Cost of microprocessor for wireless data collection is prohibitive• $150 – 800

5

Design 2

Common mouth guard dimensions (7.5 cm × 7.5 cm × 2.5 cm )Example saliva lactate sensor design (5.5mm×6.4mm×0.7mm)

Mouth Guard Architecture

Part of the mouth guard removed from where the chip and gel will be installed

Chamber for electro-sensitive gel and films connected to working electrode (red) and reference electrode (green)

Thin film of mouth guard material seals the chip and gel

Design Problems

Modifying existing saliva lactate chip to better suit this application

Connecting Working Electrode and reference electrode to the gel chamber

Selection of electro-sensitive gel Inherent variance of human lactate

baseline and threshold

Future

•Decide on design

•Synthesize

•Validate