CPAP Remote Alarm System

BME 272: Oral Report Two

Group 15Kathleen GrunderJessica Paulsen

Molly Rice

Project AdvisorDr. Roberta Leu - Clinical Instructor in the Sleep Disorders Division of Neurology, Vanderbilt University

Academic AdvisorDr. Paul King - Professor of Biomedical Engineering Emeritus, Professor of Mechanical Engineering Emeritus

Background Information

• Obstructive Sleep Apneao Most common form of sleep disorder breathingo Results in partial or complete collapse of the

upper airwayo Can lead to sleep deprivation, arrhythmia, high

blood pressure, heart disease, stroke, or death• Constant Positive Airway Pressure (CPAP)

Therapyo  Used to treat sleep apneao  Holds airway open with continuous flow of airo  Effective when used correctly

Analysis Problem Statement

• Continuous Positive Airway Pressure (CPAP) machine masks often slip off during the night; this can be especially dangerous for children, who are not compliant with wearing the mask

AnalysisPerformance Criteria

• There is currently no alarm to alert parents when their child's CPAP machine has failed

• "I'm very nervous about knowing when [the mask] comes off because I realize how important it is to keep [my son's] airway open." - Parent of a Child with Sleep Apnea

• To develop a remote alarm system to wake parents when their child’s CPAP machine has failed

AnalysisPrimary Objective

• Source power failure• Disconnected power cord• Internal machine failure• Mask displacement • Mask removal • Hose disconnection

• From mask • From machine

• Kinked hose• Punctured hose

AnalysisFailure Modes

HypothesisSolution Description

• To use an airflow sensor to determine when the airflow is outside a determined range indicating that one of the failure modes has occurred

• May consider other sensorsoCO2 ConcentrationoPressure

HypothesisGoals

• To improve pediatric compliance with CPAP masks

• To prevent complications from apneas that can occur when the machine fails

• To alert parents when the machine failso To provide parents with comfort in knowing that

the machine is working properly

HypothesisFactors

• The circuit components and complexity will most affect cost, accuracy, and quality

HypothesisPerformance Metrics• Sensitivity measurements

o How often does the machine sound when the mask is off?

• Functionalityo Does the alarm go off when the mask is off?

• Complianceo Do parents and children use the alarm?

• Cost/Benefito Is the benefit worth the cost of the alarm?

• Alarm Volumeo Does the alarm wake up the parents?

• Receiver Rangeo Can the reciever get the signal all over a house?

Progress Current Status• Met with sales representatives from

ResMed, a CPAP manufacturer• Obtained CPAP machine and three

masks from ResMed• Patent search• Literature review• Failure analysis• Consultation with Dr. Galloway 

ProgressFuture Work

• Contact Dr. Kirby Pate• Design airflow sensor• Buy system components• Begin building and testing