Avrio Medical Avrio Medical

Small Heart EKGSmall Heart EKGArrhythmia Research ToolArrhythmia Research Tool

Cardiac Mapping - Microvolt Signal AcquisitionCardiac Mapping - Microvolt Signal Acquisition

Seddrak LuuSeddrak Luu

George KweiGeorge Kwei

Jeff ChangJeff Chang

Joe MaJoe Ma

Eric ChowEric Chow

Kenny PakKenny Pak

OverviewOverview

Business aspectBusiness aspect• MarketingMarketing• CostCost

Technical aspectTechnical aspect• HardwareHardware• SoftwareSoftware

ArrhythmiaArrhythmia

Junctional Ectopic TachycardiaJunctional Ectopic Tachycardia• Disorders of the regular rhythmic Disorders of the regular rhythmic

beating of the heartbeating of the heart• Occur in children after open heart Occur in children after open heart

surgerysurgery• 1 in 10 infant goes into arrhythmia after 1 in 10 infant goes into arrhythmia after

open heart surgeryopen heart surgery• Can be lethalCan be lethal

The Big PictureThe Big Picture

understanding the understanding the patho-physiology patho-physiology of JETof JET

GoalGoal

a Small Heart EKG System to help a Small Heart EKG System to help understand the Arrhythmiaunderstand the Arrhythmia

Focus on helping those in need Focus on helping those in need rather than actual profitrather than actual profit

Executive TeamExecutive Team

Seddrak Luu Jeff ChangSeddrak Luu Jeff Chang Joe Ma Joe Ma

George Kwei Eric ChowGeorge Kwei Eric Chow Kenny Pak Kenny Pak

BCRI CorrespondenceBCRI Correspondence

Dr. Glen Tibbits Dr. Glen Tibbits • Director Cardiovascular Sciences Director Cardiovascular Sciences Professor of Kinesiology, Simon Fraser Professor of Kinesiology, Simon Fraser

University (SFU)University (SFU) Helen Sheng (Graduate Student, MD)Helen Sheng (Graduate Student, MD)

Eric Lin (Graduate Student)Eric Lin (Graduate Student)

Other Sources of InformationOther Sources of Information

Margaret Evans, Margaret Evans, • Advanced MeasurementsAdvanced Measurements

Andrew PruszynskiAndrew Pruszynski• Wireless Medical Devices, TAWireless Medical Devices, TA

SFU FacultySFU Faculty• School of Kinesiology/EngineeringSchool of Kinesiology/Engineering

Structure of the ProjectStructure of the Project

Signal Retrieval Signal Retrieval StageStage

Signal Signal TransmissionTransmission

Signal ProcessingSignal Processing Signal AnalysisSignal Analysis

Avrio Core BusinessAvrio Core Business

1. Small Heart EKG1. Small Heart EKG-- commercial introductions expected in a commercial introductions expected in a few years.few years.

Business Based on the ProductBusiness Based on the Product

2. Platinum Electrode Tips2. Platinum Electrode Tips

3. Customize Circuitry to suit the need3. Customize Circuitry to suit the need

4. Customize the Labview Interface4. Customize the Labview Interface

BusinessBusiness

Current ClientCurrent Client• Dr. Glen Tibbits of BC Research Institute Dr. Glen Tibbits of BC Research Institute

of Chilrdren’s and Women’sof Chilrdren’s and Women’s

StatisticsStatistics

In British Columbia, ~40,000 babies In British Columbia, ~40,000 babies were born*were born*

600 babies are born with congenital 600 babies are born with congenital heart diseaseheart disease

Of that about 200 will require open Of that about 200 will require open heart surgeryheart surgery

1 in 10 will go into Arrhythmia1 in 10 will go into Arrhythmia

*From Statistics Canada *From Statistics Canada

Market Strategy (Short Term)Market Strategy (Short Term) Short TermShort Term

• Research Based InstituteResearch Based Institute• Children Hospitals and Children Children Hospitals and Children

Research InstituteResearch Institute

Marketing Strategy (Long Term)Marketing Strategy (Long Term)

Long TermLong Term• Organization that supports the Organization that supports the

developing countriesdeveloping countries United NationUnited Nation UnicefUnicef Engineers / Doctors Without BordersEngineers / Doctors Without Borders

• Aim for developing countries trying to Aim for developing countries trying to do heart research with minimal budgetdo heart research with minimal budget

Improvements Improvements

Electrode Grid with more electrodeElectrode Grid with more electrode• Increase number of electrodes per gridIncrease number of electrodes per grid

Tailor specific small EKG and Tailor specific small EKG and interface for specific customerinterface for specific customerdepending on the type of heartdepending on the type of heart

PrototypePrototype

Total Cost: $ 751.16Total Cost: $ 751.16• Research: $ 134.01Research: $ 134.01

Electrodes, Gel, Gel PadElectrodes, Gel, Gel Pad

• Material: $ 575.29Material: $ 575.29 Wires, Breadboard, Wires, Breadboard,

Necessary ComponentsNecessary Components

• Shipping: $ 41.86Shipping: $ 41.86

research 76.6%

material 17.9%

shipping cost 5.5%

Product Price for Small Heart Product Price for Small Heart EKGEKG

ComponentComponent Price Price 24 x AD62024 x AD620 $6.00$6.00 4 x TL0724 x TL072 $1.00$1.00 Capacitors / ResistorsCapacitors / Resistors $15.00$15.00 Wiring (Copper)Wiring (Copper) $1.00$1.00 Wiring (Platinum)Wiring (Platinum) $4.00$4.00 BreadboardBreadboard $20.00$20.00 BatteriesBatteries $3.00$3.00 Miscellaneous and CasingMiscellaneous and Casing $5.00$5.00 NET PRODUCT PRICENET PRODUCT PRICE $58.80$58.80 Labour (6 hours)Labour (6 hours) $72.00$72.00 Labview InterfaceLabview Interface $39.00$39.00 TOTALTOTAL $169.80$169.80

Technical Aspects of Avrio Small Heart EKG

Heart SetupHeart Setup

Preparation of the heartPreparation of the heart Biology of the heartBiology of the heart

Video of the HeartVideo of the Heart

Here we present some excerpts of Here we present some excerpts of the in lab trials of our designed the in lab trials of our designed device. device.

ElectrodesElectrodes

Initial Design Initial Design Concepts/ProblemsConcepts/Problems• A grid systemA grid system• CompactCompact• IsolatedIsolated• A flexible wrapA flexible wrap

ElectrodesElectrodes

ElectrodesElectrodes

Final DesignFinal Design• Coiled platinum electrode tipsCoiled platinum electrode tips• Grounded Tin Foil ShieldingGrounded Tin Foil Shielding• Braided wires with metallic shieldingBraided wires with metallic shielding

Electrodes

Challenges IncurredChallenges Incurred

Electrode TipElectrode Tip Size & WeightSize & Weight CrosstalkCrosstalk InterferenceInterference Positioning ElectrodesPositioning Electrodes

Challenge: Electrode TipChallenge: Electrode Tip

Type of material necessaryType of material necessary Amount of surface contactAmount of surface contact Physical spacing of electrodesPhysical spacing of electrodes # of possible electrode tips# of possible electrode tips

Challenge: Size & WeightChallenge: Size & Weight

2-5 grams2-5 grams 1.5x1.5x1.5 cm dimensions1.5x1.5x1.5 cm dimensions This is a very small testing area.This is a very small testing area. We were only able to use ¼ of the We were only able to use ¼ of the

heart surface for relevant probing heart surface for relevant probing data.data.

Challenge: CrosstalkChallenge: Crosstalk

Crosstalk aka additive/subtractive Crosstalk aka additive/subtractive signalssignals

This is caused by close proximity of This is caused by close proximity of the electrodethe electrode

Solution:Solution:• Only preventative measures such as Only preventative measures such as

spacing of electrode tips could be usedspacing of electrode tips could be used• Future versions of systems will have Future versions of systems will have

software solution to this problemsoftware solution to this problem

Challenge: InterferenceChallenge: Interference

Outside electrical sources such as Outside electrical sources such as power lines and light bulbspower lines and light bulbs

Most common is the 60Hz noiseMost common is the 60Hz noise• Seen from the building power linesSeen from the building power lines

Solution:Solution:• Cross braiding of the electrode leadsCross braiding of the electrode leads• A metal shielding from artificial lightA metal shielding from artificial light

Challenge: Positioning ElectrodesChallenge: Positioning Electrodes

Initially we hand probed the heart as Initially we hand probed the heart as an initial step.an initial step.

This was sufficient for testing but not This was sufficient for testing but not very accurate.very accurate.

Solution:Solution:• A mounting device for the electrode A mounting device for the electrode

bundlebundle• Needed to carefully hand manipulate Needed to carefully hand manipulate

the electrode tips so that they made no the electrode tips so that they made no contact with each other. contact with each other.

Signal Conditioning CircuitrySignal Conditioning Circuitry

Provide GainProvide Gain• Heart signal is low-milli to high-micro Heart signal is low-milli to high-micro

Volt rangeVolt range FilteringFiltering

• Get rid of noise from environment and Get rid of noise from environment and other lab equipmentother lab equipment

The CircuitThe Circuit

Circuit DesignCircuit Design

AD620 has high Input ImpedanceAD620 has high Input Impedance Low power, low costLow power, low cost

-40dB Filter-40dB Filter Filtering Cutoff Frequencies at 15HzFiltering Cutoff Frequencies at 15Hz

A/DA/D

National National Instrument BNC-Instrument BNC-20902090

National National Instrument AT-MIO-Instrument AT-MIO-16E-1016E-10

LabviewLabview

TestingTesting Signal AcquisitionSignal Acquisition Signal ConditioningSignal Conditioning Signal AnalysisSignal Analysis

Labview: Simulating the HeartLabview: Simulating the Heart Generate small heart signalsGenerate small heart signals Generate background noiseGenerate background noise

Labview: Acquiring DataLabview: Acquiring Data

• Write data to file

• Filter acquired data

• Show frequency domain

IschemiaIschemia

Inverted T-waveInverted T-wave

Bundle Branch BlockBundle Branch Block

•Wide QRS Complex

•Caused by activation of the left ventricle prior to activation of the right ventricle

Atrial FlutterAtrial Flutter

•Wide QRS complex

•Inverted T-wave: Ischemia

•Short PR-PR intervals

•“saw tooth” pattern

Bundle Branch BlockBundle Branch Block

•Wide QRS Complex

•Caused by activation of the left ventricle prior to activation of the right ventricle

Ventricular TachycardiaVentricular Tachycardia

•AV dissociation, no relationship between P-wave and QRS complex

•Wide QRS

Final CommentsFinal Comments

What we learned from this:What we learned from this:• Biological Structure of the heartBiological Structure of the heart• Biological Signal ProcessingBiological Signal Processing• Signal AcquisitioSignal Acquisitio• Hardware FilteringHardware Filtering• Software AnalysisSoftware Analysis

Signs of SuccessSigns of Success

We learned a lot about We learned a lot about biology,software and hardware.biology,software and hardware.

We were able to obtain usable small We were able to obtain usable small signals that could be analyzed.signals that could be analyzed.

FinallyFinally• We started with 6 group members and We started with 6 group members and

we still have 6 group members. YAY!we still have 6 group members. YAY!

ContactsContacts

Company Website: Company Website: www.sfu.ca/~sluu/avriowww.sfu.ca/~sluu/avrio

Company Email: Company Email: • ensc340-wireless@sfu.caensc340-wireless@sfu.ca

Questions?Questions?

CommentsComments