Download Avrio Medical Inc. - School of Engineering Science

Avrio Medical
Small Heart EKG
Arrhythmia Research Tool
Cardiac Mapping - Microvolt Signal Acquisition
Seddrak Luu
George Kwei
Jeff Chang
Joe Ma
Eric Chow
Kenny Pak
Overview

Business aspect
• Marketing
• Cost

Technical aspect
• Hardware
• Software
Arrhythmia

Junctional Ectopic Tachycardia
• Disorders of the regular rhythmic
beating of the heart
• Occur in children after open heart
surgery
• 1 in 10 infant goes into arrhythmia after
open heart surgery
• Can be lethal
The Big Picture

understanding the
patho-physiology
of JET
Goal
a Small Heart EKG System to help
understand the Arrhythmia
 Focus on helping those in need
rather than actual profit

Executive Team
Seddrak Luu
Jeff Chang
Joe Ma
George Kwei
Eric Chow
Kenny Pak
BCRI Correspondence

Dr. Glen Tibbits
• Director Cardiovascular Sciences
Professor of Kinesiology, Simon Fraser
University (SFU)

Helen Sheng (Graduate Student, MD)
 Eric Lin (Graduate Student)
Other Sources of Information

Margaret Evans,
• Advanced Measurements

Andrew Pruszynski
• Wireless Medical Devices, TA

SFU Faculty
• School of Kinesiology/Engineering
Structure of the Project

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Signal Retrieval
Stage
Signal
Transmission
Signal Processing
Signal Analysis
Avrio Core Business
1. Small Heart EKG
- commercial introductions expected in a few
years.
Business Based on the Product
2. Platinum Electrode Tips
3. Customize Circuitry to suit the need
4. Customize the Labview Interface
Business

Current Client
• Dr. Glen Tibbits of BC Research Institute
of Chilrdren’s and Women’s
Statistics
In British Columbia, ~40,000 babies
were born*
 600 babies are born with congenital
heart disease
 Of that about 200 will require open
heart surgery
 1 in 10 will go into Arrhythmia

*From Statistics Canada
Market Strategy (Short Term)

Short Term
• Research Based Institute
• Children Hospitals and Children
Research Institute
Marketing Strategy (Long Term)

Long Term
• Organization that supports the
developing countries
United Nation
 Unicef
 Engineers / Doctors Without Borders

• Aim for developing countries trying to
do heart research with minimal budget
Improvements

Electrode Grid with more electrode
• Increase number of electrodes per grid

Tailor specific small EKG and
interface for specific customer
depending on the type of heart
Prototype

Total Cost: $ 751.16
• Research: $ 134.01

Electrodes, Gel, Gel Pad
• Material: $ 575.29

shipping cost 5.5%
Wires, Breadboard,
Necessary Components
• Shipping: $ 41.86
material 17.9%
research 76.6%
Product Price for Small Heart
EKG
Component
Price

24 x AD620
4 x TL072
Capacitors / Resistors
Wiring (Copper)
Wiring (Platinum)
Breadboard
Batteries
Miscellaneous and Casing
$6.00
$1.00
$15.00
$1.00
$4.00
$20.00
$3.00
$5.00

NET PRODUCT PRICE
$58.80

Labour (6 hours)
Labview Interface
$72.00
$39.00

TOTAL
$169.80
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Technical Aspects of
Avrio Small Heart EKG
Heart Setup


Preparation of the heart
Biology of the heart
Video of the Heart

Here we present some excerpts of
the in lab trials of our designed
device.
Electrodes

Initial Design
Concepts/Problems
•
•
•
•
A grid system
Compact
Isolated
A flexible wrap
Electrodes
Electrodes

Final Design
• Coiled platinum electrode tips
• Grounded Tin Foil Shielding
• Braided wires with metallic shielding
Electrodes
Challenges Incurred
Electrode Tip
 Size & Weight
 Crosstalk
 Interference
 Positioning Electrodes

Challenge: Electrode Tip
Type of material necessary
 Amount of surface contact
 Physical spacing of electrodes
 # of possible electrode tips

Challenge: Size & Weight
2-5 grams
 1.5x1.5x1.5 cm dimensions
 This is a very small testing area.
 We were only able to use ¼ of the
heart surface for relevant probing
data.

Challenge: Crosstalk
Crosstalk aka additive/subtractive
signals
 This is caused by close proximity of
the electrode
 Solution:

• Only preventative measures such as
spacing of electrode tips could be used
• Future versions of systems will have
software solution to this problem
Challenge: Interference
Outside electrical sources such as
power lines and light bulbs
 Most common is the 60Hz noise

• Seen from the building power lines

Solution:
• Cross braiding of the electrode leads
• A metal shielding from artificial light
Challenge: Positioning Electrodes
Initially we hand probed the heart as
an initial step.
 This was sufficient for testing but not
very accurate.
 Solution:

• A mounting device for the electrode
bundle
• Needed to carefully hand manipulate the
electrode tips so that they made no
contact with each other.
Signal Conditioning Circuitry

Provide Gain
• Heart signal is low-milli to high-micro
Volt range

Filtering
• Get rid of noise from environment and
other lab equipment
The Circuit
Circuit Design
AD620 has high Input Impedance
 Low power, low cost

-40dB Filter
 Filtering Cutoff Frequencies at 15Hz
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A/D
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National
Instrument BNC2090
National
Instrument ATMIO-16E-10
Labview
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Testing
Signal Acquisition
Signal Conditioning
Signal Analysis
Labview: Simulating the Heart

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Generate small heart signals
Generate background noise
Labview: Acquiring Data
• Write data to file
• Filter acquired data
• Show frequency domain
Ischemia

Inverted T-wave
Bundle Branch Block
•Wide QRS Complex
•Caused by activation
of the left ventricle
prior to activation of
the right ventricle
Atrial Flutter
•Wide QRS complex
•Inverted T-wave: Ischemia
•Short PR-PR intervals
•“saw tooth” pattern
Bundle Branch Block
•Wide QRS Complex
•Caused by activation
of the left ventricle
prior to activation of
the right ventricle
Ventricular Tachycardia
•AV dissociation, no relationship between P-wave and QRS
complex
•Wide QRS
Final Comments

What we learned from this:
• Biological Structure of the heart
• Biological Signal Processing
• Signal Acquisitio
• Hardware Filtering
• Software Analysis
Signs of Success
We learned a lot about
biology,software and hardware.
 We were able to obtain usable small
signals that could be analyzed.
 Finally

• We started with 6 group members and
we still have 6 group members. YAY!
Contacts
Company Website:
www.sfu.ca/~sluu/avrio
 Company Email:

• [email protected]
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Questions?
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Comments