Transcript The Visual, Real-Time Stethoscope

The Visual, Real-Time
Stethoscope
Design Team 5
Team Leader: Haoxin Sun
John Downey
Nicholas Kucher
Ami Kumordzie
Marina Pedisich
Raghav Ramachandran
Sponsored By: Angelo All, MD
Problem: Can You Hear It?
Is it mitral stenosis, indicating
mitral valve malfunction…
…or an S3 indicating left
ventricular failure?
Lack of training, sounds overlap, limited hearing, selective hearing
Favrat B, Pecoud A, Jaussi, A. Teaching cardiac auscultation to trainees in internal medicine and family
practice: Does it work? BMC Medical Education 2004, 4:1-7
http://www.blaufuss.org/tutorial/index1c.html
Answer: Now you can see it!!!
Normal
Ventricular Septal Defect (VSD)
http://www.bsignetics.com/new_page_4.htm
Mitral Stenosis
Aortic Regurgitation
Mission
To develop a visual stethoscope that enables viewing of
a real-time visual representation of a patient’s heart
sounds
GOALS
 Integrated spectrogram display screen that is large without being
cumbersome
 Visual display can be disabled, and device must be able to be used as a
traditional stethoscope
 By using this device, healthcare workers should be able to increase their
accuracy in cardiac abnormalities
Current State of the Art
Current
Technologies
Littman Electronic
Stethoscope 3200 (3M)
Compatibilities
Amplification
Noise filtering
Data transfer via Bluetooth
Amplification
Elite Electronic Stethoscope
Dual position filter
(Welch Allyn)
Data recording
Patents for signal
processing algorithms
Sound processing
Cardiac sound detection
Data recording and
storage
Visual stethoscope patents
Visual display of sounds
Data recording
On-Site
Display Options
Frequency Spectrogram
Phonocardiogram
Packaging
Constraint: Keep acoustic
stethoscope functionality untouched
Constraint: Build on the stethoscope as little as possible
•“Fill the bell”
•Enclose the unit
•Bigger compartment
Four Components
Microphone
Filtering
Battery
Visual Display
1) Microphone
Small microphone implanted in head of
stethoscope
Divide signal into cycles by identifying S1
http://www.intricontibbets.com/151.html
Waveform Processing
Two options:
1. Show sequentially:
2. Average:
2) Filtering – Algorithm 1
2) Filtering – Algorithm 2
Abbas K. Abbas and Rasha Bassam, Phonocardiography Signal Processing, Morgan & Claypool 2009
3) Power Options
Power Requirements:
Battery Decisions:
• 5 Volts for the screen 1
Rechargeable is better than disposable
• 1.2 Volts for the microphone
Needs at least an hour of use per charge
• 50 mA for the necessary size 2
Must be small enough to fit in head
Best Option:
2 Rechargeable Lithium-Ion CR2450 coin
batteries in series 3:
• 24.5 mm Diameter
• 200 mAh capacity
• 3.7 V
• 2 hour charge time
1. http://en.wikipedia.org/wiki/Liquid_crystal_display
2. http://www.sparkfun.com/commerce/product_info.php?products_id=257
3. http://www.sparkfun.com/commerce/product_info.php?products_id=8818
4) Visual Display
LCD
Pros
Cons
Power saving
Motion blur
Portable
Inherent viewing angle
Slim
Dead Pixels
OLED
Pros
Cons
Large Field of View, 170 o
Expensive
More power efficient
Color decay
Light and flexible
Water damage
Putting the Pieces Together
1. ttp://www.liquidware.com/shop/show/OLED/15+OLED+Screen
2.http://www.directindustry.com/prod/intel/microproce
ssor-33710-194227.html
Acknowledgements
Dr. Angelo All
Vikram Aggarwall
Dr. Robert Allen
Dr. Artin Shoukas
Dr. Youseph Yazdi
Dr. Pamela Ouyang
Susan Vazakas
Busra Dinc
Thank You!
Questions?
Appendix A
• Question- Why would a health care providers pay for
it?
– Pressure from insurance companies
– Lack of expertise (residents, nurses/EMTs, or care givers in
developing countries)
– Increased incentive to avoid false positives (areas with no
higher level care)
– Teaching tool
• Question- Why not use wireless?
– Simplicity is critical, especially for care providers in
disadvantaged areas
– An important goal is to maintain traditional stethoscope
shape as well as procedures for use
Appendix B:
Heart Sound Frequencies
• Ultra-low (linear frequency
band)
• Medium Low (60-120Hz)
• Medium High (120-240Hz and
240-480Hz)
• threshold of the audible heart
murmurs has a cut-off of 57 Hz
with energy level 0.98
Dyne/cm2
Appendix C: Packaging
Appendix C: Packaging
Appendix C: Packaging
Appendix D ~ costs
• According to Harvard Pilgrim HealthCare
– myocardial perfusion : $729 - $1442
– echocardiogram with interpretation: $262- $561
– Doppler Color Flow Velocity Mapping: $137-$252
– Electrocardiogram with interpretation : $32-$56
– CT scan : $297-$598
https://www.harvardpilgrim.org/portal/page?_pageid=253,192924&_dad=portal&_schema=PORTAL
Appendix E ~ market size
Visual Stethoscope Market Size
Years
% of
Growth
2006
2007
2008
2009
2010
2011
2012
Physician/Surgeons
1.4
633,000
641,862
650,848
659,960
669,199
678,568
688,068
Healthcare/Provider
2.3
Academia
1.5
2,772,000 2,835,756 2,900,978 2,967,701 3,035,958 3,105,785 3,177,218
42,000
42,630
43,269
43,918
44,577
In 2008…
•3M Health Care earn $4293 million in revenue
•8.2% increase since 2007.
•Boston Scientific Corp. earned $8,357 million in revenue
•6.9 % increase since 2007.
45,246
45,925
Appendix F ~ normal vs. abnormal