Design Team 5
Team Leader: Haoxin Sun
John Downey
Nicholas Kucher
Ami Kumordzie
Marina Pedisich
Raghav Ramachandran
Sponsored By: Angelo All, MD
The Visual, Real-Time Stethoscope
Problem: Can You Hear It?
Is it mitral stenosis, indicating mitral valve malfunction…
…or an S3 indicating left ventricular failure?
http://www.blaufuss.org/tutorial/index1c.html
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
Lack of training, sounds overlap, limited hearing, selective hearing
Answer
Answer: Now you can see it!!!
http://www.bsignetics.com/new_page_4.htm
Normal
Ventricular Septal Defect (VSD)
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
Compatibilities On-Site
Littman Electronic Stethoscope 3200 (3M)
AmplificationNoise filteringData transfer via Bluetooth
Elite Electronic Stethoscope (Welch Allyn)
AmplificationDual position filterData recording
Patents for signal processing algorithms
Sound processingCardiac sound detection Data recording and storage
Visual stethoscope patentsVisual display of soundsData recording
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 S1http://www.intricontibbets.com/151.html
Two options:
1. Show sequentially:
2. Average:
Waveform Processing
2) Filtering – Algorithm 1
2) Filtering – Algorithm 2
Abbas K. Abbas and Rasha Bassam, Phonocardiography Signal Processing, Morgan & Claypool 2009
Power Requirements:
• 5 Volts for the screen 1
• 1.2 Volts for the microphone
• 50 mA for the necessary size 2
Battery Decisions:
Rechargeable is better than disposable
Needs at least an hour of use per charge
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_display2. http://www.sparkfun.com/commerce/product_info.php?products_id=2573. http://www.sparkfun.com/commerce/product_info.php?products_id=8818
3) Power Options
4) Visual Display
Pros Cons
Power saving Motion blur
Portable Inherent viewing angle
Slim Dead Pixels
Pros Cons
Large Field of View, 170 o Expensive
More power efficient Color decay
Light and flexible Water damage
LCD
OLED
Putting the Pieces Together
1. ttp://www.liquidware.com/shop/show/OLED/1-5+OLED+Screen2.http://www.directindustry.com/prod/intel/microprocessor-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
Visual Stethoscope Market SizeYears
% 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 2,772,000 2,835,756 2,900,978 2,967,701 3,035,958 3,105,785 3,177,218
Academia 1.5 42,000 42,630 43,269 43,918 44,577 45,246 45,925
Appendix E ~ market size
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.
Appendix F ~ normal vs. abnormal