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