1. 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
The Visual, Real-Time Stethoscope

2. Problem: Can You Hear It?
Answer
Is it a split S2, possibly indicating right ventricular failure…
Let’s spend some time on this slide, we want to sell our device.
Split S2 and S3:
Split S2 is a fairly common condition. A split S2 is really always occurring to some degree, as the closing of the pulmonic and aortic valves don't both occur at the same millisecond. When the pulmonic valve closes a little later than the aortic valve, split S2 occurs
S3 can be present in childrem and athletes; however, in other people, it can indicate a non-specific impairment of ventricular function, which needs further testing.
Market Target: physicians who are cardiologists and medical trainees, this data is awesome because the subjects are our target customers!!!!
What does the table show: A group of 20 physicians, none are cardiologists, participated in this study. They first went through a training course on identifying the key sounds produced by the heart, and then were tested on real patients. They listened to 33 events, and the percentage indicates correct identification.
Audio file, get it
Look up frequency display of these
…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

3. Answer: Now you can see it!!!
Normal
Mitral Stenosis
Aortic Regurgitation
Ventricular Septal Defect (VSD)
Let’s spend some time on this slide, we want to sell our device.
Split S2 and S3:
Split S2 is a fairly common condition. A split S2 is really always occurring to some degree, as the closing of the pulmonic and aortic valves don't both occur at the same millisecond. When the pulmonic valve closes a little later than the aortic valve, split S2 occurs
S3 can be present in childrem and athletes; however, in other people, it can indicate a non-specific impairment of ventricular function, which needs further testing.
Market Target: physicians who are cardiologists and medical trainees, this data is awesome because the subjects are our target customers!!!!
What does the table show: A group of 20 physicians, none are cardiologists, participated in this study. They first went through a training course on identifying the key sounds produced by the heart, and then were tested on real patients. They listened to 33 events, and the percentage indicates correct identification.
Audio file, get it
Look up frequency display of these 3

4. 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
Stress that this is not for cardiologists, and it is NOT a diagnostic tool but an visual aid.

5. Current State of the Art
Current Technologies
Compatibilities
On-Site
Littman Electronic Stethoscope 3200 (3M)
Amplification
Noise filtering
Data transfer via Bluetooth
Elite Electronic Stethoscope (Welch Allyn)
Dual position filter
Data recording
Patents for signal processing algorithms
Sound processing
Cardiac sound detection
Data recording and storage
Visual stethoscope patents
Visual display of sounds
Don’t spend too much time on this:
1 sentence: these are some of the current technologies
Emphasize: All of these do not provide on-site display of the data, and the visual stethoscopes are bulky and inconvenient.

6. Display Options Frequency Spectrogram Phonocardiogram
What do we display?
Look up phonocardiogram
Split S2 – left or right Bundle Branch Block – cardiac dyssynchrony
Sounds from mechanical valve prostheses may largely exceed the upper limit** increase device bandwidth 6

7. Packaging
Constraint: Keep acoustic stethoscope functionality untouched
Constraint: Build on the stethoscope as little as possible
“Fill the bell”
Enclose the unit
Bigger compartment
-as long as we leave the red box untouched!
Fill the bell – use the empty space that is there and preserve the entire original shape
Seal it off – leave it concave around to preserve the way the doctor holds it – how much depends on how much we need to put in there
Gives more packing space, but is the furthest from the original shape; can get bigger screen
Nick’s button idea
Use the rest of the steth to help enclose components
Fetal heart sound using the bell
Find evi. Why we don’t use a bell
Talk about

8. Four Components
Microphone
Filtering
Battery
Visual Display 8

9. 1) Microphone Small microphone implanted in head of stethoscope
Divide signal into cycles by identifying S1

10. Waveform Processing Two options: 1. Show sequentially: 2. Average:
These are
2. Average:

11. 2) Filtering – Algorithm 1
Sources.
* Make sure we stress this is one option, not what we are going to do

12. 2) Filtering – Algorithm 2
Using the ECG-trace to pick up where a heart beat start. We understand that ECG trace and PCG trace do not line up exactly; however, we need a reliable cue that can indicate the start of a cardiac cycle, and ECG is one method that we can use.
Abbas K. Abbas and Rasha Bassam, Phonocardiography Signal Processing, Morgan & Claypool 2009

13. 3) Power Options 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. 2. 3.

14. 4) Visual Display LCD OLED 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
Don’t dismiss LCD, making it as a concept

15. Putting the Pieces Together
1. ttp:// 2.

16. Acknowledgements
Dr. Angelo All Vikram Aggarwall Dr. Robert Allen Dr. Artin Shoukas Dr. Youseph Yazdi Dr. Pamela Ouyang Susan Vazakas Busra Dinc

17. Thank You!
Questions?

18. 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

19. Appendix B: Heart Sound Frequencies
Ultra-low (linear frequency band)
Medium Low (60-120Hz)
Medium High ( Hz and Hz)
threshold of the audible heart murmurs has a cut-off of 57 Hz with energy level 0.98 Dyne/cm2

20. Appendix C: Packaging

21. Appendix C: Packaging

22. Appendix C: Packaging

23. 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

24. 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
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
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.

25. Appendix F ~ normal vs. abnormal