Advanced Auscultation Applications Ryan Fedewa, RET Fellow 2009

Maine East High SchoolMatt McDermott, SIR Fellow 2009

Illinois Math and Science Academy Mentor: Dr. Thomas Royston, PhD

Chicago Science Teachers Research (CSTR) Program

MotivationIntroduction

Conclusion

Lung Phantom Modeling

Acoustic Detection Vest

Teaching Module PlanNSF EEC-0743068 Grant

Prof. A. Linninger, RET Program Director

Dr. Gerardo Ruiz, RET Program Managing Director

Dr. Thomas Royston, Research Mentor

Zoujun Dai, PhD Candidate, UIC

Ruth Osbrink, REU, University of Illinois

University of Illinois- Chicago

AcknowledgementsStudents Will Be Able To…..

Describe the Doppler Effect as it applies to sound and light waves

Use data measured in the lab to calculate surface velocities of the lung phantom

Write a lab report describing their lab procedure and error analysis according to “The Craft of Scientific Writing.”

Visible Human Project (VHP):National Library of Medicine funded a project to make a compilation of MR and CT images from every part of the adult male and female human body1

These images are free and available to anyone These images have aided in medical and bioengineering educationPrivate companies have taken the 2-D images one step further, and have rendered complete 3-D models of the human body

Commercially Available Vests Our Alternative Vest

Audible Human Project (AHP):Auscultation offers many benefits to diagnostic medicine, namely that it is non-invasive, cheaper, and more portableAdvanced stethoscopes could be used in clinical as well as field settings, as well as in-home monitoring of intensive care patientsAuscultation is also more difficult to teach, as the field belongs to a skill set, not a knowledge setTherefore, the goals of our project are to:

1. Create a Lung Phantom with three bifurcations to advance the complexity of our current lung auscultation models

2. To create an acoustic detection vest that can be used to aid in diagnostic methods in educational and clinical settings

Results and Future Work

This image to the left shows the model we constructed of corn starch “Magic Noodles.” It was constructed to have bilateral symmetry about the sagittal plane, and to have 3 bifurcations to build upon the double bifurcation work done by Ruth Osbrink (REU Fellow, 2009).

This model was then immersed in expanding foam from Smooth-On shown to the right. The foam cured, and the corn starch was then removed by dissolving in water.

Retro-reflective tape was then applied to the model in a grid along the vertical and angular planes, and a periodic “chirp” noise was transmitted through the phantom. A reference signal was recorded via a microphone inserted through the bottom of the phantom, and the surface velocity of the phantom was measured using a Laser Doppler Vibrometer.

Along the bottom, a sequence of the surface velocity results is shown. This data, along with frequency response, will be compared to the theoretical boundary-element model being developed by Zoujun Dai (PhD Candidate, AVL).

Deep Breeze is a commercially available product that is designed for clinical or home-care use. However, its cost is prohibitive for educational use. Our goal is to design a vest with equivalent detection properties but much more cost-effective for training and educational purposes.

We sewed piezo-disc sensors to a wetsuit. These sensors are made of a piezo-electric disc with a CF-11 gel layer on top. This CF-11 layer couples the skin vibration with the disc vibrations. The wetsuit applies fairly consistent pressure to the skin in the area of interest, which insures that the sensors will collect the audio information needed to make diagnoses.

Once the vest is completed, we hope to collect data that would allow for images such as the one to the left to be taken. Human trials would most likely

require healthy subjects as well as subjects with known vascular abnormalities in order to normalize data interpretation.

Future work for the vest includes verifying time-independence of the sensors and finding an ideal reference signal placement.

The lung phantom construction was a success, as the coherency of our experiment was near-perfect. We have now begun human trials, and are in the pilot phases of said experiments.

As we have not had much time to test the Acoustic Detection Vest, our results are limited, although it does appear, from our early tests, that the vest will be able to distinguish breath noise.

Image taken from Image taken from www.digimation.comwww.digimation.com

Images taken from http://www.deepbreeze.com/deepbreezeImage taken from

http://www.hyperflexusa.com/

1. http://www.nlm.nih.gov/research/visible/visible_human.html.