Maureen LoughranGregory RagostaChristina Felarca

Adham Sohby

What is Pectus Excavatum? Deformity of the chest and rib cage Most common in children but also occurs in adults

16-Year Old Boy With Severe Pectus Excavatum

The Nuss Procedure First developed by Dr. Donald Nuss, a pediatric surgeon at

CHKD Stainless steel/titanium bar is bent according to the shape of the

patient’s chest Minimum blood loss Shorter operation and recovery time

Nuss Procedure

The Nuss Procedure cont’d The bar stays inside the patient for an average of 2-3

years 4% of pectus excavatum cases undergo the Nuss

Procedure more than once, because the bar is removed too soon

Before and After

Objective To develop a steel bar prototype that will allow

doctors to know the appropriate time to remove the bar from the patient without the risk of the chest wall regressing back to its original state, while conducting this information outside of the body wirelessly to provide the least additional discomfort for the patient. Real Proof of Concept prototype and Ideal Model

Radio Frequency Identification (RFID)

Miniature device that can wirelessly transfer data from a RFID reader

Takes in a radio signal and transmits back out the stored information on the tag

Many different uses, such as electronic payment systems, goods tracking, and systems monitoring.

Semi-passive RFIDvs. Active or Passive RFID

WISP Wireless Identification and Sensing Platform Developed by Intel Built in Gyro., Accel., and Temp. Wireless, battery-free Powered solely by RF absorbed by antenna

WISP cont’d

Wisp Functional Diagram

Intel’s Strain Gauge Solution Strain gauge PCB has to be built to interface

WISP with strainWheatstone BridgeAmplifier

SGPBC

Our Solution Our solution:

Place 1 strain gauge on the surface of the bar Using Intel’s strain gauge solution, we can connect the strain

gauges to the WISP via a Wheatstone bridge and amplifier○ The WISP will interface with the reader (outside of the patient)

and report the data using WISP’s reader software Ideal model will have 2 strain gauges with all the components

built into the bar itself.

Steel Bar

Titanium Bar• Bent at factory in ideal shape.

Stainless Steel Bar• 9 in• Young‘s Modulus: 192 Gpa• Poisson’s Ratio: 0.265

Building the WISPImpinj Speedway 1000 RFID Reader

Building the WISP cont’dAntenna (900-925 MHz)

Building the WISP cont’d

Strain Gauges• SGD-13/1000-LY11•13 mm grid, 1000 ohms

Strain Gauge

Building the WISP cont’dWISP

AutoCAD Model

Real Prototype Model

AutoCAD Model

Ideal Prototype Model (Unfinished)

PATRAN Model

PATRAN Model cont’d

Theoretical Design Redesign of the WISP, Amplifier, and

Wheatstone bridge for ideal model.Volume calculations with a design factor of 1.2Black box (Not redesigning the electrical

components). Used to fit the components within the bar

itself, including the Arcs. Unbendable components such as the MCU

of the WISP will be in straight portions.

What’s next?

GoalsTo test each set of equipment in a

piecewise manner to ensure that everything is working

To setup equipment Challenges

Building the circuit boardNoise

Gantt Chart

Questions?

References 16-Year Old Boy With Severe Pectus Excavatum. Medscape:

Medscape. Nuss Procedure.

http://surgvideo.surg.sunysb.edu/Volumes/ACSCD+July+2010/ACSCD/figures/ch0409-f6.htm

Before and After. http://www.gundluth.org/pediatrics/surgery/sunken-chest

Wisp Functional Diagram. 2011. Elsevier. Feb. 19, 2013. SGPBC. 2011. Elsevier. Feb. 20, 2013. Strain Gauge. http://www.omega.com/pptst/SGD_LINEAR1-

AXIS.html