Steel BarFinal PresentationMAE 435Maureen LoughranGregory RagostaChristina FelarcaAdham Sohby

Objective

To develop a steel bar prototype that will allow doctors to know the appropriate time to remove the bar from the patient Prevents chest wall from regressing back to its

original state Real Proof of Concept prototype and Ideal Model

Have the ability to gather this information outside of the body, wirelessly, to provide the least amount of discomfort for the patient.

OverviewPectus Excavatum

Deformity of the chest and ribs Commonly treated by the Nuss

Procedure 4% of PE patients must

undergo the surgery again due to premature removal of bar

16-Year Old Boy With Severe Pectus Excavatum

Overview cont’dRadio Frequency Identification (RFID)Miniature device that can wirelessly transfer data from a RFID readerTakes in a radio signal and transmits back out the stored information on the tagSemi-passive RFID

Wireless Identification and Sensing Platform (WISP)Developed by IntelPowered solely by RF absorbed by antenna

Wisp Functional Diagram

Overview cont’dIntel Strain Gauge Solution

Strain gauge PCB has to be built to interface WISP with strain Wheatstone Bridge Amplifier

Our Solution

Real Proof of Concept Model 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 Ideal model will have 2 strain gauges with all the components

built into the bar itself (to cancel noise and tension/compression)

Theoretical Design AutoCAD model

Theoretical Design

Equipment Setup Stainless Steel Bar (9 in.)

E=192 Gpa, v=0.265

Impinj Speedway 1000 RFID Reader

Antenna (900-925 MHz)

Strain Gauge

WISP

Equipment Setup cont’d

Assembly of Prototype Board Strain Gauge Printed Circuit Board (SGPCB)

Assembly of Prototype Board cont’d

Assembly of Prototype Board cont’d

Assembly of Prototype Board cont’dWheatstone Bridge and Amplifier

WISP Software

[ 1 byte | tag type] + [ 8 bytes | data] + [ 1 byte | WISP HW Version] + [ 2 bytes | HW Serial #]

[11]

Experimental Results

Fig. 13 WISP with leads for Vin, Vout, and Ground

Experimental Results

1 2 3 4

Limitations and Obstacles

Limited time Limited knowledge of electronic components and code Hardware limitations Comparison of results virtual and experimental

Future Work

Cost Analysis

Budget $750.00

Impinj Speedway 1000 RFID Reader $200.00

Antenna (900-925 MHz) $35.00

Strain Gauge (SGD-13/1000-LY11) $125.00

WISP Development Kit $0.00

Stainless Steel Lorenz Pectus Bar $0.00

Total $360.00

Gantt Chart

Questions?

References [1] Medscape. 1000722-1004953-746.jpg. [2] (2012, Diseases & Conditions: Pectus Excavatum. 2012(2012/12/05). Available:

http://my.clevelandclinic.org/disorders/pectus_excavatum/hic_pectus_excavatum.aspx [3] (2012, 2012/12/2). Adult Pectus Excavatum. Available:

http://www.cardiothoracicsurgery.wustl.edu/patientcare/pectusexcavatum.asp [4] (2009, 2012/12/02). Pectus Excavatum Exercise Program. [5] (2012, Pectus Excavatum. Thoracic Diseases & Disorders at Columbia University

Medical Center (2012/12/2). Available: http://www.seattlechildrens.org/medical-conditions/bone-joint-muscle-conditions/pectus-excavatum-symptoms/

[6] 2012/12/02). Our Pediatric Surgeons. Available: http://www.chkd.org/Services/Nussprocedure/Surgeons.aspx

[7] K. R. J. Redlinger RE Jr, Nuss D, Kuhn MA, Obermeyer RJ, Goretsky MJ. (2011, One hundred patients with recurrent pectus excavatum repaired via the minimally invasive Nuss technique--effective in most regardless of initial operative approach. Available: http://www.ncbi.nlm.nih.gov/pubmed/21683218

[8] M. Roberti. (2012, What Is a Semi-passive RFID Tag? RFID Journal. Available: http://www.rfidjournal.com/article/view/8117

[9] (2010, WISP: Wireless Identification and Sensing Platform. Available: http://www.seattle.intel-research.net/WISP/

[10] P. F. Federico Gasco, Jeff Braun, Joshua Smith, Patrick Stickler, Luciano DeOto. (2011, Wireless Strain Measurement for Structural Testing and Health Monitoring of Carbon Fiber Composites. Available: http://wisp.wikispaces.com/file/view/Gasco_2011_JCOMA.pdf/259732728/Gasco_2011_JCOMA.pdf

[11] P. Powledge. (2009). Working with WISP Firmware. Available: http://wisp.wikispaces.com/Working+with+WISP+firmware