1. Steel Bar Final Presentation MAE 435 Maureen Loughran Gregory Ragosta Christina Felarca Adham Sohby

2. 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.

3. Overview Pectus 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

4. Overview cont’d 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  Semi-passive RFID Wireless Identification and Sensing Platform (WISP)  Developed by Intel  Powered solely by RF absorbed by antenna Wisp Functional Diagram

5. Overview cont’d Intel Strain Gauge Solution  Strain gauge PCB has to be built to interface WISP with strain  Wheatstone Bridge  Amplifier

6. 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)

7. Theoretical Design  AutoCAD model

8. Theoretical Design

9. 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

10. Equipment Setup cont’d

11. Assembly of Prototype Board  Strain Gauge Printed Circuit Board (SGPCB)

12. Assembly of Prototype Board cont’d

14. Wheatstone Bridge and Amplifier

15. WISP Software [ 1 byte | tag type] + [ 8 bytes | data] + [ 1 byte | WISP HW Version] + [ 2 bytes | HW Serial #] [11]11

16. Experimental Results Fig. 13 WISP with leads for V in, V out, and Ground

17. Experimental Results 1234

18. Limitations and Obstacles  Limited time  Limited knowledge of electronic components and code  Hardware limitations  Comparison of results virtual and experimental

19. Future Work

20. 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

21. Gantt Chart

22. Questions?

23. 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