1. An Apparatus for Testing Devices Used for Determining Protective Foot Sensation U.S. Department of Health and Human Services (HHS) Health Resources and Services Administration (HRSA) The Bureau of Primary Healthcare (BPHC) U.S. Department of Health and Human Services (HHS) Health Resources and Services Administration (HRSA) The Bureau of Primary Healthcare (BPHC) CAPT James Foto, PE, C.Ped jfoto@hrsa.gov USPHS Scientific and Training Symposium Engineer Category Day

2. Lower Extremity Amputations > 82,000 / year - National Diabetes Fact Sheet, CDC, 2003 “The primary objective of neuropathic foot care is to reduce the epidemic occurrences of lower extremity amputations.”

3. Discussion Points Loss of Protective SensationLoss of Protective Sensation Monofilament ResearchMonofilament Research Automated Filament Tester (AFT)Automated Filament Tester (AFT) Testing the AFTTesting the AFT

4. Discussion Points Loss of Protective SensationLoss of Protective Sensation Monofilament ResearchMonofilament Research Automated Filament Tester (AFT)Automated Filament Tester (AFT) Testing the AFTTesting the AFT

5. “The whole problem is really one of mechanics, not of medicine. The biological responses of these denervated limbs are qualitatively similar to those of normal limbs. It is the permitted pattern of mechanical stress that is different.” Paul W. Brand

6. Causes of Injury Resulting from Mechanical Stress  Acute Trauma likely cause: nails, glass, accidents  Ischemia likely cause: tight shoes, foreign objects in shoes, wrinkles in socks or hosiery  Repetitive Stress likely cause: normal activities of daily living such as walking  Acute Trauma likely cause: nails, glass, accidents  Ischemia likely cause: tight shoes, foreign objects in shoes, wrinkles in socks or hosiery  Repetitive Stress likely cause: normal activities of daily living such as walking

7. Loss of Protective Sensation

9. Discussion Points Loss of Protective SensationLoss of Protective Sensation Monofilament ResearchMonofilament Research Automated Filament Tester (AFT)Automated Filament Tester (AFT) Testing the AFTTesting the AFT

10. Monofilament Research 1890 – Von Frey used varying thickness horse hair 1960 – Semmes & Weinstein used nylon filament material 1985 – VonPrince, Werner, Omer, Bell, Brand, Buford 1986 – Birke & Sims, HD and DM neuropathic feet 1988 – Bell & Buford, filament repeatability and reliability 1988 – Holewski et al, extent and progression of neuropathy 1989 – Mueller et al, interrater and intrarater reliability 1998 – Birke & Rolfson, Self Administer 2000 – Booth and Young, bench test w/ load cell 2004 – Lawrence et al, filament physical properties and wear 2009 – Feng et al, variation in application methodology

11. Semmes-Weinstein 5.07 (10g) Monofilament Designed to buckle at 10g forceDesigned to buckle at 10g force

12. Semmes-Weinstein 5.07 (10g) Monofilament Designed to buckle at 10g forceDesigned to buckle at 10g force Standard device for testing LOPSStandard device for testing LOPS

13. Semmes-Weinstein 5.07 (10g) Monofilament Designed to buckle at 10g forceDesigned to buckle at 10g force Standard device for testing LOPSStandard device for testing LOPS “Feel” / “no feel” binary response“Feel” / “no feel” binary response

14. Point of Application Holewski et al, 1988

15. Discussion Points Loss of Protective SensationLoss of Protective Sensation Monofilament ResearchMonofilament Research Automated Filament Tester (AFT)Automated Filament Tester (AFT) Testing the AFTTesting the AFT

16. Automated Filament Tester

17. Bench Top Tester Components 10 gram Load Cell & Signal Conditioner –AL Design ALD-MEGA-10G –Dataforth 8B38 Isolated Strain Gage SG Linear Potentiometer DAQ Programming Language Data Acquisition Device Ball Screw Actuator

18. Bench Top Tester Components 10 gram Load Cell & Signal Conditioner Linear Potentiometer –Unimeasure LX-PA-3.8 DAQ Programming Language Data Acquisition Device Ball Screw Actuator

19. Bench Top Tester Components 10 gram Load Cell & Signal Conditioner Linear Potentiometer DAQ Programming Language –National Instruments LabVIEW Data Acquisition Device Ball Screw Actuator

20. Bench Top Tester Components 10 gram Load Cell & Signal Conditioner Linear Potentiometer DAQ Programming Language Data Acquisition Device –NI USB-6009 14bit / 48ks/sec Multifxn DAQ Ball Screw Actuator

21. Bench Top Tester Components 10 gram Load Cell & Signal Conditioner Linear Potentiometer DAQ Programming Language Data Acquisition Device Ball Screw Actuator –Hennkwell PK22G2150-062 12v DC Gear Mtr

22. Labview Programming

23. Discussion Points Loss of Protective SensationLoss of Protective Sensation Monofilament ResearchMonofilament Research Automated Filament Tester (AFT)Automated Filament Tester (AFT) Testing the AFTTesting the AFT

24. Automatic Filament Tester

25. Output Data

26. Packaged Filaments

27. Thank You CAPTJames Foto, PE, C. Ped The National Hansen’s Disease Programs 1770 Physicians Park Dr Baton Rouge, LA 70816 (225) 756-3789 jfoto@hrsa.gov