1. Pain Stimulator Adam PlattJen Wells Biz SlyziukKalee McFadden Bryan EckerleApril 13, 2004

2. Dr. Stephen Bruehl  Research Interests  Endogenous Pain Regulatory Systems, Psychobiology of Emotions  Focus: Understanding endogenous pain regulatory systems and dysfunction associated with chronic pain.  Interaction between cardiovascular and pain regulatory systems to maintain homeostasis during painful stimuli compared to interaction in chronic pain patients

3. Blood Pressure A5 Cell Group NE Neurons and α-2 receptors Rostal Ventrolateral Medulla NE Neurons and α-2 receptors Caudal Ventrolateral Medulla NE Neurons Rostal Ventromedial Medulla α-2 receptors Intermediolateral Cell Column (SNS Preganglionic Neurons) Peripheral SNS Terminals (α-2Presynaptic Autoreceptors) Primary Afferent Fiber Terminals α-2 Presynaptic Dorsal Horn Laminae I-IV α-2 Postsynaptic Nucleus Tractus Solitarius NE Neurons and α-2 receptors Baroreceptor Input Periaqueductal Gray α-2 receptors Locus Coeruleus NE Neurons and α-2 receptors Nucleus Raphe Magnus Spinal Sites of Descending Modulation

4. Experimental Importance  NIH funded  120 subjects  Two research sessions one week apart  Stimulation of C-fibers  Placebo vs. drug Measures level of activity of receptors  Draw conclusions on natural pain systems in humans

5. Experimental Method  Dinamap Compact-T automated oscillometric BP monitor  Finapres 2300  ECG  Cannula inserted into dominant arm  Blood drawn to assess natural stress hormones and inflammatory substances  Forgione-Barber Finger Pressure Stimulator  McGill Pain Questionnaire

6. Drugs to be Tested  Yohimbine Blocks  2 adrenergic receptors which inhibit release of norepinephrine Used clinically for erectile dysfunction (orally) For Dr. Bruehl’s purposes, the FDA has only approved injections  Naloxone Blocks opiate receptors Used clinically for heroine overdose Injected into patient

7. Problems with Existing Device  No electronic output  Oral reading  No accurate measurement of pressure  Lever system with constant weight  No adjustability for height or hand dominance Adjustable only for finger placement

8. Our Design  Device  Maintain lever system  Most stable design  Reposition weight to be placed vertically above finger  Adjustable Weight  2 – 5 lbs  Contact Point  Between top two joints on index finger of dominant hand  Middle Phalanx #2

9. Our Design… Cont.  Table Provided by Dr. Bruehl Transportation Positioning  Adjustable Height  Sliding Tracks  Forearm length  Slider scale mounted to table displaying “No Pain” to “Worst Pain Imaginable” Scale mounted on each side of device

10. Device (Pressure Transducer) Slider Scale A/D Converter PC Computer LabVIEW Schematic

11. Device with Measurements

12. Materials  Aluminum  Lucite  Steel

13. Device Construction  In process  Featheringill machine shop

14. LabView  Timer  Sliding Scale  Digital Display  Graphical Output  Audiovisuals  Digital Data Storage Patient Administrator Date Experimental Data

15. LabVIEW Interface

16. Potentiometers  Circuit sensitivity ≈.62V/cm @ Vs=5V  Potentiometer sensitivity ≈ 1500Ω/cm

17. Questions?