1. Assisted Leg Holding Device For Medical Procedures By: Jennifer Bruno Katherine Etter Gehendra Kunwar Team 1 Funded by: Rehabilitation Education Research Center Client Contact Information: Dr. John D. Enderle

2. Overview 1. Introduction A. Purpose B. Requirements C. Research/Work Done By Others 2. Final Design 1. Subunits 2. Future additions 3. Budget 4. Highlighted Features 5. Conclusion/Acknowledgements/Questions

3. Introduction In the United States, about 51.2 million people are disabled Leg holding devices are required for many medical procedures  Important for patients to have a positive experience as to keep up with preventative screenings and to reduce anxiety Problems with traditional leg-holding devices.  Lack of adjustability, patients outside the “normal” range  Practitioners have difficulty positioning patients who are overweight or have severe disabilities

4. The assisted leg holding device employs anti- gravity techniques to balance each patient’s weight, so that the patient’s legs can be positioned effortlessly by a practitioner. Purpose

5. Requirements  Comfortable  Versatile (can be used by a wide variety of patients)  Adhere to medical standards  Low cost  Compact and easy to relocate  Easy to sterilize  Not imposing or intimidating  Durable and reliable

6. Product Research Allen YellofinTM Lithotomy Stirrups  intra-operative re- positing of patients  mimics natural motion of the hip  prevents excessive pressure on the calf  Accommodates patients up to 500 lbs

7. Patents 2714541  approved in August, 1955  One of the earliest patents found pertaining to this subject, stirrup only supports the patient’s foot  extremely compact and can be easily stored to maximize space within the operating room 4809687  approved in September 1989  cushioned shell that supports a patient’s foot and lower leg  accommodates for patients with joint or muscle disease 5802641  approved in September 1998  can be adjusted to support a patient against gravity  uses a motorized system

8. A Useful Paper: “A Simple Technique to Passively Gravity- Balance Articulated Mechanisms” Link Free Body DiagramTotal Potential Energy Must Equal Zero! Substituting and solving… Spring Constant K=(m*g*l)/(a*b)

9. Patients benefiting from this device: Phylis rheumatoid arthritis, joint stiffness, pain Jerry Parkinson’s disease, tremor, rigidity, and decreased range of motion Jamie T11 spinal cord injury Betty limited and asymmetrical lower extremity range of motion, limited strength in her right leg, pain caused by her hip Violet short stature Paul two below-the-knee amputations

10. Final Design Assisted Leg-Holding Device

11. Gravity-Balancing Mechanism SPRING WELDED I-HOOK CORD LINEAR SLIDE MOTOR

12. Motor – Stepper Motor MDrive23 Plus Microstepping

13. PIC Microprocessor PIC16F877

14. Foot and Thigh Supports

15. Attachment to Table Front View Top View Aluminum Support Pivot and Lock Device

16. Future Additions Scale with Bluetooth capabilities to transmit patient weight to PIC for automatic adjustment Automatic braking system to lock the device in place during a medical procedure

17. Highlighted Features Anti-gravity technology allows the practitioner to adjust the position of a patient’s leg in a “weightless” environment Device is adjustable for patients weighing up to 300 pounds Device is adjustable for a patient leg range of 20 inches to 44 inches Device is adjustable for a variety of leg positions from fully bent to fully extended Device is adjustable for a variety of leg positions from close together to widely spread Device can be removed from table and stored when not in use Medical drapings allow the device to be sterilized easily between procedures Adjustable, Velcro-secured foot and knee supports allow for extra comfort and support during procedures and can accommodate amputees

18. Budget

19. Conclusion The proposed design - provides full leg support to disabled patients -offers an easy solution for practitioners who are unable to comfortably adjust patients - allows a wide range of adjustability to ensure patient comfort and procedure integrity

20. Acknowledgements RERC-AMI Funding Dr. John D. Enderle Dave Price Rich and Serge Dave Kaputa

21. References www.census.gov/PressRelease/www/relea ses/archives/facts_for_features_special_e ditions/010102.html T. Rahman, R. Ramanathan, R. Seliktar, and W. Harwin, "A Simple Technique to Passively Gravity-Balance Articulated Mechanisms," J Mech. Des. vol. 117, pp. 655-658, 1995.

22. Questions?? Thank you for your attention!