Click add text LOWER BACK PAIN RELIEVING TILTING CHAIR HARDEEP DHALIWAL TANVI GHOSH CONAN MICKEY AMANTEJ SRAN Winter 2020 • Create an office chair which reduces the time exposed to a load by flexing or extending the spine, thus reducing creep • Provide comfort to the user and minimize interference with sedentary activities Academic Advisor: Dr. Scott Brandon, PhD, P.Eng • The presented chair can mitigate pain and prevent further damage to the spine • The user will be able to input their own tilt angles via digital software to their preferred angles providing further comfort in the future • Materials of certain components will be changed from the prototype design in the future to increase strength and sturdiness of the device while reducing cost INTRODUCTION OBJECTIVES Figure 2: Forward flexion and extension range of motion of seat. Seat can achieve angles of ± 20 ° , ± 25 ° or ± 30 ° with preset buttons. • Lower back pain is a condition effecting many • Prolonged sitting can lead to excessive loading on the spine and cause deformations such as disc bulging or herniation [1] • Creep is the phenomenon where the longer an object is exposed to a mechanical stress, the more it deforms [2] • Thus prolonged sitting in one posture increases deformation effecting strain experienced on the disc (Fig. 1) • Based on recommended sitting angles of 20 - 30 degrees flexion [4], the actuators work together to provide various preset angles for the seat position to change to. • The user can adjust the angle of the chair by pressing a button which adjusts the actuator to a fixed position, tilting the seat (Fig. 2) • The use of an electromechanical system provides the user with precise angles they can achieve at a push of a button • Allows the user to make fast adjustment of the seat angles without hinderance of their sedentary activities • Changing the position often will reduce the prolonged spine loading in one position and aid in relieving back pain CONCLUSIONS AND FUTURE WORK HOW IT WORKS THE DESIGN Figure 1: How back angle posture (degrees) effects strain (%) [3] Seesaw Hinge - Provides additional support and mounting points for actuators - Hinge aids tilt movement as actuator moves 12V Linear Actuator - Provides a 4 - inch stroke to tilt seat forward or backward Buttons for Actuator Presets Stirrups Assembly - Provides support for linear actuators, hinge, and circuitry Figure 3: Adjustable forward or backward tilting chair Metal Backrest Frame - Provides support for backrest Circuit Housing - Contains circuitry needed to power the 12V linear actuator MARKET ANALYSIS Actuator Mounting Bracket - Mounts actuator to the bottom of the seesaw hinge • The target market for this device is individuals in a sedentary lifestyle i.e. office workers, professional gamers, individuals who sit for more than half the standard workday (4 - 5 hours) [5] • The cost for constructing the prototype was $715.56 • If marketed, the aim is to reduce this cost significantly through mass producing certain parts • Aim to reduce this cost to $500 for marketing viability +20 ° +25 ° +30 ° - 20 ° - 30 ° - 25 ° 0 ° References [1] G. Rappard and A. Joshi, "What is the difference between a disc bulge and a herniation," 12 2016. [Online]. Available: https://www.spine.org/KnowYourBack/Conditions/Degenerative - Conditions/Bulge - Herniation. [Accessed 14 Feb 2020] [2] B. Pei, H. Li, D. Li, Y. Fan, C. Wang and S. Wu, "Creep bulging deformation of intervertebral disc under axial compression," Biomed Mater Eng , vol. 24, no. 1, pp. 191 - 198, 2012 [3] T. Videman , M. Nurminen , J. Troup, “Lumbar spinal pathology in cadaveric material in relation to history of back pain, occupation, and physical loading,” Spine, vol. 15, pp. 728 - 40, 1990 [4] “Correct Sitting Posture,” Correct Sitting Posture . Physio Med Limited , Leeds, UK. [5] J. Hartvigsen , C. Leboeuf - Yde , S. Lings, E. H. Corder . “Is sitting - while - at - work associated with low back pain?,” Scandinavian Journal of Public Health , vol. 28(3), pp. 230 – 239, 2000