ReducedGravitySimula tor

Topics Shown in This Presentation:  1. Project Description. 2. Physiological & Clinical Background. 3. Methods Evaluated to Solve the Problem. 4. Expected Project Outcome.Supervisor: Prof. J. MizrahiStudents: Eyal Lahav, Liron Shlomo.Additional Help: Dr. Almagor Meir, Dr. Amnon Foux.: 

Topics Shown in This Presentation: 1. Project Description. 2. Physiological & Clinical Background. 3. Methods Evaluated to Solve the Problem. 4. Expected Project Outcome. Supervisor: Prof. J. Mizrahi Students: Eyal Lahav, Liron Shlomo. Additional Help: Dr. Almagor Meir, Dr. Amnon Foux. Reduced Gravity Simulator Biomechanical engineering project 334014 winter 2004 – 2005

What We Found on the Course Website:: 

What We Found on the Course Website: “Reduced Gravity Simulator. Supervisor: Prof. J. Mizrahi, email: jm@biomed.technion.ac.il Tel. 4128, Room 245. Laboratory: Orthopedic and Rehabilitation Biomechanics. Field: Orthopedic and Rehabilitation Biomechanics. Status: AVAILABLE in Winter 2002/3 and Spring 2003 terms. Description: Gravity has a major influence on biological and physical processes. Specifically, it is assumed that gravity affects the mechanics of walking. Thus, the ability to simulate reduced gravity conditions should allow us to study in laboratory conditions the effect of gravity on the mechanics of walking. A reduced gravity simulator has an additional application in training handicapped subjects through gradually increasing weight bearing. The aim of the project is to design and realize. a reduced gravity simulator in conjunction. with treadmill walking.” Kram, Griffin, Donelan and Chang

What is a Reduced Gravity Simulator?: 

What is a Reduced Gravity Simulator? At first we got really excited. Then we looked it up. We found out that the more common phrase was: “Body Weight Supported Treadmill Training (BWSTT)”.

The Scope of this Project: 

The Scope of this Project General technical design. Defining a closed – loop control system. Choosing an appropriate force generator.

So, What is BWSTT?: 

So, What is BWSTT? Body Weight Support Treadmill Training Trunk Stabilization Unknown source

BWSTT – Target Population: 

BWSTT – Target Population An emerging rehabilitation concept which is replacing the conventional techniques used for treating patients with or after Cerebral Palsy, Multiple Sclerosis, Spinal Cord Injury, Stroke, Head Trauma etc. Based on neurophysiologic research § H. Barbeau, 2001 Statistics: There are 11,000 SCI incidents each year in the USA, totaling 250,000. Multiple Sclerosis: 200 to 250 patients per 100,000 in the western world. Cerebral Palsy is the major children development disability in the USA. It is more common than either Down syndrome, epilepsy or autism. 2,000 cases are diagnosed each year, totaling 500,000.

Project Description: 

Project Description Our aim is to design and produce an advanced apparatus that features a new concept: Variable – Pattern BWS An online adjustable weight bearing which uses an algorithm based on the properties of the preferred gait pattern. The precise BWS Pattern is determined by the operator to fit the personal requirements of the patient.

Project Description: 

The apparatus detects the gait phase(1),horizontal location on the treadmill(2), transitory vertical speed(3) and applied force(4), it allows the operator to assign different load values to different walking phases in order to strengthen various muscles. Utilizing foot switches (three on each foot) Horizontal location sensor Vertical location sensor Load Cell Further diagnosis can be achieved by using digital cameras, accelometers and other existing or future devices. Project Description

Theory: 

Theory Spinal pattern generators. Spinal cord contains circuitry to control walking. Afferent input & neural reorganization. Appropriate afferent input will shape reorganization of central control mechanisms. Physiological Control Systems: Michael C.K. Khoo

Existing Solutions: 

Existing Solutions Rubber Tubing Counter Weight Steel Springs Force generators: Pneumatic Hydraulic Electric

Existing Solutions: 

Existing Solutions Electric. AID1

Slide12: 

Pneumatic. WARD, 2000 Rubber Tubing. Kram et al. , 2000 Counter Weight. M.Morari, 2001

What we do and the others don’t:: 

What we do and the others don’t: Supplying precise loading-unloading control. Taking into consideration: The periodic nature of healthy human gait, requiring different levels of BWS. The vertical displacement of the Center of Gravity. Training specific muscle groups. Building a personal training protocol.

The Human Gait: 

The Human Gait The normal human gait cycle may be represented by seven sub-phases. Gait Analysis: Michael W. Whittle

The Human Gait: Muscle Operation: 

The Human Gait: Muscle Operation As can be seen, different muscles operate at different phases of the gait cycle. We will be able to control the specific muscle power output by changing the apparatus relevant settings. Gait Analysis: Michael W. Whittle

The Human Gait: Ground Reaction Force: 

The Human Gait: Ground Reaction Force Shown here are the three components of the ground reaction force Our aim is to lower the vertical component in a controllable fashion. Gait Analysis: Michael W. Whittle

The Human Gait:Vertical Component: 

The Human Gait: Vertical Component These are some of our requirements: Vertical Displacement, during 1.5m/s normal pacing. The Center of Gravity moves roughly 3 cm up and down during normal unencumbered pacing. The Human Gait: Wilhelm Braune; Otto Fischer.

The Human Gait:Vertical Component: 

The Human Gait: Vertical Component Vertical Speed, under same circumstances. Maximum vertical speed: ~30 cm/sec The Human Gait: Wilhelm Braune; Otto Fischer.

The Human Gait:Vertical Component: 

The Human Gait: Vertical Component Vertical Acceleration, under same circumstances. Upward max. acceleration: 300 cm/sec2. Downward max. acceleration: 600 cm/sec2. The Human Gait: Wilhelm Braune; Otto Fischer.

How we do it:: 

How we do it: Closed loop force control. Real time gait phase detection. Software induced set-point. User Interface which enables to edit and save personal training parameters. High power - fast response actuator driven system.

Control: block diagram: 

Control: block diagram Steel Cable

Possible solutions we have been examining:: 

Possible solutions we have been examining: Electric: Linear actuator Magnetic clutch Step motor Pneumatic Hydraulic Combination (“dc / ac”)

Actuator Drive:Technical Requirements:: 

Actuator Drive: Technical Requirements: Relevant Parameters: Accuracy Response time Complexity Size & Weight Energy consumption

Other System Requirements:: 

Other System Requirements: Feasibility Safety Versatility User-friendliness Maintenance requirements Spare parts availability Mobility Price

Potential Actuator Drives:: 

Potential Actuator Drives: Linear actuator Magnetic-Hysteresis clutch Electromagnetic clutch Pneumatic drive Electrohydraulic servovalve Belt driven electric actuator

See you next Semester!!: 

See you next Semester!!