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INSTITUTO POLITECNICO NACIONALEscuela Superior de Ingeniería Mecánica y Eléctrica, Unidad Azcapotzalco

DESIGN OF A MOTION ASSISTIVE ORTHOSIS

Directors:Dr. Ricardo Gustavo Rodríguez Cañizo

Dr. Emmanuel Alejandro Merchán Cruz

Students:Bautista Arteaga Aldo

Castro Lara Ignacio

REQUIREMENTS

ECONOMIC REQUIREMENTS

• LOW ACQUISTION COST

• LOW MAINTENANCE COST

FUNCTIONAL REQUIREMENTS

• Lightweight• Ergonomic• Comfortable• Anthropometric• Low noise emission• Easy to use• Low vibration level

FUNCTIONAL REQUIREMENTS

• Appropriate temperature levels• Reduced volume• Safe• Avoid injuries from continuous use• Prevent further damage by accident• Safe in prolonged use and risky situations• Adaptable to different use conditions

FUNCTIONAL REQUIREMENTS

• Have sufficient autonomy• Adaptable a different working conditions• Have the necessary freedom degrees• Sufficient range of knee flexion • Stable with heavy weights• Appropriate resolution• Compatible with other biomechanical systems• Adaptable to different motion types.

APPEARANCE REQUIREMENTS

• Anthropomorphic appearance.

• Discreet appearance.

MANUFACTURABILITY AND INSTALLATION REQUIREMENTS

• Easy installation and removal for the patient.

• Easy to manufacture.

CONSERVATION REQUIREMENTS

• Low frequency maintenance and revisions

DESIRABLE REQUIREMENTS

• Low acquisition cost • Low maintenance cost• Prevent further damage by accident• Compatible with other biomechanical systems• Anthropomorphic appearance.• Discreet appearance

DESIGN GOALS

DESIGN GOALS

• Acquisition cost under 40 000 pesos• Maintenance every 4 months • Equipment weight under 12 kg• Adaptable to user characteristics• Noise Emission under 30 db• Interpres intentions of movement and have a simple

user interface• The frequencies generated by the system, must not

come into resonance with the tissue or bone

DESIGN GOALS

• System temperature must be under 28 ° C• The diameter of the limb can´t be increased in more than

15 cm• Tested for periods longer than the intervals between

revisions, under strict conditions of use• Operate under different conditions of temperature and

humidity• Work at least 6 hours by continuous use• Adaptable to different working conditions as variable

inclinations and different soil conditions• Have at least 3 freedom degrees

DESIGN GOALS

• Range of flexion of least 80 ° at the knee • Support users with weights up to 120 kg• Resolution of 1°• Compatible with other biomechanical ankle

systems• The installation and removal by the patient

must not take more than 10 minutes• Manufacture must take 20 days or less

CONCEPT GENERATION

A)-FRAMES

(A1) Rigid frame (wothout length regulation.) Adjustable length frames .(A2)-Multipoint sliding system (with spring).(A3)-sliding system with screw fix.(A4)-cylinder system with split ring.(A5)-sliding system with slots.

Dynamic length frames (A6)-Pneumatic piston system.(A7)-Hydraulic piston system.(A8)-Electric linear actuator system.(A9)-Magnetorheological fluid damper system.

(B)-RESTRAINT AND ADJUSTMENT SYSTEMS

(B1) Velcro tapes

Adjustable straps +(B2)-MicroLock system.(B3)-Buckle lock system.(B4)-Buckle-clasp system.(B5)-Micrometric pressure buckle.

(B6) Rigid system with hinge and lock.

(C)-MOVEMENT GENERATION SYSTEMS

•(C1) Rotative electric motors.(C2) Linear electric motors.(C3) Servo Rotative motors(C4) Servo linear motors(C5) Rotative hydraulic motors.(C6) Hydraulic linear actuators.

(D)-CONTROL SYSTEMS

(D1) Microprocessors.

(D2) Microcontrollers.

(D3) PLC's.

(E) ENERGY STORAGE SYSTEMS.

(E1) Lead-acid accumulators.(E2) Alkaline Batteries.(E3) Magnesium AlkalineBatteries.(E4) Nickel-Cadmium Batteries.(E5) Nickel-Metal Hydride Batteries.(E6) Lithium Ion Batteries.(E7) Lithium Polymer Batteries.(E8) Fuel Cells (Hydrogen).

(F)-SENSING SYSTEMS

•(F1) Pressure sensors.(F2) Angular Position Sensors.(F3) Inductive Sensors.(F4) Proximity sensors.(F5) Temperature sensors.(F6) Humidity sensors.(F7) Potentiometers.(F8) Accelerometers.(F9) Encoders.(F10) Resolvers.(F11) Gyroscopes.

(G)-USER INTERFACE

For introduction of commands and information.(G1)-Keyboard.(G2)-Voice recognition system.(G3)-Touchscreen display

For feedback to the user.(G4)-LCD(G5)-Led 's(G6)-Buzzer(G7)-Speaker for voice messages.

(H)-KNEE JOINT SYSTEMS

(H1) Single axis articulation.(H2) Dual Axis Articulation (polycentric, two rotation axes)(H3) Knee Joint with wedge and rope lock

CONCEPT GENERATION

Evaluation by Feasibility

Evaluation by Availability of technology

Customer requirements based evaluation

Decision-matrix based evaluation