P17082: Elbow Model
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Detailed Design

Table of Contents

Team Vision for Detailed Design Phase

The plans of this phase were to answer the questions remaining about part modeling, part production, and prototype construction. The goals of this phase and design review are to have bone designs appropriate for a functional prototype, become better versed in the production methods for the bones (printing and casting primarily) to allow for the final selection of a method, and construct a testable prototype that appropriately meets the expectations and requirements of our customer.

It was planned to complete all models and drawings, begin the printing of bones in a variety of sizes and densities, update all documentation from the preliminary review and progress report, begin the construction of a prototype that could be tested if time allowed, and continue to communicate with necessary SMEs.

Action Item Since Progress Report

Individual Contributions

Progress Report

What does the team plan to accomplish by the Detailed Design Review?

Immediate Goals

Stretch Goals

What tasks have been accomplished so far?''

What tasks remain, and who is the owner of each?

What decisions have been made so far?

What questions does the team have for the customer and/or guide in order to continue moving forward?

Prototyping, Engineering Analysis, Simulation

Prototype 1

Prototype 1

Prototype 1

Prototype 2

Prototype 2

Prototype 2

Prototype 3

Prototype 3

Prototype 3

Casting vs. 3-D Printing

Refer to Bill of Materials for Prices on 3-D Printing and Casting.

Pros and Cons of Casting vs. 3-D Printing

Pros and Cons of Casting vs. 3-D Printing

Discussion of Density for 3D Printing

10%-40% Density

10%-40% Density

Summary

Engineering Requirements The last revision of the Engineering Requirements can be found_here

Drawings, Schematics, Flow Charts, Simulations

CAD Models

Individual Bones

Individual Bones

Assembly of Model

Assembly of Model

Radius

Radius

Ulna

Ulna

Humorous

Humorous

The Pdf Copy of the Humerus, Ulna, and Radius can be found by clicking on these links.

Schematic of the Complete System

Schematic of System

Schematic of System

Bill of Material (BOM)

Bill of Materials - Detailed Design - Updated

Bill of Materials - Detailed Design - Updated

Test Plans

To be completed by team members to indicate the validity of a prototype or model and show the satisfaction of the engineering requirements for the project.

Materials required for tests:

ER1 – Static Force of Muscle A – Attach load cell to break in muscle A string, hang 250g mass from hand hook, wait for arm to lower under the weight and settle, then get read out from Capstone. Validity- Force achieved at rest must match accepted anatomical value.

ER2 – Static Force of Muscle B – Attach load cell to break in muscle A string, hang 250g mass from hand hook, wait for arm to lower under the weight and settle, then get read out from capstone. Validity- Force achieved at rest must match accepted anatomical value.

ER3 – Static Force of Muscle C – Attach load cell to break in muscle A string, hang 250g mass from hand hook, wait for arm to lower under the weight and settle, then get read out from Capstone. Validity- Force achieved at rest must match accepted anatomical value.

ER4 – With each muscle attached and load cells strung, and the goniometer attached and reading out to Capstone, the arm is bent at the elbow and moved through the available range of motion. Validity- readout must show that the arm can move from approximately 0o and 90o.

ER5 – Hang a max load of 500g from the hand hook while holding the lower arm up to the upper arm so that the angle of the elbow is approximately 0¬o. release the lower arm and allow the weight and lower arm to fall. Validity- the arm must be able to fall and stop while still holding the weight, staying upright and stable (no concern of it being easily knocked over), and produce steady force and angel change graphs/tables through capstone. There should be no bending or material failure in a valid case, and the entire base must still be resting on the tabletop.

ER6- With load cells in place, no weights, and the lower arm resting so that the angle of the elbow is approximately 90o, measure the angles of the muscles with the bones and the distance of the muscle attachment to the bones. Validity – Both values must be within ±5%of the average adult.

ER7 & ER8- Set the model in each possible position with the 250g weight. For each position (supinated wrist, pronated wrist, flexed elbow), allow the position to be set and then allow the device to sit, with no contact with a person or extra support from an outside object (excluding tabletop), for 1 minute. Validity – The position set by the user must not deviate by more than ±1cm during the wait period.

ER9- With all loadcells attached to the muscles and the goniometer strapped to track the elbow, use Capstone software to record 30 seconds of data for each sensor by creating 4 graphical readouts of force (N) by time (s) for the loadcell sensor and angle (degrees) by time (s) for the goniometer, and then a table with a column of force readouts (N) or angle (degree) for each sensor and a column of time (s). Record the data results as a 250g weight is hung from the hook hand of the device and the elbow extends. Validity – each graph or table column can be produced, clearly shows the impact of the weight on the device, and can be saved and exported as a .txt, .m, or .xls file.

ER11- Measure the dimensions of the final model, upright, holding no weight and the elbow in such a way that the elbow is flexed and the lower arm does not extend past the base of the model. Strings may be loosened or untied to best minimize size of model. No loadcells or goniometer should be attached. Validity – The base of the device must be within 2ft by 2 ft.

Design and Flowcharts

Functional Decomposition

Functional Decomposition

Benchmarking

Benchmarking

Risk Assessment

Risk Analysis

Risk Analysis

  1. The Running risk assessment can be found in this document_Updated Risk Assessment Document P17082

Design Review Materials

Detailed Design Review Power Point Presentation

Plans for next phase

Project Plan for Next Phase and MSDII

Project Plan for Next Phase and MSDII

This project plan also includes deadlines for decisions on the number of models to be produced. A goal is to have 12 models built and tested by the end of MSD II, but dates have been set when the team must decide to continue for 12 models or pursue a smaller batch.

The full schedule can be found here Full Project Plan Schedule

Project Plan Highlights Printing bones using a higher density. Assemble model. Apply test plans on prototype.

Amanda Cook's Three Week Plan can be found_here

Chris Harley's Three Week Plan can be found_here

Shannon Keenan's Three Week Plan can be found_here

Maria Romero-Creel's Three Week Plan can be found _here


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