Table of Contents
Please refer to the Detailed Design Documents directory for additional and original documents from this phase.
Team Vision for Subsystem-Level Design PhaseThe Body Cooling System team planned on completing two sets of tasks during this phase: action items from the System-Level Design Review, and all assignments listed in the Subsystem Design node. All tasks were completed or will be completed in a later phase. See below for specific tasks.
- Add breathability to customer/engineering requirements
- Practice presentation on projector in advance to avoid technical issues
- Test for garment/skin contact in regards to flexibility
- Follow up with Xerox on using environmental control chamber
- Investigate places on RIT campus where environmental testing can be done
Subsystem Design Tasks
- Cost Analysis
- Bill of Materials
- Updated Risk Assessment
Goals for the Subsystem Design Phase
- Address and close any action items from the Systems Design Phase
- Review and identify any new requirements to ensure that we are still meeting customer needs as we move forward with the design
- Conduct a proof of concept by analyzing the critical subsystems and identifying feasible alternatives as well as beginning simulation and prototyping of these subsystems
- Conduct preliminary testing of the prototypes provided by the ID team with the goal of collecting data that they can use to improve the design in a second iteration
- Research and start the procurement process for materials that will be needed for the final testing apparatus
Action Items from System-Level Design Review
The following action items were identified at the System-Level Design Review to be completed during the Subsystem Design Phase:
Add breathability to customer/engineering requirements
- Owners: Jared
- Progress: Not feasible to include in rig - Confirmed with ID students
Test for garment/skin contact in regards to flexibility
- Owners: Team
- Progress: Postponed due to waiting for BME department lab access. Will be resumed when access is granted.
Follow up with Xerox on using environmental control chamber
- Owner: Crystal
- Progress: Postponed until ready for testing phase
Investigate places on RIT campus where environmental testing can be done
- Owners: Team
- Progress: Complete
- The saunas at the fitness center and the ice rink on campus have been identified as locations at which future testing at temperatures higher or lower than ambient temperature can be conducted.
Comparison of PASCO versus ADInstruments hardware and software costs. In order to be feasible within the current budget, the PASCO hardware and software set-up has been chosen.here.
Cost Estimates for the testing apparatushere.
Feasibility: Prototyping, Analysis, SimulationMathematical Heat Transfer Model
This model is a mathematical representation of how the cooling system will absorb thermal energy from the human host. In order to simplify this ideal model, 1-D heat transfer is assumed and heat gain from the environment is considered negligible. This model will provide values for the duration of use and the rate of cooling, but will require precise specifications of the vest, including dimensions and properties of the phase change material.
Simulated Tissue Model
This model intends to physically imitate the mathematical model in set up, with a hot plate generating the thermal energy to a sample of simulated tissue. This system holds many variables constant which enables repeatable data, though a lack of realism limits the application to only side-by-side comparisons of different cooling systems.
This model requires the use of a human test subject to wear the cooling system for the duration of the test, allowing the cooling system to heat as it would during actual use. However, it is expected that repeatability may be a problem due to inherent variations between different humans.
Predicted Temperature Profile
By applying temperature probes at on the surface of the cooling system, within the PCM, the skin surface, and the human core, we will be able to plot the temperatures as they change with time for both the simulated tissue and human model. This plot will be critical in comparing cooling systems as the slopes and values at various points will indicate too rapid or too slow of a cooling affect among other things.
Bill of Materials (BOM)here.
Design Review MaterialsFor the Design Review III Presentation, click here.
For notes from Design Review III, click here.
Plans for next phase
Key Deliverable Dates for Preliminary Detailed Design Phase
- Receive initial water-based prototype from ID team for preliminary testing: 10/26
- Receive approval for use of BME department labs and space: Week of 10/26
- Trip to Indiana to meet with PCM company: 10/29-10/30
- Preliminary drawings/designs for simulated tissue completed: 11/8
- Review of designs with faculty SMEs completed: 11/9
- Preliminary testing and data acquisition completed: 11/10
- Effective Access Technology Conference: 11/10
The timeline below details these tasks in depth and allocates each task to a team member to ensure that all tasks will be completed before the next design review.
Click on the timeline below to see it larger or click here to see the Phase IV timeline document.
The deliverables for the end of MSDI along with the items on the critical path are listed below.
Completed test apparatus design
- Approval to work in BME labs
Preliminary testing completed and data collected
- Approval to work in BME labs
- Water-based prototype received from ID Team
- PCM Company delivers materials and/or prototype
- Testing protocol written
Materials ordered and received
- Purchases approved through Innovation Center
- Purchases shipped and received in timely manner
IRB Approval forms completed and submitted
- IRB workshop for feedback