P18026: Infant Incubator
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Detailed Design

Table of Contents

Team Vision for Detailed Design Phase

During the Detailed Design Phase, the end goal was to come up with a detailed design in which the group could move forward with and begin to build and test in MSD 2. In this phase, the team was able to solidify components to be bought and request a budget increase in order to move forward with the project. A BOM was created and approved while a CAD model was completed that addressed concerns determined while addressing the ergonomics test plans.

Progress Report

Dy the end of the Detailed Design Review, the team hopes to solidify the system components as well as the overall design of the incubator. In doing this, exact components will be sent to our purchasing leas, Jen Russo and placed in the BOM. The BOM will then lead the team during the purchasing phase over break and in the beginning of the spring semester. The BOM will also help direct the team in final documentation efforts.

So far, the team has solidified a general look and design of the incubator exterior. The first prototype has also been built of wood in order to begin ergonomics testing as well as determine the location of straps for harnessing the incubator to the backpack. As far as system level design, components are still begin determined and will ultimately come down to time and budget.

Tasks that remain in the Detailed Design Phase after Thanksgiving break are to look further into a specific heating element. Major concerns have been discussed and addressed with some techniques, this will ultimately come down to safety for the infant as well as budget. Besides the heating element, humidity calculations need to be completed in order to determine whether the incubator will need a humidifier, a dehumidifier or both components. Brenna will be responsible for completing the humidity component selection and Jen will determine the best heat source. Both plan to and already have had multiple discussions with the team on each matter.

Thus far, major design selections have been made. The team has agreed on the exterior shell of the incubator as well as the placement of straps to connect to the backpack as well as straps to hold the infant in place during intense travel and potential hiking conditions.

While the team has made great progress throughout the semester, concerns will be brought to our client and guide on budget. Thus far, budget has been the largest set back in the project. In industry, there would be extensive R&D efforts to test different options for a product like an incubator which plans to keep a human alive. Without purchasing and testing different heating components used in a wide range of products, it's hard to solidify a safe, affordable option. The budget is also tight due to the cost of a light weight battery in order to be hiked and carried along the travel route of the travel incubator planned. The budget has also held the team back from purchasing and testing oxygen tanks as well as a pulse oximeter due to the high cost of medical equipment.

Prototyping, Engineering Analysis, Simulation

First Prototype

The first prototype of the incubator has been created and can be seen in an image below. This prototype was developed after the exterior of the incubator was agreed upon by the team. The prototype is being used for ergonomics testing throughout break and in the spring semester. In this phase, the roper placement of the straps was determined with the prototype in order to determine the most comfortable way of wearing the incubator and backpack system.
First Prototype with Resulting Strap Placement

First Prototype with Resulting Strap Placement

Humidity Feasibility

Humidity calculations were determined by researching the average temperature and humidity experienced in Honduras. The following conditions were determined.

Bounds for Environmental Conditions: --Humidity Range of Honduras : 61% - 93% --Temperature Range of Honduras : 12 °C - 32 °C --Humidity Target Range of Incubator : 40% - 77% --Temperature Target Range of Incubator : 30°C - 34° C

Humidity Feasibility

Humidity Feasibility

Dehumidifier

Dehumidifier

Humidifier

Humidifier

Volumetric Flow Rate

Volumetric flow rate was calculated in order to determine the best fan option for the incubator. Ideally the fan will be used to circulate clean air into the incubator.

Volumetric Flow Rate and Fan Selection

Volumetric Flow Rate and Fan Selection

Drawings, Schematics, Flow Charts, Simulations

CAD Modeling

The design of the incubator was created in Creo Parametric in order to get a 3D model of the proposed design. The exterior shape of the incubator was determined in the Preliminary Detailed Design Phase, but further specifics have been determined since.

A base handle has been added after ergonomics testing was started in order for ease of handling by the user. The handle can be used to help keep the incubator sturdy during a hike as well as help users lift the incubator for any handling needed.

Another feature added to the design is a pull out stand for the backpack unit to sit in when not being hiked with. This will allow the backpack which will hold the battery and oxygen tanks to be kept close to the incubator and prevent the tugging of wires which will be directly attached to the infant. The backpack will sit on this stand and a folded cloth inside that can be pulled around the backpack to keep it secure by using a method similar to curtain rods as seen in the photo below. This image also shows the two layers of material for the top that will be vacuum sealed as much as possible with tools the team has access to.

A harness was also designed for the infant when traveling in the incubator. The harness can be seen in a top view of the incubator which shows a diaper like strap that will sit just above the pelvis and two straps that will hold the infant's shoulders down. This strap system will allow for the infant's stomach and chest to be exposed in order to accommodate special case births where the infant is born with organs outside of it's body.

New Handle Design and Backpack Stand

New Handle Design and Backpack Stand

Backpack Stand Cloth Exterior and Hook with Vacuum Seal Top

Backpack Stand Cloth Exterior and Hook with Vacuum Seal Top

Harness Design

Harness Design

Bill of Material (BOM)

A snapshot of the current Bill of Material can be see below.
Bill of Material

Bill of Material

A live link to the Bill of Material document can be found here

Test Plans

Detailed test plans were determined in this phase in order to prepare for the spring semester as well as determine components that need to be purchased in order to complete the testings. Testings based on temperature, battery life, humidity, ergonomics and sanitation was determined by team members. Next semester the team will condense the individual testing methods into the requirements and testing document in order to have all test plans, results, and specs in one easy to access document. Test plans can be seen below.

Battery Test Plan

Battery Test Plan

Ambient Temperature and Humidity Sensor Test Plan

Ambient Temperature and Humidity Sensor Test Plan

Humidity Test Plan

Humidity Test Plan

Sanitation Test Plan Part 1

Sanitation Test Plan Part 1

Sanitation Test Plan Part 2

Sanitation Test Plan Part 2

Ergonomics Test Plan Part 1

Ergonomics Test Plan Part 1

Ergonomics Test Plan Part 2

Ergonomics Test Plan Part 2

Skin Temperature Test Plan

Skin Temperature Test Plan

Design and Flowcharts

The block schematic and wiring schematic for the proposed system level design can be seen in the images below.
Block Schematic

Block Schematic

Wiring Schematic

Wiring Schematic

Risk Assessment

Purpose

The Failure Mode Effects Analysis (FMEA) allows for an in depth evaluation of any potential risks during the use of the product. When evaluating risks, a cause and effect are assigned in order to determine the root of the issue and define countermeasures to lower the potential occurrence.

Updated Assessment Overview

The document owner is Victoria Tripp.
Risk Assessment per FMEA Standards Part 1

Risk Assessment per FMEA Standards Part 1

Risk Assessment per FMEA Standards Part 2

Risk Assessment per FMEA Standards Part 2

Risk Assessment per FMEA Standards Part 3

Risk Assessment per FMEA Standards Part 3

The updated risk assessment document can be found here.

Design Review Materials

Presentation from our Detailed Design Review can be found here

Plans for next phase

During the Detailed Design review and Gate Review the team identified remaining issues with the final design. A plan was established to address these issues during the next phase to complete the design. An outline of this gate review feedback can be found here

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