Applications & Implications

Assignments

Our tasks for this week are:

• Propose a final project masterpiece that integrates the range of units covered, answering:
  • What will it do?
  • Who’s done what beforehand?
  • What will you design?
  • What materials and components will be used?
  • Where will come from?
  • How much will they cost?
  • What parts and systems will be made?
  • What processes will be used?
  • What questions need to be answered?
  • How will it be evaluated?
  • Note | Your project should incorporate 2D and 3D design, additive and subtractive fabrication processes, electronics design and production, embedded microcontroller interfacing and programming, system integration and packaging.

My proposed masterpiece

A physical, 3-dimensional heart model which can be used to communicate and educate patient-families about normal heart anatomy.

What will it do?

It will be used as an educational aid for conversations between a cardiac surgeon or cardiologist and the patient-families.

• normal configuration of cardiac chambers, with removable VSD patch in the ventricular septum to represent a common congenital heart defect called a ventricular septal defect
• LEDs embedded in the walls illustrate the motion of blood through the chambers
• communicates with a base with a dial that can be used to adjust the heart rate faster or slower

Who’s done what beforehand?

• static 3D heart teaching models available commercially | Static color version
• project for detecting heartbeat and using it to pattern LEDs | Beating LED Heart
• project for running multiple LED strands in parallel | Neopixel Simulated Liquid Physics

What will you design?

• geometry of the normal heart anatomy with removeable viewing windows (magnets)
• custom board to run the LED strands
• method to conceal electronics

draft BOM

What materials and components will be used?

• Base assembly: plastic vacuum forming around a CNC-milled foam base or 3D printed
• Heart assembly: 3D printed resin, +/- molding & casting
• Electronics: XIAO ESP32C3; battery; LED strips; magnet sensor; side switch; potentiometer; headers

What parts & systems will be made?

Base assembly - where HR will be sensed and sent via ESP-NOW protocol Heart assembly - where the LED strips will be connected and receive signal to drive the pace of the beating pattern

What processes will be used?

• additive: 3D printing
• subtractive: CNC milling; laser cutting
• vacuum forming?
• molding & casting?
• electronic design

What questions need to be answered?

What is the best way to embed the lights in the walls to maintain modularity/accessiblity? What wall thickness diffused the light best? What wall thickness is feasible for the manufacturing process? 3D printing (resin vs FDM) vs molding & casting? Does light do a good job of illustrating the dynamic motion of a heart? Does this aid effectively communicate normal heart physiology? Are the viewing windows sufficient size/shape?

How will it be evaluated?

The teaching heart will be evaluated in Fab Academy by demonstrating the digital fabrication skills required:

• 2D design
• 3D design
• additive manufacturing processes
• subtractive manufacturing process
• electronics design & production
• embedded microcontroller interfacing and programming
• system integration and packaging

The teaching heart will be evaluated outside of Fab Academy at hospitals such as Boston Children’s Hospital:

• is it an effective teaching tool of normal/baseline cardiac anatomy for patient-families?
• is it an effective teaching tool of normal/baseline cardiac physiology for patient-families?
• do patient-families enjoy using the teaching heart?
• do providers enjoy teaching patient-families with the teaching heart?

A survey can be used to capture these data on user experience and efficacy as a teaching tool.