User:Nathanhall78/ENES-100/Project1/CDIO

Problem Statement
Design a finger clip for use with an ECG sensor attached to an Arduino Uno board.

Requirements for each element or component derived from system level goals and requirements
Requirements: Snugly fit upon any number of differently shaped fingers, without falling off. Allow the ECG sensor to properly read heart beat through fingertip pulse.

[| Here] is a Google search image results page for "finger clip."

As can be seen, most industrial designs allow for varying finger shapes to fit while maintaing sensor connectivity. This is also the aim for this project design.

The initial design
Initial design pushed towards a rudimentary cut-off rubber bulb from child's medicine dropper, with sensor attached.

Experiment prototypes and tests need for design
Using the rubber bulb as a starting point, the bottom distal end was cut out to allow the sensor to interface with the finger. A twisty-tie afixed the sensor to the rubber bulb initially, however the sensor was not secured correctly and did not read a pulse consistently. The next rudimentary design uses duct-tape (Gorilla tape) to attach the sensor.

Creative and critical thinking, and problem solving
With the rubber bulb, there are limitations, in that it will not satisfy the "one-size-fits-all" paradigm. As such, a more universal design should be looked at. For current design needs, the rubber bulb will suffice.

Work on design of a 3D-printable "MakerBot" finger clip prototype via Google SketchUp. Access the preceding link to download the software. It is available in free format and Pro.

Prior work, reuse and reverse engineering
Here is a forum created on Google for SketchUp here. Most answers have been answered and/or retired.

Modeling, simulation and test
Utilized Google Sketchup to begin a formal design outline, for possible future 3D printer.

A more refined design. Seen in the .jpg is the main body and cap.

Uploaded SketchUp file. located in Dropbox for public use and/or refinements.

Aesthetics and human factors

 * 1) Final design should not be bulky, hindering movement of any kind.
 * 2) Final design should allow for nearly all finger sizes to fit snugly, with zero sensor loss.

Next Steps

 * 1) Procure the Parallax microMedic kit (w/ Arduino shield) for $199.00, found here. The kit includes many peripherals for possible use with the project
 * 2) Complete SketchUp schematic for a 3D printer-ready finger clip
 * 3) Marry Pulse sensor-Arduino-LED code; color output dependent upon Pulse sensor-derived BPM, colleague's page here.