Spring 2016 A-TechTop Seizure Watch Subgroup Final Manufacturing
By Marena William (Manufacturing Engineer)
Introduction
Following the modifications done to minimize the size of the PCB, a new design in SolidWorks was done to reflect the changes in dimensions. The new design does not only show a change in dimensions, but it also illustrates how we overcame the electrodes’ wiring problem without having any wires coming out of the watch housing.
Table of Contents
Requirement
The design was in an effort to meet the requirement of having a form factor similar to that of an Apple Watch.
Reduction of Wires
This watch uses reusable electrodes. These electrodes are not sticky and they come with very finite non- insulated wires which was a problem. As a manufacturing engineer, I researched this issue for possible solutions and I found a great one done by MIT. The MIT design shifts the whole watch housing from the top side of the wrist to the bottom sides where the electrodes should be placed to detect the a better signal (figure 1) [1].
Figure 1: Shows the MIT design [1]
The SolidWorks Design
The new SolidWorks design has dimensions that reflect the dimensions of the minimized PCB that you can see in our previous post “Solution for Size”. The housing has dimensions of 8.5x45x38mm. The model consist of four pieces: the main housing, the cover, the display PCB and the straps. The first three parts were designed using SolidWorks.
Figure 2: Top view of the housing in SolidWorks
Figure 3: The cover showing the location of the electrodes
Soldered PCB
Constructing the Watch
From the above design a display model was 3D printed from PLA for demonstration of how the watch could look like with minimum dimensions. The straps was attached to the housing for the final design.
Figure 5: The components of the housing
Figure 6: The look of the watch with the electrodes attached
Conclusion
The above watch meets the requirements and solves the problem of electrodes’ wiring. The display PCB was 3D printed. The watch fits comfortably on a child’s wrist.