On the second week of SEED, we started off at the finish, and finished off at the start.

We started on prototype training. We had to build a safe Bijaj and race it down a zipline. We had to get there as fast as possible without our passengers (ping pong balls) getting hurt, or flying out.

We started by doing our final prototypes for the Okapi project. We prototyped a “low-fidelity prototype”, which was a basic proof of concept that consisted of arts and crafts materials like pipe cleaners and foam and cardboard. We presented to everyone, and eventually narrowed down a full solution to fully prototype. Our team originally wanted to go with a mounting system which allowed a ball with holes to be rotated 360 degrees fully around the tree stump, but we ran into many problems with the implementation and realized it would be very difficult to make. So we settled on a 2-D board with multiple tracks on it, in which a rope could travel along the tracks and the Okapi could experiment with the multiple configurations. We couldn’t figure out a way to manufacture a ball with a hole in it, so our good teammate Bruno (pictured below) decided to stay in the OEDK until 2am and 3D print a ball (which then took 8 hours to print each half). The board was laser cut 3 times before we had a feasible prototype that we could use. We gave a formal presentation to everyone to wrap up the project. Although our final prototype was not ready to be delivered, I still felt happy in having been exposed to the engineering design process for the first time, and the things I learned along the way.

Perhaps the most creative design for the Okapi project came from team elephant. It consisted of a net suspended by a wooden box above. The wooden box would have food items inside, and had a wooden sphere below it that could be spun. The wooden sphere would be spun until the food would fall through holes into the net, after which the Okapi could eat the food from the net with their tongue. Everyone marveled at the ingenuity of the prototype.

 

On Wednesday, we were given the actual projects we would be working on for SEED. Our TA, Jeremy gave a presentation on them. We toured the OEDK to look at the existing prototypes of the projects, and then filled out a form on our project preference. The following projects were as follows:

1. Diabetic Foot ulcer – Patients with diabetes often get foot ulcers beneath their feet. An inexpensive device is needed that will be able to take pictures of the patient’s feet and show it to them, to determine if they have a foot ulcer.
2. Wheelchair transfer. It’s currently very hard for caregivers to transfer people from wheelchairs, that are unable to walk. It’s especially difficult for heavier patients, and if they must be elevated to a taller height, such as moving them onto a truck. We need an inexpensive, small device that can be disassembled and assembled easily and can transfer these wheelchair patients. the current prototype is a barber-style chair. It’s very heavy (90 pounds), hard to balance in, and raises the patient up only a couple of inches. It’ll be very interesting to see what this team comes up with as a solution
3. Casting stand – when patients need a cast built, they need to stand on one leg for about 15-30 minutes. Hospitals currently have a parallel bar in which the patients can support themselves on while they wait for their cast to harden. The problem is that it is difficult for elderly people to balance for so long. A new solution is needed that will make it easier. The current prototype is a re-purposed piece of gym equipment that is adjustable to various parts. It works well, except that it rattles a lot, so it must be improved to be more stable.
4. (our team’s project!) Oxygen sensor -Certain surgeries require oxygen masks. The oxygen for these comes from an Oxygen Concentrator, which can de-calibrate itself over time. If the wrong amount of oxygen is released, it can cause many problems for the patient. The concentrator needs to be calibrated using an oxygen calibrator. These are very expensive, and run upwards of $200. This is unfeasible for many countries in low-resource settings. This team tried to design a cheaper alternative for them. The project has actually been running for 2 years, and started as part of ENGI 120 back then. The previous team members were Nishant Verma (Bioengineer), Peter Suzuki (Bioengineering), and Preston Quine (mechanical engineer).

Oxycal has done an excellent work these past 2 years, and I feel honored to have the opportunity to continue this project during the summer. The team I’m very excited to work with throughout hte summer includes:

• Carlos – a Brazillian student studying Electrical Engineering.
• Tiwonge – Malawi student in Electrical Engineering
• Charity – Malawi student studying Automobile Engineering

Carlos has had a lot of experience with Electrical Engineering, and it will be very valuable to learn from what he knows. Charity and Tiwonge have a very helpful perspective on the project, since they come from a country that is likely to use it.

The solution that Oxycal has developed takes advantage of a lithium-air battery. The battery will change voltage when exposed to Oxygen, and based on how much voltage it changes, it will be able to predict the Oxygen concentration of the air being observed. This type of approach has been taken before with existing Oxygen sensors. However, we must also take into account that the voltage of this battery can change with other things as well: temperature, pressure, humidity… Most existing solutions use expensive sensors for these variables, and then calibrate the oxygen reading to include for these factors. However, Oxycal is different in that it uses a dual battery system. It uses a second battery that’s exposed to the ambient air to standardize the values. This ingenious solution is patent-pending from the OxyCal team.

On Thursday we had a needs-finding workshop from Dr. Ghosn He talked to us about the steps that come before the engineering design process – that is, finding a project to work on, that satisfies an important need. He gave us a very calm presentation, and afterwards we were challenged to ride a wheelchair, walk blindfolded with a walking stick, and eat with twisted hands like a child with arthrogryposis. These exercises helped give us motivation for the continuation of our project, as well as be grateful for having all these abilities that we so often take for granted.