Week Six: July 13th, 2015

Mikaela Juzswik

---

We went into this week with almost nothing. This sounds like an overstatement, but it’s actually quite true. As I mentioned in the last blog, recent developments allowed our budget to more than double, opening up an entirely new avenue of solutions that we had previously ignored due to cost constraints. We realized going in to this week that it was going to be rough—the budget increase, while entirely welcome to our design process, set us back by more than a week in terms of progress (which doesn’t sound terrible as I write it now, but this program is only eight weeks long, so every day counts). With this in mind, we shoved our entire faces into the grindstone and set to work.

In order to make our condensed work schedule as efficient as possible, we each spent the three day weekend brainstorming potential solutions and modifying our previous solutions to encompass the wider scope in cost. We had previously eliminated many viable solutions on the grounds that, while cheap, they weren’t cheap enough to fit into our <$10 budget. We reconsidered these ideas, modified and combined some of them, and also considered new ideas. Ultimately, we settled on a mix of the three: a mechanism that rocked back and forth on a set of bellows that could be powered by foot.

While we found this idea quite promising, we spent much of Monday addressing some of the more pressing design aspects. How much space would this take up? Would assembly be an issue? How could we make it out of available but sturdy materials? With these questions in mind, we began to shape out the details of our idea. We decided to make the device foldable, so it could fit in less than a cubic foot of space. Despite the foldable aspect, we also wanted to make the device as easy to assemble as possible, so we settled on hinged wings to create as few components as possible. We realized that it would be possible to machine a rounded shape like we were imagining, but it would be easier to draw from pre-existing materials, such as large pipes or buckets. With this in mind, our device quickly took shape. By Monday afternoon, we had conceptually fleshed it out and created a very low-fidelity prototype for proof of concept.

 

K’nex to the rescue.

We began building a higher-fidelity prototype on Monday evening, and this endeavor lasted us through the week. We still didn’t know what materials we wanted to use for diaphragms, so we turned online. We also found that it’s surprisingly difficult to order a cheap, gallon bucket (five-gallon buckets are actually less expensive than gallon ones, although the size trade-off is unideal for us).

We ended up taking a trip to Home Depot in search of a rather eclectic variety of objects—buckets, threaded rods, hinges, and miniature plungers.

The plungers, incidentally, aren’t used to unclog your toilet (as that would involve sticking a fair portion of your hand into some unsavory waters), but for sinks. Despite the prominent labelling, Leah, Nehuwa, and I spent about half an hour giggling as we considered what fools would buy such a tiny plunger (ignoring, of course, the fact that we were buying four of them).

Our field trip complete, we set out to divide and conquer. Leah and Nehuwa began finding ways to design breast shields that could be made for less than $10—these parts would half to be purchased by each nursing woman, so keeping these costs lower would be ideal. They also began working on tube management systems, using the Medela system as a guide. They experimented with water bottles, PVC, and even 3D Printing to develop several promising solutions that we’ll be tinkering with more this week.

I ended up getting my hands dirty and returning to the larger stuff. I sawed a bucket in half, laser cut some wood, messed around with a hook-and-eye, cut up some unsuspecting bellows, laser cut some more, cut up more buckets, and duct-taped the resulting horror together.

…and it actually turned out pretty nice. Being mature, responsible adults, we quickly combined all of our pieces (Leah and Nehuwa’s breast shields and tubing with my pressure generation system) and began testing our device by suctioning people’s faces. Using a combination of educated guesswork, we’re fairly certain that the pressure generated by the device is actually in a similar range to the Medela mechanical pump, which is fantastic. We’ll be doing real testing during this week, of course.

At some point on Friday, I ended up falling into a giant coal mine. And by the I mean I attempted to Dremel one of our buckets into a rounder shape, which essentially pulverized the bucket and covered me in bucket-powder. All in the name of science, of course.

Anyway, this week was fantastic. We covered a ton of ground, and went from literally zero to a working prototype that we’re hoping to send to Malawi with Dr. Wettergreen on Tuesday. That’s all for now, but there’s still a ton of work to be done in the remaining weeks ahead.

This week has been really fun! We got our pulse sensor early on, but we decided not to use it. It was too sensitive to movement but also had to be placed accurately on the skin in order to get a reading, so it would have been difficult if not impossible to get an accurate reading every time. This was disappointing, but we quickly got to work on coding an algorithm to figure out the blood pressure in another way. Our first idea didn’t work because it required too much memory on the arduino (but we can always get a bigger and better arduino if we need to) so we started working on another code! The new idea works by only saving the last five pressure readings, as well as any relative maximums and minimums. Then, by calculating the largest maximum, it can find the mean arterial pressure.

We were also able to put the device in a laser cut box. While it is not at all conveniently sized, it’s nice to be able to carry the entire device in one hand instead of on lots of breadboards!

 

 

By the end of last week, the LEDs and LCD were working perfectly in the new box!

Next week, we hope to get the code running accurately! Then we’ll work on downsizing to a more convenient hand-held monitor.

 

Every week comes with new experiences which always leads into new discoveries.it has been a week of experiences  with the BP monitor project.

 Monday’ was really great as a goal of integrating the category switch in the circuit was met. Despite not finding the sliding switch that we suggested, the potentiometer has been incorporated such that different ranges of voltages define deferent categories of people such as child, pregnant women as well as normal adult person. .

there was much excitement on Thursday as group after designing and laser cutting the wood box for the first prototype …’getting experience in a funny way’!!! I love my team!!

finally the goal of the week was met having our first prototype with a category switch and power supply in a labeled box !!!

I just like the OEDK, for it is a conducive environment for prototyping….as far as you have an idea/a solution to a problem, the limit may be yourself not resources!!!!. I’m hoping for such a kitchen at Malawi Polytechnic for this can enhance student’s passion in solving some of the engineering problems Malawi(Warm heart of Africa) is facing.

Week seven was awesome. We finally produced of very first prototype and it feels great. The picture shows this prototype.

The operating logic has changed however due to the unreliability of the sensor we earlier hoped to use.

I  had one of the most amazing weekends in Texas so far as me, Nehuwa and some friends from church went to San Antonio for a church conference and had a chance to be at six Flags having fun riding Roller coasters.

In short, the past week was the best.

 

This week was pretty amazing. That is really the only way I know how to sum it up. My team worked extremely efficiently and accomplished more than I could have ever imagined, AND we had a great time doing it! Thinking about it puts a huge smile on my face.

Monday, we essentially started from scratch. At the end of last week, we were told that our budget was significantly larger than we had previously thought for the final prototype, so we went back to the drawing board over the weekend, thinking of new ideas and revisiting old ones. By the end of Monday, we had an outline of what we wanted in our final prototype and had begun to construct a mid-fidelity prototype. The new design consists of 2 bellows (one on each side) with a rocking mechanism in the middle, so the woman rocks her feet back and forth to generate negative pressure.

We went to Home Depot to pick up some supplies this week to build the device, and it was a great adventure! Nehuwa said that it was completely different from hardware stores in Malawi, where there is a counter that you go up to and ask for whatever you need from the worker. We went up and down the aisles searching for buckets and rods and plungers. That’s right, plungers. Instead of buying actual bellows, we decided to buy mini plungers and attach hoses to the hollow handles. This was very inexpensive and convenient to find. Also, they provide an impressive amount of suction!

As the week went on, we split up the work to complete the prototype, although we worked with each other on each of the design blocks. Nehuwa focused on the breast shields, creating a long and smooth enough nipple channel. Mikaela worked on assembling the pressure generation system, connecting the bellows and the bucket with the board to rock back and forth. I doubled down on the part that connects the breast shield, collection container, and pressure generation system. We decided to use the Medela duckbill valves based on cost and quality. I tried multiple ways of connecting the pieces and, in the end, decided to use 2 pieces of PVC at a 45 degree angle with a hole for the tygon tubing. I removed one of two seals on the Medela valve so it fit around the edge of this ½ inch diameter PVC. I cut a hole in the cap of a plastic water bottle and secured the valve through this hole so the collection container could simply be a plastic water bottle. I then protected the hole for the tubing by installing a barrier composed of thicker tygon tubing. The entire system is very low-cost and all parts except the valve are available in Malawi. By Friday morning, we had each finished our design block so we assembled the prototype. We were surprised by how easily it functioned – very little work was needed to generate pressure.

After assembling it, we tested it on our faces, like the true professionals we are.

Actually, this is how we felt the pressure from the Medela and Ameda pumps, so we could roughly understand whether or not it was generating enough pressure. We realized that it more or less was generating sufficient pressure!!! After we found out that it generated pressure, the other interns wanted to feel it for themselves. The absolute highlight of my week was when Florence tried it on her face. Initially, it did not have a complete seal, so she did not feel the pressure. However, once she adjusted the breast shield’s position on her face, she felt it immediately and was completely shocked! It was hilarious.

After a brief period of celebration Friday afternoon, we went right back to the grindstone, beginning on our second prototype with smiles that spread ear to ear.

It has been a week of learning Arduino, my colleagues had already practised it. I had just joined at the beginning of the week therefore I needed to catch up with them by doing some of the things that they had already done.

What is Arduino?

Arduino is a tool for making computers that can sense and control more of the physical world than your desktop computer. It’s an open-source physical computing platform based on a simple microcontroller board, and a development environment for writing software for the board.

Figure: Sparkfun red board programmed by Arduino

Arduino can be used to develop interactive objects, taking inputs from a variety of switches or sensors, and controlling a variety of lights, motors, and other physical outputs. Arduino projects can be stand-alone, or they can communicate with software running on your computer (e.g. Flash, Processing, MaxMSP.) The boards can be assembled by hand or purchased preassembled; the open-source IDE can be downloaded for free.

The Arduino programming language is an implementation of Wiring, a similar physical computing platform, which is based on the Processing multimedia programming environment.

Why Arduino?

• Inexpensive – Arduino boards are relatively inexpensive compared to other microcontroller platforms.
• Cross-platform – The Arduino software runs on Windows, Macintosh OSX, and Linux operating systems.
• Simple, clear programming environment – The Arduino programming environment is easy-to-use for beginners, yet flexible enough for advanced users to take advantage of as well.
• Open source and extensible software- The Arduino software is published as open source tools, available for extension by experienced programmers.
• Open source and extensible hardware – The Arduino is based on Atmel’s ATMEGA8 and ATMEGA168 microcontrollers. The plans for the modules are published under a Creative Commons license, so experienced circuit designers can make their own version of the module, extending it and improving it.

I have gained much knowledge as much as programming in Arduino is concerned and I look forward to learn more this coming week.

 

It has been another week of projects for everyone, every group was working tooth and nail in making sure that they are shifting towards their our goal, that is finishing their project with best solutions and within the planned schedule of their times.

I and my colleague Nehuwa were assigned the project of assembling a plastic filament maker, popularly named filabot wee by the manufacturer of the parts, filabot.

A filament maker is a an electro-mechanical device which is used to produce filament for 3-D printing. It takes in pellets (in our case we used ABS pellets) through the hopper, these are driven by a feed screw which is coupled to a dc motor, the pellets pass through a heated chamber. It is in this chamber where the pellets are melted due to the heat which comes from a heat filament underneath. Thereafter,the molten material is squeezed out through a nozzle, it cools as it interacts with the outside environment forming a  continuous string of plastic with an almost equal diameter called filament.

We used a kit purchased from filabot, this was because filabot is open source, it comes in a kit and above all the kit comes with detailed documentation.

Figure 1: Assembled Filabot Wee

Figure 2:Filament from ABS pellets

By the end of last week, we had finished building the device and had tested it using the ABS pellets that were provided in the kit. We were really happy to see it working.

We then turned to used PET plastic bottles to see if it was possible to produce filament from them. Many PET plastic bottles are  disposed after use, hence the idea of exploring the use of used PET plastic bottles in making filament.

The first step began with identifying PET bottles with the label shown in the diagram and gathering them together. The upper and bottom parts were removed by cutting since they are usually hard, hence would be difficult to cut into pieces, after that all remaining liquids and labels were removed, then cut into flakes by a pair of scissors.

Figure 4:PET flakes

Figure 5:Standard PET symbol

We then followed the same steps of making filament when using ABS pellets. The machine extruded a small amount of filament then jammed, we serviced it and its in good condition as I am writing this.

In conclusion, we are happy to have learn how to assemble, clean and repair a filament a maker. We believe we will be capable of teaching our fellow students when we go back to Malawi.

We thank Dr. Rebecca Richards-Kortum and Dr. Matthew Wettergreen for their contributions towards the success of our project.

 

Week Five: July 7th, 2015

Mikaela Juzswik

---

 

Things are really starting to heat up this week. A few days ago, we welcomed Nehuwa to the party, which was pretty awesome–our Best Breasties grew from a team of two to a team of three, which let us expand our options and have a more versatile approach to the prototyping process. Hurray for teamwork!

This week marks the beginning of one of the more exciting parts of the design process: prototyping. We started with low-fidelity prototypes that were meant as proof of concept models, which essentially translates to “engineering arts and crafts.” Which, for me, is basically what I do when I’m not at work anyway, so it’s a ton of fun. We spent the first few days of the week focusing on the pressure mechanisms, mostly working with the idea of using a plastic bellows or a water bottle as a diaphragm to generate pressure. Prototyping a functioning bellows is largely summed up as visiting Amazon, so we crossed that bridge in a few minutes, although we haven’t been able to test things in detail until the bellows is actually delivered here. The water bottle diaphragm, naturally, was a little more involved. We experimented with types of water bottles, springs, and tubing before settling on what would potentially be a working model, although we had some reserves about the durability of the entire device.

Later in the week, we began moving away from pressure-generating systems and instead focused on ways to manage our pressure. Tubing proved to be a relatively simple problem, as tygon tubing or flexible PVC is both cheap and readily available. However, we faced difficulties when we attempted to prototype a one-wave valve to clear the air/milk flow and generate suction. Our of $10 meant that we couldn’t afford to spend more than $1 on a one-way valve, which actually proved quite problematic. Most one-way valves are fairly cheap by our standards, ranging around $1.50 – $3.00 per unit, but we couldn’t afford to dedicate so much of our budget to such a small (but vital) part. We attempted to make our own valves, using an astounding variety of materials, such as PVC, marbles, pens, and gloves, but we couldn’t create a cheap enough one that had the tolerance we needed.

For a while, we thought we were stuck. There was a difficult line between juggling comfort, cost, and plausibility in our device, and we didn’t quite seem able to balance all three.

However, on Thursday, we got some great news! Dr. Oden suggested to us that our budget may not actually be as constraining as we had originally imagined.  With the end of the week approaching (we had Friday off to celebrate Independence Day), we weren’t able to fully understand the implications of such a change, but we expect a fair decrease in our budget-based concerns in the coming week. Hurray, and onward!

Week five was our final week working on the APGAR project.  We made five types of prototypes ready to send to the Queen Elizabeth Central Hospital– all were variations on clothespins (a resource which, as we learned from James, is common in Malawi) to help the baby’s chitenge stay fastened.

On Wednesday, we brainstormed about two dozen different solutions to the APGAR project using only materials that are readily available in Malawi, such as water bottles, cardboard, and soda cans.

Later in the day on Wednesday, we visited a neonatologist at the Houston Medical Center who had worked at QECH.  Dr. Gest answered many of our questions about APGAR scoring, and even lent us a neonatal resuscitation textbook.  at the end of the day, he offered us the opportunity to see APGAR scoring firsthand at the time of birth.  It was truly an unforgettable experience, and we plan to than him in person for his time and contributions to out project.

Next week, our team will begin to work on the incubator project and deal with issues like airflow and wire management.

 

 

As per Monday’s goal was to integrate all the circuits on one circuit board, it was quite frustrating realizing that the circuit was not working as intended afterwards. This led us to troubleshooting for us to find the problem. Troubleshooting took us the whole of Monday till Tuesday that’s when we noted the problem and everything started working per our expectation after replacing one of the IC’s.

During the week we also started integrating the 7 segment 3 digit displays on the circuit  which was suggested to be used instead of the LCD display. we also continued working on the Arduino code .

It is quite interesting noting BP project progress !!!