Semester 2- Week 5 Kierstin
Meeting with Gordon to talk about how we are manufacturing, and also discussed how we are thinning the tubing. We are thinning the whole tubing, not just a small section.
Brinkley and I worked on manufacturing 5 valves. I used two different methods to insert the small tubing into the housing. One was to feed it through the purple needle (shown above), and the other was to push it in using the purple needle. The second method was faster, but it might have caused internal folding. We made different-sized valves, and I tried to make them as thin as possible without puncturing the part where the tubes intersect.
We also worked on resetting up the benchtop testing for Fady. We had to reconnect and purge the system which took a long time. We have to ensure all the air is out to get an accurate pressure reading, so this was very important.
I went into the lab and tested each of the valves to see if they were sealed (so they wouldn’t leak) and to see if there was flow through all of the outlet legs. I labeled them for easy identification of their functionality. The small valves worked very well, though one of the legs might have been slightly folded inside. For future manufacturing, I need to use the feeding through the needle method.
Because the small valve worked well, I made a new mold in Solidworks so Brinkley could pour more molds and we could remanufacture. It took a longer time than I anticipated because I had to redraw the entire part, including the shape of the valve. I also had trouble using the extruded cut until I realized I was trying to select under the incorrect parameters.
Brinkley and I went into the lab to test the different sutures. We cleaned up the lab space so we didn’t disconnect anything accidentally and so all our tools were easily accessible. We got out the different sutures that we wanted to use. We chose nylon 2/0-5/0 to test because the material wouldn’t allow water to seep through. When we went to calibrate the pressure sensor, it wasn’t calibrated to 0, and we saw there was a big leak in the sensor. We had to switch out the sensor with another one and re-purge the system. The second sensor was reading really high voltages at 13mmhg, so we tried a third sensor which worked. This took up a lot of our lab time because we had to troubleshoot why the pressures were wrong, and then disconnect the system meaning it had to be re-purged. We also had to re-calibrate the height three times to ensure our pressure reading and eye pressure values were accurate. Setting up for this testing took much longer than expected because of all the issues we came across.
When we tested the sutures, many of them were much too small (like the 5/0, which we didn’t even test) and allowed leakage at 13mmhg, which is healthy eye pressure, so there should be no leakage. The one size that didn’t leak at 13mmhg also didn't leak at 20mmhg, which is unhealthy and should allow leakage. We then had to test polyester sutures. We had to coat it in glue so the water wouldn’t just seep out before using it. Then we had to test it at different heights to ensure that it didn’t leak at 13mmhg, but it allowed leakage at 20mmhg and higher.
Testing Specs Brainstorm and Prep:
I went through all the tests that I will have to conduct for the future deliverable and brainstormed how I could conduct tests for each one. I will need to compare a few of them to the Ahmed valve and also do surgical simulations for some others.
21 CFR Part 803 - medical device reporting
Specifications:
When reporting the medical device, it will be ensured that the user facilities, importers, manufacturers, and distributors will be reported along with the report of incidents and the things it may cause, such as death or serious injuries.
Tests
Comparison of our device reporting versus the standard device reporting.
I will look up the device reporting on the Ahmed Valve and determine what was reported for that device. Then I will report our device using a similar method, and compare the two reports.
Assigned to:
Kierstin
Shape must be safe to patient.
Specification
Must not have sharp corners.
Tests
Analysis can be done by viewing for no sharp corners
I will ensure that the soft silicone was used. I will ensure there is no excess silicone that could easily rip off. And I will visually and physically check the valve to make sure all the edges are rounded and safe for patient implant.
Assigned to:
Kierstin
Product must lower or keep surgical complexity
Specifications:
Surgeon must be able to implant it with more ease or with similar complexity of ahmed valve
Test
Compare surgical procedure with the Ahmed valve.
I will watch the Ahmed valve surgery and simulate the surgery with our valve. I will also take into account that our valve has smaller dimensions than the Ahmed valve. I will record my results of the difficulty of implantation.
Assigned to:
Kierstin
Project completion date
specification :
project must be completed by April 2023
Test
Will be ensured by meeting small goals consistently until overall goal is met
Ensure we meet 30%, 70%, 90%, and 100% goals in a timely manner to move onto testing and surgical simulations.
Assigned to:
Kierstin
Device must be portable
Specifications
Device to switch must be portable and wearable for the customer
Test
Use the device and ensure that it can be used for day to day wear .
Ensure the device will fit neatly inside the eye without major discomfort or without hindering the patient's daily life. Check by implanting in a pig head to ensure there are no issues with the implantation and negative affects on the patient.
Assign to:
Kierstin
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