This is where all of our weekly progress will be recorded

Monday 30/10.23

Today both of us were busy doing other course work

Friday 3/11.23

Monday 23/10.23

Since last Friday's test had to be done without ham, we redid the test today, but this time with ham. We bought some ham from the store and froze it down while squeezed flat as this would make it most resemble the actual prostates.

We developed a new bed lid to test friction. The new bed with metal holes had a little bit more friction. While testing we also discovered a small air-leak between the old bed lid and the rest of the bed. This means that we should be able to grip a little bit harder with a completely air-tight setup. Solving this may be as easy as adding more magnets.

We also designed an adapter for attaching the vacuum to our tube.

The test

Starting the machine: The machine took 2 hours to reach -12°C

Attaching the computer: We had zero complications.

Starting the software: We had zero complications. No calibration had to be done.

Inserting the slice: The insertion of the slice was somewhat difficult, but we had no complications.

Cutting: The cutting went well. It was performed at ~-10°C. The slice was held perfectly still. There was however the problem of spooning, which we know is worse at higher degrees. We also suspect that the drill may have been a little bit dirty, which worsened the quality of the cut.

Retrieving the slice: The retrieval of the slice went well. The plate was somewhat stuck, but with some patience it went well.

Conclusion:

The vacuum solution is strong enough to keep a frozen slice of meat fastened to the drill-bed.

Comments:

The vacuum pulled a lot of cold out of the freezer. During the procedure the temperature rose from -10°C to -3°C. We can solve this by simply pumping the air back into the freezer.

The spooning gathered around the cut, which reduced visibility, but had no impact on the quality of the cut.

By sending the video feed to our other pc we managed to get a better view of the drilling during the procedure.

Friday 28/10.23

Today we first had a meeting with our counselor and then with the ARTS team at St.Olavs.

In our first meeting we talked a little bit about our progress and the way forward. Getting answers to the questions we had after these first two months with work.

We concluded that we have approximately 4-5 weeks left until we need to start writing our project thesis.

Going forward we want to focus on improving the gripping method as that is the part of our POC that needs most work. Håvard had a good idea of using a single hole in our drill-bed and have it sealed with an o-ring.

The upside of this is that the seal between the ham and the vacuum would be tighter, thus increasing the gripping force. As no spooning can escape down into the vacuum, no filter solution would be needed. In addition there would be less leakage of cold air, removing the need for an active cooling method during drilling.

The downside of this is that the area covered by the o-ring would then be unavailable for drilling. However if this area is small enough, then if wont be that much of an obstruction.

Håvard also advised us to look at his master thesis to se how a master thesis is structured, so that we know more about how we should think when structuring our thesis.

We have also scheduled a meeting next week where we will get to learn about zotero, which will come in handy when writing our project thesis.

The feedback we got from our ARTS meeting was that they really liked what they saw, but would like to see it done on objects that have properties similar to that of a frozen prostate, only of worse quality. Thus testing the edge cases and further proving that it will work on real prostates.

Examples of this could be:

freezing ham in a way that induces internal tension in the meat
Buying a block of meat and cutting it ourselves, of getting people at MENY to cut uneven slices for us.
Freezing ham on wiggly blocks, so that the surface becomes uneven.

Monday 16/10.23

After testing the 7th iteration vacuum gripper it was decided that it was risky. There was noticeably less suction with that tube. In addition the notch margin of 0.15 mm was too small.

The day was therefore spent testing what the margin should be and looking for better tubes.

We believe the last margin test failed due to the test-prints being to narrow. This time we instead printed the whole width. 6 variations were printed, ranging from 0.20mm to 0.45mm, with a 0.05mm interval. After testing these against our bed lid we found that 0.45mm would probably be the easiest to use while still not so loose that the seal is broken.

In addition we found a tube that was flexible enough that had an internal diameter of 11mm.

Next time our bed hopefully functions properly and we can assemble the whole machine and test it.

Friday 20/10.23

We realized today that we might have prioritized wring the last 2 weeks. A better way of testing the vacuum would have been creating a bed with the largest possible tube and trying to drill, and then reducing the tube size for practical reasons, while maintaining the gripping ability.

This would have been smarter because even though we now know how the different tube-diameters acts relative to each other, we don't know accurately how much force is created by the drill.

The drill and bed was assembled and the suction seems to work well enough for our purpose. Then we calibrated the drill to the achieve the correct drill height and and refined the workspace area, so that the drill wont accidentally cut into the metal frame.

Next we accessed the camera and calibrated it to the bed. It took several tries and small adjustments to make this accurate. Now we have created an alignment method described here.

To our surprise there were no frozen chicken slices in the fridge so we had to resort to testing with a chicken slice.

In the first test the vacuum gripping was not strong enough. It could be caused by several things; too little airflow, a too hard test-material, too low-friction bed-lid, or increased shear forces due to the crooked spindle.

We then hooked the vacuum tube to the lab-vacuum and it worked perfectly.

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This is where all of our weekly progress will be recorded

The test

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Weekly prostate logs

This is where all of our weekly progress will be recorded

The test