Cost savings

The last couple months we managed to cut about 50% of the projected cost of our disposable medical device. How did we manage to do that? We have a very labor intensive device to manufacture, or at least we thought we did, we hadn't spent much time refining production.

Then we hired a part time temp and paid her less than 1/2 the rate of the two full time guys and she was able to out produce them both while working part time with a higher quality of work. Plus she actually read drawings and followed procedures so she discovered some engineering and QC problems with the product which were fixed. I don't know how you consistently hire people like that though.

Bench Testing

I've spent the last few weeks dealing with bench tests as we wait for other results to come in. Bench testing or performance testing gets stuck in section 18 of the 510(k), since it is in the back means they don't read it right? You will save yourself a lot of grief if you read the format guidance and make sure your protocols and reports line up nicely with their requirements, although you will need more than what is listed in the guidance, at least a scope.

For a small company there are several challenges to bench testing, all revolving around the number of people that have enough understanding to run the tests. My company has three plus one consultant that can run the majority of the tests, it is preferable to have employees sign off on everything so the consultant is out, and one of the three has the understanding to run the tests, but not the personality type to see it through. That leaves the two engineers, one of which is on vacation this week, so that leaves me for now. MD&DI sums up the who should do the bench testing very well.

The first problem is the protocol, which must be signed off before the test begins, the problem here is that no one besides the engineer authors are likely to really understand what is going on. This means no problems will be caught until the engineer testers try it for real. Sure, we've tested it some previously, but when everything is recorded things change. I wrote a protocol and discovered I couldn't hold a negative pressure I thought I could so had to change it up a bit. This means rewriting and walking around getting signatures to get it approved before I can start again. This is not much of a problem, unless it is after 3:30pm and QA has gone home for the day. Then I'm forced to wait around until they come in at 9 the next day. I have argued that by having my signature on it that the protocol has therefore been predefined and good to go, but I haven't gained much ground with that.

The next problem is that these tests take time, we are shooting for 24 hours of use. I rallied around testing for 26 hours but my boss vetoed that saying 1.5 times is standard, meaning 36 hour tests and every other day I have to come in at an awkward time (do not worry, I am getting my revenge- see below). I am amazed my wife hasn't accused me of cheating on her yet with the late night stops by work. The 1.5 times the maximum limit you're shooting for is a good rule of thumb, and appropriate here, but it doesn't work for everything, like negative pressures.

The last of my whining centers around the sample sizes that will not be high enough to make everyone happy. With limited product and limited resources, running a dozen 36 hour tests could take a month. Unless you are going to manufacture, sterilize, and shipping simulate a batch of samples yourself in the next week, complaining about sample size doesn't accomplish much. Do a reasonable job and if the FDA picks on it the most likely thing that will happen is they'll ask for more testing.

I mentioned in my previous post that the deadline slipped (still not my fault), this has given me time to come up with some additional bench testing to put in motion. I say put in motion because I was so confident I'd meet my part of the original 510k deadline that I planned a two week Hawaii trip starting one day before the deadline. Now all the loose ends will have to be tied up by my boss and the other engineer, I sorta feel guilty now, but about 20 minutes after landing it will be forgotten. I give the extra testing a 40% chance of not being done when I get back. I have to say though that the last year has been a blast and if you're an engineer with a good work ethic that can tolerate the risk of working for a smaller company then go for it.

Sterlization finally resolved

I posted previously on failing a natural product sterility (NPS) test in a lot release using ethylene oxide (ETO) sterilization, and we finally have everything somewhat resolved, well really a couple weeks ago we did, but I've been too busy to post. An ISO 11135 lot release requires a half cycle, then biological indicator (BI) and NPS testing which must come back sterile, then a full cycle and further BI testing which comes back sterile. Residuals and pyrogen samples are taken from the full cycle. In the previous post I mentioned we failed the half cycle NPS testing.

After that we made our full cycle the half cycle and tested the full cycle samples for NPS and doubled the sterilization time for the rest of the samples (this still confuses some people at the company). Unfortunately those NPS samples failed as well, or more precisely one of forty samples failed on Day 7 of 14. All BI samples were negative. After much debate and me being the ever eager middleman between management and the sterilizer we decided to double our sterilization time once again then proceed. However, we had to start all over with the samples because we had used so many in testing.

While we were building more samples we looked into the NPS testing. The most notable thing was that we discovered we were using twice as many samples as required, 40 instead of 20. 20 samples assumes you use 10 samples with aerobic media and 10 samples with anaerobic media. You can even use 10 samples if you use the membrane method instead of using the two types of media on the device. For us, each sample was tested individually and had their own large media jar. We made a couple minor, mostly for show changes to how the test was conducted.

So we built more samples and re-sterilized at a fairly ridiculous length of time for the half cycle and twice this ridiculous length of time for the full cycle, the length of time is so high it borders on what the FDA considers non standard sterilization. Hopefully we can lower the time some in an actual sterilization validation in the future. Oddly (IMO), the sterilizer doesn't charge by time in the chamber, so sterilizing for 1 hour costs approximately the same as sterilizing for 5 hours.

It took much begging, but we actually managed to get these sterilized half and full cycle in less than three weeks. We passed all the required testing and we are finally on our way. There is another part to our product sterilization that I'll get back to when its done. Talking to the 510(k) consultant afterwards he said sometimes companies don't file with sterility test results. I'm not exactly sure what they're filing with then.

Since then we've been bench testing like crazy and I have been unsuccessfully trying to delegate tests, but it seems like we don't have any people that understand the product well enough to pass most tests on to. We did have a Dec 31 filing deadline, but its been moved. I am happy to say that my disposables part isn't the thing that is holding everything up despite a completely failed sterilization.

Who reads medical device blogs?

Not very many people read medical device blogs, but the ranking of countries by number of visitors that read this blog is somewhat interesting:

The glamorous life of a medical device engineer

What I did today:

Got in early, ate breakfast bars while deleting junk mail. I email the biocompatibility testing lab and tell them its on, we sent samples yesterday, Merry Christmas. Let me know if there is anything you need from me, blah blah blah.

Looked at the pallets we got back from the sterilizer yesterday with a couple of the guys from manufacturing, remove the pallet wrap and organize the boxes. Complain about their condition due to our choice to not use a master carton. I send an email to the shipping testing place, tell them the box count and the PO number.

Went to talk to my boss, inform him that the 2 pallets we got from the sterilizer need to be inspected before 9:30 when they are scheduled to be driven over to shipping simulation by the president of the company- he's got the truck. I tell him he's the only quality rep here now, hint hint hint, boss says wait for QC. I look at him like he's crazy.

Walk over to the lab, see the manufacturing manager looking at the pallets, he decides to get his guys making boxes. In the lab I start setting up for today's test, a comparison of hemolysis done by our device and predicate device to make sure we're on the same page. The lab tech and I have got the test aced, we just want one more practice before the real deal. The software engineer calls, want to talk about a flowchart I wrote up for the product, I tell him I'll call him back.

QC arrives at 8:45, panics. President arrives at 9, asks me if we're ready to go, I refer him to QC, he accuses me of passing the buck.

At 10, the QA arrives with the blood for today's lab test. I start working on blood prep. QA dept starts repackaging product that needs it. I go over there and see they're using uncontrolled packaging tape, mention it, they look at me like I'm crazy. I go back to work in the lab. We get the test started around 11, I go check my email.

Testing lab wants 50% payment and has sent a bunch of standard protocols for sign off. I consider reading them then forward them to QA before I sign and fax them back. I harass the secretary to get the check and get it signed by the president who is going to buy a tarp because its raining now. I Fedex the check.

I go back to the lab, clean up, work on the hemolysis test and quickly set up a side project for my boss. QC comes over and accuses me of "not helping" I count 3 quality people and 2 manufacturing working on it, how much help do they need? I volunteer to print labels, print them, then go back to the test. Boss and other engineer come over to the lab to work on the side project, apparently this involves standing directly in front of the much used centrifuge.

12:30, the other engineer orders and gets a pizza and along with the lab tech, we eat it in the warehouse while watching the testing in the next room. We watch manufacturing and QC run around I look at the two pallets balanced in the pickup skeptically, now I wish I would have taken a picture. The president leaves for the shipping lab, we get back to work.

Software engineer calls, I tell him I'll call him back. Manufacturing manager gets me on the phone with the print shop who want to know how many staples and paper type (umm, white?) for the IFU, he then tells me we're definitely moving. We finish up the test and clean up. 3:00, I go to my desk, call the software engineer, discuss software, he tells me he pulled an all nighter last night, I feel bad because I don't see much progress.

I go back to the lab, set up the overnight experiment, finish filling out today's test data. President comes back, tells us we have no idea how to tie a load down onto a pickup, it was all messed up by the time he got there. I tell him we need to pick it back up on Monday. I start the overnight experiment, go back to my desk. I call the shipping lab, they say they might be done tomorrow, I decide to surprise the president with the good news if it pans out tomorrow and not tell him today. I print out two ECNs that I finished yesterday but didn't get to, sign them and put them on QCs desk. QC asks me if I want an email summary of damaged boxes, I tell her "no."

I go back to my desk, check my email, boss has sent me a subjectless email containing only this: " http://www.fda.gov/cdrh/ode/guidance/337.html "--What could it mean? I consider forwarding it to QC. Voice mail from a sterilizer, I call them back and talk about some testing. 4:30 go home!

Medical Device IFU and Manual

I mentioned previously that I was working on our Operator's Manual and this post is an extension of that. Our manual and Instructions for Use (IFU) are detailed and thorough and go above and beyond what others in the field have done for a number of reasons.

First off, there is patient safety to think about. A picture or sketch goes much further to describe something than plain text. I'm lobbying to get our software to include videos of various steps. I haven't gotten very far with this yet, sometimes its a struggle to not get everything written in all caps.

Second, we're eventually trying to make sales, why skimp on the manual? Frustrated users cost sales- saving the $5 by printing in black and white and limited documentation is not where you want to cut costs. Established devices can skimp, they've been around for years, everyone already knows how they work. Not us, we need to educate people, mostly everything works the same, but there are some subtle differences. Sure, no one may ever read the manual, but if they do, its only going to make them unhappier if they don't find what they're looking for.

Third, this is 2007, I can snap a picture, edit it, and stick it in the manual in about 3 minutes, likewise with sketches, everything has been drawn in Solidworks, it is not a problem to make a nice little line drawing of anything I could ask for. I can also format things exactly how I imagine them, not to take advantage of these capabilities would be foolish.

Fourth, it is something I enjoy for the most part, which helps.

I say go overboard with this stuff, someone can always remove part later if they find something disagreeable. In the past I was rather amazed at things clinical users did not know, now I am more cynical. We've talked to quite a few people that can't differentiate IV bag sizes. It was a decent struggle to tell a three liter bag from a one liter bag and even after explaining it was still not 100%. We solved this problem by going with one bag size.