Team: Sonya Makhni, Victoria Lee, and anonymous MIT students [AK] and [SG]
This content is presented courtesy of the students and used with permission.
Our project will address some of the problems the rehab center in Nicaragua faces with their electrosurgery machine. Right now, the machine runs a huge risk of burning the patients because there is a faulty circuit between the return pad and the machine's generator. They used to have a means for checking that the circuit is functioning properly, but this no longer works. As a result, several patients experience severe burns during surgical procedures.
Our first idea was to develop a low cost, easy to use electrocautery device that would have rechargeable batteries. The electrocautery machine would be able to function when plugged in to a power source and if it were simply using the batteries. Another idea we had was to develop a censor-based system that would be used with their existing electrosurgery machine itself. This system would contain an auto-shutoff mechanism that would detect if the circuit between the pad and generator was broken. In addition, this system would contain a series of indicators that would alert the user as to which portion of the circuit was not functioning properly (probably via series of on/off lights).
After a couple weeks of discussions, meetings, and research, our team has decided to shift our project's focus. We first learned that chargeable electrocautery pens could be purchased for $15, a very inexpensive price. This made us rethink our first idea of creating a cheap pen, as they already exist. We also decided to not focus on the electrosurgery idea, for this would involve hacking a system we do not have access to. We are on the road to coming up with a more innovative solution…
The cheap ($30-45) electrocautery pens were just the pen unit (no tips or one complementary tip included); typically this can be autoclaved for a certain number of times (40 times was what the representative said). On these, a box of tips (blade or needle type) can be bought for about $50 dollars as Sonya said. The tips must be disposed after each surgery because they cannot be autoclaved (we need to find out why).
The expensive pens (around $80-$125) are actually a box of ten Sterile pens with the pen attached to the tip. Each of these is disposed completely after thesurgery because it cannot be autoclaved. The low temp (which Sonya found out can only coagulate not cut) is a bit cheaper than the high temp (which apparently can cut as well, we need to confirm this).
To do some math:
For 10 surgeries: 1 autoclavable pen + 10 disposable tips = approx $90-$100 (after 40 surgeries a new pen must be bought because it can only be autoclaved 40 times)
For 10 surgeries: 10 nonautoclavable (Sterile) pen+tip units = approx $100
Basically, tips cannot be autoclaved, ever....?
Response from Future Health Concepts
List of Contacts
Production Engineering - Medical Equipment Division
6035 E. 38th Avenue, Denver, Colorado 80207 USA (303) 393-7800 FAX (303) 393-1482
Valleylab - Covidien
5088135544 Erica McLaughlin
I just got off the phone with Ailis (pronounced like alyse--whoops, I totally mispronounced her name when I called her). But I got a lot of good info, so here is a recap of the conversation:
Both electrosurgery (they call it a bipolar machine) and electrocautery are used. Electrocautery is used more often. They use elctrosurgery for procedures that involve really important structures that they don't want to damage (i.e. big vessels). It's used for a more focused area and you can dial up the intensity. Electrocautery is more general and used for a broader number of surgeries. Because its more general, you run the risk of injuring neighboring structures because you essentially have less control than with a bipolar device.
The electrocautery pens have two buttons--blue for coagulate, yellow for cut (or something like that). The surgeon presses the desired button and can immediately perform either function. Sometimes the surgeon uses a foot pedal instead of a button so that he doesn't have to touch it.
We know that they operate off of different temperatures, but we (before) were wondering why you can't coagulate with the higher temperature setting typically used for cutting. This is because cutting causes much more damage to neighboring tissue and coagulating uses the minimum temperature needed to get that job done. In other words, the high temperature used for cutting is excessive for the purposes of coagulation and would cause unnecessary damage to neighboring structures/ tissues.
From what it sounds like, the elctrocautery MGH uses is the kind that runs off of AC current that is attached to a giant machine. She was interested in knowing more about the fancy cautery pens that run off of batteries and can do cutting/coagulation, but I forget exactly where I saw this. Help if you know what I'm talking about on this one please.
They throw away the entire pen. Because it is normal for the tips to get a little bit charred during a surgical procedure (from the vaporized tissue), it seems useful to have replaceable tips. The surgeons have a scratching pad to remove the char, but if it gets to be too much they'll just replace the tip altogether.
After a surgery they get rid of the whole pen.
The pen they use is from ConMed Corp.
She will also get in touch with Yaffe to see if we can visit his OR
She'll try to get in touch with a medical device representative (the people who come and give demos of their products).
She knows another surgeon that is really into technology for the developing world and will try to help us meet him.
And, she said she could probably get her hands on an electrocautery pen/ tips for us.
K, that's all I think. Let me know if you have any questions, and please respond with comments about your ideas.
Electrocautery pens and pencils (corded - cutting)
Tips of interest:
From customer service rep -
silicone and rubber (?)
Vice President of Regulatory Affairs
I just emailed him. If he does not respond in a couple of days, I will call customer service again and other companies.
Hey guys, these are the big questions that we need to get answered (we've discussed these all before, but I just thought I would post as complete list as I have on our blog)
Hey Anna, here are a couple questions on the materials side that we said we would post. Please let us know if you have any suggestions/ ideas/ answers! Also, I don't know if the picture will go through via this email, but I'm also attaching the picture and link of a sample cordless electrocautery pen. This particular one is only high temp, another one is low temp. The company hasn't gotten back to me about the questions I asked them, but they said they would tomorrow or so.
I will be speaking with Professor Kimerling and Anu Agarwal (Principal Research Scientist in the medical area) about some of our materials. I'm planning on asking
a) withstand temperatures up to 2000 F
b) heat up/cool down quickly (from 1000 F to 2000 F)
c) be autoclaved
From the initial conversation I had with Professor Kimerling, he said:
"My guess, at this point, is that silicon is i) stable at the temperatures you mention, ii) has a low thermal expansion coefficient, iii) and grows a surface oxide during sterilization that is hard, protective and relatively chemically inert."
I have to clarify why the last 2 are desirable qualities, but if there are any other questions you think I should ask, let me know.
Hey, these are some Q&A's we were wondering about from Ailis.
Just got a response from Bovie Medical, the manufacturers of the Change-A-Tip electrocautery pens.
I asked about the tip material:
"For Bovie's cautery replacement tips, the body material is ABS with brass post."
ABS is a plastic (Acrylonitrile Butadiene Styrene) that is a common thermoplastic. It is good for impact resistance, it is tough, light, and a good electrical insulator"
I also asked about the two different temperature settings:
"When referring to the H100 (low temperature) and H101 (high temperature) there are no design differences. This was placed into Bovie's catalog as quick references for the end user using low/high temp cauteries."