Tuesday, May 25, 2010

Meditation on a Self-Extending Robotic Intestinal Flatworm

I'm trying to think about healthcare innovation generally, but I'm a detail person...

The ultimate goal for surgery, of course, is not to need it in the first place. In the case of my own appendectomy, for example, a high-fiber diet might have made it less likely. Hmmm..should high-fiber food be mandatory? I don't think so. I do support a supportive role for government, when externalities are involved: labeling, of course, but also massive data collection. Government could help provide the infrastructure for personal choice. In MyersWorld it would be easy at any time (and more common in a recession) for anybody to make a little extra money by signing up for a public health randomization study -- we really don't know what diet/exercise patterns work for whom and how well, and what testable/predictable/controllable (genetic? psychological? cultural? behavioral cues?) factors are involved. If I knew that the handful of nuts I just ate was bad for me, and in what way, I might or might not eat them anyway... I like nuts. For whom does Seth Roberts' weird Shangri-La diet work, in which of its primary variations (sugar, oil, nose-clipping, crazy-spicing...)? Such information would, I suspect, make a substantial difference to obesity and probably other healthcare factors, and it's something that could be done right now, but probably won't be. Well, the internet factor is helpful, I suspect (even though, when I mentioned having printed out a web page on appendicitis symptoms, the E.R. doc did say that ought to be illegal.)

At the other end of the spectrum, a true Singularitarian might insist on pointing out that once I get uploaded into a virtual universe, I will not only think faster and have more ways to have sex but will be completely immune to cell-based ailments 'cos I won't have any cells, and I'll be copied to multiple locations so that even if a black hole whacks the Sun some of me will be fine. But frankly I'm not sure which of me will actually be me at that point, if any of you see what some of me mean, and I'm not a true Singularitarian. I'm not even terribly interested in whether or not one or more entities a million years from now have a memory of having been me; I hope we can have better goals than that.

Still, I do expect something at least as good as my stemcell cyborg notion, if I happen to live long enough to see it.

And in between? Well, I'm really quite grateful for laparoscopic surgery; various people have expressed surprise at my being not only up and active but doing routine gardening stuff and such, but I feel fine. I'd like the principle of minimally-invasive surgery to go even further; I'd like to see an appendectomy or the like become an outpatient procedure, done at a local robotic clinic which may not even have a local G.P., just an R.N. (and it might be a room in the R.N.'s house, or then again inside Wal-Mart.) The R.N. has no specialized knowledge, but when you checked in to Google Health Searches with your Android phone, you checked off your symptoms and showed yourself to the camera in front of somebody who sent you to your local clinic. She will now get you passed via telepresence to a specialist in India, let's say, to a specialist in Costa Rica, then to a real expert in your condition who happens to be in Singapore, and then the initial incision is handled by a technician in Miami who passes it on to the actual surgeon who comes in from her Greek-island beach, puts a towel on the chair to avoid getting it wet, and starts supervising the robotic equipment. (Meanwhile, the R.N. keeps track of your case, and is your agent, as well as being the intermediary between you and geek-speak where needed.)

So what is that robotic equipment that's being supervised? Well, it's even less invasive than a current-generation laparoscopic setup, of course. And it's more general: it can go more or less anywhere in your body. How?

In laparascopic abdominal surgery, it seems you mostly put in three or even four holes, inflate the abdomen with carbon dioxide to get an almost-reasonable field of view, and push tools in on rigid arms ("trocars"). My self-extending robotic intestinal flatworms need only one hole and there's nothing rigid to push in except for the head(s); they grow into you via a version of 3d printing, replace the bad piece with a model of itself, and then the non-biodegradable parts are withdrawn. Then you sit quietly for a little bit and then somebody drives you home.

Details? Sure, but as with most not-yet-solved problems there are multiple solutions on the horizon; you can't tell which will actually arrive. The Self-Extending Robotic Intestinal Flatworm as I'm imagining it is part sensor and part Roto-Rooter. It has a flat beak, a flat head, a flat neck, and a long flexible flat tail with a row of flexible tubes, being an output tube for ground-up roto-rooted gunk, two input tubes for hydrogel components, and one or perhaps two optical fibers for laser use; the surgical cutting laser may have to be separate from the scanning laser, which does its scanning with a vibrating mirror in the head, like that of the Cornell pocket projector

The key to the technology is a small mirror, about half a millimeter across, suspended by carbon fibers. According to the Review, the fibers amplify the vibrations of a piezoelectric motor to move the mirror, which deflects a laser at different angles, causing it to sweep back and forth across a surface.

So the flatworm has a really good view of whatever it's about to cut; it can probably leave the scanner-laser inside the head, but might sometimes push it out in a transparent globe at the end of an eyestalk. Appetizing? Mostly, though, the flatworm gets its head to where it needs to be, slices through tissue and small blood vessels but plugs larger vessels with hydrogel before slicing the plugs, and butters that which it's going to remove with a layer of hydrogel (a relatively hard, tough hydrogel, now used for tissue engineering) before it starts a grind-slurp-replace cycle in which it extrudes about a cubic centimeter of hydrogel for each cubic centimeter it removes; sometimes the hydrogel input will be mixed with a stem-cell suspension.

And how does the flatworm get to the objective, e.g. from belly-button to appendix? Well, my suspicion is that at least part of the motive power can be managed if we form the tail by extruding hydrogel out a ring of little holes around the neck, forming rings: if you're turning right, you don't push as much out the right side, and so on. The tail material thus is automatically the right shape, and it never moves inside the body, although it is stretched just a bit at the end of the process when the cables and head are pulled out, leaving the hydrogel behind along with any sensors, effectors, and engineered tissue that may be the result of the surgery.

And do I really think this would work? Well, I've deleted a number of alternative approaches for the S-E RIF; even if I were an actual expert, I'd be sure to have deleted (or not thought of) some of the right ones. So I'm sure that the minimally-invasive surgery of ten (or, after healthcare reform, maybe twenty) years hence will be quite different from this image, different in detail. But it will be as good. We are getting good at sensors, getting good at micromachinery, getting good at biomimetics and tissue engineering with and without stemcells. There is no reason to think that we'll stop at this month's AnchorPort Single Incision Laparoscopy Kit. And the main takeaway here is in any case that the surgeon is not looking at the appendix, not cutting free-hand with a scalpel: he's looking at a screen, and manipulating controls for a waldo; probably just a couple of joysticks. Right there, that enables telepresence, and it already works. This in turn enables the specialization-economics of Adam Smith's pin factory. We could improve our healthcare outcomes at reduced cost, just by that. That could be done now, this year, with a steadily-increasing scale of operations over the next decade. As a later extension, the surgeon should not be viewing endoscopic imagery; he or she should be viewing a 3D model based on data from

  • prior CT scan and sonography
  • very-short-range optics
  • sonography
  • maybe teraherz radiation, capable of penetrating a bit into not-too-wet-tissue.
That would replace the field-of-view problem with a different, often-solvable problem. It couldn't be done this year, but it could be done soon.

Oh, well...then again, maybe not.

update: Maybe this is happening even faster than I thought: the NYT has produced an article on Healing by 2-Way Video - The Rise of Telemedicine.

update 2: Self-assembly from within might be better than self-extension from an external incision, and an Italian group is making progress according to Ingestible Surgical Robots—Hard To Swallow Concept? | Singularity Hub :

The ARES robot was designed to self-assemble inside the body after patients swallow up to 15 parts. Using a modular approach, each of these parts would have its own role to play—image control, communications, structural functions and diagnostics, among others—while forming whatever the structure needed to carry out a particular operation. Weighing in at 5.6g, each module is 15.4 mm in diameter and 36.5 mm in length, and each represents a single pill to be ingested by the patient.
Faster, please.

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