Cardiac prosthetics and fully implanted artificial limbs.

No matter how you cut it, heart failure is one of those conditions that sends a chill down your spine. When the heart muscle grows weak and inefficient, it compromises blood flow through the body and can cause a host of other conditions, some weird, some additionally dangerous. Depending on how severe the condition is there are several ways of treating it. For example, my father in law has an implanted defibrillator that monitors his cardiac activity, though fairly simple lifestyle changes have worked miracles for his physical condition in the past several years. Left ventricular assist devices, implantable pumps that connect directly to the heart to assist in its operation are another way of treating heart failure. Recently, a research team at the Wexner Medical Center of Ohio State University reported remarkable results with a new assistive implant called the C-Pulse. The C-Pulse is a flexible cuff that wraps around the aorta and monitors the electrical activity of the heart; when the heart muscle contracts the C-Pulse contracts a fraction of a second later which helps push blood through the aorta to the rest of the body. A lead passes through the skin of the abdomen and connects to an external power pack to drive the unit. The test group consisted of twenty patients with either class III or class IV heart failure. The patients were assessed six and twelve months after the implantation procedure, and amazingly a full 80% of the patients showed significant improvements, and three of them had no symptoms of heart failure. Average quality of life metrics improved a full thirty points among the test subjects. I'm not sure where they're going next, but I think a full clinical trial is on the horizon for the C-Pulse. One to keep an eye on, to be sure.

A common problem with prosthetics, be it a heart, an arm, or what have you is running important bits through the skin to the outside world. Whenever you poke a hole through the skin you open a door to the wide, fun world of opportunistic infections. Anything and everything that can possibly sneak through that gap in the perimeter and set up shop in the much more hospitable environment of the human body will try. This is one of the major reasons why permanently attaching prosthetic limbs has been so difficult. To date various elaborate mechanisms which temporarily attach prosthetic limbs to the remaining lengths of limbs, including straps, fitted cups, and temporary adhesives have been tried with varying degrees of success. At the Royal National Orthopaedic Hospital in London they've begun clinical trials of ITAP, or Intraosseous Transcutaneous Amputation Prosthesis. In a nutshell, they've figured out how to implant attachment sockets in the remaining bones of limb amputees that can penetrate the skin with minimal risk of infection by emulating how deer antlers pass through and bond with the skin. This means that prosthetic limbs can be locked onto the body and receive just as much physical support (if not slightly more) than organic limbs do. Test subject Mark O'Leary of south London received one of the ITAP implants in 2008 (yep, six years ago and only now is it getting any press) and was amazed at not only how well his new prosthetic limb worked, but how being able to feel the road and ground through his prosthetic and into the organic part of his leg. Discomfort on the end of his organic limb is also minimized because there is no direct hard plastic-on-skin contact causing him pain. Apparently not one to do things by halves, O'Leary put his new prosthetic limb to the test by undertaking a 62 mile walk on the installed limb, and for an encore he climbed Mount Kilimanjaro with it.

Another hurdle toward the goal of fully operational prosthetic limbs has been restoring the sense of touch. Experiments have been done over the years with everything from piezoelectric transducers to optical and capacitative pressure sensors, but mostly they've been of use to robotics research and not prosthetics because the bigger problem of figuring out how to patch into nerves on a permanent basis was impeding progress. At Case Western Reserve University a research team successfully accessed the peripheral sensory nerves of amputees and then figured out what patterns of electrical stimulation on which nerves felt like which parts of the patients' missing hands. The inductive nervelinks were connected to patterns of sensors mounted on artificial arms developed at Case Western and the Louis Stokes Veterans Affairs Medical Center in Cleveland, Ohio. Long story short, the patients can not only sense pressure, they can tell the difference between cotton, grapes, and other materials. Even more interesting, sensory input from the prosthetic limbs relieved phantom limb pain suffered by some of the test subjects. Additionally the newly installed sense of touch has given the test subjects heretofore unparalleled dexterity in their prosthetic limbs; one test subject was able to pluck stems from grapes and cherries without crushing the fruit while blindfolded. Elsewhere in the field of limb replacement, a groundbreaking procedure carried out in Sweden in 2013 (I had no idea, one of my net.spiders discovered this by accident) combines the previous two advances. At the Chalmers University of Technology a research team headed up by Max Ortiz Catalan used ITAP techniques in conjunction with transdermal nervelinks to integrate a prosthetic limb into an unnamed patient's body. The patient has been using the limb on the job for over a year now, and can also tie shoelaces and pick up eggs without breaking them. A true cybernetic feedback loop between the brain and the prosthetic limb appears to have been achieved leading to intuitive control over the prosthetic limb. The patient has shown long term ability to maintain control over and sensory access to the prosthetic limb outside of a laboratory environment. The direct skeletal connection to the limb provides mechanical stability and ease of connectivity for the limb without any need for structural adjustment. The nervelinks mean that less effort is required on the part of the wearer to manipulate the limb, greater dexterity by exploiting the intuitive proprioceptive sense of the human brain, and no need for recalibration because the nervelinks don't really change position.

Excited about the future? I am.

The Doctor | 20 October 2014, 08:42 hours | default | No comments

Synaesthesia and noise-cancelling headphones.

I've never really gone out of my way to publicize the fact that I'm a synesthete - my senses are cross-wired in ways that aren't within the middle of the bell curve. In particular, my sense of hearing is directly linked to my senses of sight, touch, proprioception, and emotional state. As one might expect, this causes a few problems in day to day life - I can't go to concerts without wearing earplugs because I shut down from sensory overload, and too much noise makes it nearly impossible to see (and thus, get anything done). The new office at work poses a particular problem because it has an open floor plan, and lots of hard and polished surfaces. This makes background noise extremely difficult to deal with because everything echoes and rattles. I'm not the only person at work who's been having trouble due to the noise, either. To help with the noise problem while still allowing us to do what we need to do (including teleconferencing) they bought each of us a pair of Bose QC-25 Noise Cancelling Headphones, which are both incredibly expensive and very helpful.

When I first put them on I was shocked that I could hear absolutely nothing at all, as if I'd put custom-made silicone rubber earplugs in. It was as if everything had suddenly gone away - like a switch had been thrown inside my head. My vision cleared, no phantom sensations... is this what it's like to have a baseline sensory cortex?

Flipping the switch on the side of the headphones to activate the noise cancelling features resulted in even deeper silence with nothing playing through them. I can't be sure but I think the noise cancellation mechanism was filtering out the sound of my breathing, or at least the experimentation I did seems to suggest this. There is quiet, and there is dead silence. These headphones seem to manufacture the latter. As for using them as headphones I'm extremely impressed with the clarity, range, and depth of the sound they generate. Old favorites sound wonderful and new music sounds crisp, clear, and attention-grabbing. These headphones even seem to do a certain amount of noise cancellation and cleanup of whatever sound you run through them; I listened to a couple of old bootlegs from the mid-1980's and they're remarkably clearer. The tape hiss and crackle from age are almost completely gone, which brings out the music and vocals much more sharply. I noted that I was listening to those bootlegs with the volume much lower than usual, and got much more out of the experience at the same time. On the whole, it is significantly easier to concentrate at work now and I find myself much more productive while wearing them because there is significantly less distraction that I have to filter out. They feel great, too - the QC-25's are very light, have earcups large enough to fit over one's ears with room to spare, and do not seem to trap heat and cause uncomfortable sweating. The QC-25 also has a built in voice activated microphone and a standard 4-pin, 2.5mm headphone/microphone plug for a smartphone which works just fine in a regular headphone jack. I know there are some laptops out there which have a smartphone-style combo jack, but Windbringer is not one of them so I can't attest to how well the microphone works. I haven't tried it on my phone yet, so I can't speak to how well it works for teleconferencing.

I think I've fallen in love with this set of headphones, and I'm considering buying a pair for myself.

The Doctor | 16 October 2014, 10:00 hours | default | No comments

Visiting the Computer History Museum.

A couple of months ago, Amberite and I visited the Computer History Museum in Mountain View, California with his father. I'll admit, I wasn't sure what to expect on the way over there. I've been to the Smithsonian quite a few times but the Computer History Museum is just that: Dedicated to the entire history of computing and nothing but. There are exhibits of the history of robotics, video games, military equipment, and of course one of practically every personal computer ever made, from the Amstrad CPC (which never really had a large community in the States, though it was quite popular in Europe) to my first love and joy, the Commodore 64. I took so many pictures there that the battery in my camera died, and I had to fall back on my cellphone.

Here's my photo album.

The Doctor | 13 October 2014, 10:15 hours | images | One comment

Notes from the Artificial Intellligence and the Singularity conference in September.

As I've mentioned several times before, every couple of week the Brighter Brains Institute in California holds a Transhuman Visions symposium, where every month the topic of presentation and discussion is a little different. Last month's theme was Artificial Intelligence and the Singularity, a topic of no small amount of debate in the community. Per usual, I scribbled down a couple of pages of notes that I hope may be interesting and enlightening to the general public. A few of my own insights may be mixed in. Later on, a lot of stuff got mixed together as I only wrote down assorted interesting bits and stopped separating the speakers in my notes. My bad. As always, all the good stuff is below the cut...


More under the cut...

The Doctor | 08 October 2014, 10:00 hours | default | No comments

More accumulated wit, wisdom, and profanity.

Once again, I've updated my .plan file. As always, use discretion when reading it at work or in public. Once things slow down at work I'll have more time to write actual posts.

The Doctor | 27 September 2014, 23:31 hours | default | No comments

Registering out of state vehicles in California.

If you're in the process of moving to California you have to get your car registered before your existing license plates and car registration expire. It also would behoove you to get your car registered as fast as possible because the longer you wait, the more you'll have to pay to get it done. It could easily run you $700us if you're not careful, and I advise you to not sell internal organs to get your paperwork through if you can avoid it. The first step of the process is to get your California driver's license. To do this you need your current out of state driver's license, your birth certificate, your Social Security card or passport, and money. You'll need to pass a vision test (I had to take mine twice at two different desks and pass both times), you need to fill out a copy of form DL 44 (which you can only get at the DMV office because each has a unique barcode printed on it), and you need to pass a 36 question written exam. You can only miss three questions on the exam, and the questions are very detailed. Study the handbook and take the practice exams until you ace them; they're online here. You'll also have a thumbprint taken with an optical scanner. You don't need to make an appointment to get your driver's license. If you pass they'll punch a hole in your existing DL and give you a printed out temporary license that's valid until your real one arrives in the mail.

As for registering your car, even if you have a paper temporary license, that's fine. Get your paperwork going and it'll sort out. Seriously. You'll need the following documents:

You don't need to make an appointment to get your car registered, either. Just show up at the DMV early, ideally an hour before the DMV office opens. They'll tell you where to park. Park there and wait for someone to give your car a walk-around. They'll fill out a copy of form REG 31 for you. At a minimum whoever checks out your car will look under the hood, write down the VIN, and take an odometer reading. Bring two or three books and be prepared to wait multiple hours. I waited nearly four hours before my number was called. When they do call your number, have all of your paperwork filled out and ready. You'll have time to do it, use it. If your paperwork is in order, they'll tell you how much you need to pay. The online calculator that tells you how much you'll probably pay is accurate to the penny in my experience, assuming that you've entered accurate information. Make sure you have enough in your budget to cover it. How much you pay is, in part, contingent upon when you first drove your car in California as what they consider a resident. You can probably lie but I don't know how deeply they check due to the privacy screens on the displays, nor do I know what would happen if they caught you lying. Good luck.

Assuming that everything's in order you'll get your permanent California license plates and registration stickers immediately. Put them on your car before you leave the parking lot and put the registration stickers on the rear license plate. Bring tools that you know you can use to add and remove license plates. You don't have to give them your old plates but you do have to put on the paperwork what you plan to do with them (send them back to the state you moved out of, keep them, give them to California). They'll honor whatever you put on it but you do have to tell them.

The Doctor | 25 September 2014, 10:00 hours | default | No comments

Video from the Global Existential Risks and Radical Futures Conference is up.

In June of 2014 the Global Existential Risks and Radical Futures conference was held in Piedmont, California, which I was invited to present at. After a delay of a couple of months videos of the presentations have been uploaded to YouTube. Among them is the presentation I gave; the audio's a little quiet due to the accoustics of the building and the Q&A has been cut off at the end but it does have the entire talk (local mirror). The presentation's slides aren't in frame but I uploaded them here shortly therafter.

The Doctor | 15 September 2014, 09:00 hours | default | No comments

DefCon 22 presentation notes

Behind the cut are the notes I took during DefCon 22, organized by name of presentation. Where appropriate I've linked to the precis of the talk. I make no guarantee that they make sense to anybody but me.


More under the cut...

The Doctor | 20 August 2014, 10:00 hours | default | Two comments

DefCon 22: The writeup.

The reason I've been quiet so much lately and letting my constructs handle posting things for me is because I was getting ready to attend DefCon 22, one of the largest hacker cons in the world. It's been quite a few years since I last attended DefCon (the last one was DefCon 9, back in 2001.ev) due to the fact that Vegas is, in point of fact, stupidly expensive and when you get right down to it I need to pay bills more than I need to fly to Las Vegas for most of a week. I'm also in the middle of finishing up moving out of DC, which would tie up most of anybody's energy and money. However, this year $work sent me with two cow-orkers so once the ink was dry we kicked into lockdown mode to get ready in the days leading up to our flight. I'll post later about what all of that entailed, based upon the hypothesis that transparently documented security protocols executed correctly should stand up to a certain amount of scrutiny; additionally, peer review and scrutiny for security protocols isn't a bad thing at all.

Due to the no photography policy at the con I took only a handful of pictures outside of the conference space, and even then only of myself with an eye for keeping as many other people out of the frame as possible. Many of us aren't comfortable being photographed anymore because we as a society are under such tight surveillance in public that it's nice to not be recorded once in a while. So, I've got no pictures of and from DefCon this time around.

Our flight to Vegas wasn't much to write home about. It was pleasant as short flights go and largely inoffensive. Protip: If you're flying Spirit Air and you've got baggage to check, do so at the front desk. Don't check your baggage when you print out your boarding pass even if you do it at home. If you do it'll cost you somewhere in the neighborhood of $50us. if you check your baggage at the front desk as an "Oh, by the way" you'll only pay $16. Save some money, you're flying to Las Vegas. You'll need it. When we stepped out of McCarran Airport to get on the shuttle bus the dry desert air slammed into us like a firm yet fluffy hammer. After a minute or two we were unable to tell the difference between the air and the exhaust from an idling truck.

From the time we flew out of our home airport the three of us were operating in what we called autistic mode, a phrase taken from Ghost In the Shell which refers to the practice of operating while entirely disconnected from the global Net. DefCon's network is renowned as possibly the most hostile network environment on the planet, where no holds are barred, zero fucks are given, and it's aliens-from-Independence Day-nuke-dog-eat-dog. In short, you run at your own risk because there is no telling what's running loose on any of the wireless networks there. There is also no telling which of the wireless access points at any given hotel are legitimate and which might be booby traps. I've heard several people over the years mention that the number of hotel access points triples in the day or two preceeding DefCon and drops abruptly the day after the con wraps up. Additionally, it is generally agreed upon by the security community that the security measures on your average smartphone vary between "laughable" and "criminally negligent"; coupled with the state of the art in GSM and CDMA interception techniques even talking on the phone at DefCon is potentially hazardous. In a later post I'll describe our OPSEC protocol along with what worked, what didn't work, and what the pain points experienced were.


More under the cut...

The Doctor | 18 August 2014, 10:00 hours | default | Two comments

What I imagine happens too often.

user@host $:~ man 3 memcpy
What could possibly go wrong?
user@host $:~

The Doctor | 16 August 2014, 22:07 hours | default | No comments

DefCon 22: The Omega of hacker cons.

Back from DefCon 22. Exhausted from the flight home. Lots of stuff to write, need to type up my notes. No pictures of the con due to the "no photography" policy. Unlocked achievement pink mohawked cyberpunk.

Greetings to everyone I met at DefCon this year. Love to old friends, you know who you are. If you're waiting for e-mail from me, please be patient because my inboxes are backed up by thousands of e-mails and I'm patching together some new bots to help me sort through it all. It might be a week.

Let's do this.

The Doctor | 11 August 2014, 20:33 hours | default | Two comments

Lifestyle update.

Not dead. Very busy, getting ready to ship out for work in a couple of days. In rather a lot of pain, too. Doing what I can to manage it.

The Doctor | 04 August 2014, 02:42 hours | default | One comment

Oaklandstuck: Trolls In Black.

I happened to be in the Bay Area with Amberite for the Fourth of July this year, and as we are wont to do we got it into our heads to do a little road testing of some costumes we've been talking about for a while, namely the trolls Sollux Captor and Terezi Pyrope from the webcomic Homestuck playing Men In Black.

If you're not interested in our costuming notes feel free to check out the photographs we took of ourselves or not as you like.

Crossposted to the content category because there are how-to notes after the cut.


More under the cut...

The Doctor | 18 July 2014, 04:13 hours | images, content | No comments

Boat tour of San Francisco Bay.

A couple of weeks ago a group of us from work went on a boat tour of San Francisco Bay after knocking off early. Here are the pictures I took.

The Doctor | 16 July 2014, 10:30 hours | images | No comments

Hardcore Devo - 28 June 2014, Oakland, CA

Earlier this year it was announced that Robert "Bob2" Casale of the band Devo passed away at the age of 61 of heart failure. Shortly after the announcement Devo publicized that they were embarking upon a memorial tour during which they would play lesser known songs from what is known as their hardcore phase which spanned the years 1974.ev through 1977.ev when they still lived, worked, and performed in Akron, Ohio. Even though I'm up to my neck in shipping crates and stuff all over the place I made the time to get tickets for the show at the Fox Theatre in Oakland, California.

The stage was set simply: Movable wall segments upstage painted to resemble cinderblock walls, a bright yellow drum kit at stage right, two sitting chairs, and a bank of synthesizers at stage left. The remaining members of Devo - Josh Freese on drums, Gerald Casale on bass guitar, "Bob1" Mothersbaugh on guitar, and Mark Mothersbaugh playing keyboards took the stage as muzak versions of classic Devo songs faded away. Bob2's absence stuck out like a monkey wrench in a birthday cake as Mark Mothersbaugh sat down behind the keyboard racks, the rest of the band took up their instruments, and Mothersbaugh picked up a newspaper and began to reminisce in an "it's still happening" way about the first half of the 1970's. He spoke through a vocoder as if he'd undergone a laryngectomy and threw packs of candy cigarettes into the crowd. The concert seemed to be set in three acts: When they were first starting out playing in somebody's basement, then when they first took their now highly stylized stage personas by donning pale blue janatorial jumpsuits ("A1 Janitorial Supplies."), and finally when they started to make it big and added surreal transparent plastic face masks to their stage costumes. Near the end of the concert the peculiar and enigmatic Booji Boy took over the show to sing what was described as a "heartfelt" solo piece. At the very end of their show Alex Casale, son of Bob2 took the stage to play second guitar, one of his father's positions on stage. Alex seems to have inherited his father's talent for music because he seamlessly performed the final few songs with the rest of the band. I sincerely hope that he joins Devo but his fate is his own, and I think I speak for all of us when I say that we wish him success and the best of luck in whatver endeavors he undertakes.

Here are the pictures I took during the show.

Duty now for the future, spuds.

The Doctor | 14 July 2014, 10:00 hours | images | No comments

A random USB port in my hotel room.

When I was in DC a couple of weeks ago, I noticed that the lamps in my hotel room had USB ports in them, presumably for plugging in smart devices to recharge in the event that the traveler did not bring a power strip. Most hotels aren't known for offering a surplus of power outlets.

Seeing as how I was back in Washington, DC, called by some The City of Spies, I couldn't help but wonder how such a thing could be used offensively. Let's say I wanted to gig somebody's smartphone with some canned exploits and a malware package. After finding out what room they were staying in I'd wait until they were out and gain access to their room, and then head right for one of those lamps. I'm not the NSA - I don't have a fancy single chip microcomputer that I could solder inline with the USB jack - but I could get hold of a USB host peripheral for a common microcontroller development platform, some storage for my smartphone pwning payload, and build an injector using a readily available development library. The injector is pretty small, maybe a third the size of my phone, and should fit nicely in the base of that lamp instead of the USB charger. There is more room inside them than it would appear from the outside With more development time I could probably get it down to the size of a cigarette lighter, which would leave plenty of room to spare in the base of that lamp. I could probably use the power supply for the USB charger to run my little beastie and supply power to a connected device to boot. Then I'd sit back in the hotel bar a few floors down and let the good times roll.

For the record, I didn't really do this. I opened up the base of the lamp to see if somebody else did (they didn't) because that's how I roll. I might build such a thing one day to see if I could do it, but I wouldn't actually use it on anyone. Instead, I'd see if I could get it accepted as a proof-of-concept at a conference like HOPE or DefCon.

The Doctor | 10 July 2014, 08:00 hours | default | One comment

Like a boss.

I clean up nice if you give me half a chance.

Taken in my hotel room before attending the EPIC Champions of Freedom Awards Dinner on 2 June 2014 in Washington, DC.


More under the cut...

The Doctor | 08 July 2014, 08:00 hours | images | No comments

Some thoughts on Google Glass.

I feel obligated to make the following disclaimer:

Yes, I am still a privacy advocate. I still teach crypto and train people in using privacy-preserving technologies. I also still don't trust any service that I can't kick because data I produce through them is the product and not the service. That said, Google and Google Glass don't seem to be going away anytime soon. So, here are some of my thoughts on Glass.

If you've been bouncing around the consumer electronics set for a while you've undoubtedly heard of Glass, Google's foray into the red-headed stepchild of computer technology for the last few decades, wearable computing. Glass is an astonishingly small and light device that fits comfortably on the earpiece of a pair of eyeglasses with a mass of just 50 grams (about as much as a quarter cup of sugar). As a bit of trivia, the prototype of Glass developed in 2011 reportedly weighed eight pounds. It's a fully self-contained computing device that incorporates a dual-CPU System On A Chip, 1GB of RAM, 16GB of onboard storage, and a unique heads up display that hovers above the wearer's right eye that looks like a translucent 25" display. It runs a standard build of Android on board, so the user doesn't have to link it to a larger device unless there is no wireless network connectivity (Glass is not cellular-enabled). Android is a general purpose operating system so it can do pretty much anything a larger device running Android can do, including run apps from the Google Play store. The inexorable advance of computing technology has solved many of the user interface problems of early wearable devices; Glass sports natural language voice control, head motion tracking, a capacitative touchpad, and can be remotely controlled with an application running on a mobile device if the user desires. It also offers native integration with many of Google's services, from Gmail to Google Search and Maps, which make it ideal as a navigational aid because the necessary information appears in the heads-up display in realtime.

Unsurprisingly the announcement of Glass has spawned a new and fresh kind of controversy, as only things intimately connected with the global Net can. Glass' forward-facing camera and microphone immediately mark it as a potential privacy concern because people in the immediate area don't immediately know if they're being recorded or not. Some people seem to believe that Glass is always recording everything around it and act accordingly. This has resulted in a number of assaults upon the users (though a certain amount of asshattery was involved in some of the altercations (video) (mirror of the video in case it gets taken down)). It's even resulted in some impressive overreactions - in January of 2014 a movie theater run by AMC summoned a team of agents from Federal Protective Services (a field division of the Department of Homeland Security) to detain and interrogate the individual because he was wearing Glass attached to his prescription spectacles. In some ways this backlash is not dissimilar to some of the problems Steven Mann has encountered with his wearable projects over the years. Something I can't help but find interesting is that the attitudes of some of the most vehement anti-Glass protestors don't seem to involve the same amount of vitrol with regard to being recorded while walking down the street, in stores, in bars and clubs, or while traveling in taxis, buses, or trains. But what do I know? Maybe the perceived risk of retaliation is less when one attacks a person rather than an actual problem.


More under the cut...

The Doctor | 07 July 2014, 10:00 hours | default | One comment

Printing memory circuits on paper and the first memristor based computer?

Computer memory chips are manufactured identically to any other kind of integrated circuit. Wafers of ultra-pure silicon are selectively doped, masked with layer after layer of circuit diagrams, etched.. you get the picture. The extreme sensitivity of the process is one of the reasons behind the cost of microprocessors and memory these days. What if, however, there was a less touchy and expensive process? A research team lead by Der-Hsien Lien, a graduate student at the National University of Taiwan in Taipei figured out how to print memory circuitry on paper with an inkjet printer. The team fabricated a form of memory called resistive RAM, which is comprised of resistor/transistor pairs and is non-volatile (when the power is cut, the data doesn't evaporate). First, a piece of paper was screen printed with carbon paste which served as both a substrate and a common electrode. Then the paper was run through an inkjet printer which used a hacked cartridge containing a solution of titanium oxide nanoparticles instead of ink to print a layer of circuitry on top of the carbon layer. Then minute dots of silver were deposited strategically atop the titanium oxide layer (exactly how isn't clear) to form the final layer. The sheet of RAM was then subjected to various functional tests to demonstrate that it did, in fact function in the way rRAM is supposed to. The tests were successful, even after the paper was folded up and retested. Lien's team reports that they were able to fab memory cells 50 micrometers in size, smaller than the end of a human hair but as visible as a speck of dust floating in the air. The printer they used could print a single megabyte of rRAM on an A4 sheet of paper, but a printer with better resolution could hypothetically achieve data densities approaching one gigabyte of storage per page. More elabrate circuitry could probably increase that theoretical information density even farther; time will tell.

A couple of years back an obscure electrical component called a memristor became a topic of research in the field of computer engineering. Memristors work a little like a resistor and a little like a capacitor and hold a charge (representing a bit of data) for extremely long periods of time even after the power's been disconnected. A couple of years ago I wrote an article about HP initiating a research program to make memristors a practical part of computer architecture. Four years later John Sontag (VP, Director of Systems Research at HP Labs) announced that they're developing The Machine, an experimental computing platform that uses memristor-based RAM and novel optical interfaces to the silicon instead of metallic interconnects. The Machine is supposed to use much less power than comparable server-class machines and will boast many terabytes of storage online. They're working on a functional architecture for The Machine (what kind of data goes where and when) and Sontag says they're going to work with the Linux community to figure out how to use it in a practical manner. Very large in-memory data stores are already pretty common today so this doesn't sound too daunting a task, and using RAM as a file system is actually a very old but effective technique. It seems that one of the potential advantages of memristor-based memory is that it could potentially eliminate an entire class of programming problems, namely, determining which parts of a data set need to be cached because they're used heavily and which aren't and can be evicted to free up space. HP plans on offering memristor-based memory modules somewhen around 2016 and The Machine will hopefully be sold as a product three years later. Again, time will tell but they've come amazingly far in so short a period of time.

The Doctor | 30 June 2014, 09:00 hours | default | No comments

Growing human retinas in vitro, patching damaged brains, and imaging an entire brain's activity.

In the journal Nature earlier this month a paper was published by one Dr. Valeria Canto-Soler who works in the field of regenerative medicine at the Wilmer Eye Institute of Johns-Hopkins University. Medical science has gotten pretty good at creating induced pluripotent stem cells, or stem cells which started out as other kinds of human body cells that were hacked to devolve back into pluripotent stem cells which can then be caused to differentiate into other, more specialized kinds of cells. Dr. Canto-Soler and her research team have taken this process to the next logical step: Causing those cultured stem cells to organize themselves into a functional organ, in this case a retina. The stem cells were redifferentiated into retinal progenitor cells which then further transformed into the various sorts of cells that make up a retina, spontaneously arranging themselves in the process. The cultured structure matches the structure of 'natural' retinas, including the seven major types of cells (one of which is actually a family of six different kinds of neurons) which are arranged into multiple interconnected layers. The cultured proto-retina not only has the same general structure and organization as a human retina but even evidences the appropriate behaviors. When the cultured retina reached a developmental stage roughly matching that of a 28 week old embryo it was instrumented with electrodes and deliberately illuminated; the cultured retina showed the bioelectrical activity which one would expect in a human eye. While implanting cultured retinas are still a ways off (we can't yet reliably splice neurons) we now have a working model which can be used to study different diseases of the eye as well as test treatments for them.

For many years it was believed that if the brain was damaged, that was it. Scar tissue might form but neurons were thought not to regenerate. More recently we've learned that this isn't actually the case. Damaged neural networks in the brain and spinal cord are capable of healing, albeit very slowly. Rachel Okolicsanyi of the Institute of Health and Biomedical Innovation at the Queensland Institute of Technology (whew!) is working on manipulating stem cells extracted from bone marrow so that they turn into neural progenitor cells, plug into the damaged neural networks, and differentiate into the appropriate neurons to restore normal functioning. As it turns out, the outer membranes of human cells are coated with patterns of variants of proteins called heparan sulfate proteoglycans which seem to act as chemical receptors that control the inner mechanisms of the cells. Her research involves figuring out what patterns of chemical stimuli are appropriate to get those stem cells to eventually transform into neurons. It's probably going to take a while but I think a lot of useful data is going to come from her experiments; if she accidentally creates cartilage cells, for example, medical science will have a better idea of how to grow cartilage from stem cells on demand. There's a high potential for fringe benefits here. I don't know where her work is at right now, but I'm going to be keeping a sensor net peeled for her work.

In nature there is a species of nematode with the scientific moniker of caenorhabditis elegans which has some interesting qualities that make it ideal for scientific study. It's a relatively complex organism with a fairly simple genetic structure comprised of about 97k 100 million base pairs that has been completely sequenced. They're easy to breed in the lab and have a fairly short life cycle, so there's no shortage of test subjects. They are also surprisingly consistent from specimen to specimen on a cellular level. Every male c.elegans has exactly 1031 cells and every hermaphroditic c.elegans (there don't seem to be purely female versions) has exactly 959 cells. Both have exactly 302 neurons arranged in a simple nervous system consisting of approximately 8000 synaptic connections. All of these things sound like trivia but they also made c.elegans one of the best studied organisms in history. When you combine these things with recent advances in biotech, some very interesting things come about... there is a biomedical technique called optogenetics which involves using genetic modification methods to make certain kinds of cells (usually neurons) sensitive to different frequencies of light; shine a light on them and they fire. Recently a scientific team at Research Institute of Molecular Pathology in Vienna, Austria published a paper which describes how they monitored all of the chemoelectrical activity of c.elegans in one shot, a heretofore unaccomplished feat in medical science. First, a group of c.elegans were bioengineered so that only the nuclei of their neurons would emit light when stimulated with laser light instead of the whole cell (which would make it difficult to see exactly what's going on inside them). A new optical technique called light sculpting had to be created to illuminate the nematode's entire neural network simultaneously to capture a nearly complete picture of the activity 80 times per second. They were able to image about 70% of the total activity of the nematodes' brains with each sample taken, something that has not been done before. The team's imaging equipment can go up to 200 frames per second, which will give a much more finely grained image of what's going on inside the diminutive critter.

Where to go from here? C.elegans is the testbed for this particular imaging technique. Once it's worked out, it seems reasonable to say that it could be applied to successively more complex organisms, gathering data each step of the way, until it can be applied to the most complex organism that we know of at this time - the human race.

The Doctor | 26 June 2014, 10:00 hours | default | Two comments
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