An excerpt from my book The End of Medicine: CAVE
I was still chuckling
when I stepped off the elevator on the sixth floor of Rhodes Hall. I followed
signs for the CAVE - Computer Assisted Virtual Environment. The demo sounded
good in the activities description, but it was past three and my interest was
fading. I was due to meet friends at Ruloffs for bloodies. The door was closed,
and as I opened it slightly, the room was mostly dark and thirty or so people
were sitting around wearing funny looking oversized glasses. I spied an empty
seat in the front row, tripped over a couple from the Class of '55 and sat down,
almost crushing a pair of those glasses.
"You want to wear those. You won't get the 3D effect from that end." The voice came from a guy with a bizarre looking headset and a short Harry Potter like wand attached to a cord. He was standing on a 10 foot by 10 foot floor, and in front of two more 10 foot by 10 foot walls - three faces of a cube.
I'll remind you, these glasses are liquid
crystal shutters, synched up to the display. We calculate and display images for
your left eye and block out your right, and then every 60th of a
second flip over, display images for your right eye and block out the left. No
more of the red and green glasses from the '50's."
The couple next to me nodded to each other and I thought I heard him whisper, "like at the drive-in, darling."
"As you can see, I can pull up menus in the CAVE, move them around, and click on what I want with this wand. But the really cool stuff is visualizing stuff. Here, let me pull up my favorite. OK, if you have ever been to Florence, you probably waited on line to see Michaelangelo's David. During it's recent restoration, …, cleaning really, they let in some Stanford researchers to do a 3D capture of David over a 30 day period, head to toe, tip to stern." Mrs. Class of '55 started giggling. "A set of lasers scanned the entire sculpture, digitizing every nook and cranny and crack." More giggles. "We cut a friendly deal and were able to obtain the very large data set - the Digital David."
"We've got a whole bunch of Windows PCs just above our
heads - Microsoft is one of the benefactors of our work. These machines crank
away, calculating how every one of the pixels should be displayed for your left
and then right eye. Here, let me show you…cue the drumroll."
In a flash, spread across both walls and the floor was David's head, curly hair, adam's apple and all. Better yet, it was being rotate around, zoomed in on. I've seen lots of 3D demos, studied ray tracing and z-planes, invested in 3D chip companies, and I was completely floored by the beauty of David sparking on the walls of a 10 foot cube.
"This is a PG show, so we are sticking with just the neck up view. Your looking at piece of a couple of billion pixels, probably now about million plus polygons, each accurate down to 2 millimeters, which is why I am able to zoom in so closely - let's look up his nostrils - there you are. Now, let's back off a bit. Here is something you probably didn't notice if you saw David in Florence. He's a bit cross-eyed. His eyes are looking in two different directions."
I'll be damned. Sure enough, one was looking right at me, and the other at Mrs. Class of '55.
"Of course, we only can capture the surface of the sculpture. It's solid marble. The way light diffuses and reflects off the marble is also lost, so we get this dull gray look, but it serves its purpose. Now, you'll notice when I turn him upside down that the model represents David hollow, assuming his skin is, oh I don't know, a centimeter thick. Saves time on calculations. But, it also let's us do something fun. It takes some gymnastics up here, but I can usually pull this off, bear with me.
The guy in the funny helmet spun his wand in a circle, which caused the head to rotate around, so we were looking at the back of David's head. Then he squatted down, looked up, and raised the wand above his head. The effect was to look up into David's skull from the hole in his neck. You could see the waves in his hair from the inside. Quite cool. But then, the wand was lowered and we were inside David's head, what basically felt as if your nose was David's nose and you were looking out his eyes.
"OK, now if I click to lock in this perspective - ah, there we are, done. Now, I am David, fetch me a slingshot, I feel strong enough to slay giants today. Let's look around."
He turned his left and right, up and down and David's inside out view changed - you felt as if you were King David sizing up your opponent. Then the screen went blank.
"OK, enough of this fun stuff, let me show you what this technology is really used for." Click, click, click.
On the walls flashed what looked like a set of Tinker Toys my 10th grade chemistry teacher used to play with. Colored balls and lines or double lines between them."
"This is the model of glucose - just to show you we can represent macromolecular structures in 3D. This is the killer app for pharmaceutical and biotech companies. Here, let me bring up the model of a tumor cell - a bit more complex.
The screens got really messy, colored balls and lines flying all over the place.
"We can look at this a lot of different ways. We can do 3D images constructed using the 3D-iso-surface module. We process them in Metamorph by low pass filtering, and then do multi-thresholding to segment the image volume and distance transform applied to create concentric shells of the cell."
"You are probably all saying 'Huh?' Here is the punchline. A scientist can study these models and then invent proteins that fit perfectly into the shape and folds of the cancer cell. This is called rational drug design and promises to bring all sorts of miracle cures. In fact, there is a company in Massachusetts…"
I heard some fidgeting next to me and Mr. Class of '55 was mumbling under his breath, "Rational drug design is about as real as the Tooth Fairy. Doris, let's go. It's time for bloodies at Ruloffs."
For the first time, I figured out where this was all going. I learned that Computed Tomography, CT scans, were advancing like flash memory, one slice per rotation to four, 16 and now 64 slice machines. Recognize those numbers? Next year we'll see 256 slice CT scanners and high-res 3D images of the human heart, captured in one tenth of a second. The Silicon Valley learning curve is about to invade medicine. This ought to be fun to watch.