Bench Press

Like my fellow Bench Press blogger Ben, I’m a fairly avid Star Trek fan. Having spent many hours during my formative years watching syndicated episodes I always wondered if we’d ever have some of the amazing devices in the show. One of the devices that captured my imagination was the Tricorder (pictured right). It amazed me that such a tiny device could provide so much utility throughout the show. The Tricorder’s versatility allowed it to do pretty much anything in the show, but what I always remembered was it’s medical utility. It allowed characters like “the Doctor” to analyze any number of ailments quickly and accurately.

While we don’t have the technology to make a Tricorder as effective as the ones used in Star Trek, the U.S. Department of Homeland Security’s Science and Technology Directorate (S&T) is developing a tool called the Standoff Patient Triage Tool (SPTT). The purpose of the SPTT is to aid first responders at a disaster triage patients quickly and accurately. Triaging patients with traditional methods can take 3-5 minutes per person. This can become an extremely difficult and time intensive task during a disaster, exactly the opposite of what we’d like. Therefore, the goal of the SPTT is to reduce triage time to 30 seconds per patient by providing accurate readings of pulse, body temperature, and respiration from up to twenty paces away all in a portable package about the size of a legal notebook.

A drawing of the proposed 15 inch by 8.5 inch x 6 inch Standoff Patient Triage Tool (SPTT) with the following features. 1) 4 x 6 display window; 2) Control button; 3) Infrared camera window; 4) Visible camera window; 5) Ranging subassembly window; 6) Shock bumpers. (Source: DHS S&T)

The SPTT takes advantage of Laser Doppler Vibrometry (LDV) in conjunction with a visual and infrared camera to make it’s readings. LDV takes advantage of the doppler shift produced when a laser bounces off a moving target. The shift in frequency upon return of the laser beam is measured and then analyzed in order to determine the velocity over time of the target. In this case, the SPTT’s vibrometer detects the movement of blood vessels and utilizes algorithms to extrapolate relevant data. So far researchers have found that the SPTT can produce strong readings from the head, chest, abdomen and foot. Currently, taking readings from the cartoid artery region of the neck appears to be the best option. Further testing needs to be done on patients in awkward positions, as well as with differing layers of clothing.

While the SPTT can’t do everything a tricorder can do, it appears to be taking a great first step in providing a portable device capable of providing first responders with accurate job critical data that will help them save lives. Maybe it’s only a matter of time before doctors start waving a small device around the patients while asking them what brings them into the office that day.

(Image Source)(DHS S&T Press Release)

My favorite character on Star Trek Voyager is “the Doctor” (pictured on the left and portrayed by the very talented Robert Picardo), who despite being “merely” a computer program was able to diagnose and treat nearly any medical ailment. The best part about him was that, because he was “merely” a hologram, he was portable and able to travel through the harshest environments and across any terrain.

While I’m pretty sure we still have years to go before we start being treated by medical holograms with Robert Picardo’s sense of style and humor, the portability of diagnosis is something which we may have just taken one large step closer towards. Christine Keating’s group at Pennsylvania State University has just developed what I’ve dubbed a “Doctor-on-a-Chip” (or DoC, after all system-on-a-chip’s are called SoCs by the semiconductor industry) which have the capability to detect any number of viral pathogens on a single computer chip.

Keating and her colleagues developed a means of coating a chip with nanowires (small wires 8 micrometers long and 300 nanometers in diameter) coated with DNA strands complementary to viral genomes (so that they will bind to viral DNA/RNA if given a chance). But, instead of haphazardly coating the chip, Keating’s group was able to develop a precise, targeted method, employing electrical fields to position the nanowires to exactly where the researchers wanted them (here’s a video showing how the method works).

The picture to the left is almost kind of eerie to me in its precision, much like one would expect on a chip fabbed by Intel or IBM (or Affymetrix) which uses photolithography rather than through electrophoresis.

Impressive to say the least, but the big question remained – does it work? To test this, Keating’s group incubated the chip with suspensions of fluorescently tagged viral DNA fragments complementary to the DNA strands on the nanowires, removed the suspension, and then subjected the chip to fluorescence. What would the result be? Would one see fluorescence organized neatly in the same rows that the nanowires were deposited? Or would there be diffuse or no fluorescence, suggesting nothing at all?

See for yourself:

So, do we have a DoC in the making? Jury’s still out – as we have yet to see if this method can be scaled up, or if its even applicable in a medical setting where time is short, accuracy needs to be very high, and the ability to run controlled samples (e.g. long DNA binding period with perfect fluorescently-labeled viral DNA fragments) is hindered. But, the Keating group is already hard at work creating electrical leads which will enable a faster (and potentially more quantitative) read process for detection.

And who knows, in a few years, this may end up looking like Robert Picardo.

(Image source – Doctor) (remainder of images come from Penn State University public image archive)

Morrow, T. Li, M. Kim, J. Mayer, T. Keating, C; Programmed Assembly of DNA-Coated Nanowire Devices; Science 16 January 2009: Vol. 323. no. 5912, p. 352 DOI: 10.1126/science.1165921