Editor's note: "Palm Readings" appeared in our Sept. print issue. The article, written by ADVANCE's Mike Gibbons, explores the now common use of handheld devices in radiology, with caution by some experts in the field. Read the original, and below--a complement--that explores iPAD-specific apps and the device as a viewer.
Apple Inc. has had a tremendous impact on my life. My first "real" computer was a Macintosh Plus, and I've finally returned to the Mac fold with the purchase of a MacBook Pro i7. I'm on my second iPhone, and my kids have gone through a plethora of iPods. Apple wasn't the first company to sell any of these things, but they now own the mobile music market, as well as a huge chunk of the smartphone arena. The Macintosh returned from near-death to account for 10 percent of computer sales in the U.S.1
A new Apple product is newsworthy, and the company plays its mystique to the hilt, dropping just enough hints on the upcoming toy to keep us waiting anxiously. By the time the iPad was officially announced on Jan. 27, we mostly knew what to expect--a tablet computer based on the iPhone operating system. And that's what we got--but there's more here than meets the eye.
In the beginning
Indulge me in a historical aside. The iPad isn't Apple's first foray into tablet computers. Ever heard of the Newton? I had one, back in 1994. It didn't work very well.
Did you know that there was another tablet-computer/personal communicator in Apple's pipeline way back when? In the early days of the Newton development project, Apple had two teams developing portable personal computing devices. Pocket Crystal was meant to be the portable mobile device, and the Newton was originally positioned as a somewhat larger tablet. Eventually, Apple had to decide which to run with, and the Newton won.
Pocket Crystal was spun off as a separate company called General Magic, which commercialized its Magic Cap operating system. The early versions suffered from a memory leak problem; by the time the bug was squashed, its credibility had been damaged irreparably.2
Features and dimensions
For those who have spent most of 2010 in a cave--or at least without broadband (which is tantamount to living in a cave)--the iPad is a wafer-thin computer with a brilliant color screen, a "Home" button on the front, volume control, a power switch, an orientation-lock switch and an earphone jack on the sides. The form factor, screen and Multi-Touch input are the iPad's key features. From Apple.com:
The Multi-Touch screen on iPad is based on the same revolutionary technology on iPhone. But the technology has been completely reengineered for the larger iPad surface, making it extremely precise and responsive. So whether you're zooming in on a map, flicking through your photos, or deleting an e-mail, iPad responds with incredible accuracy. And it does just what you want it to.
One of the first things you'll notice about iPad is how thin and light it is. The screen is 9.7 inches measured diagonally. So overall, it's slightly smaller than a magazine. At just 1.5 pounds and 0.5 inch thin, you can use it anywhere. And a slight curve to the back makes it easy to pick up and comfortable to hold.3
The 242.8 mm (9.56 inches) (height) x 189.7 mm (7.47 inches) (width) x 13.4 mm (0.53 inches) (thickness) machine will apparently fit into a pocket of a white coat, but just barely. Perhaps bib overalls (but in white) with the large pocket in the front would better suit the iPad-carrying physician?
The iPad's A4 processor runs at 1GHz (although Apple won't confirm this), and it has 256 MB of DRAM built onto the processor housing. The user can choose 16, 32 or 64 GB of flash memory for storing music, pictures, videos and, of course, applications.
The iPad screen has a rather remarkable resolution for its size, with 1024 x 768 pixels (XGA) and a 4:3 aspect ratio; measures 9.7 inches (25 cm) diagonally; and has an LED backlight. (Contrast this with the new iPhone 4 screen, which, at 326 pixels per inch, has supposedly more pixels than the human retina can see, and a resolution of 960 x 640.) Is the iPad screen adequate for diagnostic reads--at least for digital, cross-sectional imaging? Yes, according to Stephan Popp, CEO of aycan Digital:
We at aycan have measured the iPad display according to the DIN V 6868-57:2001-02 (Consistency and uniformity testing for medical displays) ... The iPad exceeds the values for medical displays category A (suitable for all kind of medical images, except mammography).4
- Luminance (min): 1,88 cd/m2
- Luminance (max): 363 cd/m2
- Contrast ratio: 193:1
- Ls: 0.33 cd/m2 (display turned off, luminance of the ambient light on the display)
This information differed from numbers quoted in an AuntMinnie.com article:
(T)he iPad has a maximum luminance of 270 cd/m2, which, while higher than the average of 150-200 cd/m2 seen in off-the-shelf displays, is much lower than your average primary interpretation display, which has an average maximum luminance of 500-600 cd/m2. The iPad's minimum luminance is 0.3 cd/m2, which yields a still-impressive contrast ratio of 900:1 for a portable device.5