Tiny cameras, big impression

If you’ve ever been to an ear, nose and throat (ENT) specialist to check out a sinus problem, you know there’s no such thing as a small camera—not when it’s going up your nose. Even at half the diameter of a pen, the flexible endoscope used by a physician exploring your sinus cavity can leave a huge impression on your psyche.

Now, however, there’s a company touting the world’s smallest camera, albeit for use with an endoscope. It’s said to have a diameter of just 0.99mm.

Here’s a quick frame of reference: At that size, the camera could fit through the head of a sewing needle, that is, if you’re good at threading a needle.

Or, to put it another way, the camera is just a bit smaller in diameter than the tip of a pen.

Shown next to the tip of a pen and a dime, the tiny camera (bottom) is considered the smallest in the world—just 0.99mm in diameter. Photo courtesy Medigus.

The new disposable endoscope is from Medigus Ltd., a medical device manufacturer based in Omer, Israel.

Medigus credits through-silicon-via (TSV) technology with allowing it to break the 1mm-diameter barrier for its line of video endoscopic devices. What’s more, the TSV process reduces manufacturing costs enough to make the camera suitable for one-time use. Free of associated sterilization costs, the disposable cameras come with a dedicated 0.66mm × 0.66mm CMOS (complementary metal-oxide semiconductor) sensor that provides an image resolution of 45,000 pixels.

Medigus projects that the global miniature camera market for disposable endoscopic devices will grow from about 4 million units in 2011 to about 7 million units in 2015.

The disposable endoscopes include a camera composed of a lens and a sensor that transforms the image into electrical signals. The endoscopes are used in medical fields such as cardiology, orthopedics, gastroenterology, gynecology, ENT, bronchoscopy and robotic surgery.

The 0.99mm camera will be integrated into endoscopic devices manufactured by Medigus and third-party manufacturers, according to the company. Among the first to get the cameras will be U.S. and Japanese companies that produce cardiology devices.

Heralded as the smallest camera in the world just a few short weeks before the Medigus announcement, this Awaiba camera is said to be about the size of a grain of salt—1mm in diameter. Photo courtesy Awaiba GmbH.

Meanwhile, a 1mm × 1mm × 1mm camera with an image resolution of 62,500 pixels also is headed for the disposable endoscopic device market. It is based on a manufacturing breakthrough developed by the Fraunhofer Institute for Reliability and Microintegration, Berlin, together with medical device maker Awaiba GmbH, Nürnberg, Germany, and the Fraunhofer Institute for Applied Optics and Precision Engineering, Jena, Germany.

The key to the new process is the way electrical contacts are attached to each image sensor—simultaneously with all sensors while they are still connected as a wafer. This allows a lens wafer to be mounted on top and only then is the stack cut into individual micro cameras, rather than cutting out each camera first and connecting the electrical contacts to the image sensor via the side of the chip one device at a time.

The current manufacturing process for such digital cameras places the electrical contacts that allow access to the image signals between the lens and the image sensor, which is made in large numbers like computer chips. “Think of a book full of postage stamps,” said Martin Wilke, a Fraunhofer scientist. “Many thousands of stamps are printed in one step, [but] if you want to use them, you have to separate one from another.”

About 28,000 image sensors can be produced on one silicon wafer, Wilke said, adding that each one has to be cut out, wired and mounted on a lens attached later.

The Fraunhofer/Awaiba technology streamlines that process by providing a new way to access the electrical contacts.

Besides endoscopes, the new micro cameras may find use in the automotive industry, according to Stephan Voltz, Awaiba’s CEO. R&D efforts are under way to determine whether the tiny cameras can replace rearview mirrors on cars. Another use could be detecting eye movement to help prevent drivers from falling asleep at the wheel. Of course, if you happen to be driving to your next colonoscopy, there’s little chance of that.

As welcome as these new micro cameras will be to patients facing such an exam, an even less invasive endoscope is on the way. Japanese researchers recently unveiled a swallowable, pill-size device that can capture images throughout the digestive system—including the small intestines, where obtaining images has proven difficult with existing technologies. Though capsule-type endoscopes are not new, the device developed by researchers from Japan’s Ryukoku University and the Osaka Medical College is the first capable of being driven like a submarine via remote control.

At about 1cm in diameter and 4.5cm in length, the new remote-controlled endoscope includes a battery that can last up to 10 hours—more than enough time to image a person’s entire digestive tract. The main risk with capsule-type endoscopes, according to the Mayo Clinic, Rochester, Minn., is that 1 in 100, shall we say, require assistance upon exiting.

Whether or not the remote-controlled capsule makes it to market, the ever-shrinking size of endoscopes—along with an estimated cost of “a few euros” each—suggests that the micro cameras will be much easier on the senses the next time you visit your ENT or gastroenterologist. And in the end, that’s all that matters. µ