provided by: 
It sounds like something from a science fiction novel—swallowing a pill that has tiny cameras in it to diagnose diseases of the esophagus. But thanks to advancements in technology it has become reality.
The desire to explore the relatively inaccessible area of the esophagus and small intestine led to the development of an ingestible miniature camera. Video capsule endoscopy provides visualization of the esophagus and GI tract by transmitting images wirelessly from a disposable capsule to a data recorder worn by the patient.
Given Imaging Ltd. (Yoqneam, Israel) manufactures the PillCam SB, which evaluates the small intestine and the PillCam ESO for the esophagus. Another capsule system has been release by Olympus in Europe and is nearing clearance and release in the United States.
About the size of a large vitamin pill, these tiny imaging systems eliminate the need for costly, invasive procedures used to diagnose and evaluate diseases of the esophagus, small intestine and GI tract.
After Micron Technology, Inc. (Boise, Idaho) acquired Photobyte, a custom imaging product company, they disbanded most of the projects that had been in the pipeline except for a solid few. One project that they maintained was the disposable capsule project from Given Imaging. "Micron looked at the market segments and opportunities and we had the tiger by the tail with this one," said Paul Gallagher, director of market development for Micron. "The simplicity of architecture that Given had developed and the simplicity of the usage models for the doctors, which translated also in significantly reduced price points for the insurance company made it a winner all around."
When the sensors for the disposable medical capsule were being developed space constraints limited the pixel and lens technology. The focus was then on shrinking the pixels. "We recently developed a 1.75 micron pixel CMOS image sensors," said Gallagher. "The benefit to pixel shrink is that we are improving the low noise performance of the sensor as well. We are trying to achieve a scale where we reduce the top end by a certain percent so we can reduce the noise scale by the same percent so we can maintain a high dynamic range. We are starting to run into the problems of physics and light where the pixels are so tiny that light isn't imaging well. There needs to be a significant breakthrough. The evolution of pixel shrink will have to be replaced by a revolutionary approach."
Gallagher noted that as the pixel size shrinks, it opens up a lot of opportunities across a wide spectrum of medical devices. "The potential for changing other more traditional medical imaging applications to a disposable method would significantly reduce the potential for cross contamination and well as reduce the cost," he said. "We are right on the front end of a monstrous opportunity."
"This technology changes the way everyone does things," said Dr. Glenn Eisen, Associate Professor of Medicine, Division of Gastroenterology, at Oregon Health and Science University. Eisen has had significant amount of experience working with capsule and has been lead investigator in studies with the PillCam ESO. "These alternative methods are a good choice for patients who cannot tolerate sedation. This is a reasonable alternative to the traditional endoscopies. It will widen the field of what kind of physicians can do these tests. It may permeate into primary care, not just reserved for gastroenterologists."
Eisen is also testing a new capsule device as an alternative to colonoscopies. "With every modification of the capsule device we will see longer battery times, wider field of views and improved optics," he said. "This is in the process of altering how we practice medicine."
PillCam™ SB capsule weighs 3.7 g and measures 11mm in diameter and 26 mm in length. The contents include a complementary metal oxide silicon (CMOS) chip camera, a short focal length lens, 6 white LED illumination sources, 2 silver oxide batteries and a UHF band radio telemetry transmitter. Image features include a 140 degree field of view, 1:8 magnification. 1 to 30 mm depth of view, and a minimum size detection of about 0.1 mm. The capsule is activated by removal from a magnetic holder and provides image accrual and transmission at a frequency of 2 frames per second until the battery expires. The capsule is passively propelled through the intestine by peristalsis while transmitting color images at 256 x 256 pixels with a transmission frequency of 431.1 MHz.
The advanced PillCam SB will acquire 4 FPS and have an increased operational time.
The PillCam ESO is used in esophageal applications and is similar to the SB capsule.
The PillCam ESO cameras transmit 14 color images per second as the capsule moves through the esophagus. The system transmits about 2,600 images of the esophagus to the recording device worn by the patient. Data is then transferred from the recorder belt to the RAPID® workstation used for editing, viewing, archiving and e-mailing the video images. Total procedure takes about 20 minutes. The PillCam is then naturally passed through the GI tract and then painlessly through the body in 24 to 72 hours.
This system is a non invasive alterative to the traditional endoscopy which involves sedation and significant recovery time.
Given Imaging received clearance from the FDA in June 2006 for RAPID® Access RT, a handheld device that enables real-time viewing during a PillCam endoscopy procedure and RAPID® Access, the software installed on the device. RAPID Access allows physicians to remotely initialize a DataRecorder to administer the PillCam video capsules to patients at satellite sites. Data can then be sent to a central location for processing and interpretation.
author: By Stacey Meacham, Managing Editor - Advanced Imaging