Saturday, May 3, 2008

Cell Phones Enable Imaging

Engineers at the University of California, Berkeley have made it possible for cell phones to make medical imaging accessible to billions of people in the world. Boris Rubinsky, UC Berkeley Professor of Bioengineering and Mechanical Engineering, head of the team that developed this new application for cell phones said “more than half of the medical equipment in developing countries is left unused or broken because it is too complicated or expensive to operate and repair.” The World Health Organization reports that three quarters of the world’s population do not have access to ultrasounds, x-rays, magnetic resonance images, and other medical imaging technology.

The National Center for Research Resources at NIH supported the university research along with the Israeli Science Foundation and the Florida Hospital in Orlando.

According to Professor Rubinsky, most medical imaging devices have the data acquisition hardware connected to the patient, image processing software, and a monitor to display the image. When these components are combined into one unit, machine parts often become redundant and this substantially increases the cost of the device.

Professor Rubinsky and his team came up with the idea of physically separating these components so that the processing software used to reconstruct the raw data into a meaningful image can reside at an offsite central location where resources are available operation and maintenance. These offsite central locations would be able to service multiple remote sites where far simpler machines would collect the raw data from the patients.

In developing cell phone technology for use in medical imaging, the researchers used Electrical Impedance Tomography (EIT) which is based upon the principle that diseased tissue transmits electrical currents differently than healthy tissues. These electric current differences in resistance can then be translated into an image.

In use, the cell phone would be hooked up to a data acquisition device to transmit the raw data to the central server where the information would be used to create an image. The server would then relay the image back to the cell phone, where it would be viewed on the cell phone’s screen. Using the cell phone significantly lowers the cost of medical imaging because the apparatus at the patient site is simplified and highly trained personnel in imaging processing do not have to be available.

The data acquisition device can be made with off-the-shelf parts that people with basic technical training can operate. The device that the research team built was a simple data acquisition device with 32 stainless steel electrodes for the experiment. Half of the electrodes were used to inject the electrical current and the other half of the electrodes were used to measure the voltage. A total of 225 voltage measurements were taken and uploaded to a cell phone which was hooked up to the device with a USB cable.

This system can work with any cell phone capable of sending and receiving multimedia messages such as graphics, video, and audio clips. As for the concern about dropped calls, the researchers say that there is no medical application that would not allow the user to redial a line.

This new technique for medical imaging is described in the April 30 issue of the peer-reviewed, open-access journal, Public Library of Science ONE (PloS ONE).