A new concept for medical imaging centered on cellular phone technology

Abstract

According to World Health Organization reports, some three quarters of the world population does not have access to medical imaging. In addition, in developing countries over 50% of medical equipment that is available is not being used because it is too sophisticated or in disrepair or because the health personnel are not trained to use it. The goal of this study is to introduce and demonstrate the feasibility of a new concept in medical imaging that is centered on cellular phone technology and which may provide a solution to medical imaging in underserved areas. The new system replaces the conventional stand-alone medical imaging device with a new medical imaging system made of two independent components connected through cellular phone technology. The independent units are: a) a data acquisition device (DAD) at a remote patient site that is simple, with limited controls and no image display capability and b) an advanced image reconstruction and hardware control multiserver unit at a central site. The cellular phone technology transmits unprocessed raw data from the patient site DAD and receives and displays the processed image from the central site. (This is different from conventional telemedicine where the image reconstruction and control is at the patient site and telecommunication is used to transmit processed images from the patient site). The primary goal of this study is to demonstrate that the cellular phone technology can function in the proposed mode. The feasibility of the concept is demonstrated using a new frequency division multiplexing electrical impedance tomography system, which we have developed for dynamic medical imaging, as the medical imaging modality. The system is used to image through a cellular phone a simulation of breast cancer tumors in a medical imaging diagnostic mode and to image minimally invasive tissue ablation with irreversible electroporation in a medical imaging interventional mode.

Figure 1. System configuration for the breast cancer tumors patient self-test screening.

Outlined arrows indicate optional reporting of results to the patient.

Figure 2. Schematic representation of the Frequency-Division Multiplexing EIT technique that has been employed for the proof-of-concept system (only 16 electrodes out of the actual 32 electrodes are shown for clarity).

Seven AC currents (at different frequencies) are injected simultaneously. Signals from voltage electrodes (V1 to V8) are connected to an analogue multiplexer (see Figure 3).

Figure 3. DAD architecture of the proof-of-concept system.

The gray shaded area contains the elements that were implemented on a single printed circuit board: a microcontroller (not shown) reads incoming commands from the computer (through the RS-232 connection) and, according to these commands, manages the digital control lines of the analog multiplexers (MUX 1∶15 and MUX 2∶16).

Figure 4. Minimally invasive surgery example.

a) The DAD of the system with two types of gel representing an area treated with irreversible electroporation, marked in red, surrounded by normal tissue. b) Reconstructed result as it was displayed on the screen of a commercial cellular phone. Warm colors represent higher conductivity regions that denote an electroporated area.

Figure 5. Breast cancer detection example.

a) The DAD of the system with two types of gel representing a breast cancer tumor surrounded by normal breast tissue. b) Reconstructed result as it was displayed on the screen of a commercial cellular phone. Warm colors represent higher conductivity regions that are typical of breast cancer lesions.