Measurement system of electrical impedance of human tissues

Data di pubblicazione






Data di priorità



International PCT patent application


Politecnico di Milano


Department of Electronics, Information and Bioengineering


Andrea Aliverti, Davide Meroni, Dario Bovio, Camilla Carpano Maglioli, Emanuele Meroni


The quantitative assessment of electrical properties of tissues represents a useful tool to improve the accuracy of current methods for cancer diagnosis. As evidenced, different tissue types exhibit different conductivity parameters and, supposing that the presence of a neoplastic tissue alters this structure, the difference in the electrical properties of normal and cancerous tissues can be a useful clinical information. The invention consists of a device that combines in-depth Electrical Impedance Spectroscopy (EIS) and Tomography (EIT) for the electrical discrimination and characterization of small in-vivo tissue areas, along a wide spectrum of frequencies. This device is able to perform a four-terminal sensing of the modulus and phase of the complex impedance of the tissue under examination in the frequency range 1 - 100 kHz. This allows to obtain an impedance map based on the conductivity contrast within heterogeneous biological tissues. The data acquisition can be carried out using a probe with 4- needles or 8-needles electrodes. This probe could be used during biopsy procedures (performed under fluoroscopic and/or endoscopic guidance) in order to improve diagnostic yield by choosing the most appropriate area for puncture.

Campo di applicazione

The main application field of this device is the diagnosis of cancer tissues. The measure of the structural homogeneity of the tissues and the visualization of the impedance maps allow to precisely analyze the area of interest defining the boundaries of the cancer region; this can be helpful in several diagnostic applications, including laparoscopic, endoscopic, and radiological procedures.


Differently from other devices for in vivo measurement of the impedance, which are able just to analyze the surface and the first layer of tissue, the proposed analyzer can provide a very detailed analysis of the whole tissue under investigation. By adjusting the needle length, the measuring region can reach the central core of the analyzed tissue. Furthermore, for the first time a four-electrode bio-impedance device is coupled to an EIT system in a single device, to take advantages from both technologies.

Stadio di sviluppo

Working Prototype.