Lausanne: A portable device can detect the presence of certain types of cancer in people's breath. Tested on patients, the new device was developed in part by EPFL researchers as part of an international collaboration. Inhale, then exhale. This simple act could now save lives. A technology developed in part at EPFL can quickly identify the presence of a head and neck cancer, such as of the throat or mouth by analysing people's breath. The new device, equipped with extremely sensitive sensors, has been tested on patients and operates with a computer or even a mobile phone. It's an innovative tool for the early diagnosis of tumours. Very few routine exams exist to detect cancer. Yet this disease is the third leading cause of death worldwide. Most tumours are found relatively late, which makes recovery less likely.
Cancer "signals" its presence in human breath
At SAMLAB in Neuchâtel, under the direction of Nico de Rooij, a team of
researchers including Frédéric Loizeau, a doctoral student at the time,
developed very precise micro-sensors able to distinguish the breath of a
healthy patient from that of a sick one. The scientists' starting point
was the observation that human breath contains not only air, but also
hundreds of volatile organic compounds (VOCs) whose presence and
concentration vary depending on the patients' state of health. The
metabolism of cancerous cells is different from that of healthy cells,
and the two types of cells produce different substances in terms of both
quantity and typology. As a result, they leave their "signature" in
researchers managed to detect these nuances with the aid of a network
of micro-sensors. The technology called MSS was initially developed
jointly by EPFL researcher and the late 1986 co-laureate of the Nobel
price of physics, Heinrich Rohrer. Each sensor is composed of a silicon
disk 500 micrometres in diameter that is covered by a polymer and
suspended by four minuscule "bridges" with integrated piezoresistors.
When exposed to a gas, the polymer absorbs certain molecules and the
disk changes shape. This deformation is detected by the four
piezoresistive bridges, which emit an electrical signal. This phenomenon
makes it possible to determine the signature of the gas and its
concentration. The trick lies in using different polymers on each
sensor, in order to obtain an overview of the gas composition.
"There are already methods for detecting molecules called ‘electronic
noses' on the market. But they have a hard time analysing very complex
gases like human breath," says Nico de Rooij. "Humidity in particular
can disrupt the reading, leading to false positives or false negatives."
With the new sensors, the detection process becomes extremely accurate.
Clinical tests on healthy and sick patients
With the collaboration of the Swiss Nanoscience Institute of the
University of Basel, the EPFL researchers were able to test their device
on actual patients from the University Hospital of Lausanne (Centre
hospitalier universitaire vaudois, CHUV) who were either sick or had
undergone surgical treatment for head and neck cancer. The results of
these tests showed that the sensors were incredibly effective. A
Neuchâtel-based company has already expressed interest in marketing this
technology, which has been patented.
Breathe into your smartphone
But the story doesn't end there for the sensors, which have numerous
applications. Recently, the NIMS/MANA research centre in Japan, another
partner in the project, connected the sensors to mobile phones. This
innovation earned them an award at the Nanotech 2015 event.
technology is also of interest to biologists. At the University of
Neuchâtel, tests are currently being run by the Laboratoire pour la
recherche fondamentale et appliquée en écologie chimique in order to
analyse the gases given off by plants when they are attacked by certain
insects or mushrooms. These gases serve to attract other insects that
will protect the plant. The ability to detect this phenomenon early on
could allow farmers to react more quickly to an attack and, as a result,
use less insecticide.
More pictures of the prototype HERE