Face mask can detect kidney disease just through breath

By Stephen Beech

A modified face mask can detect kidney disease, just through breath.

Surgical face covers became commonplace during the Covid pandemic in an attempt to stop the spread of airborne bugs.

Now, Italian scientists say a specialized mask could also protect a wearer by detecting potentially deadly health conditions early - including chronic kidney disease (CKD).

They incorporated a specialized breath sensor within the fabric of a standard face mask to detect metabolites associated with CKD.

The results of initial tests, published in the journal ACS Sensors, showed that the sensor correctly identified people with the condition most of the time.

Study co-author Dr. Sergio Bernardini, of the University of Rome Tor Vergata, explained that the kidneys remove waste products made by the body’s metabolic processes.

But in the case of CKD, the organs have become damaged and lose function over time, which can have wide-ranging implications on a person’s well-being.

Millions of people have CKD, and it is believed many more could have the disease without knowing it, possibly at an early stage.

Currently, medical professionals diagnose the condition by measuring metabolites in blood or urine.

But chemical breath sensors are one diagnostic tool currently being examined as an alternative because people with CKD exhale elevated levels of ammonia - a chemical associated with the condition.

Ammonia is also associated with other health conditions.

The Italian team wanted to create a specific sensor that simultaneously detects ammonia and other CKD-related metabolites.

For ease of use, they incorporated the sensor into a surgical face mask.

To create the breath sensor, the researchers first coated silver electrodes with a conductive polymer that is commonly used in chemical sensors.

The polymer was modified with porphyrins - molecules sensitive to volatile compounds - to boost the sensitivity.

Dr. Bernardini said: "The coated electrodes were placed between the layers of a disposable medical face mask, and wires connected the device to an electronic readout.

"When select gases interacted with this specialized polymer, it caused a measurable change of electrical resistance.

"These initial experiments in air confirmed the high sensitivity of the sensor for CKD-related metabolites, including ammonia, ethanol, propanol and acetone."

The modified face masks were then tested on 100 people. Around half of the participants had a CKD diagnosis, while the other half did not.

The sensors detected several compounds in the participants’ breath, and statistical analysis of the data revealed a "clear pattern" distinguishing the participants with CKD from the control group.

The sensor correctly identified when a patient had CKD 84% of the time, and that a patient did not have CKD 88% of the time.

The results also suggest that the sensor data can be used to estimate the stage of CKD.

The researchers say that their findings present the potential for straightforward, non-invasive and cost-effective monitoring of CKD patients.

Dr. Bernardini added: “The implementation of this technology is expected to enhance the management of CKD patients by facilitating the timely identification of changes in disease progression."