New Technology Tracks Blood Sodium Without Needles, Says Study

A group of scientists has developed a new way to check sodium levels in the blood—without using a needle. This breakthrough could lead to faster, safer, and more comfortable health checks, especially for people with conditions that require constant monitoring.

A Non-Invasive Approach

The research team used a special combination of terahertz radiation and optoacoustic technology. This allowed them to measure sodium levels through the skin without drawing blood. Unlike traditional methods, this technique avoids interference from water in the body and gives results in real time.

Monitoring sodium is very important in treating health problems like dehydration, kidney disorders, and hormonal imbalances. Until now, getting these levels required blood tests.

Why Terahertz Radiation Works

Terahertz radiation lies between microwaves and infrared light on the electromagnetic spectrum. It's safe for human tissues, doesn’t scatter much, and can detect changes in biological materials. But using it in medical settings has been tricky. It struggles to measure anything other than water and has trouble reaching deep into the body.

To solve this, researchers added optoacoustic detection. According to lead researcher Zhen Tian from Tianjin University in China, this adjustment helped them detect sodium ions inside the body for the first time using terahertz waves.

Successful Animal and Human Tests

In tests on live mice, the system tracked sodium changes in blood vessels just under the skin. Measurements taken from the ears lasted over 30 minutes and could detect sodium shifts in milliseconds. Early trials on humans also showed encouraging results. In one test, the device could tell the difference between high and low sodium levels in human blood without skin cooling.

What Comes Next

The team is now working to improve the system for human use. One idea is to take readings from areas like inside the mouth, where cooling is easier. They’re also trying to develop new ways to reduce water interference without using cold temperatures. This technology could soon allow doctors to check sodium levels in patients instantly—without a single drop of blood.