European scientists have developed an implant that can monitor a patient’s blood levels of glucose, lactate, and more for six weeks at a time.

Frequent trips to the doctor for blood tests can be annoying and time-consuming. But the growing trend toward personalized, at-home healthcare might make it possible to perform these tests outside the doctor’s office.

In a new study presented at Europe’s largest electronics conference, DATE 13, scientists demonstrate that a tiny, portable, and personal blood-testing laboratory implanted just beneath the skin can analyze the concentration of certain substances in the blood and then transmit the results directly to a doctor’s computer or smartphone.

According to the study press release, this method allows for “a much more personalized level of care than traditional blood tests,” and also helps health care providers keep a close eye on patients with chronic illness and those undergoing chemotherapy. While the prototype is still in the experimental stages, scientists have successfully demonstrated the device’s ability to detect up to five proteins and organic acids in the blood simultaneously.

“This device enables telemedicine as well as personalized medicine, which are two of the major trends in healthcare,” said lead researcher Giovanni De Micheli of the EPFL in an interview with Healthline. “Doctors and hospitals will have a continuous updates on a computer screen of the status. Any alarming record will trigger a corrective action. Some routine visits will be eliminated.”

The cylindrical implant measures about 14 millimeters long and contains five sensors, a coil for wireless power, and miniaturized electronics for radio communication. A battery patch outside the body continuously provides a tenth of a watt of power through the patient’s skin.

“A patient will go to a healthcare provider where the chip will be inserted with a syringe. This is a [common] practice,” De Micheli said. “The patient will put a smart patch over the skin and a telephone in their pocket. The patch will automatically receive data from the implant and transmit it to the telephone.”

In other words, the patch collects and sends data to the doctor over an existing cellular network. Testing can be done continuously, without the need to visit a clinic, De Micheli said.

“There is no need to remember to do a test,” he said. “The test is done on a scheduled time and transmitted to the M.D.”

According to De Micheli, one of the challenges his team faced was to develop sensors that would last long enough to effectively capture targeted substances in the body, such as lactate, glucose, or ATP. To do this, each sensor’s surface was covered with an enzyme, “a complex protein that causes a specific chemical change in all parts of the body,” according to MedlinePlus.

“Potentially, we could detect just about anything,” De Micheli said in a press release. “But the enzymes have a limited lifespan, and we have to design them to last as long as possible.” As of now, the enzymes last for about a month and a half, which is an adequate amount of time for many blood monitoring tests.

An implant that functions as a personal blood-testing lab could provide customized healthcare based on an individual’s specific needs.

Currently, oncologists use occasional blood tests to determine how well cancer patients are responding to particular chemotherapy treatments. However, this method makes it difficult to determine the optimal dose for a particular patient. A personal blood-testing implant would “allow direct and continuous monitoring based on a patient’s individual tolerance, and not on age and weight charts or weekly blood tests,” said De Micheli.

Researchers hope their ingenious device will be commercially available within four years.

“As these devices get smaller, mass-produced, and cheaper, we will see the use for many different pathologies,” De Micheli said. “They will also be used to monitor healthy elderly [patients] living alone and in remote places. Sportspeople will use them to monitor fitness and to control nutrition to be in the best shape.”