Pain relief implant

2022: Implant created that relieves pain without medication

In early July 2022, a group of researchers from Northwestern University of the United States (Northwestern University) developed a small and flexible, as well as a soluble implant that relieves pain on demand and without the use of painkillers. This first-of-its-kind device could be a much-needed alternative to opioids and other highly addictive drugs.

The biocompatible, water-soluble device works by gently wrapping around nerves and providing precise, targeted cooling that paints nerves and blocks pain signals to the brain. The external pump allows the user to remotely activate the device and then increase or decrease its intensity. After the need for the device disappears, it naturally resolves in the body, bypassing the need for surgical extraction.

The world's first soluble implant has been created that relieves pain without drugs

Researchers believe the device may prove most useful for patients who undergo elective surgeries or even amputations that typically require postoperative medications. Surgeons can implant the device during surgery to help the patient cope with postoperative pain.

The technology the implant uses bears some resemblance to those that cause numbing of the fingers when cooled. The device makes it possible to achieve such an effect in a programmable way, directly and locally affecting the target nerves, even those that are deep in the surrounding soft tissues. Although the device may seem like science fiction, it uses a well-known concept - evaporation. Just as the evaporation of sweat cools the body, the device contains a liquid refrigerant that causes it to evaporate at a specific location in the sensory nerve.

They specifically targeted the peripheral nerves that connect the brain and spinal cord to the rest of the body, the scientists said. It is these nerves that transmit sensory stimuli, including pain. By exerting a cooling effect on one or two nerves, researchers can effectively modulate pain signals in one particular area of the body.

To induce a cooling effect, the device contains tiny microfluidic channels. One channel contains a liquid refrigerant (perfluoropentane) that is already clinically approved as a contrast agent for ultrasound and for pressure inhalers. The second channel contains dry nitrogen, an inert gas. When liquid and gas enter the common chamber, a reaction occurs, as a result of which the liquid quickly evaporates. At the same time, a tiny built-in sensor monitors the temperature of the nerve to make sure it doesn't get too cold, which can lead to tissue damage. By controlling nerve temperature, the flow rate can be automatically adjusted to establish a point that blocks pain in a reversible and safe way. The current work is aimed at determining the complete set of time and temperature thresholds below which the process remains completely reversible.^[1]

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