A microsensor so small that 10 could fit on a penny can help determine the origins of back pain. Dr. Edward Benzel and colleagues at Cleveland Clinic have developed these micromachines for the spine in hopes of better diagnosing and treating back and orthopedic pain. OrthoChips by OrthoMEMS range in size from 1 mm to 6 mm, with most of this radius taken up by tiny antennae.
A single implanted sensor works as an information gatherer, measuring pressures and loads within bone, and disc spaces between vertebrae in a variety of circumstances, such as sitting, stooping and standing. The chip transmits this data wirelessly through the skin and body to a read-out device that resembles a handheld computer. Benzel hopes these crumb-size sensors will help doctors understand why a spinal disc is causing back pain.
It could prevent unnecessary spinal fusion operations, which, Benzel contends, are performed in excess in the United States. “There are all sorts of reasons why, but the real reason is we don’t have a great diagnostic test [for severe back pain].”
For now, the OrthoChip is modeled as a diagnostic tool, inserted by a needle or catheter. But it has potential when combined with other components to evolve into a “smart” system that can ad-just an implant, inject a bone-growth-enhancing material or lengthen a bone implant in a pediatric patient. The current technology should be ready for clinical trials within 18 months, Benzel pre-dicts. Smart systems are anywhere from three to 10 years down the road.
Still, patients could feasibly use an OrthoMEMS device as a biofeedback mechanism — a preven-tive system, Benzel suggests. An implanted OrthoChip could alert patients of activities that cause unhealthy pressure on the spine. “There are all sorts of possibilities,” he says. “We have only tested the water — we still cannot make bold, sweeping statements about this technology.”