In 1953, Russian archaeologist A. D. Stolyar excavated a group of 14 skeletons from a Mesolithic cemetery near Kiev, Ukraine. One of the skulls found at the 7,000 year-old site showed signs of trepanning, the surgical removal of a small piece of bone from the cranium. Some historians consider trepanation the oldest form of surgery and doctors today still drill holes in the skull to obtain and monitor essential information about brain pressure, also known as intracranial pressure (ICP). High ICP is a serious medical condition that can cut off blood supply into the brain and sometimes cause permanent damage to the nervous system and brain function.
ICP can rise due to the build-up of fluid or blood around the brain caused by head trauma, brain tumor, or swelling inside the brain. Monitoring pressure requires placing a catheter in the brain through a burr hole in the skull. But because of the risk of infection, doctors use such “invasive” monitoring only in the most severe cases even though more patients could benefit from the information. “Right now the main challenge with ICP is that the only good way to monitor it accurately and continuously is the invasive way,” says Guy Weinberg, chief executive officer of HeadSense, an Israeli startup that decided to put the drill aside and obtain ICP with sound waves.
HeadSense developed a set of disposable earbuds that emit a series of low-pitch beeps and record changes to the signals after they cross the brain. The headphones feed the data over a Bluetooth link to a tablet app that converts signal modulations to units of intracranial pressure in seconds. “This non-invasive system will allow doctors to monitor pressure continuously, determine whether medication is effective, and steer the course of treatment,” Weinberg says.
The HeadSense system is designed to listen for sound modulations caused by blood flow in the brain. As ICP goes up, blood vessels narrow to compensate for the rise in pressure, and send the pitch of the beeps higher. “It’s kind of like a pipe organ,” Weinberg says. “A pipe organ has pipes with different diameter that produce sounds with different pitch. This is exactly the same case.” The system also listens for bumps in ICP caused by breathing and feeds the data into a proprietary algorithm.
HeadSense tested and calibrated the system in human investigational trials in India, Armenia and Italy. The company just received financing by Pontifax, a leading Israeli venture capital fund, GE Ventures of Menlo Park, California, Everett Partners from Akron, Ohio, and JuMaJo, an investment group from Hamburg, Germany.
This 5,500 years old skull of was trepanned with a rock. The patient survived. Source: Natural History Museum, Lausanne Credit: Rama
Weinberg says that HeadSense will use the proceeds to obtain the necessary regulatory authorizations and bring the device to market. He estimates that in the U.S. alone there are over 3 million patients suffering from traumatic brain injury, stroke, and brain tumors, but only 200,000 receive invasive ICP monitoring due to high cost and the lack of neurosurgeons to perform the procedure. “High pressure [in the brain] is one of the most significant adverse outcomes that derive from head trauma, and one of the most serious conditions for US soldiers in Iraq and Afghanistan,” Weinberg says. “That’s why it’s so important to monitor it and measure it.”
Weinberg says that doctors are still looking at the brain like a black box. “With our device they can get a better understanding of the conditions inside and provide better and lower-cost treatment”.
Innovative headphones use sound to monitor pressure inside the brain. A tablet app then decodes the data. Obtaining the information would normally require drilling a hole in the skull. Innovative headphones use sound to monitor pressure inside the brain. A tablet app then decodes the data. Obtaining the information would normally require drilling a hole in the skull. Innovative headphones use sound to monitor pressure inside the brain. A tablet app then decodes the data. Obtaining the information would normally require drilling a hole in the skull.