Last year, scientists at Northwestern University announced a transient pacemaker that dissolves when no longer needed. They've now improved the device, and incorporated it into a linked suite of wearable sensors.
The original implant was designed for people recovering from an injury or heart surgery, or who otherwise only require a pacemaker for a short amount of time. In any case, once they've recovered from their condition – within five to seven weeks – the pacemaker will have biodegraded and been harmlessly absorbed by their body.
This means that only one surgery is required, to initially implant the flexible device on the heart. Additionally, because it's wirelessly powered by an external antenna, it doesn't have to be wired to a separate battery. The whole thing is just 250 microns thick, and weighs less than half a gram.
Among the improvements in the new version is its ability to stretch as well as flex – thus allowing it to better conform to the surface of a beating heart – plus it now releases an anti-inflammatory drug as it dissolves, in order to prevent foreign-body immune reactions.
Additionally, the pacemaker now wirelessly communicates with four other soft-electronic devices, temporarily adhered to the skin on various parts of the patient's upper body.
These gadgets include a hemodynamics module on the forehead, which monitors blood oxygen levels, tissue oxygenation and blood vessel tone; a respiratory module at the base of the throat, that monitors coughing and other respiratory activity; a haptic feedback module worn anywhere on the body, which vibrates to alert the patient of malfunctions or other problems; and a cardiac module, located on the chest.
The latter device wirelessly powers the pacemaker, monitors the sounds and electrical activity of the heart, plus it continuously modulates the pacemaker's electrical stimulation patterns based on feedback from itself and the other sensors. All of the data is wirelessly transmitted to a nearby internet-connected smartphone or tablet, allowing the patient's doctor to remotely monitor their condition.
"For temporary cardiac pacing, the system untethers patients from monitoring and stimulation apparatuses that keep them confined to a hospital setting," said Prof. John Rogers, who is leading the research along with professors Igor Efimov and Rishi Arora. "Instead, patients could recover in the comfort of their own homes while maintaining the peace of mind that comes with being remotely monitored by their physicians. This also would reduce the cost of health care and free up hospital beds for other patients."
A paper on the study was recently published in the journal Science.
Source: Northwestern University
