With little thought given to the reliability of its pulse, the steady drum of a heartbeat can fade into the background.
If you develop an arrhythmia, your heartbeat is monitored and controlled by life-saving devices, which deliver shocks to the heart to stop it from quivering.
Small animals are often used as models for studying how a heart stumbles and stutters. Their size makes it difficult to monitor and respond to changes in their tiny hearts.
A team of scientists led by Philipp Gutruf of the University of Arizona developed a device that makes it easier to study the cardiology of small animals. It could be the basis of a new way to treat heart conditions in humans.
The device has been designed to be flexible so that it can be used on small test subjects. When abnormal rhythms are detected, it uses light to give gentle shocks.
The system can provide continuous recordings of heartbeats, even when it needs to defibrillate, because it uses light to stimulation the heart.
"Current pacemakers record a simple threshold, and they will tell you, 'This is going into arrhythmia, now shock!'" says Gutruf.
This device has a computer that you can use to pace in a more advanced way. It's used for research.
Researchers designed the device to deliver more precise stimulation of the heart, even though it has only been tested in mice.
It works by using a technique called optogenetics, in which cells in the heart or brain can be stimulated with light. Mouse cardiomyocytes were genetically engineered to express a blue light-sensitive proteins. Cells jump into action when the light is switched on.
The device has a soft thin-film array that envelope the heart. The snug fit is different to how current pacemakers connect to the heart.
People who have a pacemaker can experience pain around the implant site. Complex regional pain syndrome can be developed in some rare cases.
defibrillation of the heart is less precise when stimulated through one or two points.
Gutruf says pacing or defibrillation is painful because all of the cells inside the heart get hit at once. The heart muscle is affected by it.
The researchers hope that with this new device, they could offer a more comfortable and precise way of synchronized irregular heartbeats.
New defibrillation devices can do more precise targeting, making defibrillation more effective and less painful, according to an engineer at a university.
The prototype device was implanted just outside the ribcage of the mouse and shared heart rate data with an uplink.
The researchers first analyzed the geometry and mechanics of a beating mouse heart, using that information to design and laser-fabricate the flexible, four-pronged mesh so it could move with the heart.
The researchers showed the device could detect abnormal rhythms in mice without the heat from the light pulse damaging cardiac tissue.
The researchers found that the device's accuracy in detecting abnormal heartbeats was similar to current commercially available devices.
It's still very early days for the use of optogenetics in humans, even though the findings from animal studies are promising. Gene therapy and an electronic device are required for the technique to work.
While optogenetics has been used in clinical trials to treat rare inherited eye diseases, using the technique to monitor and possibly treat heart irregularity is an emerging approach that needs a lot more research in animals.
Delivery of genetic instructions to heart cells is one of the challenges to overcome.
Gutruf and colleagues note that more work needs to be done to model the intricacies of heart rhythm disorders.
The flower-like device is an elegant research tool that can be used to study arrhythmias and other heart problems in animal models.
The study was published in a peer-reviewed journal.