A highly innovative prototype controlled and powered wirelessly by a network of sensors in special patches has been created at Northwestern University (USA).
The field of pacemakers, the electronic devices that keep abnormal heartbeats under control, may be about to see a significant breakthrough, thanks to a new generation resorbable pacemaker developed by a team of researchers at Northwestern University, one of the leading universities in the U.S. The researchers, who have been working on this project for years, have published the results in the journal Science.
So, what is it all about? There has long been a need for minimally invasive pacemakers to help people with a slow heartbeat awaiting a permanent pacemaker, or who are coming out of cardiac surgery (or even after a heart attack or overdose), but there has never been a satisfactory solution until now.
Those who need a temporary pacemaker get a traditional device, which involves inserting a stimulator under the collarbone (or elsewhere) and an electrode into the heart in the operating theatre. It has to be powered and monitored through external equipment, which in some cases the connecting cables can trigger infections. These devices generally only work in response to the heart rate, usually without monitoring other parameters. When the temporary pacemaker is no longer needed, a second operation is then performed to remove it.
All the shortcomings of temporary implants may be overcome if tests on a large number of patients prove successful, thanks to new pacemakers like the Bio-MEMS (micro-electro-mechanical system) developed by Northwestern University.
This device is made from special bioplastics and water-soluble metals that are reabsorbed with no trace and dissolve after five or six weeks. It is very thin and weighs less than half a gram. Its soft, flexible structure incorporates electrodes that are gently implanted on the surface of the heart to deliver an electrical impulse.
A pacemaker based on a wireless network
The Bio-MEMS 'system' includes the actual pacemaker, together with a coordinated network of wireless sensors applied to the skin with special patches. As well as heart rate, these sensors measure temperature, blood oxygen levels, respiration, muscle tone, physical activity and more. The new resorbable pacemaker does not need any wires, as it is powered by an external mini-power supply that also wireless, through a patch.
Another small patch to be worn wherever the patient wants, for example on the arm, alerts them with a vibration if there is a problem like a malfunction or difficulty in reading data, so that action can be taken quickly.
Data collected is constantly processed by an algorithm, which decides when and how to assist the heartbeat as needed and is sent directly to the doctor's smartphone or tablet. The doctor can then monitor the situation remotely and the patient is free to move around and, when possible, return to their home. This new type of pacemaker also releases anti-inflammatories as it dissolves, and can produce an electrocardiogram at any time, which, when compared with ‘classic’ ones, has proved to be absolutely equivalent, and therefore reliable.
A possible aid for children
The device has been tested on laboratory animals (dogs and rats) and also on human hearts and has performed the functions expected. It will now undergo extensive testing before it can be used on a large-scale.
If the results are positive, people who need a temporary pacemaker will benefit considerably from this kind of device. It will also bring significant savings to healthcare facilities, because of the drastic reduction in hospital stays.
Resorbable pacemakers will also be able to help children born with a faulty closure of the communicating chambers between the atria and ventricles of the heart. These young patients often need an operation and, immediately afterwards, a pacemaker for a few days until the heart functions normally. A soft, wireless device would be perfect for them.
