3D printing helps create tailor-made wrap-around heart sensor array

Researchers have used 3D-printed models of the heart to create a personalized wrap-around heart sensor array which can transmit highly detailed information on a patient’s cardiac health and may thus help to predict and prevent serious medical problems.

The buzz surrounding 3D printing sometimes gives the impression that the technology provides a miracle solution for making any manufactured product more cheaply. In fact the main advantage of the technology is to be able to produce prototypes cheaper and faster or to customize products and components. The medical sector may well be among the first to benefit from this latter approach by using the technique, formally known as additive layer manufacturing (ALM), to produce tailor-made surgical implants. At the moment, medical researchers are focusing on highly ambitious projects such as ‘printing’ replacement organs from a person’s own stem cells, but this procedure will take years of development before it can be widely used on patients. Recently researchers have used 3D printing to help create a rather more modest device which could be incorporated fairly quickly into treatment procedures. Every heart has its own unique size and shape, and medical procedures need to be adjusted accordingly in order to deliver fully personalised treatment. Now researchers Igor Efimov of Washington University in St Louisand John Rogers at the University of Illinois have demonstrated a new type of tailor-made cardiac sensor array which increases the quantity and improves the quality of the information gathered, and thus help prevent certain cardiac problems.

Precision sensor-placement

Efimov, a cardiac physiologist and bioengineer, and Rogers, a materials scientist, used optical images of rabbits’ hearts to demonstrate the concept of creating an ALM model of the heart in order to make the sensor array. In fact CT or MRI scans of each person’s heart would be used to make devices for human patients. Having 3D-printed the model of the heart, they then built a stretchy electronic mesh structure – a sort of envelope – to wrap round the model. The stretchy material can then be peeled off the printed model and wrapped around the real heart in a perfect fit. This technique enables a far more precise approach than has hitherto been feasible and the research team were able to integrate an unprecedented number of components into the device, including embedded sensors, oxygenation detectors, thermometers and electrodes that can, if need be, deliver electric shocks to stimulate a flagging heart. Although the device has been developed specifically to treat ventricular deformation andcardiacarrhythmia, it could incorporate different types of sensors in order to improve treatment for a number of other heart conditions, inter alia enabling medicines to be delivered to the exact spot where they are needed.

Implanting electronic devices into organs

Igor Efimov reveals that “the next step is a device with multiple sensors, and not just more electrical sensors.” Sensors that measure acidity, for instance, could provide an early warning of a blocked coronary artery. So far, the researchers have tested their technology on beating rabbit hearts outside the body. The next stage will be to demonstrate that this approach can work in live animals before it can be tested on people. Although devices made in this kind of custom-manufacturing process would probably be more expensive than mass-produced medical implants, using ALM to ‘print’ the basic heart model will bring the cost down considerably and help to ensure that the technology becomes available to patients who need it. In any case, argues Stanford University materials scientist Zhenan Bao, “for these kinds of life-or-death applications, the market is likely to bear the cost,” given the rich information that the device will provide, enabling early treatment of potentially serious conditions. The idea of incorporating IT devices into organs is becoming more commonplace and there could be many medical applications, such as devices to assist bladder control or mitigate conditions of the nervous system. In a less life-and-death field, the technology could also be used for body digitisation with a view to producing tailor-made clothing.