The past few years the science and art of prosthetics has developed rapidly, and research in the field of soft robotics has been particularly interesting. The same methods that are used in the construction of the robot, help to create more complex and delicate designs, including the heart.
A qualitatively working artificial heart is a necessity: about 26 million people around the world suffer from heart failure, and organs from donors are not enough. Artificial pumps that pump blood, help to reduce waiting time until the patient receives the heart of the donor or restores his own work.
Today there are no effective robots that completely replace such an important organ as the heart. However, there are useful developments that partially fill the functions of the heart. For example, a soft robotic clutch developed by researchers at Harvard University and the Boston Children's Hospital is made precisely around the contours of the heart and surrounds it, and then shrinks to the rhythm of the natural rhythm, helping the body cope with work in conditions of heart failure.
In Switzerland, scientists managed to create an artificial human heart, as close as possible to the real one. The silicone model was developed by the doctoral student Nicholas Cohrs under the guidance of Wendelin Stark, a professor of functional materials development at the Swiss Higher Technical School in Zurich.
There are many reasons why scientists seek to recreate the natural forms and functional of the heart in an artificial implant. In those pumps that are used now, there are drawbacks: their metal and plastic mechanisms in some cases are difficult to integrate with natural tissues after transplantation, and the patient does not have a physiological pulse. Therefore, the goal of scientists is to create an artificial heart that is as close to the organic as possible in its shape and function.
The researchers printed a soft artificial heart made of silicone using wax casting technology that made it possible to create a complex internal structure, And the flexibility of the raw material. The heart itself is a monoblock, so there is no need to worry about how the mechanical parts of the heart will interact with the tissues of the body, with the exception of the input and output arteries through which the blood will pass to the implant
Such a heart with a volume of 679 cm 3 weighs 390 grams. For comparison, on average, the weight of the human heart is 331 grams. The model consists of the right and left ventricles, which are separated not by a septum, but by an additional chamber. Through this chamber is compressed air, which pumps fluid from one chamber to another, simulating the contraction of the muscles of the human heart.
Another group of researchers evaluated the work of this artificial heart. Scientists have confirmed that it works and shrinks like a human heart. Nevertheless, he still has a problem: now the model can withstand about 3 thousand strokes – 30-45 minutes of continuous operation, and then the material does not withstand deformation.
Cors explains that their goal was not to imagine a heart ready for implantation, but to set a new direction for the development of artificial hearts. Of course, they plan to greatly improve the strength and productivity of the material.
All the work was done at the University of Medicine of Zurich in the framework of the Zurich Heart Project. In total, there are 20 research groups from different institutions in Zurich and Berlin. Part of the research focuses on improving existing blood pumps, for example, reducing blood damage caused by the operation of the mechanical parts of the pump. Another team investigates elastic membranes and other biocompatible materials and surfaces.
The environment for testing artificial hearts was also developed here, with the help of which it is possible to simulate the cardiovascular system of a person. The Kors team used it for their development process, which also included working with a fluid that was comparable in viscosity to human blood.
doi: 10.1111 / aor.12956