Polish Artificial Heart 3D printed on Zortrax M200
Taken from an article by Ludmiła Rafalska
This case of the artificial heart shows the potential of 3D printing in creating the necessary medical equipment that helps to advance the study on life-saving devices. It is amazing how incorporating 3D printers can push forward the work on an artificial heart by allowing not only to create the model but the complete computerised test stand.
The heart is one of the most important and complex organs in every human organism, responsible for performing life activities. Unfortunately, the number of hearts available for transplant are not sufficient for the number of patients needing a heart transplant.
An artificial heart could be used as a bridge during the period between of waiting for an available heart and the transplant surgery. Although there are 3D printers that can print with cells that are biocompatible with the human tissue, creating a model of a working artificial heart is still in the the distant future. Apart from having multiple models of artificial hearts, ventricular assist devices or cardiopulmonary bypasses, making a model of a well-functioning device that can replace the poorly working organ is an urgent need.
Put Heart in Teamwork
The idea of a model of an artificial heart was initiated by the team from the Department of Optoelectronics of the Silesian University of Technology coordinated by Prof Tadeusz Pustelny, PhD Eng. A few years ago also the people from the Faculty of Cybernetics of the Military University of Technology in Warsaw joined the project, supervised by Krzysztof Murawski, PhD Eng., Leszek Grad, PhD Eng. and Artur Arciuch, PhD Eng. The main objective of the project was to create a computerised built-in system, including the software and equipment, to measure the stroke volume from the chamber of the artificial heart in real time.
Together they have already printed four models of artificial hearts that are used for tests whereby applying particular algorithms, the efficiency of the models is being tested. Having the models of devices that are used to transplantations allows testing the measuring techniques, which boosts the safety of surgeries. Currently three models are used by the MUT and are being tested with the use of camera, and one model is used by SUT for optic examinations. The models created by the teams are inspired by the pump for the pneumatic heart assist device known as Religa EXT, a modernised and more efficient version of POLVAD heart.
Fighting the Figures
The costs of creating an artificial heart using traditional methods were really big, as making a single chamber requires spending the enormous sum of US$130 000. However, such high financial outlay didn’t discourage the teams but in fact served as a trigger to search for alternative methods that would allow them to finish their works. The project named Center of the Advanced Studies on Engineering Systems led by Tomasz Górski, PhD Eng. allowed them to purchase a Zortrax M200 and start work on creating the artificial heart and computerised stand.
Meet the Models
The model of the artificial heart consists of several parts including blood and air chambers which were 3D printed on the Zortrax M200 with Z-ULTRAT and Z-PETG. The first material was also used to prepare a mould to cast the diaphragms. The process was divided into three stages: first, the model of a diaphragm was created in a modelling program; next the total volume of the diaphragm was checked; and lastly the 3D printing of the cast for silicone moulds was prepared. The thickness of the diaphragms in the working part is max. 1mm and its volume is 35ml.
3D printing and assembling of the artificial heart was in fact only the half of the success, as testing the models also required a professional computerised test stand. Again the teams decided to trust in the quality of the Zortrax M200 and 3D-print all the elements on it. The chamber consisted of more than 12 types of elements including various handles, manifolds and guides. The Zortrax 3D printer also served as a tool that allowed the creation of a model of the chamber.
Thanks to the additive manufacturing technology, all the parts were created quickly and cost-effectively, helping the teams to stay within budget and speed up the development of their study. The approximate cost of producing a single artificial heart on Zortrax M200 is US$21.
The Matter of a Layer
The most vital parts that determine the quality and usability of the 3D printed models are layer thickness and material type. In Zortrax M200 devices, this parameter can be set by the user who has is able to choose from 0.9 to 0.39, depending on the particular printing material. The thickness is inextricably connected with the level of precision and the overall length of the printing time.
Choosing the minimum layer thickness guarantees that the final result will be the closest to the effects obtained by the injection moulding machines. It means, that by choosing the small layer thickness we are given the smoothest surface that also makes the process of removing the support much easier. Without any big marks left after removing the support, the models don’t require any further post-processing and can be used as end-use products.
When it comes to the application of the LPD technology offered by Zortrax, medicine is the field where it can be well incorporated. According to the opinions of the team, the technology can be used to create 3D printed models that illustrate the particular surgeries and prototypes of customised prostheses.
Having Zortrax 3D printers allows the creation of the customised tools that are necessary for performing specific operations (but they are not available for purchase). One of the invaluable opportunities given by 3D printing is the ability to create spare parts of devices, so that the repair of the tools is fast and does not involve wasting time and money for servicing.
If you are interested in other medical cases, see the Zortrax 3D printed Boluses helping to improve radiotherapy standards case study.