Application of 3D printed models to visual measurement in the new innovative depth from defocus method

Abstract

The new innovative Depth from Defocus (DFD) method was used to visual measurement of the stroke volume of the extracorporeal pneumatic heart assist pump. The heart pump developed in the framework of the Polish Artificial Heart is the object of the study. However, the current studies are conducted on its adequate model. Using this model is justified because of the significant costs of the original prosthesis. The model was equipped with an adapter to mount the camera. This makes it possible to observe the surface of the membrane from the pneumatic chamber side without obstructing its normal operation, in particular without affecting the blood chamber. The model was designed in CAD software then it was 3D printed. The momentary surface shape of the flaccid membrane affects the volume of the blood chamber. The difficulty of the accuracy verification of the shape mapping is that heart assist pump fitted with a flaccid membrane has only two membrane states with a known mathematical description. Using reverse engineering, the authors have invented new technique to 3D modeling of any surface shape of the flaccid membrane with well-known geometric dimensions. The rigid models of different membrane states were designed in CAD software and printed on a 3D printer. The process of modeling and 3D printing and ready prototypes were presented.