**2.1 Cardiac support net with patient-specific design**

In 2005, I read a newspaper article introducing a computer-controlled three-dimensional (3D) knitting machine (Shimaseiki Co. Ltd., Wakayama, Japan). This machine can produce 3D knitted product without sewing "WHOLEGARMENT". I came up with an idea that if we prefabricate patient-specific cardiac support net with this computer-controlled 3D knitting machine using the patient's heart images, then we do not need to adjust the net size (**Figure 1**. right panel). It will eliminate the surgeon's arbitrary adjustment and shorten the operation time.
