Pectus bar bender and designer software to enhance pectus excavatum surgeries

Abstract

Pectus excavatum is caused by inward collapse of the rib cage, which may cause the patient’s internal organs to become flush and fail to function. In 1986, Donald Nuss developed the most common treatment method today, also known as the Nuss technique. The Nuss technique is performed by opening incisions from each side of the patient’s rib cage and placing a bent bar under the cage as required by the rib cage. It is still made with the help of machines that can be compared to simple hand tools. For this reason, it is difficult to adjust the bar according to the patient and usually more than one attempt is made to find the correct shape. In this process, the submerged rib cage is especially likely to come into contact with vital organs such as the heart and lung. Since the pericardium sticked to the sternum, it has to be torn in some surgeries, where the bar is in direct contact with the heart. For all these reasons, it is very important to place this bar in the patient’s rib cage with least trials. In order to reduce the problems seen during the treatment phase, a web-based software using medical images is built to shape the drawn bar along with a bending machine. This allows the bender to bend the bar correctly using DICOM images of the patient before surgery, and any errors that may occur can be corrected beforehand. In addition, it is expected that the machine will shorten the operation time, reduce the number of lifethreatening situations and improve the patient’s quality of life. The system bends bars with an error rate under 8% at any given point on the bar, which is sufficient according to consultant surgeon. Also, the bending process is completed under 1 minute with the help of 28 Nm stepper motor.|Keywords : Pectus excavatum, bender, designer.