# Design and Development of a Flexible 3D-Printed Endoscopic Grasping Instrument
## 1 Introduction  
Minimally invasive therapeutic technology is currently emerging in all areas of operative medicine due to the benefits it delivers to patients, such as reduced scarring and recovery time [1; 2; 3; 4; 5; 6; 7; 8; 9]. Furthermore, it allows physicians to perform novel procedures that were not possible otherwise. Interventional therapeutic endoscopy was able to replace several surgical procedures within the therapeutic spectrum of disease management in the upper and lower gastrointestinal (GI) tract [4; 5; 6; 7]. Consequently, more complex procedures can be performed by the endoscopists, such as the endoscopic resection of GI tumors, endoscopic myotomy, plication, and GI wall closure [4; 5; 6; 7; 8; 9; 10; 11].  
The constant flow of innovative ideas and novel concepts regarding therapeutic procedures requires a prompt response from the side of engineers to develop devices to fulfill these clinical needs. The early testing of such innovative ideas allows for their selection, and they may have a high potential of becoming successful in future clinical practice. To achieve this, technologies based on rapid prototyping have emerged in several segments of medical device development to enhance the efficiency and effectiveness of the process. Three-dimensional (3D) printing has attracted significant research interest overthe past decade regarding rapid prototype development to solve different clinical problems encountered in disease management [12; 13; 14; 15; 16; 17; 18].  
Our working group is a multidisciplinary team of gastroenterologists, surgeons, and engineers involved in improvements in flexible endoscopic technology and procedures by applying the concept of \"endoneering\" [19; 20]. In recent years, several attempts have been performed to improve endoscopic instruments and procedures, based on input from clinical experts [17; 21; 22; 23; 24]. The concept of tight collaboration between medical experts and engineers is continually expanding due to the rising demand for precisely tailored solutions to various clinical problems and needs.  
Nonetheless, current state-of-the-art endoscopic methods for performing interventional therapeutic procedures have several limitations. Most of the concepts are based on the use of the endoscope itself as a foundation and expanding its functionality through attaching various over-tubes or add-on caps to it. Such over-tubes and add-on caps are restricted by the capabilities of the endoscope used and often require extensive assembly times. Endoscopic instruments that can be inserted and used independently alongside the endoscope are usually rare and very costly. This makes them unappealing for daily clinical use where costs play a significant role [17; 25; 26; 27; 28]. Furthermore, state-of-the-art instruments lack the flexibility and the ability to achieve high bending angles at the distal tip, usually not bending more than 90\({}^{\circ}\). The lack of such features limits the number of options physicians have when treating patients with different conditions. Addressing these limitations can greatly enhance the accuracy and success of complex endoscopic procedures [29; 30].  
In the present work, we explored viable rapid prototyping solutions for the above-mentioned limitations of the current state-of-the-art devices. The aim was to design an affordable instrument based on the combination of flexible endoscopic technology with laparoscopic elements to allow for a novel approach in interventional endoscopy using minimally invasive surgical concepts [29; 30; 31; 32; 33]. To achieve this, we relied on rapid prototyping methodologies to develop an affordable prototype instrument tailored for use in interventional therapeutic endoscopic procedures. Additionally, we evaluated the performance of the instrument in a series of bench tests and assessments conducted in a porcine explant model.