Since the minimally invasive surgery has significant benefits for the patient, special equipment and techniques are constantly enhanced in this relatively new surgical field, so that more challenging surgical applications can be achieved. Thereby, the major aim is to enable the surgeon to manipulate instruments inside the human body intuitively, despite restricted access to the operating field and limited workspace. With our spine like overtube system for use with standard endoscopes and standard endoscopic instruments, we provide a system facilitating tissue manipulation with sufficient triangulation. In this paper we describe our 3D-printed manipulator system for minimally invasive applications and its pure mechanical control and actuation concepts. Following our aim of an individualized disposable system, in a first step we demonstrate the feasibility of a 3D-printed surgical robotic system by laboratory experiments and a clinical evaluation on a porcine model.

The use of flexure hinges offers significant benefits compared to conventional revolute joints, such as the use for compact monolithic designs of flexural structures, no friction losses and reduced assembly and manufacturing costs. The combination of this design concept with additive manufacturing (AM) techniques provides huge potential for kinematics design, because of the ability to manufacture complex kinematic structures in one part with integrated adjustable functional elements, i.e. flexure hinges. Considering that there is sparse knowledge of thin-walled structures fabricated using additive manufacturing in current literature, it is obvious that the design of flexure hinge mechanisms for soft robotic applications is challenging today. Therefore, this paper describes software for simulation of plane flexure hinge structures based on investigations on the material characteristics of laser sintered polyamide, especially fatigue strength. Furthermore, the software enables automated design of these flexural structures (e.g. manipulator structures) as STL files, representing the standard interface to all additive manufacturing technologies.

One standard procedure in minimally invasive surgery (MIS) is the endoscopic submucosal dissection (ESD), where neoplastic mucosal tissue is being removed. To execute an ESD the surgeon needs to be well-trained and experienced to operate the flexible instruments precisely under visual monitoring. One of the main drawbacks is the unintuitive control of standard systems and the limited possibility for triangulation. Big motions on the endoscope's handle are transmitted into small movements of the endoscope's distal end inside the stomach and changing the field of view also changes the instrument's orientation and vice versa. We chose the ESD as a starting point to advance to Natural Orifice Transluminal Endoscopic Surgery (NOTES) later on. To improve the ESD, we develop a telemanipulation system, mainly fabricated by selective laser sintering (SLS) of a biocompatible polymer. In this paper we present our spine-inspired kinematic driven via push rods and bowden cables that provides sufficient triangulation with a promising trade-off between flexibility to insert the systems into the patient and adequate stiffness to reliably manipulate the mucosal tissue. To connect the actuators, we use a magnetic coupling to separate sterile and non-sterile parts.

The next step in minimally invasive surgery is the further reduction of incisions by surgery through natural orifices (NOTES) or one single artificial incision (Single-Port). However, physicians pointed out, that those procedures are only possible if new technologies will increase the dexterity of the instruments inside of the body. Especially the missing ability to manipulate tissue from two sides (triangulation), needs to be obtained. This article is about the development of different kinematics for a Multi Arm Snake-Like Robot to manipulate flexible endoscopic instruments at the tip of a flexible endoscope. By using Selective Laser Sintering (SLS) it is feasible to create various shapes and designs, custom made for different patients. We are using flexure hinges and compliant mechanisms to create defined movements in serial kinematic structures. In the experiments, the relation between different structures and the influence of the inserted flexible endoscopic instrument are compared. The proposed kinematics are able to manipulate flexible endoscopic instruments. That proves that SLS structures get more advances towards a use for a flexible Single-Port Multi Arm Snake-Like Robot.