A formerly developed ultrasound liver phantom for testing of surgical navigation systems and liver resection trainings was evaluated experimentally. The phantom was scanned with CT and the dataset was analyzed with existing segmentation techniques. A virtual 3D model was generated on the basis of the segmentation; it was later used for phantom registration in a surgical assistance navigation system. Within an experiment, ten test persons have tried to touch three tumor models hidden in the phantom with the tip of a resection instrument. In 67% of overall 30 touch trials it was a successful touch at the first go. It means that the developed liver phantom is appropriate for testing of surgical navigation systems, as well as for computer assisted liver resection trainings.

In clinical routine of liver surgery there are a multitude of risks such as vessel injuries, blood loss, incomplete tumor resection, etc. In order to avoid these risks the surgeons perform a planning of a surgical intervention. A good graphical representation of the liver and its inner structures is of great importance for a good planning. In this work we introduce a new planning system for liver surgery, which is meant for computer tomography (CT) data analysis and graphical representation. The system is based on automatic and semiautomatic segmentation techniques as well as on a simple and intuitive user interface and was developed with the intention to help surgeons by planning an operation and increasing the efficiency in open liver surgery.

In this paper we present the kinematic design of the endoscope manipulator system (EMS), developed for endo-and transnasal sinus surgery which enables the surgeon to operate bimanually. It is characterized by its miniaturized size of a human hand, its extreme lightweight construction and its special kinematics to serve the workspace in the paranasal sinuses. Using a parallel kinematics, it is possible to engineer a stiff and light system. The kinematic design allows bringing the pivot point close to the nostrils, without moving the whole system closer to the patient's head and to obstruct the passage for the surgeon's instruments. This system has been used during a surgical intervention for the first time. The surgeon's feedback is promising.

Objective: The purpose of this study was to explore the impact of stereolithographic models for surgical planning and intraoperative orientation during heart transplantation in children with failing single ventricle physiology.

The transfer of applications and navigation concepts towards soft tissue surgery is facing a number of challenges. Main problem still is the registration between a deformable and moveable anatomy with existing or intraoperatively produced medical image data. In addition new approaches for application for surgical instruments need to be identified and evaluated clinically. In this contribution, we present and discuss navigation concepts for the employment of a surgical ultrasound aspirator that will have to serve as a navigated instrument during liver surgery.

In this article an approach for assistance for soft tissue surgery through instrument navigation is presented. It can sufficiently be integrated into the clinical workflow. The presented methods are part of an assistance system for open liver surgery and supports surgeons during tumor resections or living donor liver transplantation. To combine preoperative CT data with intraoperative ultrasound images, the registration process is directly controlled by the surgeon through a 6D mouse (space ball). This simple yet effective approach overcomes existing limitations of automatic algorithms relying on stable image features within both ultrasound and CT images. As a first result, the described surgery assistance system was successfully applied in clinical routine.

In this contribution we present a method to derive anatomical heart models from 3D printing. In contrast enhanced CT/MRI data of patient's hearts important structures were segmented, a surface model was created and subsequently transferred to a 3D printing process. After manufacturing of the models they served as a simple yet powerful method to plan an optimal surgical strategy in otherwise complicated interventions. The contribution describes the reproduction of the models, benefits and drawbacks of the method.

Preoperative risk analyses for oncologic liver interventions have only a limited value when new tumour findings are made during operation. We propose a new method that allows an intraoperative risk analysis adaptation by merging newly detected tumors with a preoperative risk analysis. To determine the exact positions and sizes of these tumors we make use of an ultrasound-based navigation system. For the first time, we provide surgeons with an intraoperational tool for risk analyses adaptation that can easily be integrated into a surgical workflow.