Intraoperative augmented reality: the surgeons view.

Augmented Reality (AR) is a promising tool for intraoperative visualization. Two different AR systems, one projector based, one based on see-through glasses were used on patients. The task was the transfer of preoperative planning into the intraoperative reality, or the visualization of space occupying lesions, respectively. The intraoperative application of both systems is discussed from the surgeons point of view.

First clinical tests with the augmented reality system INPRES.

In this paper we present the results of the first patient experiment in craniofacial surgery of the INPRES system - an augmented reality system on the basis of a tracked see-through head-mounted display.

A VR-system supporting symmetry related cranio-maxillofacial surgery.

The reconstruction of patients with large deformations in the facial area should consider functional aspects as well as aesthetical ones. In this paper, an integrated virtual reality system which allows bone manipulation, osteotomy planning, calculation of implants for soft tissue and bones combined with the calculation of the post-operative appearance is presented. It is a valuable tool for a wide range of cranio-maxillofacial surgeries. Due to the generalized approach of the underlying algorithms, it is a basis for further clinical applications in other surgical fields.

Evaluation of INPRES--Intraoperative Presentation of surgical planning and simulation results.

In this paper we present fundamental results of the first evaluation of INPRES in a laboratory environment. While the system itself--an HMD-based approach for intraoperative augmented reality in head and neck surgery--has been described elsewhere several times, this paper will focus on methods and outcome of recently accomplished test procedures.

[See-through head-mounted display augmented reality for maxillofacial surgery]. / Brillenbasierte erweiterte Realität für die Mund-Kiefer-Gesichtschirurgie.

In this paper we present the medical augmented reality system INPRES for Intraoperative Presentation of surgical planning and simulation results. The system is based on a see-through head-mounted display for data visualization and overlay. Key challenges are tracking of the display and the patient, registration of virtual data with the real world and calibration of the display device. Further tasks are detection of occlusions, intuitive man-machine-cooperation and evaluation of the complete setup. The system configuration and the methods are shown, first results are given and future work is outlined.

Volumetric implant-planning based on Symmetry Considerations.

Symmetry Considerations can be used not only to plan the desired shape of reconstructured bone structures, but also to generate prototypes for soft tissue implants. The poster describes a system which allows to calculate a symmetry plane in the facial area automatically and computes proposals for implants or transplants. The system presented has been used to calculate soft tissue implants and a replacement for parts of the lower jaw.

Interactive simulation of the teeth cleaning process using volumetric prototypes.

In this paper, an interactive simulation system for teeth cleaning is presented. This simulation system offers assistance for optimizing design and manufacturing of new toothbrushes. Data acquisition and pre-processing techniques for the model generation are shown and the mathematical method for modelling of the elastic behaviour of the toothbrushes parts is explained. Afterwards, a new approach to collision detection based on simple volumetric prototypes is described, user interaction is discussed and results of the project are shown.

Risk reduction in craniofacial surgery using computer-based modeling and intraoperative immersion.

We present a two-stage concept for risk reduction in craniofacial surgery, consisting of preoperative risk modeling and intraoperative risk reduction. Preoperatively it is important to find and to visualize risk sources in order to minimize them. Our risk model is composed by superimposition of an isotropic risk potential and an anisotropic tissue field constituent. It is being applied to preoperative planning and simulation of craniofacial surgeries, for example to determine an access path with least overall risk value. In the operation room risks arise mainly from the absence of preoperative planning and simulation data in the operation field. We use a see-through head-mounted display to optimize this situation in order to allow the surgeon to maintain accuracy in the whole process of computer aided surgery. Main steps of the intraoperative immersion are optical tracking of the surgeon wearing the head-mounted display and of the patient, registration of preoperatively calculated planning data with the patient and visualization of the data within the glasses.