Tilo Gockel

A system for facial reconstruction using distraction and symmetry considerations

Abstract The goal of the system presented in this paper is to support several facial surgeries that are aiming to transform an unsymmetrical face to a symmetric one. There are two main techniques to achieve this goal: distraction of the lower jaw and adding or removing tissue or bone at certain facial regions. Both planning tasks are done based on segmented CT or MRI data. The distraction of the lower jaw is simulated by cutting the jaw, moving it in 3D along a distraction axis and choosing a distractor for this procedure after determining, which is the best result. Furthermore, we are working on consideration of soft tissue movement so the patient can see what he or she will look like after the surgery. For supporting implants in craniofacial surgery, we are proposing a tool based on symmetry considerations. Nowadays, if implants have to be fitted to the patients bone, they are handmade while the surgery is running. This is quite time consuming and it would be helpful to shorten this procedure by producing the implants preoperatively. Our system allows to determine regions where implants should be set and proposes an initial contour for the implants.

Calibration issues for projector-based 3D-scanning

In this paper we want to introduce an approach to 3D scanning of dynamic scenes. This implementation enables the user not only to manually move a scan head over the object to scan but also to capture moving objects. Registration from scan to scan is done in real-time. The user interacts with the system and watches the scene assembling. He can immediately respond on shadings that occur due to undercuts in the scene. The chosen structured light scan method uses a primarily unknown speckle image that can be easily etched on a chrome-on-glass slide and projected using a strobe light. In the current large scale implementation we are using a standard video beamer and a standard digital camera. Miniaturization and adaptation for special purposes (i. e. medical applications) are scheduled for next year. Focus in this paper shall be laid on calibration issues regarding camera and projector.

3D Vision Sensing for Grasp Planning: A New, Robust and Affordable Structured Light Approach

In this paper we present a new approach to 3D shape acquisition. This implementation enables a robot arm to move the scan unit over the object without the scan unit being tracked. The chosen structured light approach uses an initially unknown white noise pattern that can easily be projected with any fixed pattern projection system. Object points are acquired on the basis of finding correspondences in the pattern in the camera image of the current scene. This is achieved by using a fast SSD correlation algorithm. In the current test setup we are using a standard video beamer and a standard digital camera, but we have also set up a scan head for fixation on a robots’ wrist. The special requirements of this miniaturized system will be explained as well as our implementation. Our approach reduces hardware complexity to a minimum using only one calibrated camera and one calibrated fixed pattern projector. In this paper we present the whole system also including the calibration procedure. The focus will be on the hardware setup, but we also give an introduction to the software methods used.

EduKaBot - Aufbau eines edukativen Roboter-Baukastensystems

In dieser Veroffentlichung mochten wir unsere Herangehensweise und Spezifizierung fur die Auswahl einer low-cost-Robotertechnologie fur den Einsatz in Lehrveranstaltungen und Praktika erlautern. Dieses offene Roboter-Baukastensystem soll Studierende im Grundstudium Informatik und Ingenieurswissenschaften an die Technik autonomer, mobiler Roboter heranfuhren. Bei der Komponentenauswahl stand die Transparenz des Systems in Hinblick auf Hard- und Software im Vordergrund: so werden keine vorgefertigten Blackbox-Module eingesetzt, sondern der Student soll den langsam im Zuge eines Praktikums entstehenden Roboter von Grund auf kennen- und verstehen lernen.

3D shape acquisition using a combined SSD and least squares correlation approach

We want to present a new approach to 3D shape acquisition. This implementation enables the user to manually move the scan unit over the object without the scan unit being tracked. Registration from scan to scan is done on-the-fly to allow user interaction with the system. Since the user can watch the scene assembling gradually during the scan process he can immediately respond to occuring shadings due to shadows and undercuts. The chosen structured light scan approach uses an initially unknown white noise pattern that can easily be projected with any fixed pattern projection system. Object points are acquired on the basis of finding correspondences in the pattern in the camera image of the current scene. This is achieved by using a combination of a SSD and a least squares correlation algorithm. In the current test setup we are using a standard video beamer and a standard digital camera. Our approach reduces hardware complexity to a minimum using only one camera and a fixed pattern projector which both can be miniaturized. In this paper we want to present the whole system also including the calibration procedure. The focus will be on the correlation method.

Interactive simulation of teeth cleaning

Abstract 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, an editor for modelling of the elastic behaviour of the toothbrush parts is presented and the mathematical method for modelling of flexible parts of the toothbrush is explained. After the introduction of the PHANToM haptoid and the explanation of a new approach to collision detection, first results of the project are shown.

Inter-IC-Bus-Komponenten

Nachdem im vorigen Kapitel die Grundlagen des I2C-Busses erklart und einfache Routinen fur Lese- und Schreibzugriffe vorgestellt wurden, soll nun in diesem Kapitel auf die Ansteuerung spezieller I2C-Bausteine eingegangen werden.

Legacy-Schnittstellen und digitale IOs

Moderne Desktop-PCs und Notebooks weisen mittlerweile oft nur noch Schnittstellen zur Benutzerinteraktion und zur Netzwerkkommunikation auf (DVI, VGA, USB, Ethernet).

Gerätetreiber und Kernelmodule

In Linux-Systemen muss sich der Benutzer ublicherweise eher selten mit Details zur Hardware beschaftigen.

Debian auf dem Embedded-PC OpenRISC-Alekto

Der OpenRISC-Rechner Alekto der Fa. VisionSystems wurde fur den Einsatz im industriellen Umfeld konzipiert und wird mit einem vollstandigen Debian-GNU/Linux-Betriebssystem fur ARM geliefert [Vision Systems 08].