Application Of Navigation System Research Articles

Autonomous Navigation Environment with Self-Calibrating Transceivers

An operable navigation system which demonstrates successful self-calibration and precise local navigation has been developed by EADS Astrium. This paper presents the architecture of the autonomous navigation environment with the ability to calibrate itself as well as the results of field tests. The Self-calibrating autonomous Navigation Environment (SekaN) can be used as stand-alone navigation system for applications where satellite signals are not available or where autonomy and high precision is required. Cargo drop, navigation in canyons and open pit mines, indoor navigation and extraterrestrial navigation are just examples of possible applications. The self-calibrating feature of SekaN is of special interest in conflict areas where a temporary autonomous navigation environment has to be installed quickly and where it is not possible to calibrate the locations of the pseudolites a priori. Furthermore, the system can be operated as augmentation system to classical satellite navigation systems. Therefore a mixed mode has been introduced which allows for simultaneous tracking of both satellite signals and pseudolite signals. Referencing of the local coordinate system to e.g. WGS84 becomes possible. The SekaN system comprises the following HW units developed by EADS Astrium: at least 4 Transceivers (TCs), a Rover receiver (ROV) and a Master Control Station (MCS). A WLAN data link is used between the units. Each TC comprises a GNSS signal generator NSG 5100 which supports both GPS and Galileo signals and an Astriumspecific GPS/PSL receiver. The number of TCs in the network is scalable and dependent on the specific application of the SekaN. Various TC-array sizes are supported as the output power of the pseudolites can be varied in a wide range. The rover receiver positioning takes place at the MCS. However, several receivers may be registered at the MCS. The TCs are operated unsynchronized and differential concepts are applied to eliminate the clock errors. Presently the pulsed signals with pseudolite spreading codes at the GPS L1 and dummy navigation messages are used as navigation signals. As soon as low-cost Galileo receivers are available the system can be switched to any Galileo frequency band. In a batch process the exact locations of the TC TX-antennas are determined without any a priori knowledge of the geometric array configuration. The general idea behind the self-calibration algorithms is based on the solution algorithm for self-calibrating pseudolite arrays presented in (LeMaster and Rock, 2002). However, several modifications were necessary to adapt the algorithms to the SekaN system requirements. The rover which is used for data collection during the self-calibration process is designed as a Receiver-only module instead of a TC module. This makes the rover hardware less complex, smaller and lighter, but also complicates the self-calibration process. Self-differencing between the stationary TCs and the rover TC can no longer be applied. The ranges between the rover RX and the TCs are therefore not directly observable. The selfcalibration and navigation algorithms developed for the SekaN work in both 2-D and 3-D scenarios. Although multipath effects, non-linearities and the near-far-effect are inherent in these kinds of ground-based navigation systems, precise user positioning at the sub-meter level becomes possible even with low-cost receivers within the self-calibrated navigation environment.

Clinical contrast of cervical pedicle screw fixation assisted by C-arm fluoroscopy or 3D navigation system

To evaluate the feasibility and accuracy of cervical (C(2)-C(7)) pedicle screw fixation assisted by C-arm fluoroscopy or 3D navigation system (CT-based navigation system or Iso-C 3D navigation system). One hundred and forty-five cervical pedicle screws inserted with C-arm fluoroscopy and 187 pedicle screws inserted with 3D navigation system were observed by postoperative CT or Iso-C 3D scan. The process of navigation was investigated. In the 145 screws inserted with C-arm fluoroscopy, 133 screws are accurate (91.7%), and in the 187 screws inserted by 3D navigation system, 183 screws are accurate (97.9%) (chi2 = 6.705, P = 0.010), and the 4 misplaced screws occurred in the early stage of navigation system application. The process of navigation was investigated in twenty-five patients. With CT-based navigation, the mean time for registration and surface matching was 3.5 minutes; with Iso-C 3D navigation, the mean time for images collection and transfer was 6.2 minutes. The mean time for screw-marker insertion was 2 minutes. 3D navigation system can increase accuracy of cervical pedicle screw fixation obviously.

A new small, light and mobile navigation system for application within the sterile situs

A new small, light and mobile navigation system for application within the sterile situs

耳鼻咽喉科領域におけるナビゲーションサージャリー

Application of navigation systems to otorhinolaryngology head and neck surgery should permit safer, sounder operationswhen attempting revision surgery on anatomically ambiguous target organs, surgery on lesions expanding to organswith risk factors for complications, and in minimally invasive surgery. If such systems were used in ear surgery, the locationof important organs in the temporal bone could be checked. In operations on the nose or paranasal sinus at risk organscould be avoided (e.g. orbit and basal skull) and residual cells and incision locations on postoperative cyst could be identified.When operating tumors of head and neck, the preoperative and pretreatment status could be grasped and the area oftumors resection could be determined, including the safety margin. In addition to these applications, navigation systemsare useful for operations such as choanal atresia and aural atresia, fracture repair, skull base surgery, and on biopsy, nerveblock and surgical training. Although this system has the potential to improve the surgeon's confidence and knowledgeof patient anatomy, the overestimate its ability should be careful without any knowledge of anatomy and surgical experiences.

Shaping up simple cell's receptive field of animal vision by ICA and its application in navigation system

Scientists and experts have explored the mechanism of visual systems for decades for smart image processing and pattern recognition in order to satisfy sophisticated engineering applications. In this paper we apply independent component analyses' (ICA) unsupervised learning to natural images, topography images and other special environment images for demonstrating the simple-cell's process in animal vision. Our results confirm an early biological experiment (Nature 228 (1970) 419) about the growth of simple cells in cat's V1 area. Furthermore, by applying ICA methodology and the simplex algorithm, the unsupervised neural synapse's learning can obtain the receptive fields in visual cortex and can simulate the growth of the visual cortex of young animal in the special environment. These findings imply that an input image can be efficiently represented by ICA bases. An application of image matching in the navigation by ICA is shown that the animal visual system method is indeed better than those classical methods at least more than 5%.

1.画像誘導内視鏡下経鼻孔経蝶形骨洞手術:手術器械の開発,画像誘導法の応用,手術法の確立

1.画像誘導内視鏡下経鼻孔経蝶形骨洞手術:手術器械の開発,画像誘導法の応用,手術法の確立

Application of Navigation System to Ear Surgery

Application of Navigation System to Ear Surgery

耳鼻咽喉科手術ナビゲーションシステム

耳鼻咽喉科手術ナビゲーションシステム

Controversies in the management of pediatric facial fractures : Bartlett S.P.; DeLozier J.B. IIIClin. Plast. Surg. (1992) 19/1 (245–258)

The oral and maxillofacial region has a complicated anatomy with critical contiguous organs, including the brain, eyes, vital teeth, and complex networks of nerves and blood vessels. Therefore, advances in basic scientific research within the field of intraoperative oral and maxillofacial surgery have enabled the introduction of the features of these techniques into routine clinical practice to ensure safe and reliable surgery. A navigation system provides a useful guide for safer and more accurate complex in oral and maxillofacial surgery. The effectiveness of a navigation system for oral and maxillofacial surgery has been indicated by clinical applications in maxillofacial trauma surgery including complex midfacial fractures and orbital trauma reconstruction, foreign body removal, complex dentoalveolar surgery, skull base surgery including surgery of the temporomandibular joint (TMJ), and orthognathic surgery. However, some fundamental issues remain involving the mobility of the mandible and difficulty in updating images intraoperatively. This report presents an overview and feasible applications of available navigation systems with a focus on the clinical feasibility of the application of navigation systems in the field of oral and maxillofacial surgery and solutions to current problems.