Position Of Surgical Instrument Research Articles

Application of computer assisted navigation system in orthopaedics

计算机辅助导航系统将空间立体导航技术、计算机图像处理及可视化技术与临床手术结合起来,使手术器械的位置在术中通过影像实时显示,从而确保手术的安全.因精确 性、安全性及快速性的特点使其在临床逐渐得到广泛应用,在脊柱、脊髓、关节外科、创伤 外科等方面也充分发挥了重要作用.随着科技的发展,计算机辅助导航系统将发挥更大的作用.

Neuronavigation in Skull Base Tumors

Computer-assisted neuronavigation was used in 87 cases of skull base lesions (SBLs). Preoperative planning and intraoperative identification of anatomic landmarks is especially important in SBLs since it helps to avoid or minimize surgical morbidity and mortality. In this study, we assessed the accuracy and the clinical usefulness of a frameless system based on the optical digitizer in SBLs. Between April 2000 and March 2003, eighty-seven patients with SBLs were operated on in our department using cranial neuronavigation. A passive-marker-based neuronavigation system was used for intraoperative image guidance. There were 56 women and 31 men. The patient's ages ranged from 4 to 76 years (average: 45.7 year). The locations of the tumors reported in this series were as follows: frontobasal, 24 cases; sellar/parasellar, 32 cases; petroclival, 16 cases; tentorial/subtemporal, 15 cases. The computer-calculated registration accuracy ranged between 0.3 and 1.7 mm (mean, 1.1 mm). Gross total removal of the SBLs was accomplished in 82 out of 87 patients as was confirmed on postoperative CT and MRI scans. The follow-up period ranged from 1 month to 48 months (average: 20.1 months). Overall mortality and severe morbidity (meningitis, permanent cranial nerve deficits, and cerebrospinal fluid fistulae) rates were 4.6 % and 33.3 %, respectively. The image-guided surgery is a valuable aid for safe, helpful and complete removal of SBLs of the brain where accurate localization of the lesion is critical. Although our preliminary series is not large, interactive image guidance provides a constant display of surgical instrument position during surgery and its relationship with the SBLs components, surrounding normal brain, and vascular structures, providing valuable guidance to the surgeon during an operation. Our experience with the neuronavigation suggests that image guidance is helpful in this type of lesions, providing better anatomic orientation during skull base surgery, delineating tumor margins and their relation to critical neurovascular structures.

An interactive mechatronic assistance system to support surgical interventions

This paper illustrates the concept of a versatile surgical assistance system which combines an optical navigation system and a mechatronic arm. Compared to pure navigation systems, it offers additional functionality by automatic positioning of surgical instruments in preoperatively planned locations, but it does not perform any action without interaction and control of the surgeon. A particular advantage is given by the applicability of new surgical instruments, such as medical laser systems or microtools, which cannot be used in manual surgery. The mechatronic arm may thus be regarded as a controlled machine actuator of a navigation system that substitutes for manual instrument guidance. Interactive properties are provided by a versatile haptic interface. After successful clinical tests in hip surgery, the modular design concept will be exploited to adapt the system to a variety of surgical applications.

Autonomous 3-d positioning of surgical instruments in robotized laparoscopic surgery using visual servoing

This paper presents a robotic vision system that automatically retrieves and positions surgical instruments during robotized laparoscopic surgical operations. The instrument is mounted on the end-effector of a surgical robot which is controlled by visual servoing. The goal of the automated task is to safely bring the instrument at a desired three-dimensional location from an unknown or hidden position. Light-emitting diodes are attached on the tip of the instrument, and a specific instrument holder fitted with optical fibers is used to project laser dots on the surface of the organs. These optical markers are detected in the endoscopic image and allow localizing the instrument with respect to the scene. The instrument is recovered and centered in the image plane by means of a visual servoing algorithm using feature errors in the image. With this system, the surgeon can specify a desired relative position between the instrument and the pointed organ. The relationship between the velocity screw of the surgical instrument and the velocity of the markers in the image is estimated online and, for safety reasons, a multistages servoing scheme is proposed. Our approach has been successfully validated in a real surgical environment by performing experiments on living tissues in the surgical training room of the Institut de Recherche sur les Cancers de l'Appareil Digestif (IRCAD), Strasbourg, France.

Automatic positioning of surgical instruments during laparoscopic surgery with robots using automatic visual feedback

This paper presents a robotic vision system that automatically retrieves and positions surgical instruments in the robotized laparoscopic surgical environment. The goal of the automated task is to bring the instrument from an unknown or hidden position to a desired location specied by the surgeon on the endoscopic image. To achieve this task, a special instrument-holder is designed that projects laser dot patterns onto the organ surface which are seen on the endoscopic images. Then, the surgical instrument positioning is done using an automatic visual servoing from the endoscopic image. Our approach is successfully validated in a real surgical environment by performing experiments on living pigs in the surgical training room of IRCAD.

Interactive images in the operating room.

Fluoroscopy has made endourology possible, but its two dimensionality and poor tissue contrast limit its applications. Recent advances in computer technology are making it possible for surgeons to interact with three-dimensional CT and MR images. Initial interactive navigation systems tracked the position of surgical instruments on previously acquired images using optical, ultrasonic, or electromagnetic devices. More recently, real-time imaging and instrument tracking have become possible, such as with the open interventional MR scanners. The problems created by patient motion and tissue deformation during manipulation may thereby be overcome.

Voxel-based 2-D/3-D registration of fluoroscopy images and CT scans for image-guided surgery.

Registration of intraoperative fluoroscopy images with preoperative three-dimensional (3-D) CT images can be used for several purposes in image-guided surgery. On the one hand, it can be used to display the position of surgical instruments, which are being tracked by a localizer, in the preoperative CT scan. On the other hand, the registration result can be used to project preoperative planning information or important anatomical structures visible in the CT image onto the fluoroscopy image. For this registration task, a novel voxel-based method in combination with a new similarity measure (pattern intensity) has been developed. The basic concept of the method is explained at the example of two-dimensional (2-D)/3-D registration of a vertebra in an X-ray fluoroscopy image with a 3-D CT image. The registration method is described, and the results for a spine phantom are presented and discussed. Registration has been carried out repeatedly with different starting estimates to study the capture range. Information about registration accuracy has been obtained by comparing the registration results with a highly accurate "ground-truth" registration, which has been derived from fiducial markers attached to the phantom prior to imaging. In addition, registration results for different vertebrae have been compared. The results show that the rotation parameters and the shifts parallel to the projection plane can accurately be determined from a single projection. Because of the projection geometry, the accuracy of the height above the projection plane is significantly lower.

Computer-assisted neurosurgery system: Wayne state university hardware and software configuration

Computer-assisted neurosurgery uses the latest technological advancements in imaging, computers, mechanics, and electronics to improve the accuracy and reduce the invasiveness and risk of neurosurgical procedures. We describe the Wayne State University, Detroit, Michigan, computer-assisted neurosurgical system with the emphasis on software and discuss the theory guiding the development of this system and its application in realtime position tracking systems. Our system consists of the Neurological Surgery Planning System (NSPS) software which we developed at our medical center and three types of position tracking systems: the Zamorano-Dujovny (Z-D) arc digitizer for lrrame-based procedures, an articulated arm, and an infrared-based digitizer for frameless procedures. The NSPS software is designed to offer neurosurgeons a safe and accurate method to approach intracranial lesions by preoperatively planning a surgical trajectory. Software consisting of the most advanced technologies in computer vision, computer imaging/graphics, and stereotactic numeric analysis forms the core of the system. Capabilities for correlating data from imaging studies to facilitate image reconstruction, image mapping, and three-dimensional (3D) visualization of target volumes enable the neurosurgeon to simulate surgical procedures into a preoperative protocol to be used during surgery, both to follow the preplanned trajectory and to track the position of surgical instruments in real-time on the computer monitor. The tracking systems position and orient the surgical instruments relative to the patient's head. With these devices, the display of the surgical instruments together with the virtual images create an excellent intraoperative tool.

IMAGE GUIDED NEUROSURGERY: PRESENT STATE AND PERSPECTIVES

The image guided neurosurgery was made possible by the great developments of modern neuroradiology whose origins could be identify in UK on 1974 when Hounsfield invented the computer tomography (CT Scan) and on 1980 Lauterbur developed the first magnetic resonance (MR) allowing the direct visualization of the brain. The term neuronavigation is used to describe the set of computer assisted technologies used by neurosurgeons to guide or “navigate” within the brain. The set of hardware for these purposes is referred to as a “neuronavigator”. Since the beginning the purpose of this technology was to create a mathematical model describing a proposed coordinate system for the space within the skull. This “fiducial spatial coordinate system” is used as a reference to describe the position of specific structures within this arbitrary defined space with high accuracy. Robust computer technologies made possible the real-time quantitative spatial fusion of images of the patient’s brain with the 3D instantaneous position of surgical instruments or probes detected by motion capture technologies guiding the surgeon to selected targets. The experiences and the results obtained by these new approaches at the Istituto Neurologico Besta are illustrated and the expected developments in the near future are discussed.