The advent of 3D endoscope has revolutionized the field of industrial and medical inspection. It allows visual examination of inaccessible areas like underground pipes and human cavity. Miniature-sized objects like kidney stone and industrial waste products like slags can easily be monitored using 3D endoscope. In this paper, we present a technique to track small objects in 3D endoscopic vision using feature detectors. The proposed methodology uses the input of the operator to segment the target in order to extract reliable and stable features. Grow-cut algorithm is used for interactive segmentation to segment the object in one of the frames and later on, sparse correspondence is performed using SURF feature detectors. SURF feature detection based tracking algorithm is extended to track the object in the stereo endoscopic frames. The evaluation of the proposed technique is done by quantitatively analyzing its performance in two ex vivo environment and subjecting the target to various conditions like deformation, change in illumination, and scale and rotation transformation due to movement of endoscope.
Object. Utilization of pedicle screws (PS) for spine stabilization is common in spinal surgery. With reliance on visual inspection of anatomical landmarks prior to screw placement, the free-hand technique requires a high level of surgeon skill and precision. Three-dimensional (3D) computer-assisted virtual neuronavigation improves the precision of PS placement and minimize steps. Methods. Twenty-three patients with degenerative, traumatic, or neoplastic pathologies received treatment via a novel three-step PS technique that utilizes a navigated power driver in combination with virtual screw technology. 1) Following visualization of neuroanatomy using intraoperative CT, a navigated 3-mm match stick drill bit was inserted at anatomical entry point with screen projection showing virtual screw. 2) Navigated Stryker Cordless Driver with appropriate tap was used to access vertebral body through pedicle with screen projection again showing virtual screw. 3) Navigated Stryker Cordless Driver with actual screw was used with screen projection showing the same virtual screw. One hundred and forty-four consecutive screws were inserted using this three-step, navigated driver, virtual screw technique. Results. Only 1 screw needed intraoperative revision after insertion using the three-step, navigated driver, virtual PS technique. This amounts to a 0.69% revision rate. One hundred percent of patients had intraoperative CT reconstructed images to confirm hardware placement. Conclusions. Pedicle screw placement utilizing the Stryker-Ziehm neuronavigation virtual screw technology with a three step, navigated power drill technique is safe and effective.
In this paper we present novel solutions to support the application of computer assisted surgical interventions in which optical surgical navigation systems based on stereo cameras are used. The objective is to improve both the pre-operative setup and the intra-operative use of the navigation system. Following a short introduction describing the potential for improvements of existing navigation systems new approaches and the components to implement them are described. The pre-operative alignment of the stereo camera is made easier by attaching a small graphic display to its tripod which can show how much of the operating area is covered by the measurement volume of the camera. The intra-operative application is improved by a mechanism for motorized camera motions in order to follow the position of surgical instruments. Furthermore a small display can be attached to a surgical instrument which clearly indicates to the surgeon how to guide the instrument in order to stay on the planned trajectory.
Mini-display (white) and RB (yellow) attached to a reamer tool used for hip replacement surgery.
Spatial positioning accuracy is a key issue in a computer-assisted orthopaedic surgery (CAOS) system. Since intraoperative fluoroscopic images are one of the most important input data to the CAOS system, the quality of these images should have a significant influence on the accuracy of the CAOS system. But the regularities and mechanism of the influence of the quality of intraoperative images on the accuracy of a CAOS system have yet to be studied.Two typical spatial positioning methods – a C-arm calibration-based method and a bi-planar positioning method – are used to study the influence of different image quality parameters, such as resolution, distortion, contrast and signal-to-noise ratio, on positioning accuracy. The error propagation rules of image error in different spatial positioning methods are analyzed by the Monte Carlo method.Correlation analysis showed that resolution and distortion had a significant influence on spatial positioning accuracy. In addition the C-arm calibration-based method was more sensitive to image distortion, while the bi-planar positioning method was more susceptible to image resolution. The image contrast and signal-to-noise ratio have no significant influence on the spatial positioning accuracy. The result of Monte Carlo analysis proved that generally the bi-planar positioning method was more sensitive to image quality than the C-arm calibration-based method.The quality of intraoperative fluoroscopic images is a key issue in the spatial positioning accuracy of a CAOS system. Although the 2 typical positioning methods have very similar mathematical principles, they showed different sensitivities to different image quality parameters. The result of this research may help to create a realistic standard for intraoperative fluoroscopic images for CAOS systems.
A new approach for safe planning transfer using semi-automatically adjustable instrument guides, by Jeromin et al. MRCAS (2018) e1907
Abstract:
Accurate planning transfer is a prerequisite for successful operative care. For different applications, diverse computer‐assisted systems have been developed and clinically evaluated. This paper presents the implementation and evaluation of a new modular concept. The approach is based on passive application specific kinematics that are semi‐automatically adjusted using a universal hand‐held computer controlled Smart Screw Driver.
The system was realized for pedicle screw instrumentation and evaluated according to IEC 60601‐1‐6 (usability engineering). The accuracies of the drill holes achieved were comparable with robotic approaches, while operation time and radiation were reduced compared with conventional operation techniques. The adjustment procedure has proven high learnability and user satisfaction.
The next step will be optimization of the kinematic structure and fixation to the patient in order to increase accuracies of planning transfer as well as evaluation of the overall system by medical staff in preclinical and clinical studies.
Experimental set‐up for usability evaluation of the whole 4 DOF mechanism and SSD system for planning transfer of drilling sleeve poses
Purpose
The aim of study is to evaluate the accuracy of a navigation system during curved peri-acetabular osteotomy (CPO).
Methods
Forty-seven patients (53 hips) with hip dysplasia were enrolled and underwent CPO with or without navigation during surgery. Clinical and radiographical evaluations were performed and compared between the navigation group and non-navigation group, post-operatively.
Results
The clinical outcomes were not significantly different between the navigation and non-navigation groups. Furthermore, post-operative reorientation of the acetabular fragment was similar between the navigation and non-navigation groups. However, the discrepancy between the pre-operative planning line and post-operative osteotomy line was significantly improved in the navigation group compared with that in the non-navigation group (p < 0.05). Further, the complication rate was significantly improved in the navigation group (p < 0.001).
Conclusion
The accuracy of the osteotomy’s position was significantly improved by using the navigation. Therefore, the use of navigation during peri-acetabular osteotomy can avoid complications.
The measurement of the distance between the 100-mm radius sphere line that was determined during pre-operative planning and the post-operative iliac bone surface (the error distance) on the a coronal and b axial planes. a The error distance outside the pelvis on the coronal plane (50–45.5 mm= 4.5 mm). b The error of the distance inside the pelvis on the axial plane (57.8–50 mm= 7.8 mm)
Since the early 1970s, total knee arthroplasties have undergone many changes in both their design and their surgical instrumentation. It soon became apparent that to improve prosthesis durability, it was essential to have instruments which allowed them to be fitted reliably and consistently. Despite increasingly sophisticated surgical techniques, preoperative objectives were only met in 75% of cases, which led to the development, in the early 1990s, in Grenoble (France), of computer-assisted orthopaedic surgery for knee prosthesis implantation. In the early 2000s, many navigation systems emerged, some including pre-operative imagery (“CT-based”), others using intra-operative imagery (“fluoroscopy-based”), and yet others with no imagery at all (“imageless”), which soon became the navigation “gold standard”. They use an optoelectronic tracker, markers which are fixed solidly to the bones and instruments, and a navigation workstation (computer), with a control system (e.g. pedal). Despite numerous studies demonstrating the benefit of computer navigation in meeting preoperative objectives, such systems have not yet achieved the success they warrant, for various reasons we will be covering in this article. If the latest navigation systems prove to be as effective as the older systems, they should give this type of technology a well-deserved boost.
Objective
Advances in video and fiber optics since the 1990s have led to the development of several commercially available high-definition neuroendoscopes. This technological improvement, however, has been surpassed by the smartphone revolution. With the increasing integration of smartphone technology into medical care, the introduction of these high-quality computerized communication devices with built-in digital cameras offers new possibilities in neuroendoscopy. The aim of this study was to investigate the usefulness of smartphone-endoscope integration in performing different types of minimally invasive neurosurgery.
Methods
The authors present a new surgical tool that integrates a smartphone with an endoscope by use of a specially designed adapter, thus eliminating the need for the video system customarily used for endoscopy. The authors used this novel combined system to perform minimally invasive surgery on patients with various neuropathological disorders, including cavernomas, cerebral aneurysms, hydrocephalus, subdural hematomas, contusional hematomas, and spontaneous intracerebral hematomas.
Results
The new endoscopic system featuring smartphone-endoscope integration was used by the authors in the minimally invasive surgical treatment of 42 patients. All procedures were successfully performed, and no complications related to the use of the new method were observed. The quality of the images obtained with the smartphone was high enough to provide adequate information to the neurosurgeons, as smartphone cameras can record images in high definition or 4K resolution. Moreover, because the smartphone screen moves along with the endoscope, surgical mobility was enhanced with the use of this method, facilitating more intuitive use. In fact, this increased mobility was identified as the greatest benefit of the use of the smartphone-endoscope system compared with the use of the neuroendoscope with the standard video set.
Conclusions
Minimally invasive approaches are the new frontier in neurosurgery, and technological innovation and integration are crucial to ongoing progress in the application of these techniques. The use of smartphones with endoscopes is a safe and efficient new method of performing endoscope-assisted neurosurgery that may increase surgeon mobility and reduce equipment costs.
Intraventricular neuroendoscopy with the use of a smartphone for aqueductal stenosis in a 6-month-old male infant, in whom an abnormal progressive increase in head circumference had developed since birth. A: Photograph obtained during surgery with an MR image of the brain demonstrating hydrocephalus due to idiopathic aqueductal stenosis (red arrow in inset). The endoscopic procedure is performed in a standard manner except for the addition of the iPhone attached to the endoscope, which provided a viewing screen that allowed the surgeon’s gaze to remain on the surgical field. B–E: The iPhone provided the surgeon with endoscopic views of the foramen of Monro (B), an ideal spot for fenestration (C and D), and the final aspect of the field (E). The 4K camera resolution allows adequate visualization of perforating arteries, thus allowing the surgeon to avoid causing inadvertent injuries. After this surgery the patient progressed well with no need for additional procedures.
Primary bone sarcoma of the pelvis is one of the more challenging pathologies treated by orthopedic oncologists. In particular, their anatomic complexity contributes to delays in diagnosis and high rates of positive margins with associated high rates of local recurrence, all contributing to poor outcomes in this patient population. Computer-assisted surgery in the form of navigation and patient-specific instrumentation has shown promise in other fields of orthopedics. Intuitively, in an effort to improve tumor resections and improve oncologic outcomes, surgeons have been working to apply these advances to orthopedic oncology. Early studies have demonstrated benefits from guided pelvic resections, with studies demonstrating improved resection accuracy, fewer positive margins and decreased rates of local recurrence. Although these techniques are promising and will likely become an essential tool for orthopedic oncologist, surgeons must understand the limitations and costs associated with each technology before blind adoption.
The preoperative computed tomography and magnetic resonance imaging were utilized to create a virtual resection plane and representative 3-dimensional model (3D Systems, Rock Hills, SC). A, Preoperative virtual 3-dimensional model of the sacral-based chondrosarcoma with the associated resection planes and planned postresection defect. B, Virtual representation of 3D-printed resection guides and their intraoperative placement. C, Stereolithographic 3D-printed pelvic model (3D Systems, Rock Hills, SC) made from a photopolymer resin with patient-specific sacral mass, vascular anatomy, and resection planes.
Objective
Advanced three-dimensional (3D) diagnostics and preoperative planning are the first steps in computer-assisted surgery (CAS). They are an integral part of the workflow, and allow the surgeon to adequately assess the fracture and to perform virtual surgery to find the optimal implant position. The goal of this study was to evaluate the accuracy and predictability of 3D diagnostics and preoperative virtual planning without intraoperative navigation in orbital reconstruction.
Methods
In 10 cadaveric heads, 19 complex orbital fractures were created. First, all fractures were reconstructed without preoperative planning (control group) and at a later stage the reconstructions were repeated with the help of preoperative planning. Preformed titanium mesh plates were used for the reconstructions by two experienced oral and maxillofacial surgeons. The preoperative virtual planning was easily accessible for the surgeon during the reconstruction. Computed tomographic scans were obtained before and after creation of the orbital fractures and postoperatively. Using a paired t-test, implant positioning accuracy (translation and rotations) of both groups were evaluated by comparing the planned implant position with the position of the implant on the postoperative scan.
Results
Implant position improved significantly (P < 0.05) for translation, yaw and roll in the group with preoperative planning (Table 1). Pitch did not improve significantly (P = 0.78).
Conclusion
The use of 3D diagnostics and preoperative planning without navigation in complex orbital wall fractures has a positive effect on implant position. This is due to a better assessment of the fracture, the possibility of virtual surgery and because the planning can be used as a virtual guide intraoperatively. The surgeon has more control in positioning the implant in relation to the rim and other bony landmarks.
