A self-developed and constructed robot for minimally invasive cochlear implantation

Conclusion: A robot built specifically for stereotactic cochlear implantation provides equal or better accuracy levels together with a better integration into a clinical environment, when compared to existing approaches based on industrial robots. Objectives: To evaluate the technical accuracy of a robotic system developed specifically for lateral skull base surgery in an experimental setup reflecting the intended clinical application. The invasiveness of cochlear electrode implantation procedures may be reduced by replacing the traditional mastoidectomy with a small tunnel slightly larger in diameter than the electrode itself. Methods: The end-to-end accuracy of the robot system and associated image-guided procedure was evaluated on 15 temporal bones of whole head cadaver specimens. The main components of the procedure were as follows: reference screw placement, cone beam CT scan, computer-aided planning, pair-point matching of the surgical plan, robotic drilling of the direct access tunnel, and post-operative cone beam CT scan and accuracy assessment. Results: The mean accuracy at the target point (round window) was 0.56 ± 41 mm with an angular misalignment of 0.88 ± 0.41°. The procedural time of the registration process through the completion of the drilling procedure was 25 ± 11 min. The robot was fully operational in a clinical environment.

Surfactant protein D modulates allergen particle uptake and inflammatory response in a human epithelial airway model

Background Allergen-containing subpollen particles (SPP) are released from whole plant pollen upon contact with water or even high humidity. Because of their size SPP can preferentially reach the lower airways where they come into contact with surfactant protein (SP)-D. The aim of the present study was to investigate the influence of SP-D in a complex three-dimensional human epithelial airway model, which simulates the most important barrier functions of the epithelial airway. The uptake of SPP as well as the secretion of pro-inflammatory cytokines was investigated. Methods SPP were isolated from timothy grass and subsequently fluorescently labeled. A human epithelial airway model was built by using human Type II-pneumocyte like cells (A549 cells), human monocyte derived macrophages as well as human monocyte derived dendritic cells. The epithelial cell model was incubated with SPP in the presence and absence of surfactant protein D. Particle uptake was evaluated by confocal microscopy and advanced computer-controlled analysis. Finally, human primary CD4+ T-Cells were added to the epithelial airway model and soluble mediators were measured by enzyme linked immunosorbent assay or bead array. Results SPP were taken up by epithelial cells, macrophages, and dendritic cells. This uptake coincided with secretion of pro-inflammatory cytokines and chemokines. SP-D modulated the uptake of SPP in a cell type specific way (e.g. increased number of macrophages and epithelial cells, which participated in allergen particle uptake) and led to a decreased secretion of pro-inflammatory cytokines. Conclusion These results display a possible mechanism of how SP-D can modulate the inflammatory response to inhaled allergen.

Automated Portal Placement for Arthroscopic Hip Surgery

Placing portal incisions during arthroscopic hip surgery presents challenges for surgeons in terms of anatomic accessibility and patient safety. Based on key anatomic landmarks and portal placement information from recent literature, suggested portal incisions were determined. Guidance in the placement of the three most common portal incision locations (anterior, anterolateral, and posterolateral) for arthroscopic surgery; in addition to visual feedback on tool trajectory to the hip joint is provided in real time by a computer aided system for hip arthroscopy. By simplifying the portal placement process, one of the most challenging aspects of arthroscopic hip surgery, an increased use of this minimally invasive technique could be possible. In addition to portal information, improvements to an existing computer aided system for arthroscopic hip surgery, including a new hip model and redesigned mechanical tracking linkage, were completed.

Intraoperative three-dimensional fluoroscopic cholangiography

Precise intraoperative assessment of the architecture of the biliary tree could reduce lesions to intra- or extrahepatic bile ducts. The aim of this study was to test feasibility of intraoperative three-dimensional imaging during liver resections. Isocentric C-arm fluoroscopy acquires three-dimensional images during a 190 degrees orbital rotation. The bile ducts were displayed three-dimensionally by realtime rotational projections or multiplanar reconstructions. The technique was established ex vivo in a preserved cadaveric human liver. Intraoperative three-dimensional cholangiography was performed in five patients with centrally located liver malignancies. Complete data acquisition in 3 patients depicted precise anatomical details of the architecture of the biliary tree up to third order divisions. Biliary imaging can be improved by the application of real-time intraoperative three-dimensional cholangiography. For the development of computer-aided navigation in hepatobiliary procedures, this technique could be an important prerequisite for defining landmarks of the liver in a three-dimensional space.

Augmenting the effective field of view of optical tracking cameras--a way to overcome difficulties during intraoperative camera alignment

An Internet survey demonstrated the existence of problems related to intraoperative tracking camera set-up and alignment. It is hypothesized that these problems are a result of the limited field of view of today's optoelectronic camera systems, which is usually insufficiently large to keep the entire site of surgical action in view during an intervention. A method is proposed to augment a camera's field of view by actively controlling camera orientation, enabling it to track instruments as they are used intraoperatively. In an experimental study, an increase of almost 300% was found in the effective volume in which instruments could be tracked.

Accuracy of navigated surgery of the pelvis after surface matching with an a-mode ultrasound probe

Computer-aided surgery (CAS) allows for real-time intraoperative feedback resulting in increased accuracy, while reducing intraoperative radiation. CAS is especially useful for the treatment of certain pelvic ring fractures, which necessitate the precise placement of screws. Flouroscopy-based CAS modules have been developed for many orthopedic applications. The integration of the isocentric flouroscope even enables navigation using intraoperatively acquired three-dimensional (3D) data, though the scan volume and imaging quality are limited. Complicated and comprehensive pathologies in regions like the pelvis can necessitate a CT-based navigation system because of its larger field of view. To be accurate, the patient's anatomy must be registered and matched with the virtual object (CT data). The actual precision within the region of interest depends on the area of the bone where surface matching is performed. Conventional surface matching with a solid pointer requires extensive soft tissue dissection. This contradicts the primary purpose of CAS as a minimally invasive alternative to conventional surgical techniques. We therefore integrated an a-mode ultrasound pointer into the process of surface matching for pelvic surgery and compared it to the conventional method. Accuracy measurements were made in two pelvic models: a foam model submerged in water and one with attached porcine muscle tissue. Three different tissue depths were selected based on CT scans of 30 human pelves. The ultrasound pointer allowed for registration of virtually any point on the pelvis. This method of surface matching could be successfully integrated into CAS of the pelvis.

Concept Fire Truck

A prototype Concept Fire Truck was designed using Autodesk Inventor 3D Design Software. Various pictures of old-time and toy fire trucks were utilized for this project. The prototype was printed using a 3D printer to verify that all parts of the truck would fit and work as intended.

[Navigation and robotics of the lateral skull base]

Computer-aided microscopic surgery of the lateral skull base is a rare intervention in daily practice. It is often a delicate and difficult minimally invasive intervention, since orientation between the petrous bone and the petrous bone apex is often challenging. In the case of aural atresia or tumors the normal anatomical landmarks are often absent, making orientation more difficult. Navigation support, together with imaging techniques such as CT, MR and angiography, enable the surgeon in such cases to perform the operation more accurately and, in some cases, also in a shorter time. However, there are no internationally standardised indications for navigated surgery on the lateral skull base. Miniaturised robotic systems are still in the initial validation phase.