Augmented navigation

Spinal fixation procedures have the inherent risk of causing damage to vulnerable anatomical structures such as the spinal cord, nerve roots, and blood vessels. To prevent complications, several technological aids have been introduced. Surgical navigation is the most widely used, and guides the surgeon by providing the position of the surgical instruments and implants in relation to the patient anatomy based on radiographic images. Navigation can be extended by the addition of a robotic arm to replace the surgeon’s hand to increase accuracy. Another line of surgical aids is tissue sensing equipment, that recognizes different tissue types and provides a warning system built into surgical instruments. All these technologies are under continuous development and the optimal solution is yet to be found. The aim of this thesis was to study the use of Augmented Reality (AR), Virtual Reality (VR), Artificial Intelligence (AI), and tissue sensing technology in spinal navigation to improve precision and prevent surgical errors. The aim of Paper I was to develop and validate an algorithm for automatizing the intraoperative planning of pedicle screws. An AI algorithm for automatic segmentation of the spine, and screw path suggestion was developed and evaluated. In a clinical study of advanced deformity cases, the algorithm could provide correct suggestions for 86% of all pedicles—or 95%, when cases with extremely altered anatomy were excluded. Paper II evaluated the accuracy of pedicle screw placement using a novel augmented reality surgical navigation (ARSN) system, harboring the above-developed algorithm. Twenty consecutively enrolled patients, eligible for deformity correction surgery in the thoracolumbar region, were operated on using the ARSN system. In this cohort, we found a pedicle screw placement accuracy of 94%, as measured according to the Gertzbein grading scale. The primary goal of Paper III was to validate an extension of the ARSN system for placing pedicle screws using instrument tracking and VR. In a porcine cadaver model, it was demonstrated that VR instrument tracking could successfully be integrated with the ARSN system, resulting in pedicle devices placed within 1.7 ± 1.0 mm of the planed path. Paper IV examined the feasibility of a robot-guided system for semi-automated, minimally invasive, pedicle screw placement in a cadaveric model. Using the robotic arm, pedicle devices were placed within 0.94 ± 0.59 mm of the planned path. The use of a semi-automated surgical robot was feasible, providing a higher technical accuracy compared to non-robotic solutions. Paper V investigated the use of a tissue sensing technology, diffuse reflectance spectroscopy (DRS), for detecting the cortical bone boundary in vertebrae during pedicle screw insertions. The technology could accurately differentiate between cancellous and cortical bone and warn the surgeon before a cortical breach. Using machine learning models, the technology demonstrated a sensitivity of 98% [range: 94-100%] and a specificity of 98% [range: 91-100%]. In conclusion, several technological aids can be used to improve accuracy during spinal fixation procedures. In this thesis, the advantages of adding AR, VR, AI and tissue sensing technology to conventional navigation solutions were studied

Evaluation of a Novel Teleradiology Technology for Image-Based Distant Consultations: Applications in Neurosurgery.

To access publisher's full text version of this article, please click on the hyperlink in Additional Links field or click on the hyperlink at the top of the page marked DownloadIn emergency settings, fast access to medical imaging for diagnostic is pivotal for clinical decision making. Hence, a need has emerged for solutions that allow rapid access to images on small mobile devices (SMD) without local data storage. Our objective was to evaluate access times to full quality anonymized DICOM datasets, comparing standard access through an authorized hospital computer (AHC) to a zero-footprint teleradiology technology (ZTT) used on a personal computer (PC) or SMD using national and international networks at a regional neurosurgical center. Image datasets were sent to a senior neurosurgeon, outside the hospital network using either an AHC and a VPN connection or a ZTT (Image Over Globe (IOG)), on a PC or an SMD. Time to access DICOM images was measured using both solutions. The mean time using AHC and VPN was 250 ± 10 s (median 249 s (233-274)) while the same procedure using IOG took 50 ± 8 s (median 49 s (42-60)) on a PC and 47 ± 20 s (median 39 (33-88)) on a SMD. Similarly, an international consultation was performed requiring 23 ± 5 s (median 21 (16-33)) and 27 ± 1 s (median 27 (25-29)) for PC and SMD respectively. IOG is a secure, rapid and easy to use telemedicine technology facilitating efficient clinical decision making and remote consultations. Keywords: clinical decision-making; neurosurgery; remote consultation; telemedicine; teleradiology

Feasibility and accuracy of a robotic guidance system for navigated spine surgery in a hybrid operating room: a cadaver study.

To access publisher's full text version of this article, please click on the hyperlink in Additional Links field or click on the hyperlink at the top of the page marked DownloadThe combination of navigation and robotics in spine surgery has the potential to accurately identify and maintain bone entry position and planned trajectory. The goal of this study was to examine the feasibility, accuracy and efficacy of a new robot-guided system for semi-automated, minimally invasive, pedicle screw placement. A custom robotic arm was integrated into a hybrid operating room (OR) equipped with an augmented reality surgical navigation system (ARSN). The robot was mounted on the OR-table and used to assist in placing Jamshidi needles in 113 pedicles in four cadavers. The ARSN system was used for planning screw paths and directing the robot. The robot arm autonomously aligned with the planned screw trajectory, and the surgeon inserted the Jamshidi needle into the pedicle. Accuracy measurements were performed on verification cone beam computed tomographies with the planned paths superimposed. To provide a clinical grading according to the Gertzbein scale, pedicle screw diameters were simulated on the placed Jamshidi needles. A technical accuracy at bone entry point of 0.48 ± 0.44 mm and 0.68 ± 0.58 mm was achieved in the axial and sagittal views, respectively. The corresponding angular errors were 0.94 ± 0.83° and 0.87 ± 0.82°. The accuracy was statistically superior (p < 0.001) to ARSN without robotic assistance. Simulated pedicle screw grading resulted in a clinical accuracy of 100%. This study demonstrates that the use of a semi-automated surgical robot for pedicle screw placement provides an accuracy well above what is clinically acceptable

”HAR DU INTE GODA RELATIONER INOM ELEVGRUPPEN SÅ KOMMER JU ELEVER ATT OTRIVAS” : -En kvalitativ studie om relationskapande i fritidshemmet

Examensarbetets syfte var att få en fördjupad förståelse och kunskap om relationsarbete på fritidshemmet, hur fritidslärares bemötande och förhållningssätt främjar och påverkar relationer och deras betydelse för eleverna. För syftet insamlades empiriska data i en kvalitativ intervjustudie med åtta informanter, samtliga yrkesverksamma fritidspedagoger/fritidslärare i fritidshemmet. Intervjuerna transkriberades och analyserades tematiskt i förhållande till studiens teoretiska utgångspunkt, ett sociokulturellt perspektiv på lärande. I studiens resultat framkommer att fritidslärarnas arbete för att främja goda relationer och nå alla elever med olika behov är grundläggande för att få en fungerande verksamhet på fritidshemmet. Goda relationer utgör enligt studiens informanter grunden för elevernas trivsel, trygghet och mående som i sig utgör grunden för lärande. Samtliga av de medverkande fritidslärarna strävar efter att främja goda relationer, genom att använda sig av olika former av samtal och lekar. Studiens resultat ligger därmed teoretiskt i linje med det sociokulturella perspektivet på lärande. Studiens övergripande slutsats är att fritidslärare i sin dagliga verksamhet behöver ha en bred verktygslåda för att kunna variera sitt förhållningssätt och bemötande av alla olika elever

”HAR DU INTE GODA RELATIONER INOM ELEVGRUPPEN SÅ KOMMER JU ELEVER ATT OTRIVAS” : -En kvalitativ studie om relationskapande i fritidshemmet

Examensarbetets syfte var att få en fördjupad förståelse och kunskap om relationsarbete på fritidshemmet, hur fritidslärares bemötande och förhållningssätt främjar och påverkar relationer och deras betydelse för eleverna. För syftet insamlades empiriska data i en kvalitativ intervjustudie med åtta informanter, samtliga yrkesverksamma fritidspedagoger/fritidslärare i fritidshemmet. Intervjuerna transkriberades och analyserades tematiskt i förhållande till studiens teoretiska utgångspunkt, ett sociokulturellt perspektiv på lärande. I studiens resultat framkommer att fritidslärarnas arbete för att främja goda relationer och nå alla elever med olika behov är grundläggande för att få en fungerande verksamhet på fritidshemmet. Goda relationer utgör enligt studiens informanter grunden för elevernas trivsel, trygghet och mående som i sig utgör grunden för lärande. Samtliga av de medverkande fritidslärarna strävar efter att främja goda relationer, genom att använda sig av olika former av samtal och lekar. Studiens resultat ligger därmed teoretiskt i linje med det sociokulturella perspektivet på lärande. Studiens övergripande slutsats är att fritidslärare i sin dagliga verksamhet behöver ha en bred verktygslåda för att kunna variera sitt förhållningssätt och bemötande av alla olika elever

Fluoroscopy-Assisted C1&ndash;C2 Posterior Fixation for Atlantoaxial Instability: A Single-Center Case Series of 78 Patients

Background and Objectives: Posterior C1&ndash;C2 fixation, with trans-articular screws (TAS) or screw-rod-construct (SRC), is the main surgical technique for atlantoaxial instability, and can be performed with a fluoroscopy-assisted free-handed technique or 3D navigation. This study aimed to evaluate complications, radiological and functional outcome in patients treated with a fluoroscopy-assisted technique. Materials and Methods: A single-center consecutive cohort study was conducted of all adult patients who underwent posterior C1&ndash;C2 fixation, using TAS or CRS, between 2005&ndash;2019. Results: Seventy-eight patients were included, with a median follow-up time of 6.8 years. Trauma was the most common injury mechanism (64%), and cervicalgia the predominant preoperative symptom (88%). TAS was used in 33%, and SRC in 67% of cases. Surgery was associated with a significant reduction in cervicalgia (from 88% to 26%, p &lt; 0.001). The most common complications were vertebral artery injury (n = 2, 2.6%), and screw malposition (n = 5, 6.7%, of which 2 were TAS and 3 were SRC). No patients deteriorated in their functional status following surgery. Conclusions: Fluoroscopy-assisted C1&ndash;C2 fixation with TAS or SRC is a safe and effective treatment for atlantoaxial instability, with a low complication rate, few surgical revisions, and pain relief in the majority of the cases

An organic electronic biomimetic neuron enables auto-regulated neuromodulation

a b s t r a c t Current therapies for neurological disorders are based on traditional medication and electric stimulation. Here, we present an organic electronic biomimetic neuron, with the capacity to precisely intervene with the underlying malfunctioning signalling pathway using endogenous substances

Feasibility and Accuracy of Thoracolumbar Pedicle Screw Placement Using an Augmented Reality Head Mounted Device

Background: To investigate the accuracy of augmented reality (AR) navigation using the Magic Leap head mounted device (HMD), pedicle screws were minimally invasively placed in four spine phantoms. Methods: AR navigation provided by a combination of a conventional navigation system integrated with the Magic Leap head mounted device (AR-HMD) was used. Forty-eight screws were planned and inserted into Th11-L4 of the phantoms using the AR-HMD and navigated instruments. Postprocedural CT scans were used to grade the technical (deviation from the plan) and clinical (Gertzbein grade) accuracy of the screws. The time for each screw placement was recorded. Results: The mean deviation between navigation plan and screw position was 1.9 ± 0.7 mm (1.9 [0.3–4.1] mm) at the entry point and 1.4 ± 0.8 mm (1.2 [0.1–3.9] mm) at the screw tip. The angular deviation was 3.0 ± 1.4° (2.7 [0.4–6.2]°) and the mean time for screw placement was 130 ± 55 s (108 [58–437] s). The clinical accuracy was 94% according to the Gertzbein grading scale. Conclusion: The combination of an AR-HMD with a conventional navigation system for accurate minimally invasive screw placement is feasible and can exploit the benefits of AR in the perspective of the surgeon with the reliability of a conventional navigation system

Diffuse reflectance spectroscopy sensor to differentiate between glial tumor and healthy brain tissue: A proof-of-concept study

Glial tumors grow diffusely in the brain. Survival is correlated to the extent of tumor removal, but tumor borders are often invisible. Resection beyond the borders as defined by conventional methods may further improve prognosis. In this proof-of-concept study, we evaluate diffuse reflectance spectroscopy (DRS) for discrimination between glial tumors and normal brain ex vivo. DRS spectra and histology were acquired from 22 tumor samples and nine brain tissue samples retrieved from 30 patients. The content of biological chromophores and scattering features were estimated by fitting a model derived from diffusion theory to the DRS spectra. DRS parameters differed significantly between tumor and normal brain tissue. Classification using random forest yielded a sensitivity and specificity for the detection of low-grade gliomas of 82.0% and 82.7%, respectively, and the area under curve (AUC) was 0.91. Applied in a hand-held probe or biopsy needle, DRS has the potential to provide intra-operative tissue analysis

Multi-view 3D skin feature recognition and localization for patient tracking in spinal surgery applications

Background Minimally invasive spine surgery is dependent on accurate navigation. Computer-assisted navigation is increasingly used in minimally invasive surgery (MIS), but current solutions require the use of reference markers in the surgical field for both patient and instruments tracking. Purpose To improve reliability and facilitate clinical workflow, this study proposes a new marker-free tracking framework based on skin feature recognition. Methods Maximally Stable Extremal Regions (MSER) and Speeded Up Robust Feature (SURF) algorithms are applied for skin feature detection. The proposed tracking framework is based on a multi-camera setup for obtaining multi-view acquisitions of the surgical area. Features can then be accurately detected using MSER and SURF and afterward localized by triangulation. The triangulation error is used for assessing the localization quality in 3D. Results The framework was tested on a cadaver dataset and in eight clinical cases. The detected features for the entire patient datasets were found to have an overall triangulation error of 0.207 mm for MSER and 0.204 mm for SURF. The localization accuracy was compared to a system with conventional markers, serving as a ground truth. An average accuracy of 0.627 and 0.622 mm was achieved for MSER and SURF, respectively. Conclusions This study demonstrates that skin feature localization for patient tracking in a surgical setting is feasible. The technology shows promising results in terms of detected features and localization accuracy. In the future, the framework may be further improved by exploiting extended feature processing using modern optical imaging techniques for clinical applications where patient tracking is crucial