Excitation coil for sentinel lymph node harvesting: design, digital twin and prototype.

A recently developed prototype (Laparoscopic Differential Magnetometer, in short LapDiffMag) identifies magnetic tracer accumulated inside sentinel lymph nodes (SLNs) during clinical laparoscopic procedures. The LapDiffMag relies on excitation of superparamagnetic iron oxide nanoparticles (SPIONs) and subsequent laparoscopic detection based on a nonlinear detection principle. The prototype uses an excitation coil to generate a magnetic field needed to activate SPIONs. This study reports on the process of developing a new excitation coil by describing the design choices based upon clinical requirements, by modeling delivered magnetic field using digital twin, and by comparing the magnetic fields of modeled and manufactured prototype. Digital twin technology was used to produce relevant and reliable data to demonstrate the safety and effectiveness of the excitation coil. The magnetic field originating from manufactured prototype was validated at two different heights above the excitation coil and have shown a good concordance to the data generated by its digital twin. Clinical Relevance- Current standard-of-care for a variety of tumor types consists of minimally invasive radical resection of primary tumor and regional lymph nodes (LNs). The newly introduced excitation coil will (after full validation) enable minimally invasive harvesting of sentinel LNs by means of magnetic tracer detection.

Efficiency in image-guided robotic and conventional camera steering: a prospective randomized controlled trial.

BACKGROUND: Robotic camera steering systems have been developed to facilitate endoscopic surgery. In this study, a randomized controlled trial was conducted to compare conventional human camera control with the AutoLap™ robotic camera holder in terms of efficiency and user experience when performing routine laparoscopic procedures. Novelty of this system relates to the steering method, which is image based. METHODS: Patients undergoing an elective laparoscopic hemicolectomy, sigmoid resection, fundoplication and cholecystectomy between September 2016 and January 2018 were included. Stratified block randomization was used for group allocation. The primary aim of this study was to compare the efficiency of robotic and human camera control, measured with surgical team size and total operating time. Secondary outcome parameters were number of cleaning moments of the laparoscope and the post-study system usability questionnaire. RESULTS: A total of 100 patients were randomized to have robotic (50) versus human (50) camera control. Baseline characteristics did not differ significantly between groups. In the robotic group, 49/50 (98%) of procedures were carried out without human camera control, reducing the surgical team size from four to three individuals. The median total operative time (60.0 versus 53.0 min, robotic vs. control) was not significantly different, p = 0.122. The questionnaire showed a positive user satisfaction and easy control of the robotic camera holder. CONCLUSION: Image-based robotic camera control can reduce surgical team size and does not result in significant difference in operative time compared to human camera control. Moreover, robotic image-guided camera control was associated with positive user experience.

Comparative analysis of virulence determinants and mass spectral profiles of Finnish and Lithuanian endodontic Enterococcus faecalis isolates.

INTRODUCTION: Putative virulence factors of Enterococcus faecalis have been proposed by several workers and, by analogy, these have been linked to strains of endodontic origin. However, their distribution within the cell population is unknown. In the present study, isolates were taken from the dental root canals of two defined human populations, Lithuanian and Finnish, and examined for a range of virulence properties. In addition, surface-associated molecules and intracellular proteins were compared using matrix-assisted laser desorption-ionization/mass spectrometry (MALDI-TOF-MS) and ProteinChip capture/MS (SELDI-TOF-MS), respectively. METHODS: Twenty-three Lithuanian and 35 Finnish dental root canal isolates were included. The esp, gelE, ace and efaA genes were detected by polymerase chain reaction, and cytolysin and gelatinase phenotypes were determined by hydrolysis of horse blood agar and gelatine agar, respectively. Protein extracts and surface-associated molecules of whole cells were analysed by SELDI-TOF-MS and MALDI-TOF-MS, respectively. RESULTS: Presence of esp (n = 15), cytolysin (n = 9), ace (n = 55) and efaA (n = 58) was not statistically different in the two samples, whereas gelE and gelatinase production was detected more frequently in the Finnish material (chi-squared, P < 0.01). Analysis of protein profiles by SELDI-TOF-MS showed clustering of cytolysin-producing strains, whereas MALDI-TOF-MS generated profiles that clustered according to the samples' origin and, furthermore, to atypical quinupristin-dalfopristin susceptibility. CONCLUSION: A high prevalence of virulence factors was demonstrated in both population types. SELDI-TOF-MS and MALDI-TOF-MS proved useful in distinguishing between different E. faecalis phenotypes and they may be useful technologies for elucidating the eco-distribution of E. faecalis in humans.