Robust realtime instrument tracking in ultrasound images for visual servoing

Abstract-Minimally invasive surgery in combination with ultrasound (US) imaging imposes high demands on the surgeon's hand-eye-coordination capabilities. A possible solution to reduce these requirements is minimally invasive robotic surgery in which the instrument is guided by visual servoing towards the goal defined by the surgeon in the US image. This approach requires robust tracking of the instrument in the US image sequences which is known to be difficult due to poor image quality. This paper presents computer vision algorithms and results of visual servoing experiments. Adaptive thresholding according to Otsu's method allows to cope with large intensity variations of the instrument echo. Subsequently applied morphological operations suppress noise and echo artefacts. A fast labelling algorithm based on run length coding allows for realtime labelling of the regions. A heuristic exploiting region size and region velocity helps to overcome ambiguities. The overall computation time is less than 10 ms per frame on a standard PC. The tracking algorithm requires no information about texture and shape which are known to be very unreliable in US image sequences. Experimental results for different instrument materials (polyvinyl chloride, polyurethane, nylon, and plexiglas) are given, illustrating the performance of the proposed approach: when chosing the appropriate material the reconstructed trajectories are smooth and only few outliers occur. As a consequence, the visual servoing loop showed to be robust and stable

Factors Associated to the Onset of Mental Illness Among Hospitalized Migrants to Italy: A Chart Review

Migration is a complex phenomenon and mental illness among immigrants remains a major matter of concern in Italy and worldwide. 243 medical and pharmacy records of patients admitted to University of Foggia hospital between 2004 and 2018 were retrospectively screened and included in the study. Socio-demographic data and clinical characteristics of inpatients were compared in those with and without first-episode of mental illness (FEMI). Subjects (140 men, 103 women; aged 34.4 ± 10.2 years) represented 6.66 ± 3.73% of all hospitalizations in 15 years. Nearly half of them (48.5%) had emigrated from other European countries. 30.8% were diagnosed with a DSM-IV TR unspecified psychosis. 103 patients (42.3%) were in first-lifetime episodes of mental illness. Factors significantly associated with FEMI were: younger age, sex (men), immigrating from Africa, poor language proficiency, lower amount of prescribed psychotropics. Mental health among immigrants is of major concern in Italy. Our findings report on factors possibly associated to the onset of mental illness among immigrant psychiatric inpatients

Muscle atonia index during multiple sleep latency test: A possible marker to differentiate narcolepsy from other hypersomnias

Objective: The complexity and delay of the diagnosis of narcolepsy require several diagnostic tests and invasive procedures such as lumbar puncture. Our study aimed to determine the changes in muscle tone (atonia index, AI) at different levels of vigilance during the entire multiple sleep latency test (MSLT) and each nap in people with narcolepsy type 1 (NT1) and 2 (NT2) compared with other hypersomnias and its potential diagnostic value.Methods: Twenty-nine patients with NT1 (11 M 18F, mean age 34.9 years, SD 16.8) and sixteen with NT2 (10 M 6F, mean age 39 years, SD 11.8) and 20 controls with other hypersomnias (10 M, 10F mean age 45.1 years, SD 15.1) were recruited. AI was evaluated at different levels of vigilance (Wake and REM sleep) in each nap and throughout the MSLT of each group. The validity of AI in identifying patients with narcolepsy (NT1 and NT2) was analyzed using receiver operating characteristic (ROC) curves.Results: AI during wakefulness (WAI) was significantly higher in the narcolepsy groups (NT1 and NT2 p < 0.001) compared to the hypersomniac group. AI during REM sleep (RAI) (p = 0.03) and WAI in nap with sudden onsets of REM sleep periods (SOREMP) (p = 0.001) were lower in NT1 than in NT2. The ROC curves showed high AUC values for WAI (NT1 0.88; Best Cut-off > 0.57, Sensitivity 79.3 % Specificity 90 %; NT2 0.89 Best Cut-off > 0.67 Sensitivity 87.5 % Specificity 95 %; NT1 and NT2 0.88 Best Cut-off > 0.57 Sensitivity 82.2 % Specificity 90 %) in discriminating subjects suffering from other hypersomnias. RAI and WAI in nap with SOREMP showed a poor AUC value (RAI AUC: 0.7 Best cutoff 0.7 Sensitivity 50 % Specificity 87.5 %; WAI in nap before SOREMP AUC: 0.66, Best cut-off < 0.82 sensitivity 61.9 % and specificity 67.35 %) differentiating NT1 and NT2.Conclusions: WAI may represent an encouraging electrophysiological marker of narcolepsy and suggests a vulnerable tendency to dissociative wake / sleep dysregulation lacking in other forms of hypersomnia.Significance: AI during wakefulness may help distinguish between narcolepsy and other hypersomnias.(c) 2023 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved