scholarly journals A novel 3D-vision–based collaborative robot as a scope holding system for port surgery: a technical feasibility study

2022 ◽  
Vol 52 (1) ◽  
pp. E13
Keyword(s):  
Longitudinal Axis ◽  
Visual Observation ◽  
High Definition ◽  
Technical Feasibility ◽  
3D Vision ◽  
3D Camera ◽  
Stable Vision ◽  
Optimal Illumination ◽  
User Friendly

OBJECTIVE A clear, stable, suitably located vision field is essential for port surgery. A scope is usually held by hand or a fixing device. The former yields fatigue and requires lengthy training, while the latter increases inconvenience because of needing to adjust the scope. Thus, the authors innovated a novel robotic system that can recognize the port and automatically place the scope in an optimized position. In this study, the authors executed a preliminary experiment to test this system’s technical feasibility and accuracy in vitro. METHODS A collaborative robotic (CoBot) system consisting of a mechatronic arm and a 3D camera was developed. With the 3D camera and programmed machine vision, CoBot can search a marker attached to the opening of the surgical port, followed by automatic alignment of the scope’s axis with the port’s longitudinal axis so that optimal illumination and visual observation can be achieved. Three tests were conducted. In test 1, the robot positioned a laser range finder attached to the robot’s arm to align the sheath’s center axis. The laser successfully passing through two holes in the port sheath’s central axis defined successful positioning. Researchers recorded the finder’s readings, demonstrating the actual distance between the finder and the sheath. In test 2, the robot held a high-definition exoscope and relocated it to the setting position. Test 3 was similar to test 2, but a metal holder substituted the robot. Trained neurosurgeons manually adjusted the holder. The manipulation time was recorded. Additionally, a grading system was designed to score each image captured by the exoscope at the setting position, and the scores in the two tests were compared using the rank-sum test. RESULTS The CoBot system positioned the finder successfully in all rounds in test 1; the mean height errors ± SD were 1.14 mm ± 0.38 mm (downward) and 1.60 mm ± 0.89 mm (upward). The grading scores of images in tests 2 and 3 were significantly different. Regarding the total score and four subgroups, test 2 showed a more precise, better-positioned, and more stable vision field. The total manipulation time in test 2 was 20 minutes, and for test 3 it was 52 minutes. CONCLUSIONS The CoBot system successfully acted as a robust scope holding system to provide a stable and optimized surgical view during simulated port surgery, providing further evidence for the substitution of human hands, and leading to a more efficient, user-friendly, and precise operation.

Circumferential, not longitudinal, colonic stretch increases synaptic input to mouse prevertebral ganglion neurons

2003 ◽  
Vol 285 (6) ◽  
pp. G1129-G1138 ◽  
Author(s):  
Steven M. Miller ◽  
J. H. Szurszewski
Keyword(s):  
Synaptic Input ◽  
Muscle Tension ◽  
Circular Muscle ◽  
Longitudinal Axis ◽  
Muscle Layer ◽  
Intraluminal Pressure ◽  
Colon Wall ◽  
Mesenteric Ganglion ◽  
Ganglion Neurons

The relationship between longitudinal and circular muscle tension in the mouse colon and mechanosensory excitatory synaptic input to neurons in the superior mesenteric ganglion (SMG) was investigated in vitro. Electrical activity was recorded intracellularly from SMG neurons, and muscle tension was simultaneously monitored in the longitudinal, circumferential, or both axes. Colonic intraluminal pressure and volume changes were also monitored simultaneously with muscle tension changes. The results showed that the frequency of fast excitatory postsynaptic potentials (fEPSPs) in SMG neurons increased when colonic muscle tension decreased, when the colon relaxed and refilled with fluid after contraction, and during receptive relaxation preceding spontaneous colonic contractions. In contrast, fEPSP frequency decreased when colonic muscle tension increased during spontaneous colonic contraction and emptying. Manual stretch of the colon wall to 10-15% beyond resting length in the circumferential axis of flat sheet preparations increased fEPSP frequency in SMG neurons, but stretch in the longitudinal axis to 15% beyond resting length in the same preparations did not. There was no increase in synaptic input when tubular colon segments were stretched in their long axes up to 20% beyond their resting length. The circumferential stretch-sensitive increase in the frequency of synaptic input to SMG neurons persisted when the colonic muscles were relaxed pharmacologically by nifedipine (2 μM) or nicardipine (3 μM). These results suggest that colonic mechanosensory afferent nerves projecting to the SMG function as length or stretch detectors in parallel to the circular muscle layer.

scholarly journals Microvessel Chaste: An Open Library for Spatial Modelling of Vascularized Tissues

2017 ◽  
Author(s):  
J.A. Grogan ◽  
A.J. Connor ◽  
B. Markelc ◽  
R.J. Muschel ◽  
P.K. Maini ◽  
...  
Keyword(s):  
Open Source ◽  
Tumour Growth ◽  
Spatial Models ◽  
3D Models ◽  
Tissue Growth ◽  
Coronary Perfusion ◽  
Analysis Model ◽  
User Friendly

AbstractSpatial models of vascularized tissues are widely used in computational physiology, to study for example, tumour growth, angiogenesis, osteogenesis, coronary perfusion and oxygen delivery. Composition of such models is time-consuming, with many researchers writing custom software for this purpose. Recent advances in imaging have produced detailed three-dimensional (3D) datasets of vascularized tissues at the scale of individual cells. To fully exploit such data there is an increasing need for software that allows user-friendly composition of efficient, 3D models of vascularized tissue growth, and comparison of predictions with in vivo or in vitro experiments and other models. Microvessel Chaste is a new open-source library for building spatial models of vascularized tissue growth. It can be used to simulate vessel growth and adaptation in response to mechanical and chemical stimuli, intra- and extra-vascular transport of nutrient, growth factor and drugs, and cell proliferation in complex 3D geometries. The library provides a comprehensive Python interface to solvers implemented in C++, allowing user-friendly model composition, and integration with experimental data. Such integration is facilitated by interoperability with a growing collection of scientific Python software for image processing, statistical analysis, model annotation and visualization. The library is available under an open-source Berkeley Software Distribution (BSD) licence at https://jmsgrogan.github.io/MicrovesselChaste. This article links to two reproducible example problems, showing how the library can be used to model tumour growth and angiogenesis with realistic vessel networks.

scholarly journals The Fundamental Comparison of Zn–2Mg and Mg–4Y–3RE Alloys as a Perspective Biodegradable Materials

Materials ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 3745 ◽  
Author(s):  
Kubásek ◽  
Dvorský ◽  
Šedý ◽  
Msallamová ◽  
Levorová ◽  
...  
Keyword(s):  
Hot Extrusion ◽  
Visual Observation ◽  
Structure Characterization ◽  
Zinc Alloy ◽  
Biodegradable Materials ◽  
Medical Implants ◽  
Conventional Casting ◽  
Tension And Compression

Biodegradable materials are of interest for temporary medical implants like stents for restoring damaged blood vessels, plates, screws, nails for fixing fractured bones. In the present paper new biodegradable Zn–2Mg alloy prepared by conventional casting and hot extrusion was tested in in vitro and in vivo conditions. Structure characterization and mechanical properties in tension and compression have been evaluated. For in vivo tests, hemispherical implants were placed into a rat cranium. Visual observation of the living animals, an inspection of implant location and computed tomography CT imaging 12 weeks after implantation were performed. Extracted implants were studied using scanning electron microscopy (SEM) on perpendicular cuts through corrosion products. The behaviour of zinc alloy both in in vitro and in vivo conditions was compared with commercially used Mg-based alloy (Mg–4Y–3RE) prepared by conventional casting and hot extrusion. Both compressive and tensile yield strengths of Zn and Mg-based alloys were similar; however, the brittleness of Mg–4Y–3RE was lower. Zn and Mg-based implants have no adverse effects on the behaviour or physical condition of rats. Moreover, gas bubbles and the inflammatory reaction of the living tissue were not detected after the 12-week period.

pqsfinder web: G-quadruplex prediction using optimized pqsfinder algorithm

2019 ◽  
Vol 36 (8) ◽  
pp. 2584-2586 ◽  
Author(s):  
Dominika Labudová ◽  
Jiří Hon ◽  
Matej Lexa
Keyword(s):  
Sequence Analysis ◽  
Recursive Algorithm ◽  
Supplementary Information ◽  
Potassium Ions ◽  
Bioconductor Package ◽  
G Quadruplex ◽  
Weak Points ◽  
User Friendly

Abstract Motivation G-quadruplex is a DNA or RNA form in which four guanine-rich regions are held together by base pairing between guanine nucleotides in coordination with potassium ions. G-quadruplexes are increasingly seen as a biologically important component of genomes. Their detection in vivo is problematic; however, sequencing and spectrometric techniques exist for their in vitro detection. We previously devised the pqsfinder algorithm for PQS identification, implemented it in C++ and published as an R/Bioconductor package. We looked for ways to optimize pqsfinder for faster and user-friendly sequence analysis. Results We identified two weak points where pqsfinder could be optimized. We modified the internals of the recursive algorithm to avoid matching and scoring many sub-optimal PQS conformations that are later discarded. To accommodate the needs of a broader range of users, we created a website for submission of sequence analysis jobs that does not require knowledge of R to use pqsfinder. Availability and implementation https://pqsfinder.fi.muni.cz, https://bioconductor.org/packages/pqsfinder. Supplementary information Supplementary data are available at Bioinformatics online.

scholarly journals Silver nanoparticles induce genetic, biochemical, and phenotype variation in chrysanthemum

2020 ◽  
Vol 143 (2) ◽  
pp. 331-344
Author(s):  
Alicja Tymoszuk ◽  
Dariusz Kulus
Keyword(s):  
Silver Nanoparticles ◽  
In Vitro Regeneration ◽  
Adventitious Shoots ◽  
Issr Markers ◽  
Phenotype Variation ◽  
Inter Simple Sequence Repeats ◽  
Tremendous Progress ◽  
Genetic Level ◽  
User Friendly

Abstract Despite the tremendous progress in breeding, novel and user-friendly techniques of plant improvement are desirable. The study aimed to analyze the usefulness of silver nanoparticles (AgNPs) in the breeding of chrysanthemum: one of the top ornamental plant species. In vitro regeneration of adventitious shoots from internodes of chrysanthemum ‘Lilac Wonder’ was induced on the modified Murashige and Skoog (MS) medium supplemented with 0.6 mg L−1 6-benzylaminopurine (BAP), 2 mg L−1 indole-3-acetic acid (IAA) and AgNPs at 0, 5, 10 and 20 ppm concentration. The efficiency of callogenesis and caulogenesis were analyzed after 10 weeks of culture. The concentration of chlorophylls, carotenoids, and phenolic compounds in shoots and calli were estimated. Plants obtained from 20 ppm AgNPs treatment were additionally analyzed on the genetic level using randomly amplified polymorphic DNA (RAPD) and inter simple sequence repeats (ISSR) markers. In vitro rooted shoots were acclimatized in the glasshouse and subjected to biochemical and phenotype stability evaluation. AgNPs at the highest concentration (20 ppm) suppressed both callogenesis and caulogenesis in vitro. The concentration of metabolites in callus was stable, regardless of AgNPs treatment, except for carotenoids which production was enhanced by 20 ppm AgNPs. In contrast, the content of chlorophyll a and b in shoots varied depending on AgNPs treatment. Polymorphic loci were detected in 12 and 9 AgNPs-treated-plants by RAPD and ISSR markers, respectively (one of which was common to both marker systems). Rooting and acclimatization were fully successful in all experimental combinations. Phenotype alternations were detected in six plants; one from 10 ppm AgNPs treatment and five from 20 ppm treatment. They included variation in pigment content (anthocyanins and carotenoids) and/or inflorescence shape. Interestingly, only two plants revealed both genetic and phenotype polymorphisms. No genetic or phenotype variation was detected in the control plants. In conclusion, AgNPs can be used in chrysanthemum breeding.

scholarly journals SELF-NANO EMULSIFYING DRUG DELIVERY SYSTEM OF EFAVIRENZ: FORMULATION, IN VITRO EVALUATION AND CHARACTERIZATION

2019 ◽  
pp. 217-226
Author(s):  
PAMU SANDHYA
Keyword(s):  
Drug Delivery ◽  
Dissolution Rate ◽  
Drug Delivery System ◽  
Delivery System ◽  
In Vitro Release ◽  
Visual Observation ◽  
Stability Study ◽  
In Vitro Dissolution ◽  
Tween 20

Objective: The main objective of this study was to preparation and evaluation of efavirenz (EFV) to enhance its solubility and dissolution rate by self-emulsifying drug delivery system. Methods: EFV self-emulsifying drug delivery systems (SNEDDS) were formulated using different oils, surfactant, and co-surfactant. Peceol, Tween 20, and Capmul MCM were used as oil, surfactant, and co-surfactant, respectively, followed by the evaluation by the performance of different tests such as visual observation, solubility studies, thermodynamic stability study, transmittance studies, drug content, and in-vitro release study. Results: Fourier-transform infrared studies revealed negligible drug and polymer interaction. From the phase diagram, it was observed that self-emulsifying region was enhanced with increasing surfactant and co-surfactant concentrations with oil. F13 was selected as optimized formulation on the basis of physicochemical parameters, particle size, and in-vitro dissolution studies with the release of 98.39±5.10% drug in 1 hour. The optimized formulation size was found to be 156.7 nm as mean droplet size and Z-Average of 808.6 nm with -18.3 mV as zeta potential. Conclusion: The study demonstrated that SNEDDS was a promising strategy to enhance the dissolution rate of EFV by improving solubility.

scholarly journals Integrating Thermographic Images in A User-Friendly Platform to Support Inspection of Railway Bridges

Proceedings ◽  
2019 ◽  
Vol 27 (1) ◽  
pp. 12
Author(s):  
Olmi ◽  
Palombi ◽  
Durazzani ◽  
Poggi ◽  
Renzoni ◽  
...  
Keyword(s):  
Visual Inspection ◽  
3D Model ◽  
Imaging Techniques ◽  
3D Scanning ◽  
Easy Access ◽  
High Definition ◽  
Railway Bridges ◽  
Maintenance Program ◽  
User Friendly

preventive inspection of railway bridges is a key step for an effective maintenance program. The TOSCA-FI project has developed an integrated ICT platform for easy access to a wide set of data, obtained with several imaging techniques (high definition photography, photogrammetry, 3D scanning, fluorescence LIDAR and thermography) and integrated into a 3D model of the bridge. The aim is to provide a tool to support the inspection of railway bridges, often based exclusively on the visual inspection. In this paper, we present selected results obtained on masonry bridges by using thermography and their integration in the TOSCA-FI platform.

Waxing and waning of slow waves in intestinal musculature

1986 ◽  
Vol 250 (1) ◽  
pp. G28-G34 ◽  
Author(s):  
N. Suzuki ◽  
C. L. Prosser ◽  
W. DeVos
Keyword(s):  
Slow Wave ◽  
Electrical Coupling ◽  
Longitudinal Axis ◽  
Slow Waves ◽  
Rabbit Intestine ◽  
Rabbit Small Intestine ◽  
Intestinal Musculature ◽  
Pattern Of Variation

Electrical slow waves from cat or rabbit small intestine show more variability when recorded in vivo than in vitro. One pattern of variation is waxing and waning of amplitude, or "spindling," during which two rhythms of slightly different frequency come in and out of phase. Fourier power analyses of slow waves during spindles show two frequency peaks of slow waves differing by 0.4-5.0 waves/min and corresponding to measured spindle durations of 12-150 s. Spindles can be induced in vitro in rabbit intestine by K depolarization of approximately 15 mV. Histograms of intracellular recordings of slow nonspindling waves show variation of 0.5-1.0 s on either side of a mean slow wave duration. Spindles are abolished by treatments that reduce electrical coupling between cells, e.g., hypertonic sucrose or lowered pH, but changes in calcium do not alter spindles. Simultaneous recordings by two electrodes in the longitudinal axis show synchrony of spindles at 2- to 3-mm but not at 5-mm separation and synchrony circumferentially to the opposite side of a segment. Contractions, both in vivo and in vitro, correspond with electrical spindles in amplitude. Spindle durations were significantly shorter in vivo than in vitro, indicating a significantly greater difference in vivo in the competing frequencies at the point of recording (P less than 0.01). Three conditions favoring waxing and waning are slight depolarization, variation in slow wave frequency at a point, and electrotonic coupling between muscle fibers. Spindles provide for rhythms of contractions of a 1- to 2-min period.

Measurement of axial forces during emptying from the human stomach

1992 ◽  
Vol 263 (2) ◽  
pp. G230-G239 ◽  
Author(s):  
M. J. Vassallo ◽  
M. Camilleri ◽  
C. M. Prather ◽  
R. B. Hanson ◽  
G. M. Thomforde
Keyword(s):  
Axial Force ◽  
Longitudinal Axis ◽  
Force Transducer ◽  
Human Stomach ◽  
In Vitro Studies ◽  
In Vivo Studies ◽  
Dependent Manner ◽  
Axial Forces

Our aim was to measure axial forces in the stomach and to evaluate their relation to circumferential contractions of the gastric walls and the emptying of gastric content. We used a combination of simultaneous radioscintigraphy, gastroduodenal manometry, and an axial force transducer with an inflatable 2-ml balloon fluoroscopically placed in the antrum. In vitro studies demonstrated that the axial force transducer records only antegrade forces along the longitudinal axis of this probe in an intensity-dependent manner. In vivo studies were performed in five healthy subjects for at least 3 h after ingestion of radiolabeled meals. When administered separately, the emptying of liquids or solids from the stomach is associated with generation of antral axial forces and coincident phasic pressure activity; however, almost 20% (average) of gastric axial forces during emptying of liquids or solids are unassociated with proximal or distal antral pressure activity ("isolated" forces). High amplitude antral axial forces and pressures occur during both lag and postlag emptying phases. During emptying of liquids, there is a trend for axial forces to be coincident more often with proximal than with distal antral pressure activity and vice versa for the emptying of solids (P = 0.015). These data suggest that when placed in the antrum, the transducer can semiquantitatively record axial forces during gastric emptying. By combining these observations with the data from in vitro studies, it appears that axial forces predominantly result from traction on the balloon by the longitudinal vector resulting from circumferential gastric contractions. The combination of radioscintigraphy and measurement of antral axial forces is a promising method to evaluate mechanical forces involved in the emptying of the human stomach.

The effect of eating on lower esophageal sphincter electrical activity

2009 ◽  
Vol 296 (4) ◽  
pp. G793-G797
Author(s):  
Claudia P. Sanmiguel ◽  
Yuichiro Ito ◽  
Masanobu Hagiike ◽  
Jeffrey L. Conklin ◽  
David Lalezari ◽  
...  
Keyword(s):  
Electrical Activity ◽  
Lower Esophageal Sphincter ◽  
Esophageal Manometry ◽  
Longitudinal Axis ◽  
Implantable Device ◽  
Solid Food ◽  
Standard Meal ◽  
Esophageal Sphincter

Electrical activity of the lower esophageal sphincter (LES) has been recorded mainly in vitro and in anesthetized animals. Swallowing produces relaxation of the LES, followed by its contraction. These changes should be associated with changes in LES electrical activity. To determine whether changes in LES electrical activity can be used to recognize the beginning of a meal, four dogs were implanted with two electrodes in the longitudinal axis of the LES. The electrodes were connected to an implantable device for recording of electrical activity. After recovery, dogs underwent two experiments: 1) combined recordings of LES electrical activity and esophageal manometry to test the effect of dry swallows, water, and solid food swallows on LES electrical activity and 2) telemetric recording of LES electrical activity during a standard meal. All amplitudes were in mV, means ± SD, ANOVA, P < 0.05. In experiment 1, an increase in the amplitude of LES electrical activity was associated with the substance being swallowed, i.e., at rest: 0.31 ± 0.06; dry swallows: 0.6 ± .0.1; water: 0.67 ± 0.12; solid food: 1.06 ± 0.17, P < 0.001. In experiment 2, there was a pronounced and characteristic increase in amplitude of LES electrical activity during feeding, 0.26 ± 0.1; during fasting, 0.99 ± 0.23; while eating, 0.31 ± 0.1 postprandial, P < 0.001. In conclusion, the beginning and duration of a meal are identified by distinct, easily recognizable changes in the amplitude of LES electrical activity. These changes depend on the type of the substance being swallowed and are most prominent with solid food. Changes in LES electrical activity can potentially be used for automatic eating detection.

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