39 research outputs found
Segmentation of articular cartilage and early osteoarthritis based on the fuzzy soft thresholding approach driven by modified evolutionary ABC optimization and local statistical aggregation
Articular cartilage assessment, with the aim of the cartilage loss identification, is a crucial task for the clinical practice of orthopedics. Conventional software (SW) instruments allow for just a visualization of the knee structure, without post processing, offering objective cartilage modeling. In this paper, we propose the multiregional segmentation method, having ambitions to bring a mathematical model reflecting the physiological cartilage morphological structure and spots, corresponding with the early cartilage loss, which is poorly recognizable by the naked eye from magnetic resonance imaging (MRI). The proposed segmentation model is composed from two pixel's classification parts. Firstly, the image histogram is decomposed by using a sequence of the triangular fuzzy membership functions, when their localization is driven by the modified artificial bee colony (ABC) optimization algorithm, utilizing a random sequence of considered solutions based on the real cartilage features. In the second part of the segmentation model, the original pixel's membership in a respective segmentation class may be modified by using the local statistical aggregation, taking into account the spatial relationships regarding adjacent pixels. By this way, the image noise and artefacts, which are commonly presented in the MR images, may be identified and eliminated. This fact makes the model robust and sensitive with regards to distorting signals. We analyzed the proposed model on the 2D spatial MR image records. We show different MR clinical cases for the articular cartilage segmentation, with identification of the cartilage loss. In the final part of the analysis, we compared our model performance against the selected conventional methods in application on the MR image records being corrupted by additive image noise.Web of Science117art. no. 86
INFLUENCE OF THE USE OF GRAVITY SETS IN A PRESSURE VOLUMETRIC INFUSION PUMP WITH AN IMPACT ON THE ACCURACY OF INFUSION SOLUTION FLOWS
The subject of the work was the experimental verification of the negative influence of gravity sets in a pressure volumetric infusion pump with an impact on the accuracy of infusion solution dosing. The quality criterion for gravity sets was the accuracy of the flow versus the reference set by the volumetric infusion pump. The solution consisted of 14-hour measurements with two types of gravity sets, Intrafix® Primeline sets were used as universal sets and Standardline IS‑103 gravity sets. The insulin pump flow rate was set at 300 ml/h and 50 ml/h, and the actual flow rate of the infusion solution was recorded every hour using a graduated cylinder. Used gravity sets were also processed by mechanical tests, unused sets were subjected to these tests and the obtained data were compared with each other. Experiments carried out showed that at the set flow rate of 300 ml/h, the flow error with the universal set was -3% and at a set flow rate of 50 ml/h the error was +2.3%. Flow accuracy using gravity sets was worse, a flow error of -7.2% was detected for a flow rate of 50 ml/h and a flow error of -7.7% was measured for 300 ml/h. The volumetric pump used declares a tolerated inaccuracy of ± 3% when used with standard infusion sets. Based on the data, it can be concluded that the replacement of set types has an influence on the dosage of infusion solutions
Wavelet-based filtration procedure for denoising the predicted CO2 waveforms in smart home within the Internet of Things
The operating cost minimization of smart homes can be achieved with the optimization of the management of the building's technical functions by determination of the current occupancy status of the individual monitored spaces of a smart home. To respect the privacy of the smart home residents, indirect methods (without using cameras and microphones) are possible for occupancy recognition of space in smart homes. This article describes a newly proposed indirect method to increase the accuracy of the occupancy recognition of monitored spaces of smart homes. The proposed procedure uses the prediction of the course of CO2 concentration from operationally measured quantities (temperature indoor and relative humidity indoor) using artificial neural networks with a multilayer perceptron algorithm. The mathematical wavelet transformation method is used for additive noise canceling from the predicted course of the CO2 concentration signal with an objective increase accuracy of the prediction. The calculated accuracy of CO2 concentration waveform prediction in the additive noise-canceling application was higher than 98% in selected experiments.Web of Science203art. no. 62
RESPIRATORY ARRHYTHMIA AS AN ENCOURAGEMENT OF INAPPROPRIATE ICD THERAPY
Implantable cardioverter-defibrillators (ICDs) are active cardiac implants for immediate treatment of ventricular arrhythmias. They provide life-saving therapy, but may also deliver inappropriate therapy. These two cases demonstrate a possibility of ICD therapy detection or induction encouraged by physiological patient breathing. The cases of 64-year-old and 30-year-old women patients are reported. The first one has received some therapy, the second one has not. The devices records did not show any abnormalities in trends or electrical parameters. As a solution, the detection parameters of the devices were optimized, with reference to individual physiologically reachable heart rates of the patients
FLEXIBLE TEG ON THE ANKLE FOR MEASURING THE POWER GENERATED WHILE PERFORMING ACTIVITIES OF DAILY LIVING
In this work, a commercial flexible thermoelectric generator (f-TEG) was used to harvest the body thermal energy during the execution of activities of daily living (ADL). The f-TEG was placed at the level of the ankle, and the performed activities were sitting at the desk and walking. In the first stage of measurements, tests were performed to choose the value of the resistor load that maximizes the power output. Then, while performing ADL, the values of generated power were in the range from 100 to 450 µW. Moreover, while users are walking, the pattern of the output signal of f-TEG is compatible to a sine function with frequency close to that one of human gait. This preliminary result may represent a new way to study the movement of human body to recognize AD
Monitoring of CRT-D devices during radiation therapy in vitro
Background: Using of active cardiac medical devices increases steadily. In Europe,
there were 183 implants of ICD and 944 implants of PM, 119 of biventricular ICD and 41
of biventricular PM, all per million inhabitants in 2014. Healthcare environments, including
radiotherapy treatment rooms, are considered challenging for these implantable
devices. Exposure to radiation may cause the device to experience premature elective
replacement indicator, decreased pacing amplitude or pacing inhibition, inappropriate
shocks or inhibition of tachyarrhythmia therapy and loss of device function. These
impacts may be temporary or permanent. The aim of this study was to evaluate the
influence of linear accelerator ionizing radiation dose of 10 Gy on the activity of the
biventricular cardioverter-defibrillator in different position in radiation beam.
Methods: Two identical wireless communication devices with all three leads were
used for the measurement. Both systems were soused into solution saline and exposed
in different position in the beam of linear accelerator per 10 Gy fractions. In comparison
of usually used maximum recommended dose of 2 Gy, the radiation doses used in test
were five times higher. Using the simultaneous monitoring wireless communication
between device and its programmer allowed watching of the devices activities, noise
occurrence or drop of biventricular pacing on the programmer screen, observed by
local television loop camera.
Results: At any device position in radiation beam, there were no influences of the
device activity at dose of 10 Gy neither a significant increase of a solution saline temperature
in any of the measured positions of CRT-D systems in linear accelerator.
Conclusions: The results of the study indicated, that the recommendation dose for
treating the patients with implantable devices are too conservative and the risk of
device failure is not so high. The systems can easily withstand the dose fractions of tens
Gy, which would allow current single-dose-procedure treatment in radiation therapy.
Even though the process of the random alteration of device memory and electrical
components by scatter particles not allowed to specify a safe dose during ionizing
radiation, this study showed that the safe limit are above the today used dose fractions.Web of Science15art. no. 2
Complexity stage model of the medical device development based on economic evaluation-MedDee
The development of a new product is essential for the progress and success of any company. The medical device market is very specific, which is challenging. Therefore, this paper assesses an economic model for medical device evaluation using the economic, health, technology regulatory, and present market knowledge to enable the cost-time conception for any applicant. The purpose of this study is to propose a comprehensive stage model of the medical device development to subsequently describe the financial expenditure of the entire development process. The identification of critical steps was based on the literature review, and analysis, and a comparison of the available medical device development stages and directives. Furthermore, a preliminary assessment of the medical device development steps and procedures on the basis of the interviews was performed. Six interviews were conducted with an average duration of one hour, focusing on areas: relevance and level of detail of the medical device development stages, involvement of economic methods, and applicability of the proposed model. Subsequently, the improvement and modification of the medical device investment process, based on respondents' responses, were conducted. The authors have proposed the complexity model MedDee-Medical Devices Development by Economic Evaluation. This model is comprised of six phases: initiation, concept, design, production, final verification, and market disposition in which the economic methods are incorporated.Web of Science125art. no. 175
Review: Development and technical design of tangible user interfaces in wide-field areas of application
A tangible user interface or TUI connects physical objects and digital interfaces. It is more interactive and interesting for users than a classic graphic user interface. This article presents a descriptive overview of TUI's real-world applications sorted into ten main application areas-teaching of traditional subjects, medicine and psychology, programming, database development, music and arts, modeling of 3D objects, modeling in architecture, literature and storytelling, adjustable TUI solutions, and commercial TUI smart toys. The paper focuses on TUI's technical solutions and a description of technical constructions that influences the applicability of TUIs in the real world. Based on the review, the technical concept was divided into two main approaches: the sensory technical concept and technology based on a computer vision algorithm. The sensory technical concept is processed to use wireless technology, sensors, and feedback possibilities in TUI applications. The image processing approach is processed to a marker and markerless approach for object recognition, the use of cameras, and the use of computer vision platforms for TUI applications.Web of Science2113art. no. 425
OPTICAL NERVE SEGMENTATION USING THE ACTIVE SHAPE METHOD
The paper deals with the segmentation procedure for optical nerve localization and the consequent determination of geometrical parameters such as optical nerve area, radius and diameter. An extraction of these geometrical parameters is especially important for clinical practice particularly in the case where retinal lesions are present. On the base of the optical nerve extraction, we are capable of comparing it with area of retinal lesions. Via this approach it is possible to track time evaluation of retinal lesions. The proposed algorithm for segmentation of optical nerve area is performed within two main steps. In the first step, the active contour method is used specially for the localization of the optical nerve. This part of the algorithm generates mathematical model of the optical nerve in binary form. Consequently, on the base of this mathematical model of the optical nerve respective geometrical parameters are worked out for future comparison with retinal lesions. Image preprocessing is an integral part of the segmentation procedure, improving the observability of the optical nerve to ensure as relevant detection of the optical nerve as possible