cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.6084/m9.figshare.6943631.v1
title: Ultrasonic method of microvibration detection: part II - additional processing method and applications

description: Abstract Introduction In the last 28 years, the scientific community has been using elastography to evaluate the mechanical properties of biological tissue. The aim of this work was the optimization of the UDmV method, presented in Part I of the series, by means of modifying the technique employed to generate the reference sine and cosine functions, used for phase-quadrature demodulation, and determining how this modification improved the performance of the method. Additionally, the UDmV was employed to characterize the acoustic and mechanical properties of a 7% gelatin phantom. Methods A focused transducer, T F, with a nominal frequency of 2.25 MHz, was used to induce the shear waves, with frequency of 97.644 Hz. Then, the modified UDmV method was used to extract the phase and quadrature components from ultrasonic RF echo-signals collected from four positions along the propagation path of the shear wave, which allowed the investigation of the medium vibration caused by wave propagation. The phase velocity, c s, and attenuation, α s, of the phantom were measured and employed in the calculation of shear modulus, μ, and viscosity, η. Results The computational simulation demonstrated that the modification in UDmV method resulted in more accurate and precise estimates of the initial phases of the reference sinusoidal functions used for phase-quadrature demodulation. The values for c s and μ of 1.31 ± 0.01 m·s-1 and 1.66 ± 0.01 kPa, respectively, are very close to the values found in the literature (1.32 m·s-1 and 1.61 kPa) for the same material. Conclusion The UDmV method allowed estimating of the acoustic and viscoelastic parameters of phantom.
DOI: 10.6084/m9.figshare.6943631
title: Ultrasonic method of microvibration detection: part II - additional processing method and applications

description: Abstract Introduction In the last 28 years, the scientific community has been using elastography to evaluate the mechanical properties of biological tissue. The aim of this work was the optimization of the UDmV method, presented in Part I of the series, by means of modifying the technique employed to generate the reference sine and cosine functions, used for phase-quadrature demodulation, and determining how this modification improved the performance of the method. Additionally, the UDmV was employed to characterize the acoustic and mechanical properties of a 7% gelatin phantom. Methods A focused transducer, T F, with a nominal frequency of 2.25 MHz, was used to induce the shear waves, with frequency of 97.644 Hz. Then, the modified UDmV method was used to extract the phase and quadrature components from ultrasonic RF echo-signals collected from four positions along the propagation path of the shear wave, which allowed the investigation of the medium vibration caused by wave propagation. The phase velocity, c s, and attenuation, α s, of the phantom were measured and employed in the calculation of shear modulus, μ, and viscosity, η. Results The computational simulation demonstrated that the modification in UDmV method resulted in more accurate and precise estimates of the initial phases of the reference sinusoidal functions used for phase-quadrature demodulation. The values for c s and μ of 1.31 ± 0.01 m·s-1 and 1.66 ± 0.01 kPa, respectively, are very close to the values found in the literature (1.32 m·s-1 and 1.61 kPa) for the same material. Conclusion The UDmV method allowed estimating of the acoustic and viscoelastic parameters of phantom.
DOI: 10.6084/m9.figshare.6943556
title: Enhancing quality in Diffusion Tensor Imaging with anisotropic anomalous diffusion filter

description: Abstract Introduction: Diffusion tensor imaging (DTI) is an important medical imaging modality that has been useful to the study of microstructural changes in neurological diseases. However, the image noise level is a major practical limitation, in which one simple solution could be the average signal from a sequential acquisition. Nevertheless, this approach is time-consuming and is not often applied in the clinical routine. In this study, we aim to evaluate the anisotropic anomalous diffusion (AAD) filter in order to improve the general image quality of DTI. Methods A group of 20 healthy subjects with DTI data acquired (3T MR scanner) with different numbers of averages (N=1,2,4,6,8, and 16), where they were submitted to 2-D AAD and conventional anisotropic diffusion filters. The Relative Mean Error (RME), Structural Similarity Index (SSIM), Coefficient of Variation (CV) and tractography reconstruction were evaluated on Fractional Anisotropy (FA) and Apparent Diffusion Coefficient (ADC) maps. Results The results point to an improvement of up to 30% of CV, RME, and SSIM for the AAD filter, while up to 14% was found for the conventional AD filter (p&lt;0.05). The tractography revealed a better estimative in fiber counting, where the AAD filter resulted in less FA variability. Furthermore, the AAD filter showed a quality improvement similar to a higher average approach, i.e. achieving an image quality equivalent to what was seen in two additional acquisitions. Conclusions In general, the AAD filter showed robustness in noise attenuation and global image quality improvement even in DTI images with high noise level.
DOI: 10.6084/m9.figshare.6943556.v1
title: Enhancing quality in Diffusion Tensor Imaging with anisotropic anomalous diffusion filter

description: Abstract Introduction: Diffusion tensor imaging (DTI) is an important medical imaging modality that has been useful to the study of microstructural changes in neurological diseases. However, the image noise level is a major practical limitation, in which one simple solution could be the average signal from a sequential acquisition. Nevertheless, this approach is time-consuming and is not often applied in the clinical routine. In this study, we aim to evaluate the anisotropic anomalous diffusion (AAD) filter in order to improve the general image quality of DTI. Methods A group of 20 healthy subjects with DTI data acquired (3T MR scanner) with different numbers of averages (N=1,2,4,6,8, and 16), where they were submitted to 2-D AAD and conventional anisotropic diffusion filters. The Relative Mean Error (RME), Structural Similarity Index (SSIM), Coefficient of Variation (CV) and tractography reconstruction were evaluated on Fractional Anisotropy (FA) and Apparent Diffusion Coefficient (ADC) maps. Results The results point to an improvement of up to 30% of CV, RME, and SSIM for the AAD filter, while up to 14% was found for the conventional AD filter (p&lt;0.05). The tractography revealed a better estimative in fiber counting, where the AAD filter resulted in less FA variability. Furthermore, the AAD filter showed a quality improvement similar to a higher average approach, i.e. achieving an image quality equivalent to what was seen in two additional acquisitions. Conclusions In general, the AAD filter showed robustness in noise attenuation and global image quality improvement even in DTI images with high noise level.
DOI: 10.6084/m9.figshare.6944000.v1
title: Populational brain models of diffusion tensor imaging for statistical analysis: a complementary information in common space

description: Abstract Introduction: The search for human brain templates has been progressing in the past decades and in order to understand disease patterns a need for a standard diffusion tensor imaging (DTI) dataset was raised. For this purposes, some DTI templates were developed which assist group analysis studies. In this study, complementary information to the most commonly used DTI template is proposed in order to offer a patient-specific statistical analysis on diffusion-weighted data. Methods 131 normal subjects were used to reconstruct a population-averaged template. After image pre processing, reconstruction and diagonalization, the eigenvalues and eigenvectors were used to reconstruct the quantitative DTI maps, namely fractional anisotropy (FA), mean diffusivity (MD), relative anisotropy (RA), and radial diffusivity (RD). The mean absolute error (MAE) was calculated using a voxel-wise procedure, which informs the global error regarding the mean intensity value for each quantitative map. Results the MAE values presented a low MAE estimate (max(MAE) = 0.112), showing a reasonable error measure between our DTI-USP-131 template and the classical DTI-JHU-81 approach, which also shows a statistical equivalence (p&lt;0.05) with the classical DTI template. Hence, the complementary standard deviation (SD) maps for each quantitative DTI map can be added to the classical DTI-JHU-81 template. Conclusion In this study, variability DTI maps (SD maps) were reconstructed providing the possibility of a voxel-wise statistical analysis in patient-specific approach. Finally, the brain template (DTI-USP-131) described here was made available for research purposes on the web site (http://dx.doi.org/10.17632/br7bhs4h7m.1), being valuable to research and clinical applications.
DOI: 10.6084/m9.figshare.6944000
title: Populational brain models of diffusion tensor imaging for statistical analysis: a complementary information in common space

description: Abstract Introduction: The search for human brain templates has been progressing in the past decades and in order to understand disease patterns a need for a standard diffusion tensor imaging (DTI) dataset was raised. For this purposes, some DTI templates were developed which assist group analysis studies. In this study, complementary information to the most commonly used DTI template is proposed in order to offer a patient-specific statistical analysis on diffusion-weighted data. Methods 131 normal subjects were used to reconstruct a population-averaged template. After image pre processing, reconstruction and diagonalization, the eigenvalues and eigenvectors were used to reconstruct the quantitative DTI maps, namely fractional anisotropy (FA), mean diffusivity (MD), relative anisotropy (RA), and radial diffusivity (RD). The mean absolute error (MAE) was calculated using a voxel-wise procedure, which informs the global error regarding the mean intensity value for each quantitative map. Results the MAE values presented a low MAE estimate (max(MAE) = 0.112), showing a reasonable error measure between our DTI-USP-131 template and the classical DTI-JHU-81 approach, which also shows a statistical equivalence (p&lt;0.05) with the classical DTI template. Hence, the complementary standard deviation (SD) maps for each quantitative DTI map can be added to the classical DTI-JHU-81 template. Conclusion In this study, variability DTI maps (SD maps) were reconstructed providing the possibility of a voxel-wise statistical analysis in patient-specific approach. Finally, the brain template (DTI-USP-131) described here was made available for research purposes on the web site (http://dx.doi.org/10.17632/br7bhs4h7m.1), being valuable to research and clinical applications.
DOI: 10.6084/m9.figshare.5792268.v1
title: Adaptation of a smart walker for stroke individuals: a study on sEMG and accelerometer signals

description: Abstract Introduction: Stroke is a leading cause of neuromuscular system damages, and researchers have been studying and developing robotic devices to assist affected people. Depending on the damage extension, the gait of these people can be impaired, making devices, such as smart walkers, useful for rehabilitation. The goal of this work is to analyze changes in muscle patterns on the paretic limb during free and walker-assisted gaits in stroke individuals, through accelerometry and surface electromyography (sEMG). Methods The analyzed muscles were vastus medialis, biceps femoris, tibialis anterior and gastrocnemius medialis. The volunteers walked three times on a straight path in free gait and, further, three times again, but now using the smart walker, to help them with the movements. Then, the data from gait pattern and muscle signals collected by sEMG and accelerometers were analyzed and statistical analyses were applied. Results The accelerometry allowed gait phase identification (stance and swing), and sEMG provided information about muscle pattern variations, which were detected in vastus medialis (onset and offset; p = 0.022) and biceps femoris (offset; p = 0.025). Additionally, comparisons between free and walker-assisted gaits showed significant reduction in speed (from 0.45 to 0.30 m/s; p = 0.021) and longer stance phase (from 54.75 to 60.34%; p = 0.008). Conclusions Variations in muscle patterns were detected in vastus medialis and biceps femoris during the experiments, besides user speed reduction and longer stance phase when the walker-assisted gait is compared with the free gait.
DOI: 10.6084/m9.figshare.5792544
title: Correction equations to estimate body fat with plicometer WCS dual hand

description: ABSTRACT Introduction This study aimed to propose regression equations for the correction of fat percentage values obtained with the WCS Dual Hand skinfold caliper, using the Lange skinfold caliper as a reference. Methods This study evaluated 112 undergraduate students from the Physical Education and Physical Therapy programs of the Faculdade Dom Bosco, located in Curitiba, Paraná, Brazil. Of these, 58 women were 24.9±5.8 years old and 54 men were 27.6±7.9 years old. The evaluation comprised the following measurements: height, body mass, and nine skin folds with WCS Dual Hand and Lange skinfold calipers used in biceps, triceps, subscapular, suprailiac, pectoral, average axillary, medial thigh, abdominal, and calf measurements. Results Through the simple linear regression analysis, eight equations were generated to correct the relative body fat obtained with equations commonly used in Brazil. For these correction equations, R2 was between 0.830 and 0.961 and p-value was 0.000 for all measurements. Conclusion These results indicate the use of equations for the correction of estimated values of relative body fat measured with the WCS Dual Hand skinfold caliper, whenever the Lange skinfold caliper is not available, in order to minimize the difference between them.
DOI: 10.6084/m9.figshare.5792268
title: Adaptation of a smart walker for stroke individuals: a study on sEMG and accelerometer signals

description: Abstract Introduction: Stroke is a leading cause of neuromuscular system damages, and researchers have been studying and developing robotic devices to assist affected people. Depending on the damage extension, the gait of these people can be impaired, making devices, such as smart walkers, useful for rehabilitation. The goal of this work is to analyze changes in muscle patterns on the paretic limb during free and walker-assisted gaits in stroke individuals, through accelerometry and surface electromyography (sEMG). Methods The analyzed muscles were vastus medialis, biceps femoris, tibialis anterior and gastrocnemius medialis. The volunteers walked three times on a straight path in free gait and, further, three times again, but now using the smart walker, to help them with the movements. Then, the data from gait pattern and muscle signals collected by sEMG and accelerometers were analyzed and statistical analyses were applied. Results The accelerometry allowed gait phase identification (stance and swing), and sEMG provided information about muscle pattern variations, which were detected in vastus medialis (onset and offset; p = 0.022) and biceps femoris (offset; p = 0.025). Additionally, comparisons between free and walker-assisted gaits showed significant reduction in speed (from 0.45 to 0.30 m/s; p = 0.021) and longer stance phase (from 54.75 to 60.34%; p = 0.008). Conclusions Variations in muscle patterns were detected in vastus medialis and biceps femoris during the experiments, besides user speed reduction and longer stance phase when the walker-assisted gait is compared with the free gait.
DOI: 10.6084/m9.figshare.5792544.v1
title: Correction equations to estimate body fat with plicometer WCS dual hand

description: ABSTRACT Introduction This study aimed to propose regression equations for the correction of fat percentage values obtained with the WCS Dual Hand skinfold caliper, using the Lange skinfold caliper as a reference. Methods This study evaluated 112 undergraduate students from the Physical Education and Physical Therapy programs of the Faculdade Dom Bosco, located in Curitiba, Paraná, Brazil. Of these, 58 women were 24.9±5.8 years old and 54 men were 27.6±7.9 years old. The evaluation comprised the following measurements: height, body mass, and nine skin folds with WCS Dual Hand and Lange skinfold calipers used in biceps, triceps, subscapular, suprailiac, pectoral, average axillary, medial thigh, abdominal, and calf measurements. Results Through the simple linear regression analysis, eight equations were generated to correct the relative body fat obtained with equations commonly used in Brazil. For these correction equations, R2 was between 0.830 and 0.961 and p-value was 0.000 for all measurements. Conclusion These results indicate the use of equations for the correction of estimated values of relative body fat measured with the WCS Dual Hand skinfold caliper, whenever the Lange skinfold caliper is not available, in order to minimize the difference between them.
DOI: 10.6084/m9.figshare.5792592
title: Brazilian clinical engineering regulations: health equipment management and conditions for professional exercise

description: Abstract Introduction In Brazil, professionals, scientific community, and members of regulatory bodies have not yet achieved a consensus regarding who can legally perform the professional duties of a clinical engineer. We aim at clarifying this aspect, based on a detailed analysis of the pertinent regulations. Methods We acted on three fronts: (i) reviewing the current legislation regarding the clinical engineering exercise; (ii) visiting hospitals and working as trainee to understand how this exercise is implemented on Brazil’s Federal District; (iii) one of the authors participated in virtual discussion groups of clinical engineering professionals, monitoring collective understanding of regulations, checking consistency of proper knowledge, and acting as an active opinion leader in the subject among peers. Results We try to make a formal definition of clinical engineer and indicate their characteristic activities. We propose a synthesis of the regulation regarding healthcare products’ integrity protection and health technology management, identifying the engineering activities necessary to achieve those legal requirements. We analyze the legal constraints and conditions to exert engineering, indicating the necessary professionals’ attributions and the way to obtain them. Finally, we provide a brief analysis of the technical requirements presented by the Brazilian Consumer Protection Code and of the 15.943 Brazilian Standard (NBR). Discussion We conclude that, despite the lack of consensus about the Clinical Engineering activity, there exists in Brazil a Clinical Engineering regulation, but it is spread in complex laws and normative resolutions, defining compulsory responsibilities and attributions, as well as conditions and prerequisites for role performance.
DOI: 10.6084/m9.figshare.5792592.v1
title: Brazilian clinical engineering regulations: health equipment management and conditions for professional exercise

description: Abstract Introduction In Brazil, professionals, scientific community, and members of regulatory bodies have not yet achieved a consensus regarding who can legally perform the professional duties of a clinical engineer. We aim at clarifying this aspect, based on a detailed analysis of the pertinent regulations. Methods We acted on three fronts: (i) reviewing the current legislation regarding the clinical engineering exercise; (ii) visiting hospitals and working as trainee to understand how this exercise is implemented on Brazil’s Federal District; (iii) one of the authors participated in virtual discussion groups of clinical engineering professionals, monitoring collective understanding of regulations, checking consistency of proper knowledge, and acting as an active opinion leader in the subject among peers. Results We try to make a formal definition of clinical engineer and indicate their characteristic activities. We propose a synthesis of the regulation regarding healthcare products’ integrity protection and health technology management, identifying the engineering activities necessary to achieve those legal requirements. We analyze the legal constraints and conditions to exert engineering, indicating the necessary professionals’ attributions and the way to obtain them. Finally, we provide a brief analysis of the technical requirements presented by the Brazilian Consumer Protection Code and of the 15.943 Brazilian Standard (NBR). Discussion We conclude that, despite the lack of consensus about the Clinical Engineering activity, there exists in Brazil a Clinical Engineering regulation, but it is spread in complex laws and normative resolutions, defining compulsory responsibilities and attributions, as well as conditions and prerequisites for role performance.
DOI: 10.6084/m9.figshare.5792823
title: Low cost system to measure active power in electrosurgical units

description: Abstract Introduction: The real-time measurement of active power delivered to patients during the electrosurgical act is still an engineering challenge. Besides, there is no electrosurgical unit on the market capable of doing it according to the normative requirement. Methods This work presents the design of an electronic structure capable to probe the electrosurgical equipment output electrical signals, using low-costs very common resistors, and High Frequency distortions compensation circuits, and process them to provide an analogue signal proportional to the active power, allowing the knowledge and control of the energy delivered to the biological tissue. The reading circuits and the active power calculation method are presented. The power calculation is performed in two stages. The first one consists of a multiplier circuit that uses the readings voltage and current quantities to determine the instantaneous output power, and the second stage is formed by an integrating circuit which determines the average power value, resulting in a rippled continuous voltage, proportional to the active power delivered to the patient or biological tissue. Results Practical tests of the compensation technical are statistically evaluated by means of linear regressions. Results of 23 tests are summarized in a way to demonstrate de effectiveness of the proposed system. Conclusion Analysis of the results demonstrate the efficiency of the proposed system, whose average error is lower than 5%, and correlating them with the standard IEC 60601-2-2, that regulates the operation of electrosurgery units.