Wearable E-Textile and CNT Sensor Wireless Measurement System for Real-Time Penile Erection Monitoring

Erection measurements are the most important indicator of male urological disease diagnosis, treatment, and results. Rigiscan has been used widely in studies and diagnoses for nocturnal penile tumescence for evaluating erectile dysfunction by measuring the number and timing of erectile dysfunctions during sleep. However, this device has limitations such as the weight and bulk of the device and has been questioned for its role as a standard for ED Erectile Dysfunction (ED) diagnosis. In this study, we propose a real-time wearable monitoring system that can quantitatively measure the length and circumference of the penis using electronic textiles (E-textile) and carbon nanotube (CNT) sensors. The E-textile sensor is used to measure the length, circumference, and gradient with portability, convenience, and comfort. Sensors were created by coating CNTs on latex for flexibility. The CNT-based latex condom-type sensor in our proposed system shows the length, circumference, and curvature measurements with changes in resistance, and the E-textile performance shows a 1.44% error rate and a cavity radius of 110 to 300. The results of this conceptual study are for supplementary sensor development with a combination of new technologies with alternatives or existing methods for measuring erection function.

Curvature Measurement of Thin Plates with the Help of Digital Image Processing

The verification of different plate bending problems require a punctual measurement method of the bent shape. However, with a proper curvature measurement procedure the calculations can be made more accurate. This is due to the workaround this method provides by neglecting the inaccuracies of the beam theory and the tensile tests, measuring directly the function between the curvature and bending moment for a given sheet metal. The measurements in this paper are made with the help of a digital camera and telephotographic lens. The evaluations of these images are compared to the results obtained from the Euler-Bernoulli beam theory. While the results regarding the curvature measurements have a significant deviation, the shape of the plate is in good agreement with the numerical calculations.

NONLINEAR MODELS BASED ON QUANTILES IN THE FITTING OF GROWTH CURVES OF PEPPER GENOTYPES

This study aimed to fit nonlinear regression models to model the growth of the characters fruit length (FL) and fruit width (FW) of pepper genotypes (Capsicum annuum L.) over time using the method of ordinary least squares (OLS); and identify the model with the best fit and compare it to the model obtained via nonlinear quantile regression (QR) in the 0.25, 0.5, and 0.75 quantiles. Three regression models (Logistic, Gompertz, and von Bertalanffy) and four fit quality evaluators were adopted: Akaike information criterion, residual mean absolute deviation, and parametric and intrinsic curvature measurements. Five commercial genotypes of pepper were evaluated. Characters FL and FW were evaluated weekly from seven days after flowering, totaling ten measurements. In the estimation by OLS, the Logistic and von Bertalanffy models were considered adequate according to the quality evaluators. In the comparison between the models above by OLS and QR, the superiority of models obtained by QR was verified for the character FL. For the character FW, QR was efficient in three out of the five genotypes, being a valuable alternative in the study of fruit growth.

Estimation of breast height diameter and trunk curvature with linear and single-photon LiDARs

Key message New technologies can take us towards real precision forestry: the terrestrial single-photon avalanche diode (SPAD) light detection and ranging (LiDAR) has a great potential to outperform conventional linear mode LiDARs in measuring tree parameters at the stand level. Context Precision forestry together with new sensor technologies implies Digital Forest Inventories for estimation of volume and quality of trees in a stand. Aims This study compared commercial LiDAR, new prototype SPAD LiDAR, and manual methods for measuring tree quality attributes, i.e., diameter at breast height (DBH) and trunk curvature in the forest stand. Methods We measured 7 Scots pine trees (Pinus sylvestris) with commercial LiDAR (Zeb Horizon by GeoSLAM), prototype SPAD LiDAR, and manual devices. We compared manual measurements to the DBH and curvature values estimated based on LiDAR data. We also scanned a densely branched Picea abies to compare penetrability of the LiDARs and detectability of the obstructed trunk. Results The DBH values deviated 1–3 cm correlating to the specified accuracies of the employed devices, showing close to acceptable results. The curvature values deviated 1–6 cm implying distorted range measurements from the top part of the trunks and inaccurate manual measurement method, leaving space for improvement. The most important finding was that the SPAD LiDAR outperformed conventional LiDAR in detecting tree stem of the densely branched spruce. Conclusion These results represent preliminary but clear evidence that LiDAR technologies are already close to acceptable level in DBH measurements, but not yet satisfactory for curvature measurements. In addition, terrestrial SPAD LiDAR has a great potential to outperform conventional LiDARs in forest measurements of densely branched trees.

PARAMETERIZATIONS OF THE VON BERTALANFFY MODEL FOR DESCRIPTION OF GROWTH CURVES

The growth curves of animals, in general, have an “S” shape, also known as sigmoidal curves. This type of curve is well fitted by nonlinear regression models, including von Bertalanffy’s model, which has been widely applied in several areas, being presented in literature through different parameterizations, which in practice, can complicate its understanding, affect nonlinearity measures and inferences about parameters. To quantify the nonlinearity present in a Bates and Watts model, a geometric concept of curvature has been used. The aim of this work was to analytically develop three parameterizations of the von Bertalanffy’s nonlinear model referring to its nonlinearity, implications for inferences and to establish relationships between parameters in the different ways of expressing the models. These parameterizations were adjusted to the growth data of sheep. For each parameterization, the intrinsic and parametric curvature measurements described by Bates and Watts were calculated. The parameterization choice affects nonlinearity measures, consequently, influences the reliability and inferences about estimated parameters. The forms most used in literature showed the greatest deviations from linearity, showing the importance of analyzing these measures in any growth curve study. Parameterization should be used in which the b estimate represents the abscissa of the inflection point, as it presents minor linearity deviations and direct biological interpretation for all parameters.

Assessment of the plane of maximum curvature for patients with adolescent idiopathic scoliosis via computed tomography

Background: In the assessment of three-dimensional features of adolescent idiopathic scoliosis, the plane of maximum curvature was compared with the coronal Cobb angle. Objectives: To investigate the intrarater reliability, variability, and difference of the prone plane of maximum curvature measurements taken from computed tomography using the constrained and unconstrained Cobb methods; to assess the difference and correlation between the prone plane of maximum curvature measurements obtained using the constrained and unconstrained Cobb methods; and to examine differences and correlation between the prone plane of maximum curvature Cobb angle and coronal Cobb angle measurements. Study design: Retrospective study. Methods: Records of 29 subjects with adolescent idiopathic scoliosis aged 15.8 ± 3.5 years were reviewed (25 thoracic and 24 thoracolumbar/lumbar curves). An experienced rater measured the plane of maximum curvature using the constrained and unconstrained Cobb methods, and the coronal Cobb angles using the conventional Cobb method on computed tomography images 3 times each with 1-week interval. The intraclass correlation coefficient (2,1), Pearson correlation coefficient ( r), one-way repeated measures analysis of variance, and paired t test were applied for various analyses. Results: The intraclass correlation coefficients for all intrarater reliability assessments were greater than 0.87. The plane of maximum curvature measurements of the two Cobb methods were excellently correlated ( r ⩾ 0.97) with no significant difference ( P > 0.05). The mean plane of maximum curvature Cobb angle was moderately correlated with ( r > 0.72) but significantly greater ( P < 0.001) than the mean coronal Cobb angle. Conclusion: The plane of maximum curvature measurements obtained from computed tomography were found to be reliable while the plane of maximum curvature measurements of the two Cobb methods were comparable. The mean plane of maximum curvature Cobb angle was moderately correlated with but significantly greater than the mean coronal Cobb angle. Clinical relevance The plane of maximum curvature measurements taken from computed tomography was found to be reliable, hence it could be used as a supplement to the coronal Cobb angle in the assessment and management of adolescent idiopathic scoliosis. With technological advancement, the radiation dose of computed tomography can be further reduced to a safer level for a broader range of cases.

Determination of Stresses in Incrementally Deposited Films From Wafer-Curvature Measurements

We report closed-form formulas to calculate the incremental-deposition stress, the elastic relaxation stress, and the residual stress in a finite-thickness film from a wafer-curvature measurement. The calculation shows how the incremental deposition of a new stressed layer to the film affects the amount of the film/wafer curvature and the stress state of the previously deposited layers. The formulas allow the incremental-deposition stress and the elastic relaxation to be correctly calculated from the slope of the measured curvature versus thickness for arbitrary thicknesses and biaxial moduli of the film and the substrate. Subtraction of the cumulative elastic relaxation from the incremental-deposition stress history results in the residual stress left in the film after the whole deposition process. The validities of the formulas are confirmed by curvature measurements of electrodeposited Ni films on substrates with different thicknesses.