Total Root Mean Square Values Research Articles

Establishment of a Feeding Rate Prediction Model for Combine Harvesters

Feeding rates serve as a vital indicator for adjusting the working parameters of the combine harvester. A non-invasive diagnostic approach to predicting the feed rates of combine harvesters by collecting vibration signals of the inclined conveyor was introduced in this study. To establish a feed rate prediction model, the correlation between feeding rates and vibration signal characteristics was investigated. Vibration signal characteristics in both the time domain and frequency domain were also analyzed in detail. The RMS (root mean square) value and the total RMS value of the one-third octave extracted from the vibration signal were utilized to establish a feed rate prediction model, and field tests were conducted to verify the model performance. The experimental results indicated that the relative errors of the established model range from 3.1% to 4.9% when harvesting rice. With the developed feed rate prediction system, the control system of the combine harvester can acquire feed rate information in real time, and the working parameters can be adjusted in advance, thereby, it can be expected to greatly enhance the working performance of the combine harvesters.

Clinical comparative study on the accuracy of palatal rugae in models obtained by different impression materials and intraoral scanning.

Palatal rugae are frequently used in the evaluation of tooth movement after treatment in orthodontics and as a stable region in superimposition. It is important to note that the impression method and material used to record the rugae region affect the accuracy of the impression. The aim of this study is to compare the accuracy of palatal rugae, in three-dimensional (3D) by employing both conventional and digital impression methods. In this study, 22 patients (12 females, 10 males) mean age of 13.5 ± 1.7years old were selected with complete permanent dentition. Three different impressions were taken from the maxillae of the patients: conventional impression using silicone rubber impression material, conventional impression using alginate impression material, and optical impression using an intraoral scanner. The impressions' digital data were analyzed by the GOM Inspect (Version 2018, Braunschweig, Germany), a 3D analysis software. The Root Mean Square (RMS) values of the total ruga region were evaluated in this software. The data were statistically analyzed using the Jamovi program. The Kruskal-Wallis test and Mann-Whitney U test were performed due to the non-normal distribution of the data. There is no statistically significant difference between the comparison points of the right and left rugae's medial and lateral points and total rugae regions' RMS values. Although there was no statistically significant difference, the total RMS values of alginate and digital scan measurements showed closer results than the RMS values of silicone and digital scan measurements. The study found that there was no statistically significant difference in the total RMS values of the ruga region between traditional and digital impression methods. The treatment period in orthodontics is long. Different impression materials and methods can be used for diagnostic, mid-treatment, and final impressions. For superimpositions and treatment and post-treatment palatal ruga evaluations, traditional and digital impression methods are clinically acceptable and can be used as alternatives to each other.

The effect of layer thıckness on the accuracy of the dıfferent ın-house clear alıgner attachments.

The accuracy of the attachments, one of the key components of clear aligner therapy, is important for obtaining more precise tooth movement. The aim of this study was to evaluate the accuracy of the ovoid, hemi-ellipsoid, and vertical rectangular attachments produced by the digital light-processing(DLP) 3-dimensional printing technologies with 25µm, 75µm, and 125µm layer thickness. The ovoid, hemi-ellipsoid, and vertical rectangular attachments were positioned onto the convex surface of the central incisor by the software. The printing process was carried out by a DLP printer using a commercially printed resin with 25µm, 75µm, and 125µm layer thickness (n = 30, for each group). All test models' digital data was exported into the reverse engineering software for the superimposition. After selecting the 5 comparison points for the ovoid and vertical rectangular attachments, and 6 comparison points for the hemi-ellipsoid attachment, the Root Mean Square (RMS) was evaluated for each group. There is a statistically significant difference between the 25µm and 125µm layer thickness of total RMS values in the ovoid, hemi-ellipsoid, and vertical rectangular attachment groups (p = 0.001, p = 0.03, and p = 0.00 respectively). The printing time with the 25µm layer thickness was 4 times longer than with the 125µm layer thickness. This study revealed that the accuracy of the attachments used for in-house clear aligner therapy is affected by the layer thickness of the 3D printer. The layer thickness of the 3D printer is a crucial factor in determining attachment accuracy, but its clinical significance is minimal. Clinicians should make informed decisions about the appropriate layer thickness, taking into account their workflow preferences, time constraints, and other practical considerations specific to their clinical practice.

Higher-order aberrations following wavefront-guided photorefractive keratectomy and laser in situ keratomileusis

Background: We aimed to evaluate higher-order aberrations (HOAs) following wavefront-guided photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK) in patients with myopia and myopic astigmatism.
 Methods: This retrospective observational case-control study included patients who underwent wavefront-guided PRK (40 eyes of 20 patients) or LASIK (40 eyes of 20 patients) between August 2018 and November 2018 at the refractive surgery unit of Kayseri City Hospital Eye Clinic, Turkey. The corrected distance visual acuity (CDVA), manifest refraction, corneal topography, and HOAs were evaluated preoperatively and 3 months postoperatively in all patients.
 Results: The mean age ± standard deviation (SD) was 27.13 ± 5.54 years and 29.10 ± 4.38 years in the PRK and LASIK groups, respectively (P = 0.06). Both groups had a mean CDVA of 1.00. The mean ± SD of spherical and spherical equivalent values was -2.09 ± 1.56 diopter (D) and -3.03 ± 1.72 D in the PRK group and -2.23 ± 1.69 D and -3.35 ± 1.71 D in the LASIK group, respectively (P = 0.58). When the preoperative and postoperative HOAs and root mean square (RMS) values (for a 6-mm pupil diameter) were compared in the PRK group, a significant difference was found in vertical coma and total RMS values (P = 0.003 and P ˂ 0.001, respectively); in the LASIK group, there was a significant difference in preoperative and postoperative vertical coma and total RMS values (P = 0.0.001 and P ˂ 0.001, respectively). There was no significant difference in preoperative and postoperative vertical coma values between the two groups (P = 0.735 and P = 0.583, respectively).
 Conclusions: In terms of HOAs, total RMS values decreased significantly and vertical coma values increased significantly at 3 months postoperatively in both PRK and LASIK groups. However, there were no differences between the two groups.

Comparison of wavefront aberrations in eyes with multifocal and monofocal iols before and after Nd:YAG laser capsulotomy for posterior capsule opacification.

The aim of this study was to compare wavefront aberrations before and after Nd:YAG capsulotomy in multifocal intraocular lens (MfIOL) and monofocal (MoIOL) pseudophakic eyes with posterior capsule opacification (PCO). Wavefront aberrations were measured using a ARK-10000 topographer before and after Nd:YAG capsulotomy in eyes that underwent MfIOL or MoIOL implantation and developed PCO. Total and higher-order aberrations (HOAs) values were evaluated as root mean square (RMS). The study included 64 eyes with MfIOLs (64 patients) and 72 with MoIOLs (72 patients) that developed PCO. Total RMS values before and 1month after Nd:YAG capsulotomy were 0.863 ± 0.27 and 0.504 ± 0.24 in the MFIOL group and 0.862 ± 0.31 and 0.466 ± 0.26 in the MoIOL group, respectively. Total RMS values did not differ significantly between the groups before (p = 0.914) or 1month after Nd:YAG laser capsulotomy (p = 0.357), but decreased significantly after Nd:YAG capsulotomy compared to baseline in both the MfIOL (p = 0.027) and MoIOL (p = 0.012) groups. HOA values before and 1month after Nd:YAG capsulotomy were 0.546 ± 0.23 and 0.364 ± 0.19 in the MfIOL group and 0.500 ± 0.21 and 0.346 ± 0.18 in the MoIOL group, respectively. HOA values did not differ significantly before (p = 0.828) or after Nd:YAG capsulotomy (p = 0.111), while both groups showed significant reduction in HOAs after Nd:YAG capsulotomy (MfIOL: p = 0.021, MoIOL: p = 0.027). Nd:YAG capsulotomy reduces total and HOAs to the same extent in eyes with both MfIOLs and MoIOLs, with no significant impact of the IOL design.

Displacement Monitoring of the Slope at Tunnel Face Based on PhotoModeler Scanner System

This paper describes a simple slope displacement monitoring system based on PhotoModeler Scanner. Multi-angle images of displacement observation points located in the slope at tunnel face were rapidly acquired by a cheap and calibrated CCD camera. After the image enhancement processing, images were imported into PhotoModeler Scanner system. Then, using several software function modules to process image data, we get the X-Y-Z three component coordinate values of all the displacement monitoring points. Through a long-term monitoring, each component displacement curve of the monitoring points was drawn out. In order to test the reliability of the results, three-dimensional coordinate values of each point were measured by the high-precision total station instrument simultaneously. These three-dimensional coordinate values were treated as true values. Under the requirements of the accuracy of 0.1 mm, the displacement values of photogrammetric measurement were compared to the true values. The results showed that, RMS (Root Mean Square) values of the most points were about ±2.0 mm, in addition to very few. And the total RMS value was ±2.8 mm. It indicates that the digital close-range photogrammetry based on PhotoModeler Scanner Systerm can satisfy the requirement of the general slope displacement monitoring. Moreover, the 3D displacement values got by our way can be used to appraise the security state of slopes in similar areas.

Comparison of the femtosecond laser and mechanical microkeratome for flap cutting in LASIK.

To compare refractive results, higher-order aberrations (HOAs), contrast sensitivity and dry eye after laser in situ keratomileusis (LASIK) performed with a femtosecond laser versus a mechanical microkeratome for myopia and astigmatism. In this prospective, non-randomized study, 120 eyes with myopia received a LASIK surgery with the VisuMax femtosecond laser for flap cutting, and 120 eyes received a conventional LASIK surgery with a mechanical microkeratome. Flap thickness, visual acuity, manifest refraction, contrast sensitivity function (CSF) curves, HOAs and dry-eye were measured at 1wk; 1, 3, 6mo after surgery. At 6mo postoperatively, the mean central flap thickness in femtosecond laser procedure was 113.05±5.89 µm (attempted thickness 110 µm), and 148.36±21.24 µm (attempted thickness 140 µm) in mechanical microkeratome procedure. An uncorrected distance visual acuity (UDVA) of 4.9 or better was obtained in more than 98% of eyes treated by both methods, a gain in logMAR lines of corrected distance visual acuity (CDVA) occurred in more than 70% of eyes treated by both methods, and no eye lost ≥1 lines of CDVA in both groups. The difference of the mean UDVA and CDVA between two groups at any time post-surgery were not statistically significant (P>0.05). The postoperative changes of spherical equivalent occurred markedly during the first month in both groups. The total root mean square values of HOAs and spherical aberrations in the femtosecond treated eyes were markedly less than those in the microkeratome treated eyes during 6mo visit after surgery (P<0.01). The CSF values of the femtosecond treated eyes were also higher than those of the microkeratome treated eyes at all space frequency (P<0.01). The mean ocular surface disease index scores in both groups were increased at 1wk, and recovered to preoperative level at 1mo after surgery. The mean tear breakup time (TBUT) of the femtosecond treated eyes were markedly longer than those of the microkeratome treated eyes at postoperative 1, 3mo (P<0.01). Both the femtosecond laser and the mechanical microkeratome for LASIK flap cutting are safe and effective to correct myopia, with no statistically significant difference in the UDVA, CDVA during 6mo follow-up. Refractive results remained stable after 1mo post-operation for both groups. The femtosecond laser may have advantages over the microkeratome in the flap thickness predictability, fewer induced HOAs, better CSF, and longer TBUT.

Assessment of aberrations and visual quality differences between myopic and astigmatic eyes before and after contact lens application.

OBJECTIVE:To evaluate the aberration and visual quality differences between myopic and astigmatic eyes before and after contact lens application by using corneal aberrometer and low- contrast sensitivity chart.METHODS:Eighty eyes of 40 patients were included in this study. Patients were divided into two groups as myopic (40 eyes, n=20) and astigmatic groups (40 eyes, n=20). We used aspheric Balafilcon A (Purevision and Purevision Toric Bausch&Lomb, Rochester, USA) lenses for each group. Corneal aberrations and low-contrast sensitivity values were measured and compared for each patient in both groups.RESULTS:There were no statistically significant differences between myopic and astigmatic groups when we compared low-contrast sensitivity values for both on- and off-eyes. Mean total higher-order aberration (HOA) values for off-eye, were 0.29±0.10 μm, and 0.33±0.10 μm for on-eye in the myopic group, while they were 0.42±0.14 μm in off-eye and 0.37±0.23 μm in on-eye in the astigmatic group. Off-eye mean coma, irregular astigmatism and total higher-order aberration RMS (root-mean-square) values were significantly higher in the astigmatic group compared to the myopic group (p=0.006, p=0.001, p=0.001) but mean on-eye RMS values were not.CONCLUSION:Myopic and astigmatic patients differ in terms of high-order aberrations and these differences cannot be equalized after contact lens application, but visual quality can be improved in both patients by using contact lenses.

Background intensity correction for terabyte-sized time-lapse images.

Several computational challenges associated with large-scale background image correction of terabyte-sized fluorescent images are discussed and analysed in this paper. Dark current, flat-field and background correction models are applied over a mosaic of hundreds of spatially overlapping fields of view (FOVs) taken over the course of several days, during which the background diminishes as cell colonies grow. The motivation of our work comes from the need to quantify the dynamics of OCT-4 gene expression via a fluorescent reporter in human stem cell colonies. Our approach to background correction is formulated as an optimization problem over two image partitioning schemes and four analytical correction models. The optimization objective function is evaluated in terms of (1) the minimum root mean square (RMS) error remaining after image correction, (2) the maximum signal-to-noise ratio (SNR) reached after downsampling and (3) the minimum execution time. Based on the analyses with measured dark current noise and flat-field images, the most optimal GFP background correction is obtained by using a data partition based on forming a set of submosaic images with a polynomial surface background model. The resulting image after correction is characterized by an RMS of about 8, and an SNR value of a 4 × 4 downsampling above 5 by Rose criterion. The new technique generates an image with half RMS value and double SNR value when compared to an approach that assumes constant background throughout the mosaic. We show that the background noise in terabyte-sized fluorescent image mosaics can be corrected computationally with the optimized triplet (data partition, model, SNR driven downsampling) such that the total RMS value from background noise does not exceed the magnitude of the measured dark current noise. In this case, the dark current noise serves as a benchmark for the lowest noise level that an imaging system can achieve. In comparison to previous work, the past fluorescent image background correction methods have been designed for single FOV and have not been applied to terabyte-sized images with large mosaic FOVs, low SNR and diminishing access to background information over time as cell colonies span entirely multiple FOVs. The code is available as open-source from the following link https://isg.nist.gov/.

Visual performance and contrast sensitivity after phacoemulsification with implantation of aspheric foldable intraocular lenses

To compare visual performance after phacoemulsification with implantation of an aspheric intraocular lens (IOL). Tertiary eyecare center in north India. This prospective study comprised patients with visually significant age-related cataract having clear corneal phacoemulsification with implantation of 1 of 3 types of aspheric IOLs. Twelve weeks postoperatively, visual acuity and contrast sensitivity were recorded. Wavefront analysis was performed with the Optical Path Difference scanner. All patients completed a questionnaire on subjective quality of vision. Main outcome measures were best corrected visual acuity (BCVA), contrast sensitivity, visual function score, and patient satisfaction. Of the 130 eyes (130 patients), a Tecnis Z9003 IOL was implanted in 43 eyes, an AcrySof SN60WF IOL in 41 eyes, and an Akreos Adapt AO IOL in 46 eyes. Contrast sensitivity and BCVA were similar between groups. With 4.0 mm, 5.0 mm, and 6.0 mm pupil diameters, the mean spherical aberrations were significantly less with AcrySof SN60WF and Akreos Adapt AO IOLs than with the Tecnis Z9003 IOL. There were no significant differences in total higher-order root-mean-square (RMS) values between IOLs. Visual performance scores with the 3 IOLs were comparable. All 3 aspheric IOLs significantly decreased positive spherical ocular aberration after phacoemulsification and may induce negative spherical aberration. However, there was no significant difference in total higher-order RMS values between the IOLs. The 3 IOL models provided comparable contrast sensitivity and visual performance.

Visual outcome and corneal aberrometry after implantation of intracorneal ring segments (INTACS) for keratoconus

Abstract Purpose: To analyze corneal aberrometry and visual outcome after implantation of intracorneal ring segments (INTACS) in keratoconus patients. Methods: Corneal aberration was measured in 15 keratoconus eyes pre and post implantation of INTACS. Root Mean Square values (RMS), (Total, RMS for corneal astigmatism and RMS for coma) where recorded for 5, 6 and 7 pupil diameters, and where divided into two groups due to their previous levels of coma and total RMS. Comatic aberration was divided in vertical (Z3‐1) an horizontal (Z3+1) Zernicke Coeficcients. All data was recorded pre‐op and three months after surgery. Best corrected visual acuity (BCVA), uncorrected visual acuity (UCVA), spherical equivalent and astigmatism where also analyzed. Results: We found statistically significant decrease in spherical equivalent (p&lt;0,01) and increase of UCVA (p&lt;0,01). Significant increase (p=0,04) in coma and total RMS in patients with lower previous values for 5 and 6mm and significant decrease in patients with higher previous values for 7mm (p=0,03) Conclusions: INTACS implantation for keratoconus reduces the mean spherical refractive error, increases UCVA and improves keratoconus aberrations for 7mm pupil diameter in patients with previous high levels of coma and total RMS.

Comparison of wavefront aberration after cataract surgery with acrylic intraocular lens implantation

To compare aberration changes in pseudophakic eyes with 3 types of acrylic intraocular lenses (IOLs) and in normal phakic eyes. Department of Ophthalmology, Asan Medical Center, Seoul, Korea. This single-center prospective study comprised 51 cataract patients who had cataract surgery and 12 phakic eyes. Fourteen eyes received an AcrySof MA60BM (Alcon), 18 eyes received a Sensar AR40 (AMO), and 19 eyes, a Corneal ACR6D (Corneal Laboratoire). One month after cataract surgery, aberrations in the eyes were measured using a Hartmann-Shack-type aberrometer. The same measurements were done in the 12 age-matched normal phakic eyes. Individual Zernike polynomials and the root-mean-square (RMS) 3rd- and 4th-order aberrations in the 2 groups were compared. The total RMS value was also compared. The RMS value of the 3rd- and 4th-order aberrations did not differ significantly between groups, nor did the total RMS value. In all IOL groups, an individual Zernike coefficient (C3(3), triangular astigmatism with base on the y-axis) was significantly different than that in the normal phakic group. There was no statistically significant difference in overall higher-order aberrations between normal eyes and eyes implanted with 3 types of acrylic IOLs.