scholarly journals Electrode movement prevention – an animal model

2019 ◽  
pp. 667-673
Author(s):  
V. Masopust ◽  
I. Petríková ◽  
M. Mlček ◽  
J. Holubová ◽  
R. Rokyta ◽  
...  
Keyword(s):  
Animal Model ◽  
Digital Image ◽  
Statistical Evaluation ◽  
Optical Methods ◽  
Fixation Method ◽  
Lateral Migration ◽  
Common Complication ◽  
Significance Level ◽  
Electrode Displacement ◽  
Lead Fixation

Electrode migration is the most common complication of spinal cord stimulation (SCS). The problem of longitudinal migration has already been solved, but lateral migration remains the most common current complication. The present article describes new electrodes fixation opportunities for the reduction of lateral migration in SCS. The pig was chosen as an animal model to illustrate a new protocol of electrode fixation for the control of lateral and longitudinal migration. The displacement of the electrode was measured using two different optical methods: the digital image stereo-correlation and the digital image processing methods. Fixation with two anchors has always considerably reduced electrode displacement and when fixation is done with two anchors and a loop then lateral migration is reduced by 62.5 % and longitudinal migration is reduced by 94.1 %. It was shown that the results are significantly different at the α=0.001 significance level. Based on a statistical evaluation it is possible to state that the differences between experimental results obtained for three different protocols of lead fixation are statistically significant and we can recommend the new fixation method for common practice.

scholarly journals Factors influencing incidents of complications while using nickel-titanium rotary instruments for root canal treatment

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Ahmad A. Madarati
Keyword(s):  
Root Canal ◽  
Nickel Titanium ◽  
Influential Factor ◽  
Common Complication ◽  
Pilot Studies ◽  
Significance Level ◽  
Rotary Instruments ◽  
Chi Squared ◽  
Final Questionnaire ◽  
General Dentists

Abstract Background To investigate the complications associated with the use of nickel titanium rotary instruments (NiTi-RIs) for root canal treatments (RCTs), in Saudi Arabia dental practice, and to explore the influencing factors. Methods After obtaining an ethical approval, two pilot studies were conducted to formulate the final questionnaire. The sample size was measured taking into consideration 60% expected response rates and confidence level of 99.9%. The questionnaire was emailed to 600 general dentists (GDs) randomly selected from the dental register and all of the endodontists (175). The email’s introduction clarified objectives of the study and guaranteed that all of the collected information would remain confidential. A reminder was sent after 10 weeks. The data were collected and analyzed using the chi-squared test at a 0.05 significance level. Results With a 51% overall response rate, 71.9% off the respondents used NiTi-RIs. The majority (83.1%) experienced complications while using NiTi-RIs; with the instruments’ fracture being significantly the most common complication (52.7%) (p < 0.001). The majority (87.7%) experienced NiTi-RIs’ fractureat least once; with more endodontists (94.3%) than GDs (83.3%) (p < 0.001). The greater the number of weekly performed RCTs and participants’ experiences, the more NiTi-RIs fractures and the greater the number of fracture incidents (p < 0.001). While 60% of those who performed 1–3 RCTs per week experienced NiTi-RIs fractures, 100% of those who performed more than 12 RCTs per week did so. The highest percentage of those who experienced more than 10 fractured NiTi-RIs (60%) was within the group who performed more than 12 RCTs per week. Although fracture incidents decreased with a smaller number of reuses, there was no significant correlation between the number of fractured instruments and NiTi-RIs discard strategy (p ≥ 0.05). Conclusion Fracture incidence was the most common complication while using NiTi-RIs, regardless of the clinicians’ experiences and skills. While the single use may reduce NiTi-RIs fractures, to some extent, the greater number of RCTs performed per week was the most influential factor.

scholarly journals Sequential-Digital Image Correlation for Mapping Human Posterior Sclera and Optic Nerve Head Deformation

2014 ◽  
Vol 136 (2) ◽  
Author(s):  
Jeffrey D. Pyne ◽  
Katia Genovese ◽  
Luciana Casaletto ◽  
Jonathan P. Vande Geest
Keyword(s):  
Optic Nerve ◽  
Digital Image Correlation ◽  
Optic Nerve Head ◽  
Digital Image ◽  
Complex Geometry ◽  
Open Angle Glaucoma ◽  
Image Correlation ◽  
Optical Methods ◽  
Retinal Ganglion ◽  
Position Measurement

Optic nerve head (ONH) deformations may be involved in the onset or further development of glaucoma, including in patients with relatively normal intraocular pressures (IOPs). Characterizing posterior scleral deformations over physiological pressures may provide a better understanding of how changes in IOP lead to changes in the mechanical environment of the ONH and possibly retinal ganglion cell death. Pressure inflation measurement test protocols are commonly used to measure deformation of the peripapillary sclera with full-field noncontact optical methods. The purpose of this work was to develop and validate a new sequential 3D digital image correlation (S-DIC) approach for quantification of posterior scleral pressure induced deformation that improves z (in-depth) resolution of the DIC measurement without losing in-plane sensitivity, while also being able to contour and map deformations of the complex-shaped ONH. Our approach combines two orthogonal axes of parallax with standard 3D DIC methods using a single high-resolution camera. The enhanced capabilities of S-DIC with respect to standard 3D DIC has been demonstrated by carrying out a complete benchmark for shape, deformation, and strain measurement on an object of known complex geometry. Our S-DIC method provided a reconstruction accuracy of 0.17% and an uncertainty in z-position measurement of 8 μm. The developed methodology has also been applied to a human posterior scleral shell, including the full peripapillary sclera and optic nerve. The relatively inexpensive S-DIC approach may provide new information on the biomechanical deformations of the optic nerve head and, thus, the death of retinal ganglion cells in primary open angle glaucoma.

scholarly journals Fixation of Light Weight Polypropylene Mesh with n-Butyl-2-cyanocrylate in Pelvic Floor Surgery: Experimental Design Approach in Sheep for Effectiveness Evaluation

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Sandra Barbosa ◽  
Tania Nieves ◽  
Félix García ◽  
Eva Cepeda ◽  
Xavier Moll ◽  
...  
Keyword(s):  
Animal Model ◽  
Experimental Design ◽  
Mesh Size ◽  
Synthetic Mesh ◽  
Fixation Method ◽  
Light Weight ◽  
Pilot Studies ◽  
Fixation Methods ◽  
Post Surgery ◽  
High Degree

Objective. The aim of this study was to find a proper experimental design and to evaluate n-butyl-2-cyanoacrylate (Histoacryl) as a fixation method for a light-weight and large pore PP mesh (Synthetic PP Mesh-1) using the sheep as an animal model.Methods. Posterior vaginal implantation by means of episiotomy was used to implant 8 ewes which were evaluated macroscopically and histologically at 3 months (n=4) and 6 months (n=4) post-surgery. In previous pilot studies anterior vaginal implantation was evaluated, as well as different synthetic mesh materials, sizes and fixation methods (n=1to 3) during three weeks. In all cases a clinical evaluation of the animal was performed.Results. A reduction in the mesh size (Synthetic PP Mesh-1) together with precise application of the surgical glue Histoacryl to fix the mesh yielded significantly better histocompatibility results (P<0.01) compared to larger size or other fixation methods.Conclusion. The combination ofSynthetic PP Mesh-1with Histoacryl offered a high degree of graft integration without vaginal ulceration and a minimal foreign body reaction, being the sheep a proper animal model to test these types of medical devices.

scholarly journals Statistical analysis of the influence of print run on surface roughness of digital flexo printing plates’ solid tone areas

2020 ◽  
Author(s):  
Sandra Dedijer ◽  
◽  
Magdolna Pál ◽  
Ivana Tomić ◽  
Stefan Poljak ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Statistical Analysis ◽  
Statistical Evaluation ◽  
Statistical Significance ◽  
Test Method ◽  
Roughness Parameters ◽  
Printing Plate ◽  
Significance Level ◽  
Surface Roughness Parameters ◽  
The Difference

In this study we have aimed to present statistical evaluation of changes in the surface roughness of the solid tone areas on CtP flexo printing plate in dependence of print run. Changes in flexo plate surface roughness is influenced by the plate-making process, printing pressure and speed, the interaction with the ink and printing substrate and by the wear of the printing plate due to long print-runs. Thus, the aim of this research was to evaluate the changes in the amplitude surface roughness parameters (Ra, Rp, Rv and Rz), between the printing plates used for different print runs. In the experiment, we have employed three sets of CtP flexo printing plates, for three colors-cyan, magenta and blue. The first set was not used for printing, the second was used to print 7 rolls of substrate and the third is used to print 11 rolls of printing substrate. The amplitude surface roughness parameters were compared by applying independentsamples t-test method using the software SPSS (Statistical Package for Social Science) with a 0.05 significance level. Statistical analysis revealed that the difference between the amplitude surface roughness parameters measured on CtP flexo printing plates are significant with a 95% confidence level, whereas the statistical significance pointed out that with the longer print runs, the difference will be strongly expressed.

scholarly journals The Use of Optical Methods in the Analysis of the Areas with Stress Concentration

2018 ◽  
Vol 68 (2) ◽  
pp. 61-76 ◽  
Author(s):  
Miroslav Pástor ◽  
Peter Frankovský ◽  
Martin Hagara ◽  
Pavol Lengvarský
Keyword(s):  
Stress Concentration ◽  
Digital Image Correlation ◽  
Mechanical Stress ◽  
Digital Image ◽  
Image Correlation ◽  
Optical Methods ◽  
Stress Fields ◽  
Plane Model ◽  
Technical Systems

AbstractAnchoring parts of technical systems are often damaged due to the heavy forces acting on these systems during their operation. For that reason, various modifications are suggested and created on the anchoring screws, which should help to reduce the mechanical stress values in a place of the first load-bearing thread of a female screw. For the determination of stress fields on the surface of a plane model of a threaded joint, two non-contact optical methods were used – conventional transmission photoelasticimetry and modern digital image correlation.

Ultimate Load Measuring System for Fixation of Soft Tissue to Bone

2021 ◽  
pp. 107110072110405
Author(s):  
Tatsuya Fujii ◽  
Makoto Tateura ◽  
Masato Ogawa ◽  
Satoru Ozeki
Keyword(s):  
Animal Model ◽  
Experimental Animal ◽  
Ultimate Load ◽  
Testing Machine ◽  
Graft Fixation ◽  
Experimental Animal Model ◽  
Fixation Method ◽  
Lateral Ankle ◽  
Fixation Methods ◽  
Significant Difference

Background: The initial ultimate load for graft fixation is one of the essential factors in the reconstruction of lateral ankle ligaments. Several anchoring devices have been developed to fix the substitute ligament into the bone. A fair comparison of these fixation methods warrant a reproducible examination system. The purpose of this study was to make an experimental animal model and to compare the initial ultimate loads of 3 graft fixation methods, including the use of EndoButton (EB), interference screw (IFS), and a novel socket anchoring (SA) technique. Methods: Porcine calcaneus bones and 5-mm-wide split bovine Achilles tendons were used as fixation bases and graft materials, respectively. Both ends were firmly sutured side-by-side, using the circumferential ligation technique as a double-strand substitute that was 45 mm in length. Porcine calcanei with similar characteristics to adult human calcanei were mounted on a tensile testing machine, and substitutes were fixed into bones using the 3 fixation methods. A polyester tape was passed through the tendon loop and connected to a crosshead jig of the testing machine. The initial ultimate loads were measured in 15 specimens for each fixation method to simulate a lateral ankle ligament (LAL) injury. Results: The ultimate loads (ULs) were 223.6 ± 52.7 N for EB, 229.7 ± 39.7 N for SA, and 208.8 ± 65.3 N for IFS. No statistically significant difference was observed among the 3 groups ( P = .571). All failures occurred at the bone–ligament substitute interface. Conclusion: The initial ULs in all 3 fixation methods were sufficient for clinical usage. These values were larger than the UL of the anterior talofibular ligament; however, these were smaller than the UL of the calcaneofibular ligament. Clinical Relevance: In an experimental animal model, ULs for SA, EB, and IFS techniques showed no significant difference. All failures were observed in the fixation site of the calcaneus and were overwhelmingly related to suture fixation failure.

scholarly journals Assessment of modified Forssell’s myectomy success rate in the treatment of crib biting in horses

2015 ◽  
Vol 84 (1) ◽  
pp. 63-69 ◽  
Author(s):  
Šárka Krisová ◽  
Zdeněk Žert ◽  
Kristína Žuffová
Keyword(s):  
Retrospective Study ◽  
Surgical Treatment ◽  
Success Rate ◽  
Early Treatment ◽  
Statistical Evaluation ◽  
Positive Outcome ◽  
Term Outcome ◽  
Long Term Outcome ◽  
Significance Level

The objective of this retrospective study was to assess the success rate of Forssell’s modified myectomy – surgical treatment of crib biting on 33 horses of various breeds identified as stereotypical cribbers which were referred to the Equine Clinic in Brno between January 2001 and December 2010. The long term outcome was available for all horses. The overall success of the surgery without considering influencing factors was 61%. Thirteen horses (39%) returned to the stereotypical behaviour sooner or later after the surgery. In this retrospective study we confirmed the dependence of success of the surgery on the necessity of early treatment of the problem (up to 6 months after the appearance of initial signs), with the significance level of P = 0.037. Any connection between age, breed or sex, and positive outcome of the surgery were not confirmed during statistical evaluation. When the horses were diagnosed early enough, an 80% success rate in surgical treatment performed within 6 months from the initial signs of crib biting was recorded, which seems to be very promising. It can be concluded that surgical treatment of crib biting by modified Forsell’s myectomy is the recommended option in the therapy of this oral stereotype.

scholarly journals Association between constitution, medical history, axiography and postural control in women aged between 21 to 30 years

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
C. Doerry ◽  
V. Fisch ◽  
S. Schamberger ◽  
S. Kopp ◽  
C. Erbe ◽  
...  
Keyword(s):  
Postural Control ◽  
Medical History ◽  
Statistical Evaluation ◽  
Mouth Opening ◽  
Measured Data ◽  
Body Sway ◽  
Control Parameters ◽  
Significance Level ◽  
Healthy Female ◽  
Pair Comparisons

AbstractThe aim of this study was to determine association between constitutional, medical history and axiographic parameters with postural control parameters. Overall, 106 healthy female subjects aged between 21 and 30 years were measured. Data collection was carried out by completing a questionnaire on constitutional parameters, illnesses, accidents and medical/orthodontic therapies, as well as by axio- and posturographic measurements. Data were analyzed using correlations, pair comparisons and group comparisons. The significance level was set at p ≤ 0.05. The statistical evaluation showed significant correlations between sporting exercise and body sway in the sagittal direction (p ≤ 0.03), the BMI and the load on the forefoot/rear foot (p ≤ 0.01), the mouth opening and the load on the forefoot/rearfoot (p ≤ 0.01) and the presence of a deviation with the load on the left/right foot (p ≤ 0.01). The physical condition as well as the temporo-mandibular system are associated with the postural control in young women. Therefore, a holistic diagnosis and therapy will be supported by the present outcomes.

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