scholarly journals Geometric validation of a computer simulator used in radiography education

BJR|Open ◽  
2020 ◽  
Vol 2 (1) ◽  
pp. 20190027
Author(s):  
Philip Cosson ◽  
Zenghai Lu
Keyword(s):  
Image Plane ◽  
Human Form ◽  
The Real ◽  
Computer Simulator ◽  
Two Dimensional Image ◽  
Digitally Reconstructed Radiographs ◽  
Projection Radiography ◽  
Axial Ct ◽  
The Mean ◽  
Radiography Education

Objectives: The radiographical process of projection of a complex human form onto a two-dimensional image plane gives rise to distortions and magnifications. It is important that any simulation used for educational purposes should correctly reproduce these. Images generated using a commercially available computer simulation widely used in radiography education (ProjectionVRTM) were tested for geometric accuracy of projection in all planes. Methods: An anthropomorphic skull phantom was imaged using standard projection radiography techniques and also scanned using axial CT acquisition. The data from the CT was then loaded into the simulator and the same projection radiography techniques simulated. Bony points were identified on both the real radiographs and the digitally reconstructed radiographs (DRRs). Measurements sensitive to rotation and magnification were chosen to check for rotation and distortion errors. Results: The real radiographs and the DRRs were compared by four experienced observers and measurements taken between the identified bony points on each of the images obtained. Analysis of the mean observations shows that the measurement from the DRR matches the real radiograph +1.5 mm/−1.5 mm. The Bland Altman bias was 0.55 (1.26 STD), with 95% limits of agreement 3.01 to −1.91. Conclusions: Agreement between the empirical measurements is within the reported error of cephalometric analysis in all three anatomical planes. The image appearances of both the real radiographs and DRRs compared favourably. Advances in knowledge: The commercial computer simulator under test (ProjectionVRTM) was able to faithfully recreate the image appearances of real radiography techniques, including magnification and distortion. Students using this simulation for training will obtain feedback likely to be useful when lessons are applied to real-world situations.

The Y-shaped trabecular bone structure in the odontoid process of the axis: a CT scan study in 54 healthy subjects and biomechanical considerations

2019 ◽  
Vol 30 (5) ◽  
pp. 585-592 ◽  
Author(s):  
Nicola Montemurro ◽  
Paolo Perrini ◽  
Vittoriano Mangini ◽  
Massimo Galli ◽  
Andrea Papini
Keyword(s):  
Ct Scan ◽  
Healthy Subjects ◽  
Bone Structure ◽  
Cone Beam Ct ◽  
Odontoid Process ◽  
Trabecular Structure ◽  
Anatomical Entity ◽  
Significant Difference ◽  
Axial Ct ◽  
The Mean

OBJECTIVEOdontoid process fractures are very common in both young and geriatric patients. The axial trabecular architecture of the dens appears to be crucial for physiological and biomechanical function of the C1–2 joint. The aim of this study is to demonstrate the presence of a Y-shaped trabecular structure of the dens on axial CT and to describe its anatomical and biomechanical implications.METHODSFifty-four C2 odontoid processes in healthy subjects were prospectively examined for the presence of a Y-shaped trabecular structure at the odontocentral synchondrosis level with a dental cone beam CT scan. Length, width, and axial area of the odontoid process were measured in all subjects. In addition, measurements of the one-third right anterior area of the Y-shaped structure were taken.RESULTSThe Y-shaped trabecular structure was found in 79.6% of cases. Length and width of the odontoid process were 13.5 ± 0.6 mm and 11.2 ± 0.9 mm, respectively. The mean area of the odontoid process at the odontocentral synchondrosis was 93.5 ± 4.3 mm2, whereas the mean one-third right anterior area of the odontoid process at the same level was 29.3 ± 2.5 mm2. The mean area of the odontoid process and its length and width were similar in men and women (p > 0.05). No significant difference was found in the mean area of the odontoid process in people older than 65 years (94 ± 4.2 mm2) compared to people younger than 65 years (93.3 ± 4.4 mm2; p > 0.05).CONCLUSIONSThe authors identified a new anatomical entity, named the Y-shaped trabecular structure of the odontoid process, on axial CT scans. This structure appears to be the result of bone transformation induced by the elevated dynamic loading at the C1–2 level. The presence of the Y-shaped structure provides new insights into biomechanical responses of C2 under physiological loading and traumatic conditions.

Analysis of the Real Area of Contact Between a Polymeric Magnetic Medium and a Rigid Surface

1984 ◽  
Vol 106 (1) ◽  
pp. 26-34 ◽  
Author(s):  
Bharat Bhushan
Keyword(s):  
Complex Modulus ◽  
Critical Value ◽  
Computer Applications ◽  
Hard Material ◽  
Rigid Surface ◽  
Magnetic Medium ◽  
The Real ◽  
Real Area Of Contact ◽  
The Mean ◽  
Real Area

The statistical analysis of the real area of contact proposed by Greenwood and Williamson is revisited. General and simplified equations for the mean asperity real area of contact, number of contacts, total real area of contact, and mean real pressure as a function of apparent pressure for the case of elastic junctions are presented. The critical value of the mean asperity pressure at which plastic flow starts when a polymer contacts a hard material is derived. Based on this, conditions of elastic and plastic junctions for polymers are defined by a “polymer” plasticity index, Ψp which depends on the complex modulus, Poisson’s ratio, yield strength, and surface topography. Calculations show that most dynamic contacts that occur in a computer-magnetic tape are elastic, and the predictions are supported by experimental evidence. Tape wear in computer applications is small and decreases Ψp by less than 10 percent. The theory presented here can also be applied to rigid and floppy disks.

A-136 The Transfer of Cognitive Training to Real-World Functioning: Results of our First Six Pilot Subjects at Six-Month Follow-Up

2021 ◽  
Vol 36 (6) ◽  
pp. 1187-1188
Author(s):  
Jason A Blake ◽  
Brandon Mitchell ◽  
Staci McKay ◽  
Gitendra Uswatte ◽  
Edward Taub
Keyword(s):  
Cognitive Training ◽  
Real World ◽  
Cognitive Task ◽  
Case Series ◽  
Performance Measure ◽  
The Real ◽  
Cognitive Activities ◽  
The Mean ◽  
Laboratory Measures

Abstract Objective Currently, the majority of cognitive training research measures treatment efficacy using in-laboratory measures, with minimal focus on real-world treatment changes. This case series demonstrates the feasibility of transferring cognitive improvements from the laboratory into the everyday life setting. Method This case series includes 6 chronic post-stroke participants; mild to moderate cognitive impairment. The intervention combines cognitive training with behavioral techniques, known as the Transfer Package (TP). The TP involves components that target functionality on IADLs in the real-world. Performance on cognitively-based IADLs in the real world are measured pre-treatment, post, and 6-month follow-up. Measures of real-world ability are the: Canadian Occupational Performance Measure (COPM), Cognitive Task Activity Log (CTAL) and Inventory of Improved and New Abilities (INCA). In-laboratory measures included the D-KEFS and Timed IADL assessments. Results The real-world outcome measures used in this study were the COPM and two measures developed for this study, the CTAL and INCA. The mean change from pre to post on the COPM Performance Scale was 2.18 (SD = 1.33) and the mean change on the COPM Satisfaction Scale was 2.70 (SD = 1.27). The mean change on the CTAL was 1.96 (SD = 0.93). On the INCA, the mean number of improved real-world cognitive activities was 11.8 (SD = 4.9) and the mean number of new cognitive activities was 7.6 (SD = 3.9). Follow-up reported near-perfect retention on CTAL and continued improvement on the INCA. There were minimal changes on in-laboratory measures. Conclusions This case series provides a framework for achieving the transfer of cognitive training treatment effects in the real-world life situation by overcoming behavioral barriers to functioning.

scholarly journals Anatomic considerations for C2 pedicle screw placement: the use of computerized tomography measurements

2009 ◽  
Vol 8 (1) ◽  
pp. 80-83
Author(s):  
Adebukoa Onibokun ◽  
Simona Bistazzoni ◽  
Marco Sassi ◽  
Larry T. Khoo
Keyword(s):  
Pedicle Screw ◽  
Computerized Tomography ◽  
Preoperative Planning ◽  
Screw Placement ◽  
Pedicle Screw Placement ◽  
C2 Pedicle Screw ◽  
Anatomical Knowledge ◽  
Axial Ct ◽  
The Mean ◽  
Pedicle Width

OBJECTIVE: more detailed anatomical knowledge of the C2 pedicle is required to optimize and minimize the risk of screw placement. The aim of this study was to evaluate the linear and angular dimensions of the true C2 pedicle using axial CT. METHODS: ninety three patients (47 males, 46 females mean age 48 years) who had cervical spinal CT imaging performed were evaluated for this study. Axial images of the C2 pedicle were selected and the following pedicle parameters were determined: pedicle width (PW, the mediolateral diameter of the pedicle isthmus, perpendicular to the pedicle axis) and pedicle transverse angle (PTA, that is, the angle between the pedicle axis and the midline of the vertebral body). RESULTS: the overall mean pedicle width was 5.8 1.2mm. The mean pedicle width in males (6.01.3mm) was greater than that in the female subjects (5.6 1.1mm). This difference was not found to be statistically significant (p=.6790). The overall mean pedicle transverse angle was 43.93.9 degrees. The mean PTA in males was 43.23.8 degrees, while that in females was 44.73.7 degrees. CONCLUSION: preoperative planning is absolutely mandatory, particularly in determining not only screw trajectory, but in analyzing individual patient anatomy and reception to a C2 pedicle screw.

scholarly journals Laryngopharyngeal Reflux: Is It the Real Culprit in Patients with Laryngeal Complaints?

2017 ◽  
Vol 7 (1) ◽  
pp. 6-9 ◽  
Author(s):  
Rajesh Vishwakarma ◽  
Ruta V Shah
Keyword(s):  
Laryngopharyngeal Reflux ◽  
Reflux Symptom Index ◽  
Symptom Index ◽  
Female Ratio ◽  
The Real ◽  
Body Sensation ◽  
Male Female Ratio ◽  
The Mean ◽  
Nose And Throat

ABSTRACT Aim The aim of this study is to evaluate the role of laryngopharyngeal reflux (LPR) in patients with laryngeal complaints and study the correlation between reflux symptom index (RSI) and reflux finding score (RFS). Materials and methods This is a study of 104 patients, who presented in the ear, nose, and throat outpatient department at the Civil Hospital, Ahmedabad, India, from April 2015 to April 2016, with complaints like change of voice, chronic cough, foreign body sensation, throat clearing, difficulty swallowing, and regurgitation. All the patients were examined with 90° endoscope by a single examiner, and an RSI ≥13 was considered as indicative of reflux. Observation and discussion The mean age of the 104 patients was 47.2 years. The male-female ratio was 1:1.8. The RSI ranged from 5 to 44, with a mean of 22.99 and standard deviation (SD) of 7.43. The RFS ranged from 4 to 22, with a mean of 11.04 and SD of 3.07. Both the parameters showed high correlation (correlation coefficient 0.98). Conclusion The LPR plays an important contributory role in patients with laryngeal complaints. The RFS and RSI can be used as routine parameters in establishing the diagnosis of reflux. How to cite this article Shah RV, Vishwakarma R. Laryngopharyngeal Reflux: Is It the Real Culprit in Patients with Laryngeal Complaints? Int J Phonosurg Laryngol 2017; 7(1):6-9.

scholarly journals Estimating Parametersof Gumbel Distribution For Maximum Values By using Simulation

2016 ◽  
Vol 13 (4) ◽  
pp. 707-713
Author(s):  
Baghdad Science Journal
Keyword(s):  
Gumbel Distribution ◽  
Estimation Methods ◽  
Sample Sizes ◽  
Random Data ◽  
The Real ◽  
The Mean ◽  
Distribution Type

In this research estimated the parameters of Gumbel distribution Type 1 for Maximum values through the use of two estimation methods:- Moments (MoM) and Modification Moments(MM) Method. the Simulation used for comparison between each of the estimation methods to reach the best method to estimate the parameters where the simulation was to generate random data follow Gumbel distributiondepending on three models of the real values of the parameters for different sample sizes with samples of replicate (R=500).The results of the assessment were put in tables prepared for the purpose of comparison, which made depending on the mean squares error (MSE).

scholarly journals About estimation of base station output power in GSM like systems under real conditions

2020 ◽  
Vol 30 (1) ◽  
pp. 109-119
Author(s):  
Aleksandar Lebl ◽  
Dragan Mitic ◽  
Zarko Markov ◽  
Verica Vasiljevic
Keyword(s):  
Computer Simulation ◽  
Output Power ◽  
Mobile User ◽  
Base Station ◽  
Cumulative Distribution ◽  
Real Case ◽  
The Real ◽  
The Mean

The output power of traffic channels in one cell of GSM like systems is estimated in this paper. We consider the real case: the number of users is much higher than the number of channels, the output power of one channel depends on the cube of the distance between a mobile user and the base station, and the distribution of users in the cell is uniform. We derive the expressions for cumulative distribution of output power of one channel and for the mean output power of the whole base station. Results of the calculation are confirmed by computer simulation.

scholarly journals The influence of kihap on the impact of Dolio-chagui kicks in taekwondo

2014 ◽  
Vol 20 (1) ◽  
pp. 54-57
Author(s):  
Rodrigo Dias Martins ◽  
Debora Cantergi ◽  
Jefferson Fagundes Loss
Keyword(s):  
Martial Arts ◽  
Random Order ◽  
T Test ◽  
Real Effect ◽  
The Real ◽  
The Mean ◽  
The Difference ◽  
The Impact

The kihapis a technique used in several oriental martial arts. It is a yell used by practitioners with the ex pectation of enhancing the force of a hit. However, the real effect of using the kihapis unknown. Therefore, this study aims to compare the peak of acceleration of the Dolio-chaguikick in taekwondo performed with and without the use of kihap. Twenty two experienced taekwondo practitioners performed 30 kicks each against a punching bag, alternating in random order with and without kihap, while the acceleration of the punching bag was measured. A t-test was used to compare the difference between the mean acceleration in both conditions. Higher values were found with the use of kihap(7.8 ± 2.8 g) than without the use of kihap(7.1 ± 2.4 g), p< 0.01, r= 0.57. The results indicate that kihapenhances the impact of the kick.

Aristóteles Contra o Bem dos Economistas

2021 ◽  
Vol 77 (1) ◽  
pp. 217-234
Author(s):  
Mário Maximo
Keyword(s):  
Economic Theory ◽  
Moral Philosophy ◽  
Real Function ◽  
Capability Approach ◽  
Capabilities Approach ◽  
Ethical Naturalism ◽  
Human Form ◽  
The Real ◽  
Weak Points ◽  
The Capability Approach

Despite its origins within moral philosophy, economists think their science has nothing to do with the good. They appeal to some kind of Hume’s guillotine that divides the descriptive and the normative. With that in hand, they affirm the solely descriptive aspect of their discipline. I argue this is not the case. Economists have, as they need to, an all encompassing notion of the good. I suggest going back to Aristotelian arguments to show the shortcomings of this good of economists. Aristotle is helpful because of his analysis of chrematistics and the real function of money. Hence, the loosely utilitarian good of the economists is confronted with a robust sense of the good and the human form. The capability approach is the first to identify these weak points on economic theory and to propose a sort of Aristotelian comeback. However, I claim the capabilities approach itself doesn’t follow the Aristotelian arguments used to attack economists to its necessary conclusion. Therefore, I suggest that the recent advances in neo-Aristotelian ethical naturalism can be used to reformulate economics by dispossessing economists of their sumo bonnun.

Sign in / Sign up

Export Citation Format

Share Document