ABSTRACT
ABSTRACT: Objective To develop a convolutional neural network ï¼CNNï¼ that can identify isokinetic knee exercises moment of force-time diagrams under different levels of efforts. Methods The 200 healthy young volunteers performed concentric isokinetic right knee flexion-extension reciprocating exercises with maximal effort as well as half the effort at angular velocities of 30°/s and 60°/s twice, respectively, with an interval of 45 min. The moment of force-time diagrams were collected. The 200 subjects were randomly divided into the training set ï¼140 subjectsï¼ and the testing set ï¼60 subjectsï¼. The moment of force-time diagrams from subjects in the training set were used to train CNN model, and then the fully trained model was used to predict types of curves from the testing set. Random sampling of subjects along with subsequent development of models were performed 3 times. Results Under the circumstances of isokinetic knee exercises with maximal effort and half the effort, 2 400 moment of force-time diagrams were produced, respectively. Classification accuracy rates of the CNN models after the 3 trainings were 91.11%, 90.49% and 92.08%, respectively, and the average accuracy rate was 91.23%. Conclusion The CNN models developed in this study have a good effect on differentiating isokinetic moment of force-time diagrams of maximal effort exercises from those made with half the effort, which can contribute to identifying levels of efforts exerted by subjects during isokinetic knee exercises.
Subject(s)
Knee Joint , Muscle, Skeletal , Humans , Knee , Muscle Contraction , Neural Networks, ComputerABSTRACT
ABSTRACT: Objective To explore a kind of visual evoked potential test equipment and method that is more suitable for the application of forensic clinical visual acuity evaluation. Methods Thirty-four volunteers ï¼68 eyesï¼ were selected, including 15 males and 19 females, aged between 20 and 40 years. Test lenses were placed before the tested eyes of volunteers to induce refractive myopia with insert method, and the diopter lenses were adjusted so that the visual acuity level of one eye of volunteers was above 0.8, and the visual acuity of the other eye was at moderate damage level ï¼<0.3 and ≥0.1ï¼. The tests were carried out under the binocular simultaneous asynchronous stimulation mode ï¼hereinafter referred to as "binocular mode"ï¼ and monocular separate stimulation mode ï¼hereinafter referred to as "monocular mode"ï¼ of virtual reality-pattern visual evoked potential ï¼VR-PVEPï¼, and the amplitude of PVEP of volunteers under the two modes was compared at four spatial frequencies of 8×8, 16×16, 24×24 and 32×32. Results The differences in the amplitude of P100 wave between monocular and binocular modes at 8×8 spatial frequency had no statistical significance and the differences in amplitude of P100 wave between monocular and binocular modes at 16×16, 24×24, and 32×32 spatial frequencies had statistical significance ï¼P<0.05ï¼. The amplitude of the same eye in monocular mode was higher than that in binocular mode. Through correlation analysis, it was found that the amplitude of P100 wave in monocular mode was moderately correlated with amplitude of P100 wave in binocular mode. Conclusion In forensic identification practice, VR-PVEP is helpful for overcoming the disturbance of poor fixation, and to increase the reliability of PVEP evaluation results. It can greatly shorten the detection time of PVEP and improve work efficiency.
Subject(s)
Evoked Potentials, Visual , Virtual Reality , Adult , Eye , Female , Humans , Male , Reproducibility of Results , Visual Acuity , Young AdultABSTRACT
ABSTRACT: Gradation of Disability in Human Body Injuries ï¼hereinafter referred to as Gradationï¼ has been released and used since January 2017, and has become the most widely used standard in forensic science practice. This paper calculates and rates the visual system evaluation provisions of the current domestic disability evaluation criteria represented by the Gradation which used the methods of Guides to the Evaluation of Permanent Impairment ï¼hereinafter referred to as GEPIï¼ issued by American Medical Association ï¼AMAï¼. Through comparing, a good correlation between the provisions in Gradation and whole person impairment rating index in GEPI was shown. On the basis of this, suggestions are put forward to amend some provisions of Gradation, in order to provide reference for the revision and further improvement of domestic standards and provisions.
Subject(s)
Disability Evaluation , Disabled Persons , Guidelines as Topic , American Medical Association , China , Forensic Medicine/standards , Forensic Sciences , Humans , United StatesABSTRACT
ABSTRACT: Objective To research the correlation between the visual acuity ratio and pattern reversal visual evoked potential ï¼PRVEPï¼ P100 waveform amplitude ratio of both eyes. Methods Forty-seven volunteers were selected, and the visual chart visual acuity of both eyes was measured. The visual acuity ratio of the eye with poor vision to the eye with better vision was calculated by five grade notation method. The amplitudes of P100 waveforms of both eyes were recorded respectively by using black-and-white checkerboard PRVEP and chosing 1°, 15' stimulating visual angle, and the ratio of amplitudes between the two eyes was also calculated. SPSS 20.0 software was used to analyze the correlation between the visual acuity ratio and the ratio of P100 waveform amplitudes between the two eyes. Return test and linear regression analysis with the binocular ratio of P100 waveform amplitudes as the independent variable ï¼xï¼ and the binocular visual acuity ratio as the dependent variable ï¼yï¼ were made. Results There was a positive correlation between the binocular visual acuity ratio and the ratio of P100 waveform amplitudes under 15' stimulating visual angle ï¼Pearson correlation coefficient was 0.62, P=0.000ï¼. The fitting linear regression equation was y=0.090 x+0.846 ï¼F=20.954, P=0.000ï¼. There was no significant correlation between the binocular ratio of visual acuity and the binocular ratio of P100 waveform amplitudes under 1° stimulating visual angle ï¼P>0.05ï¼. Results of return test showed that there was no statistical significance in the difference between visual acuity estimated by equation and actual detected visual acuity. Conclusion In forensic appraisal of monocular injury, fitting linear regression equation of binocular visual acuity ratio and the binocular ratio of P100 waveform amplitudes under 15' stimulating visual angle, is helpful for visual acuity level estimation of the injured eye to some extent.
Subject(s)
Evoked Potentials, Visual , Eye/physiopathology , Vision, Ocular , Visual Acuity , Humans , Regression AnalysisABSTRACT
OBJECTIVES: To explore the assessment method of original height of L1-2 after vertebral compression fracture and its application value in forensic clinical practice. METHODS: A total of 154 normal thoracic and lumbar X-ray films were collected, and 140 cases were used as experimental group while 14 cases as validation group. The heights of anterior ï¼Haï¼ and posterior ï¼Hpï¼ vertebral body of T12-L3 vertebrae in each X-ray image were measured. In the experimental group, the correlation analysis between HaL1 and HaT12, HpT12, HpL1, HaL2 and HpL2 was carried out, and regression equation was established via fitting. The correlation analysis between HaL2 and HaL1, HpL1, HpL2, HaL3, HpL3 was performed, and the regression equation was also established via fitting. The difference between the predicted and measured values of HaL1 and HaL2 in validation group was compared. RESULTS: In the 140 normal subjects, HaL1 ï¼y1ï¼ was well correlated with HaT12 ï¼x1ï¼ and HaL2ï¼x2ï¼, and the multiple linear regression equation was y1=2.545+0.423 x1+0.486 x2 ï¼determining coefficient R²=0.712, P<0.05; F=169.206, P<0.05ï¼. There was no significant difference between the predicted and actual measured values of HaL1 in the validation group ï¼ P>0.05ï¼. HaL2 ï¼y2ï¼ was well correlated with HaL1 ï¼x3ï¼ and HaL3 ï¼x4ï¼, and the multiple linear regression equation was y2=4.354+0.530 x3+0.349 x4 ï¼determining coefficient R²=0.689, P<0.05; F=151.575, P<0.05ï¼. There was no significant difference between the predicted and actual measured values of HaL2 in the validation group ï¼ P>0.05ï¼. CONCLUSIONS: It is more appropriate to evaluate the original height of L1 or L2 single vertebrae by comparing with the height of the anterior edge of the upper and lower adjacent vertebral bodies.
Subject(s)
Fractures, Compression , Lumbar Vertebrae/diagnostic imaging , Spinal Fractures/surgery , Thoracic Vertebrae/diagnostic imaging , Aged , Humans , Middle AgedABSTRACT
Binocular vision refers to a progress of analysing and integrating the binocular visual signals into a whole and three-dimensional sensory perception by higher nerve centre. In this process, the interac- tion between the two eyes results in the changes of output signal, which is called binocular interaction. Through a series of subjective and objective experiments, it can be concluded that binocular interaction can be divided into three typesï¼ facilitation, summation and suppression, and the forms of binocular interaction in different visual states are different. In general, the visual signal is processed by binocular interaction, so that there are some differences between binocular vision and monocular vision. The extent of the difference can be affected by the damage of monocular vision and then affects the binocular vision. Thus, it is necessary for forensic scientists to further study the effects of the monocular visual impairment on visual function. Based on relevant data, this paper reviews the mechanism of the monocular visual impairment in binocular vision, the research methods and the application prospect in forensic science.
Subject(s)
Vision Disorders , Vision, Binocular , Vision, Monocular , Visual Acuity , Adult , Humans , Vision, OcularABSTRACT
Accurate evaluation of muscle function helps to understand the recovery of muscle, bone, nervous system diseases or injuries, especially for muscle dysfunction caused by peripheral nerve injury. Therefore, the methods of muscle function evaluation have been the focus of researchers, with new methods having been constantly proposed. Muscle strength testing is an important part of muscle function evaluation. Besides hand muscle strength assessment, currently used muscle function assessments include simple instrumental test, isokinetic muscle test, electrophysiological test, etc. In addition, the application of needle electromyography, motor unit number estimation, motion unit index in muscle function evaluation has also been reported for several times. This paper reviews the research progress and practical application of these methods.
Subject(s)
Nervous System Diseases , Peripheral Nerve Injuries , Electromyography , Humans , Muscle Strength , Muscle, Skeletal , Nervous System Diseases/diagnosis , Peripheral Nerve Injuries/diagnosisABSTRACT
OBJECTIVES: To study the characteristic of contrast visual evoked potentials ï¼CVEPï¼ in patients with ocular trauma. METHODS: Sixty patients defined as ocular trauma by forensic clinical examination in our center were selected, and split into 0.2-0.3 ï¼Group Aï¼, 0.3-0.5 ï¼Group Bï¼ and ≥0.5 ï¼Group Cï¼ according to the best corrected visual acuity. The variation characteristics of wave amplitude and latency of CVEP under 100%, 25% and 10% contrast were observed and analyzed statistically. RESULTS: ï¼1ï¼ Under the same contrast, the wave amplitude of P100 decreased with the decrease of stimulus perspective. ï¼2ï¼ Under the same stimulus perspective, the wave amplitude of P100 decreased with the decrease of contrast ï¼P<0.05ï¼. ï¼3ï¼ Under the contrast of 100% and 25% with the same stimulus perspective ï¼except 100% 7' perspective stimulusï¼, the difference between group A and group B had no statistical significance ï¼P>0.05ï¼. Between group A and group C, group B and group C, the wave amplitude of P100 gradually increased with the increase of vision ï¼P<0.05ï¼. Under the contrast of 10% with 15' stimulus perspective, the wave amplitude of P100 increased with the increase of vision ï¼P<0.05ï¼. ï¼4ï¼ Under the same contrast with the same stimulation perspective, the latency of P100 wave shortened with the increase of vision, while the difference had no statistical significance ï¼P>0.05ï¼. Under the same stimulus perspective, the latency of P100 wave was prolonged with the decrease of contrast ï¼P>0.05ï¼. CONCLUSIONS: CVEP may become one of the possible methods for the evaluation of contrast visual acuity.
Subject(s)
Evoked Potentials, Visual/physiology , Eye Injuries/physiopathology , Pattern Recognition, Visual/physiology , Visual Acuity , Humans , Photic Stimulation , Vision, OcularABSTRACT
OBJECTIVES: To compare the differences between Hertel exophthalmometry and CT on exophthalmos measurement, and explore its practical application value in forensic medicine. METHODS: Fifty-six normal individuals without eye injuries or diseases were selected as the control group. The absolute values of exophthalmos were measured in the standardized CT image workstation. The difference of binocular exophthalmos was compared in normal group. Forty-seven cases with unilateral orbital fracture were divided into injured eye group and normal eye group according to the presence of binocular orbital fractures. The differences of the absolute values of eophthalmos from the same eye and the relative values of eophthalmos between two eyes for same person measured by Hertel exophthalmometry and CT were analyzed. RESULTS: There was no statistical difference of exophthalmos between the normal eyes measured by CT method. In the normal eye group, the absolute value of exophthalmos measured by CT method was ï¼16.66±5.41ï¼ mm, which was ï¼16.16±4.45ï¼ mm when measured by the Hertel exophthalmometry method. There was no statistical difference between two groups ï¼P>0.05ï¼. In the injured eye group, there was statistical difference between the absolute values of exophthalmos measured by two measurement methods ï¼ P<0.05ï¼. There was no statistical difference of the relative values of exophthalmos between the injured eyes and the normal eyes by two measurement methods ï¼P>0.05ï¼. CONCLUSIONS: CT method has a good consistency with Hertel exophthalmometry, which can be applied into the practice of medicolegal expertise.
Subject(s)
Diagnostic Techniques, Ophthalmological/instrumentation , Exophthalmos/diagnostic imaging , Eye Injuries/diagnostic imaging , Eye/diagnostic imaging , Orbital Fractures/diagnostic imaging , Adult , Case-Control Studies , Eye/pathology , Forensic Medicine , Humans , Male , Orbit/diagnostic imaging , Orbit/pathology , Reference Standards , Tomography, X-Ray ComputedABSTRACT
OBJECTIVES: To explore the range of reasonable weight coefficient of hip joint in lower limb function. METHODS: When the hip joints of healthy volunteers under normal conditions or fixed at three different positions including functional, flexed and extension positions, the movements of lower limbs were recorded by LUKOtronic motion capture and analysis system. The degree of lower limb function loss was calculated using Fugl-Meyer lower limb function assessment form when the hip joints were fixed at the aforementioned positions. One-way analysis of variance and Tamhane's T2 method were used to proceed statistics analysis and calculate the range of reasonable weight coefficient of hip joint. RESULTS: There were significant differences between the degree of lower limb function loss when the hip joints fixed at flexed and extension positions and at functional position. While the differences between the degree of lower limb function loss when the hip joints fixed at flexed position and extension position had no statistical significance. In 95% confidence interval, the reasonable weight coefficient of hip joint in lower limb function was between 61.05% and 73.34%. CONCLUSIONS: Expect confirming the reasonable weight coefficient, the effects of functional and non-functional positions on the degree of lower limb function loss should also be considered for the assessment of hip joint function loss.