卷积神经网络在识别等速运动配合程度中的应用

目的开发识别不同配合程度下等速膝关节运动力矩-时间图的卷积神经网络(convolutional neu⁃ral network,CNN)模型。方法200名健康青年志愿者分别在30°/s和60°/s角速度下各进行两次、间隔45min的等速向心右侧膝关节全力和半力屈伸往复运动,收集力矩-时间图。200名受试者随机分为训练集(140名)与测试集(60名),用训练集受试者的力矩-时间图训练CNN模型,再用训练好的模型预测测试集内图形的类别。共进行3次随机取样与模型开发。结果在等速膝关节全力及半力运动条件下各收集2400张力矩-时间图。3次训练的CNN模型分类准确率分别为91.11%、90.49%和92.08%,平均准确率为91.23%。结论本研究开发的CNN模型对全力及半力等速力矩-时间图具有较好的区分效果,有助于识别受试者在等速膝关节运动过程中的配合程度。     

正常人不同姿势膝关节等速肌力测试

目的：研究应用CON-TREX Biomechanical Test and Training系统测试膝关节肌力时,分析不同姿势对测试结果的影响,从而选择最适用于法医学鉴定的肌力检测条件。方法对52例正常人分别在未固定姿势和固定姿势两种条件下进行60°/s和30°/s速度的等速肌力测试,对这两种条件下双侧膝关节屈、伸肌的峰力矩（peak torque,PT）、峰力矩角度（peak torque angle,PTA）进行统计学分析。结果在未固定姿势,两种测试速度下受试者膝关节屈、伸肌的PT双侧比较差异均存在统计学意义（P〈0.05）;在固定姿势,两种测试速度下受试者膝关节屈、伸肌的PT双侧比较差异均无统计学意义（P〉0.05）。不论受试者身体姿势是否加以固定,其膝关节屈、伸过程的PTA双侧比较差异均无统计学意义（P〉0.05）。结论受试者姿势的规范对测试结果,对PT有影响,因此,在进行膝关节等速肌力测试时应规范受试者的姿势。     

图形异同判别ERP技术检测伪装认知损害的研究

目的探讨图形异同判别ERP范式对鉴别伪装认知损害的法医学价值。方法 40例健康志愿者在合作和伪装认知损害两种情境下,进行二项必选数字记忆测验(BFDMT)及图形异同判别ERP范式检测,对照组为20例合作的三级脑外伤者。结果三组被试完成相同、无关、相似图形刺激后引出的ERP波均包括N1、P2、N2、P3和N3五个成分,三组样本组间的N2、P3和N3的潜伏期和波幅均存在差异。其中,伪装组相同图形的N3潜伏期与正常组无显著性差异,明显短于外伤组(P<0.01);伪装组无关图形的N3潜伏期较正常组延长,但短于外伤组,波幅较正常组降低(P<0.05);伪装组相似图形的N3潜伏期较正常组和外伤组缩短(P<0.01),波幅较正常组降低(P<0.01)。以N3潜伏期为指标进行判别分析,探查伪装认知损害的敏感性为81.8%、特异性为76.9%、命中率为79.2%。结论图形异同判别范式可引出稳定的特征性ERP成分,其中N3的波幅和潜伏期有显著的组间差异,对判断伪装认知损害有一定的参考价值。     

对比度视力容许区间在鉴别伪装视力降低中的应用

目的探索法医学鉴定中运用对比度视力方法鉴别被鉴定人伪装或夸大视力降低的价值。方法根据前期对比度视力与投影仪视力相关性的研究结果,收集正常志愿者166眼作为对照组,分别检测投影仪视力与100%、25%、10%视标对比度下的对比度视力,获得不同投影仪视力水平与以上视标对比度下相应的视力95%容许区间;收集眼外伤被鉴定人64眼,根据其100%对比度视力值是否在相应对比度视力的容许区间内,分为A组（初步排除伪装或夸大视力降低）与B组（疑有伪装或夸大视力降低组）。运用统计学软件进行数据分析。结果投影仪视力检测值≤0.3以及0.4~0.7组的受检眼,在不同对比度视标检测下,A、B组的差异均有统计学意义（P≤0.05）;投影仪视力检测值≥0.8组的受检眼,在不同对比度下,A、B组的差异无统计学意义（P≥0.05）。结论当被鉴定人受伤眼的投影仪视力在0.8以下,可加测对比度视力。参照投影仪视力对应的对比度视力容许区间,当受检眼对比度视力值在容许区间以外,应考虑其存在伪装或夸大视力降低。     

对比度视力容许区间在鉴别伪装视力降低中的应用

目的 探索法医学鉴定中运用对比度视力方法鉴别被鉴定人伪装或夸大视力降低的价值.方法 根据前期对比度视力与投影仪视力相关性的研究结果,收集正常志愿者166眼作为对照组,分别检测投影仪视力与100％、25％、10％视标对比度下的对比度视力,获得不同投影仪视力水平与以上视标对比度下相应的视力95％容许区间;收集眼外伤被鉴定人64眼,根据其100％对比度视力值是否在相应对比度视力的容许区间内,分为A组(初步排除伪装或夸大视力降低)与B组(疑有伪装或夸大视力降低组).运用统计学软件进行数据分析.结果 投影仪视力检测值≤0.3以及0.4～0.7组的受检眼,在不同对比度视标检测下,A、B组的差异均有统计学意义(P≤0.05);投影仪视力检测值≥0.8组的受检眼,在不同对比度下,A、B组的差异无统计学意义(P≥0.05).结论 当被鉴定人受伤眼的投影仪视力在0.8以下,可加测对比度视力.参照投影仪视力对应的对比度视力容许区间,当受检眼对比度视力值在容许区间以外,应考虑其存在伪装或夸大视力降低.     

不同温度下离体人静脉血ATP含量与死亡时间的关系

目的探讨在环境温度变化条件下,人体静脉血ATP降解与死亡时间的关系。方法健康志愿者48名,随机分为6组,肱静脉取静脉血,置于10℃、15℃、20℃、25℃、30℃和35℃下保存;每4h应用ATP检测仪对不同温度下的ATP含量进行检测;应用SPSS统计软件进行回归分析,MATLAB软件进行差值函数分析拟合。结果各温度组ATP值随死亡时间延长均呈下降趋势,从取血即刻的1 573.683 E-13mol/L,降至6.00 E-13mol/L左右,所经历的时间分别为236h(10℃)、163h(15℃)、124h(20℃)、92h(25℃)、72h(30℃)和64h(35℃),对所得数据进行回归分析,得到各温度组下ATP含量变化与PMI关系的二元三次曲线方程(R2范围为0.976～0.990);进行差值拟合,得到10～35℃范围内ATP含量变化与PMI关系的三元四次曲面方程。结论在不同温度下,人体静脉血ATP降解与PMI关系符合三元四次方程分布,利用差值函数拟合的方法可在温度变化条件下进行死亡时间推断。     

基于紫外可见积分球反射光谱法鉴定血痕经历时间

目的建立一种快速鉴定血痕陈旧度的方法。方法在实验室条件(20℃、25℃、30℃)下,使用UV-2450型紫外可见分光光度计,利用反射附件ISR-240A积分球,以BaSO_4标准白板做参比,间隔一定时间测定健康人耳静脉血血痕纱布的反射光谱,采集特定波长反射率R_(541)、R_(577),计算R_(541)/R_(577)值,使用SPSS 17.0软件进行直线拟合与回归分析。结果一定条件下8 h内,血痕经历时间与其特定波长紫外可见反射率比值回归分析的R~2均大于0.8,回归方程成立,血痕经历时间与R_(541)/R_(577)值具有高度相关性。结论所建立的方法简便、快速、无损,可靠性好,可以对实验室条件下8 h内血痕经历时间进行鉴别。     

常染色体STR分型鉴定半同胞关系的亲缘关系指数计算

目的获得双方生母均参与情形下计算两个或三个孩子间半同胞关系指数(half-sib index, HSI)的简化公式。方法在给定的前提假设下,根据HSI值的定义,首先推导出单基因座上HSI值的统一表达式,再获得不同基因型组合下的计算公式,最后归纳出两种鉴定情形下的简化公式。将简化公式应用于1例典型的半同胞关系鉴定,根据39个常染色体STR位点的分型计算不同鉴定情形下的累积HSI值。结果成功地推导和归纳出双方生母均参与情形下计算两个或三个孩子间HSI值的简化公式。实际案例的计算结果显示,当双方生母均参与时,任意两个孩子间的累积HSI值与生母均不参与时相比均发生了数量级的改变,即在半同胞关系情形下大约为10~4～10~6倍,在无关个体情形下大约为10~(-4)～10~(-3)倍。结论所推导出的简化公式可用于计算双方生母均参与情形下两个或三个孩子间的HSI值。     

多温度下死后心血pH值随时间变化的三维拟合函数研究

目的 探讨通过测量多温度条件下家兔右心血液pH值进行死亡时间推断的可行性.方法 48只家兔随机分为6组,空气栓塞法处死后于10℃、15℃、20℃、25℃、30℃和35℃的不同死亡时间点采集右心血液;用PB-10型pH仪测量样本pH值;SPSS统计软件进行回归分析;MATLAB软件进行数学分析.结果 各温度组右心血液pH值变化与死亡时间呈高度相关(R2=0.974 ～0.982);获得拟合的曲面方程.结论 利用插值函数拟合pH值与死亡时间的曲面方程可进行温度变化条件下的死亡时间推断.     

外温变化下小鼠肝细胞18s rRNA降解与死亡时间关系研究

目的探讨在外界环境温度变化条件下,小鼠肝细胞18s rRNA降解与死亡时间的关系。方法小鼠断颈处死后置于10℃、15℃、20℃、25℃、和30℃温度下保存;从死后6h至72h,每6h分别提取肝细胞组织中总RNA。利用实时荧光定量PCR检测18s rRNA循环阈值(Ct值)的变化。应用插值函数进行分析拟合,建立死亡时间推断方程。结果各温度组Ct值随死亡时间延长均呈上升趋势,对所得数据进行插值拟合,得到一定温度变化区间内(10℃~30℃),Ct值变化与PMI关系的三元五次曲面方程:f(x,y)=-426.9+30.82x+44.48y-1.297x~2-1.837xy-1.388y~2+0.034 38x~3+0.038 17x~2y+0.038 67xy~2+0.028 77y3-0.000 612 9x~4-3.897e~(-7)x~3y-0.001 223x~2y~2+0.000256 6xy3-0.000 537 4y~4+3.606e~(-6)x~5-2.846e~(-6)x~4y+1.009e~(-5)x~3y~2-3.439e~(-6)x~2y3-2.556e~(-7)xy~4+2.664e~(-6)y~5(r2=0.999 4)。结论在外界温度变化条件下,小鼠肝细胞18s rRNA降解与死亡时间关系符合三元五次方程分布,利用插值函数拟合的方法可在外界环境温度变化条件下进行死亡时间推断。     

Can APB 2000 Be Used to Discern Sincerity of Effort in Unimpaired Subjects from Maximal Performance in Subjects with Shoulder Pain?

The automated pegboard (APB 2000), which has been found to objectively quantify motor performance, was used to differentiate maximal motor performance among subjects with shoulder pain, healthy unimpaired subjects performing normally and also while feigning shoulder pain. Six participants with shoulder pain and 15 healthy unimpaired individuals participated. Individuals with shoulder pain were tested on the APB 2000 using their affected upper extremity. Unimpaired participants were instructed to perform normally on the test with randomly selected upper extremity and to feign shoulder pain with the other upper extremity. The two tests for the unimpaired participants were conducted 1 week apart. There were significant differences in mean performance time for normal, patient, and feigned performance, with 80, 111, and 149 sec for the three groups respectively (p < 0.0005). There was also considerable overlap in the three distributions of performance times. These preliminary findings suggest that the APB 2000 is able to distinguish performance time between these three groups. Whether it can be used to distinguish between maximal performance and submaximal performance in individuals suspected of submaximal performance requires further study.     

Symptom validity testing of feigned dissociative amnesia: A simulation study

Abstract

It has been argued that Symptom Validity Testing (SVT) has limited sensitivity in correctly identifying feigned autobiographical memory loss (e.g., dissociative amnesia) because malingerers would easily understand that below change performance on the SVT implies feigned memory loss. The current study tested this assumption in a sample of undergraduate students (N = 20) who committed a mock crime and then were instructed to feign complete amnesia for this event. Next, they had to answer 15 forced-choice questions that always contained the correct answer and an equally plausible alternative. Results show that a nontrivial minority of participants (40%) performed below chance. As well, understanding the SVT rationale appeared not to be related to random behaviour. Taken together, the results indicate that SVT procedures might be helpful in identifying feigned dissociative amnesia.     

等速肌力检测在辨别伪肢体瘫中的应用

目的：探讨等速肌力检测在法医学鉴定中辨别伪肢体瘫的应用价值,为建立规范、统一的法医学肌力评价方法提供科学依据。方法选取骨折或神经损伤者57例（损伤组）和伪装者128例（伪装组）,应用等速肌力测试系统对损伤组两侧膝关节与伪装组膝关节进行检测,对双侧膝关节屈、伸肌的峰力矩（peak torque,PT）、峰力矩角度（peak torque angle,PTA）进行比较,归纳两组膝关节的力矩-时间图特征。结果损伤组膝关节屈、伸肌的双侧PT的比较差异有统计学意义（P＜0.05）,PTA的比较差异无统计学意义（P＞0.05）;伪装组膝关节屈、伸肌的双侧PT、PTA的比较差异均有统计学意义（P＜0.05）。损伤组两侧膝关节力矩-时间图主要为单峰前置型,伪装组膝关节力矩-时间图主要为多峰型。结论在法医学鉴定中,等速肌力检测在辨别伪肢体瘫方面可以通过力矩-时间图的相关特点进行评价。     

Reliability Study on Quantitative Detection of Extensor Digitorum Brevis Strength with Needle Electromyography and Nerve Conduction

Objective To study the objectivity and reliability of needle electromyography and nerve con- duction for detection of musculus extensor digitorum brevis strength, which may provide a basis for es- tablishing a quantitative detection of muscle strength in forensic clinical study. Methods Forty-four healthy people were enrolled as the subjects, and during toe dorsiflexion, the following items including needle electromyography indexes, motor unit potential （MUP） amplitude, MUP count, recruitment reaction type, and nerve conduction detection indexes, compound muscle action potential （CMAP） amplitude, CMAP latent period and motor nerve conduction velocity （MNCV）, were simultaneously detected under the co- operation and disguise condition. Results Under the cooperation condition, regardless of the same opera- tor or different operators, there were good test-retest reliabilities in MUP amplitude, CMAP amplitude, CMAP latent period and MNCV, while there were normal test-retest reliabilities in MUP count and re- cruitment reaction type and the repeatability of the same operator was slightly better than the repeatabili- ty between different operators. Under the disguise condition, test-retest reliabilities of MUP amplitude, CMAP amplitude, CMAP latent period and M-NCV were relatively high, while test-retest reliabilities of MUP count and recruitment reaction type were relatively low. Conclusion There are good test-retest reli- abilities in MUP amplitude, CMAP amplitude, CMAP latent period and M-NCV, which can be conducive to comparison between different operators and results at various times; MUP count and recruitment reac- tion type, which can be easily affected by subjectivity of operators and examinees, can be used to dif- ferentiate whether an examinee disguises or not. The indexes used to objectively judge muscle strength remain to be further investigated.     

Violence in relationships: A seventh grade inventory of knowledge and attitudes

The purpose of this research was to contribute to existing efforts of battered women's advocates, schools, and researchers by developing a valid and reliable inventory to evaluate educational interventions regarding violence in relationships. Content validity was established by national experts (N=32)solicited to complete an inventory rating scale and comment on the statements' ability to elicit early adolescents' knowledge and attitudes about violence in relation-ships. The revised inventory was tested with seventh grade health education students (N=99).The test-retest reliability criterion was .50. Spearman's rho correlations were .566 for the knowledge section and .669 for the attitude section. Knowledge and attitude sections were measured for internal con- sistency with Cronbach's alpha, with respective values of .3178 and .7207. Item analyses with Wilcoxon Rank Sum tests identified 11 knowledge statements and one attitude statement as significantly discriminating at both test and retest. Gender differences were noted and additional findings were reported. Recommendations for the further establishment of a valid and reliable inventory were made.     

Effect of wrist restraint on maximal exercise capacity in healthy volunteers

Each year, reports occur of deaths in individuals, while struggling against physical restraint. The mechanism of these deaths remains unclear. This study aimed to determine the effect of wrist restraint on cardiorespiratory function during maximal exercise. Twelve healthy volunteers underwent 3 incremental maximal exercise tests on a cycle ergometer. In a randomized order, they exercised while unrestrained, with the wrists tied in front of the body or wrists tied behind the back. The primary outcome measures were the number of minutes exercised in each position and heart rate and whole blood lactate level for each stage and on reaching maximum exercise capacity. The mean exercise duration was 19 minutes 6 seconds unrestrained (95% confidence interval [CI] 16 minutes 52 seconds to 20 minutes 57 seconds), 18 minutes 51 seconds (95% CI 17 minutes 51 seconds to 20 minutes 50 seconds) with arms restrained in front and 16 minutes 51 seconds (95% CI 14 minutes 6 seconds to 19 minutes 20 seconds) with the arms restrained behind the body (P = 0.16). There was no significant difference in heart rate or lactate measurements. It is probable that other factors make a more important contribution than wrist restraint behind the body to cardiorespiratory compromise in a struggling and fatigued individual.     

Detecting Feigned Attention-Deficit/Hyperactivity Disorder (ADHD): Current Methods and Future Directions

Feigned attention-deficit/hyperactivity disorder (ADHD) in adults is a significant issue in clinical settings, particularly regarding academic accommodations and access to controlled substances by university students. This article discusses the definitions, base rates, external incentives, psychometric detection strategies, and ethical implications of feigned ADHD. ADHD is characterized by a pattern of developmentally inappropriate inattentive, overactivity, and/or impulsivity, often persisting into adulthood. Estimates of the prevalence of non-credible ADHD in university settings range from 25 to 50%. Feigned ADHD may be detected with symptom and performance validity measures. The existing empirical research has failed to produce a clear psychometric solution to this important differential diagnosis. Identifying feigned ADHD is a difficult task, possibly because of the highly transparent, face-valid diagnostic criteria, and an atypical malingering strategy that evades established detection methods. Performance validity tests remain the best available method for identifying non-credible presentation during psychological evaluations of ADHD. Future practice recommendations should consider educational policy, diagnostic criteria, and psychometric research, including the development of self-report measures that reliably differentiate between genuine and feigned ADHD.     

Age assessment by magnetic resonance imaging of the knee: a preliminary study

The authors developed an original magnetic resonance imaging (MRI) staging system for epiphyseal fusion of growth plate maturation of the knee and evaluated its reliability and validity for age assessment of living individuals. A total of 290 MRI scans of the knee were reviewed retrospectively in patients aged from 10 to 30 years old (138 males, 152 females). Five original MRI stages were defined to assess the degree of maturation of the distal femoral and proximal tibial epiphyses. Intra-observer variability was excellent and inter-observer variability was good, demonstrating the reliability and the validity of this original MRI staging system. In both sexes, the changes of growth plates (proximal tibial or distal femoral) were associated with age (p<0.001). Our results agreed with classic data on skeletal maturation of the knee, with globally earlier maturation in females than in males, and also earlier maturation of the proximal tibial epiphysis than of the distal femoral epiphysis. MRI of the knee is an efficient non-invasive method of age assessment, without the disadvantage of X-ray exposure. Further studies with larger groups are needed to support our results.