Batch process method for kinematics data of mass population based on MATLAB / 医用生物力学

Objective To develop a batch process method for kinematics data of mass population based on MATLAB. Methods Based on MATLAB, the original coordinate data of markers from motion capture system were first batch-read with interpolation processing for eliminating the error points. The body-fixed base of contiguous rigid body attached on human body was then constructed as the reference base and body-fixed base of relative joint kinematics computing. The flexion/extension, abduction/adduction, internal and external rotation angular displacement, angular velocity and angular acceleration of joints were obtained based on the rigid body kinematics, the basic description of rigid body posture and the direction cosine matrix. Results Taking climbing upstairs and squatting as samples, the joint kinematics of lower extremity were analyzed and calculated by the batch process method for kinematics data of mass population based on MATLAB to prove the effectiveness and accuracy of the method. Conclusions The batch process method for kinematics data of mass population based on MATLAB was proved to be effective and accurate, and can be provided as a statistical analysis tool for anthropometry, human engineering, etc.

Risk assessment of nerve conduction velocity in workers exposed to lead / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To explore the dose-effect relationship between lead exposure and nerve conduction velocity, and to assess risk characteristics of nerve conduction velocity induced by lead exposure.</p><p><b>METHODS</b>The external dose, internal dose (blood lead, urine lead) and the conduction velocity of peripheral nerve were examined. The benchmark dose of a population exposed to occupational lead was estimated to develop risk assessment of nerve conduction velocity in worker exposed to lead by use of BMDS (version 1.3.3). The BMDL in terms of blood lead and urine lead was calculated.</p><p><b>RESULTS</b>There was correlation between blood lead and urine lead. The sense nerve conduction velocity was decreased significantly in the group of lead exposure workers (P < 0.05). The BMDLs-05 for median nerve conduct velocity, ulnar nerve conduction velocity, and superficial peroneal nerve conduction velocity in terms of blood lead were 456.99, 332.36 and 468.38 microg/L respectively; the BMDLs-05 in terms of urine lead were 14.1, 9.2 and 13.6 microg/gCr respectively.</p><p><b>CONCLUSION</b>The internal dose is the better index to reflect the level of lead exposure. Blood lead is identified as a specific and sensitive biomarker for sense nerve conduction velocity reduction. Ulnar nerve conduction velocity can be used as highly sensitive biomarkers to screen the high risk population of lead exposure.</p>

Risk assessment of renal dysfunction caused by occupational lead exposure / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To assess the risk of renal dysfunction caused by occupational lead exposure through epidemiological investigation.</p><p><b>METHODS</b>The workers in a battery factory were selected as the subjects for the exposure and effect assessment. The occupational environmental monitoring data was collected and used to calculate the total external dose of lead. The relationship between external dose and internal dose of lead was analyzed. The external dose, blood lead (BPb) and urinary lead (UPb) were used as exposure biomarkers while the urinary N-acetyl-D-glucosaminidase (UNAG), and urinary albumin (UALB) were used as the effect biomarkers for the renal dysfunction caused by lead. Software of BMDS (BMDS 11311) was used to calculate BMD.</p><p><b>RESULTS</b>The external and internal does of lead was positively correlated (BPb: r = 0.466, P < 0.01; UPb: r = 0.383, P < 0.01). The levels of BPb, UPb in exposure group (654.03 microg/L, 143.45 microg/g Cr) were significantly higher than those in the control group (57.12 microg/L, 7.20 microg/g Cr), so were UALB, UNAG; in addition, all of them presented significant dose-response relationship. The BPb BMD of UALB, UNAG were 607.76, 362.56 microg/L respectively and the UPb BMD of UALB, UNAG were 117.79, 78.79 microg/gCr respectively.</p><p><b>CONCLUSION</b>Occupational lead exposure can cause renal dysfunction, which presents dose-response relationship; the risk assessment of renal dysfunction caused by occupational lead exposure is performed by BMD calculation of BPb and UPb.</p>