OBJECTIVETo establish the cervicothoracic spine finite element model with three-dimensional finite element method, verify the effectiveness of this model and explore the stress distribution.

METHODSDICOM image data of one normal healthy young male volunteer were obtained by spiral CT scan and processed with Mimics software. Datas were imported to ANSYS software to become a 3D entity. Disc structure and the main ligament were added. Disc structure was added using the shell-nuclear unit, representing the annulus fibrosus and nucleus pulposus. Ligament structure was established with 2-node cable element, the beginning and ending points of the ligament and the cross-sectional area were determined in accordance with references. C(6,7) and C7T1 facet joints were definded as the nonliner contact joints with friction coefficient. The lower surface of TI in all the directions was completely fixed in this model. In the model 2.0 Nm pure torque were imposed on C6, and the extension, flexion, axial rotation and lateral bending experiment were conducted. The experimental results were compared with the in vitro biomechanical tests.

RESULTSThe cervicothoracic spine finite element model included 169,317 nodes and 106,242 units, and consistent with the in vitro biomechanical tests. The three-dimensional finite element model was in good running under external force.

CONCLUSIONIt is a convenient and precise method for physicians to establish the finite element model of the cervicothoracic junction. This method facilitates the computer study on the biomechanical behavior of the local structures of the model under various pressure conditions.

Cervical Vertebrae ; anatomy & histology ; physiology ; Computer Graphics ; Finite Element Analysis ; Humans ; Male ; Models, Anatomic ; Software ; Stress, Mechanical ; Thorax ; anatomy & histology ; physiology

OBJECTIVETo observe the hemodynamic changes and liver and kidney function variations in pregnant rats with pre-eclampsia after treatment with low-energy laser irradiation.

METHODSForty pregnant SD rats were randomly divided into the experimental group (group A), experimental control group (group B), blank control group (group C) and blank exposure group (group D) (n=10). The rats in groups A and B were injected with 1 µg/kg endotoxin via the tail vein at the 14th day of gestation, and those in groups C and D received normal saline injections. In groups A and B, low-energy laser irradiation of the chest was carried out since day 16 of gestation. Blood pressure, urine protein, liver and kidney function and the hemodynamic changes in the rats were observed.

RESULTSAfter the treatment, blood pressure, urine protein, ALT, BUN and Cr of group A were lower than those of group B (P<0.05), but similar with those in groups C and D (P>0.05). The blood and plasma viscosity and hematocrit of group A were also lower than those of group B (P<0.01), but comparable with those in groups C and D.

CONCLUSIONLow-energy laser irradiation in the chest area may improve the hemodynamic indices, decrease blood pressure and urine protein, and ameliorate liver and kidney functions in pregnant rats with pre-eclampsia.

Animals ; Blood Pressure ; Female ; Hemodynamics ; Kidney ; physiology ; Lasers ; Liver ; physiology ; Pre-Eclampsia ; blood ; therapy ; Pregnancy ; Proteinuria ; Rats ; Rats, Sprague-Dawley ; Thorax ; radiation effects

The principle of ambulatory cardiac output (CO) measuring technique is introduced in this paper. Experimental studies about the applicability of the two-compartment coaxial cylindrical model for ambulatory measurement of cardiac output with spot-electrodes have been carried out with using our newly-developed multi-channel impedance mapping system. The key factors using a spot-electrode array instead of a conventional band-electrode array for non-invasive CO) measurement are elaborated. The variations of the electric impedance pulsatile component (deltaZ waveform) and the two kinds of typical modes of deltaZ distributions measured by six electrodes on the midsternal (midian) line from the medial portion at the level of clavicle to the portion above the xiphisternum are discussed. The applicability of the two-compartment coaxial cylindrical model for ambulatory measurement of CO with spot-electrodes is analyzed. Synthesizing the deltaZ distributions and their typical changing models on the midsternal (midian) line during blood inflowing into aorta is the optimal positions of a pair of spot-electrodes for voltage pick-up at the level of clavicle for the upper electrode and the position at the level of nipple for the lower electrode when spot-electrode is being used to measure non-invasive CO.
Biomedical Engineering ; Cardiac Output ; physiology ; Cardiography, Impedance ; instrumentation ; methods ; Electrocardiography, Ambulatory ; instrumentation ; methods ; Electrodes ; Equipment Design ; Heart ; physiology ; Humans ; Models, Cardiovascular ; Thorax

The emergence of Dirofilarial infections in Asia including Vietnam is a clinically significant threat to the community. We here report a rare case of subcutaneous Dirofilaria repens infection on the posterior thoracic wall in a young woman presenting a painful, itchy, and palpable nodule. The adult worm was identified by mitochondrial cox1 and nuclear ITS-2 sequence determination. The diagnosis was additionally confirmed by 16S rRNA sequencing of the endosymbiont Wolbachia pipientis commonly co-existing with D. repens. This is a rare case of subcutaneous human infection on the posterior thoracic region caused by D. repens.
Adult ; Animals ; Dirofilaria repens/classification/genetics/*isolation & purification/physiology ; Dirofilariasis/diagnosis/*parasitology ; Female ; Humans ; Phylogeny ; Thorax/*parasitology

PURPOSE: During cardiopulmonary resuscitation (CPR), chest compression (CC) depth is influenced by the surface on which the patient is placed. We hypothesized that training healthcare providers to perform a CC depth of 6-7 cm (instead of 5-6 cm) on a manikin placed on a mattress during CPR in the hospital might improve their proper CC depth. MATERIALS AND METHODS: This prospective randomised controlled study involved 66 premedical students without CPR training. The control group was trained to use a CC depth of 5-6 cm (G 5-6), while the experimental group was taught to use a CC depth of 6-7 cm (G 6-7) with a manikin on the floor. All participants performed CCs for 2 min on a manikin that was placed on a bed 1 hour and then again 4 weeks after the training without a feedback. The parameters of CC quality (depth, rate, % of accurate depth) were assessed and compared between the 2 groups. RESULTS: Four students were excluded due to loss to follow-up and recording errors, and data of 62 were analysed. CC depth and % of accurate depth were significantly higher among students in the G 6-7 than G 5-6 both 1 hour and 4 weeks after the training (p<0.001), whereas CC rate was not different between two groups (p>0.05). CONCLUSION: Training healthcare providers to perform a CC depth of 6-7 cm could improve quality CC depth when performing CCs on patients who are placed on a mattress during CPR in a hospital setting.
Adult ; Beds ; Cardiopulmonary Resuscitation/*education/*methods ; Female ; Health Personnel/*education ; Hospitals ; Humans ; Male ; *Manikins ; Pressure ; Prospective Studies ; *Students, Medical ; Thorax/*physiology

This study compared the effectiveness two-finger chest compression technique (TFCC) performed using the right vs. left hand and the index-middle vs. middle-ring fingers. Four different finger/hand combinations were tested randomly in 30 healthcare providers performing TFCC (Test 1: the right index-middle fingers; Test 2: the left index-middle fingers; Test 3: the right middle-ring fingers; Test 4: the left middle-ring fingers) using two cross-over trials. The "patient" was a 3-month-old-infant-sized manikin. Each experiment consisted of cardiopulmonary resuscitation (CPR) consisting of 2 minutes of 30:2 compression: ventilation performed by one rescuer on a manikin lying on the floor as if in cardiac arrest. Ventilations were performed using the mouth-to-mouth method. Compression and ventilation data were collected during the tests. The mean compression depth (MCD) was significantly greater in TFCC performed with the index-middle fingers than with the middle-ring fingers regardless of the hand (95% confidence intervals; right hand: 37.8-40.2 vs. 35.2-38.6 mm, P = 0.002; left hand: 36.9-39.2 vs. 35.5-38.1 mm, P = 0.003). A deeper MCD was achieved with the index-middle fingers of the right versus the left hand (P = 0.004). The ratio of sufficiently deep compressions showed the same patterns. There were no significant differences in the other data. The best performance of TFCC in simulated 30:2 compression: ventilation CPR performed by one rescuer on an infant in cardiac arrest lying on the floor was obtained using the index-middle fingers of the right hand. Clinical Trial Registry at the Clinical Research Information Service (KCT0001515).
Adult ; Cardiopulmonary Resuscitation/*methods ; Cross-Over Studies ; Female ; *Fingers ; Hand ; Heart Arrest/*therapy ; Humans ; Infant ; Male ; Manikins ; Models, Cardiovascular ; Thorax/physiology ; Young Adult

In order to enhance the position accuracy of ablation catheter in heart electrophysiology operation, signals of respiration and heartbeat must be removed for subsequent data processing. Based on locating principle of electrical field with low frequency, synchronous detector with MC1496 has been developed in this study. In the present research, several methods are utilized to optimize the circuit performance, such as coupling and stopping direct current, low-pass filtering, as well as limiting ripple voltage etc. Through simulation results, it showed that the demodulation performance of the circuit was fine. Through simulation platform of thorax electric field and animal experiment, the circuit feasibility were further proved good for extracting signals of respiration and heartbeat.
Atrial Fibrillation ; surgery ; Catheter Ablation ; methods ; Computer Simulation ; Electromagnetic Fields ; Heart ; anatomy & histology ; physiology ; Humans ; Models, Biological ; Signal Processing, Computer-Assisted ; Thorax

OBJECTIVETo propose a new method for acquiring pulmonary function parameters based on measurement of volume changes of thoracic impedance.

METHODSWe studied the relationship between the volume changes of thoracic impedance and pulmonary function parameters during forced breathing based on bioimpedance measurement, and developed an instrument for measuring thoracic impedance. Using this instrument and a MRI spirolab III lung function test instrument, both based on flowmeter measurement, we measured such pulmonary function parameters including forced vital capacity (FVC), forced expiratory volume in one second/FVC (FEV1/FVC), and peak expiratory flow in 10 healthy volunteers and compared the measurement results.

RESULTSThe differences in the parameters measured using the two instruments were all within two folds of the positive and negative standard deviations of the average values, demonstrating good consistency in the measurement between the two methods.

CONCLUSIONSThe measurement results of the bioimpedance-based instrument we developed show good consistency with those by the commercially available pulmonary function test instrument.

Adult ; Electric Impedance ; Forced Expiratory Volume ; Humans ; Peak Expiratory Flow Rate ; Respiratory Function Tests ; methods ; Thorax ; physiology ; Vital Capacity ; Young Adult

OBJECTIVETo establish the intrauterine growth curves of neonates in Shenzhen, China and to investigate the intrauterine growth of neonates in Shenzhen.

METHODSCross-sectional cluster sampling was performed for an on-the-spot investigation of 16 887 neonates (9 418 males and 7 469 females) with a gestational age of 27-42 weeks who were born in two hospitals in Shenzhen from April 2013 to September 2015. The Lambda Mu Sigma (LMS) method was used for the curve fitting of body weight, body length, head circumference, chest circumference, and crown-rump length.

RESULTSThe 3rd-97th percentile intrauterine growth curves for body weight, body length, head circumference, chest circumference, and crown-rump length were plotted for the neonates with a gestational age of 27-42 weeks who were divided into three groups (male, female, and mixed). The male neonates had significantly higher curves for the five indices than the female counterparts. The pattern and changing trend of body weight curves of these neonates were basically consistent with those in China Neonatal Network.

CONCLUSIONSThe percentile intrauterine growth curves for body weight, body length, head circumference, chest circumference, and crown-rump length in neonates with a gestational age of 27-42 weeks in Shenzhen which has been established can provide a reference for clinical practice in the department of neonatology.

Body Height ; Body Weight ; Cross-Sectional Studies ; Crown-Rump Length ; Female ; Fetal Development ; physiology ; Gestational Age ; Head ; anatomy & histology ; Humans ; Infant, Newborn ; Male ; Thorax ; anatomy & histology

Cardiopulmonary resuscitation (CPR) is vital for cardio arrest victims; in this field, researches have been aiming at its mechanism, operation guidelines, new CPR machines and so on. This paper summarized the studies on the mechanical characteristics of the thorax under CPR, and on the simulation work of sternal-displacement relationship in CPR manikins. The data from modeling work showed that the thorax's sternal-displacement relationship could be graphically represented by a hysteresis curve. As the actual CPR manikins' mechanical structures of the thorax are too simplified, it is necessary to do the work of improvement.
Cardiopulmonary Resuscitation ; Computer Simulation ; Heart Arrest ; etiology ; therapy ; Heart Massage ; Humans ; Manikins ; Physical Stimulation ; methods ; Stress, Mechanical ; Teaching Materials ; Thorax ; physiology