Perioperative monitoring of blood coagulation is critical to better understand causes of hemorrhage, to guide hemostatic therapies, and to predict the risk of bleeding. Point-of-care (POC) coagulation monitoring devices assessing the viscoelastic properties of whole blood may overcome several limitations of routine coagulation tests in the perioperative setting. The advantage of these techniques is that they have the potential to measure the clotting process, starting with fibrin formation and continue through to clot retraction and fibrinolysis at the bedside, with minimal delays. Furthermore, the coagulation status of patients is assessed in whole blood, allowing the plasmatic coagulation system to interact with platelets and red blood cells, and thereby providing useful additional information on platelet function. Viscoelastic POC coagulation devices are increasingly being used in clinical practice, especially in the management of patients undergoing cardiac and liver surgery, assessment of hypo-and hypercoagulable states, guiding pro- and anticoagulant therapies, monitoring of antiplatelet therapy and procoagulant therapy. To ensure optimal accuracy and performance, standardized procedures for blood sampling and handling, strict quality controls and trained personnel are required.
【Abstract】 Objective To explore the midterm efficacy of superelastic cage implantation for the treatment of osteonecrosisof femoral head (ONFH). Methods From July 1996 to January 1998, 54 patients (75 hips) of ONFH were treatedwith superelastic cage and followed up. Among 54 patients, 5 patients were lost to follow up and 3 patients were dead of myocardialinfarction, renal failure and gastric cancer, respectively. Forty-six patients completed follow up including 32 males and14 females, aged from 21 to 61 with an average of 39 years old. Twenty-nine hips were classified as Ficat Stage Ⅱ and 36 as StageⅢ . Harris score was 58.20 ± 13.82. All patients were evaluated both cl inically and radiographically. Results Postoperatively,forty-six patients (65 hips) were followed up for 86 to 125 months with an average of 8 years and 8 months. Harris score was 80.78 ± 18.77. Twenty-nine hips were rated excellent, 21 good, 2 fair and 13 poor．A total of 76.9% of overall cl inical results were rated as good or excellent. Eight hips (12.3%) with the cage broken were turned to total hip replacement. Radiographicevaluation: 16 hips (24.6%) rated as grade Ⅰ , 34 (52.3%) grade Ⅱ and 15 (23.1%) grade Ⅲ . Conclusion Superelastic cage implantation is one of alternative treatments for ONFH at early and midterm stages. However, long-term follow-up is needed to know whether it is able to cure ONFH and whether cages will be broken as time passes by.
Abstract The fracture of the prosthetic stem after prosthetic replacement of femoral head is not rare. In this study, the photoeastic instrument was used to study the stress distribution on the prosthetic stem following its insertion and to analyse the factors influencing the fracture of the stem. Through the examination of 9 places in 8 cases, it was found that:(1) The removal of femoral calcar and the inframedullary filling of the bone cement directly influenced the stress distribution. (2) The valgus or varus condition of the prosthesis would lead to stress concentration on the stem. (3) Once lossening of the prosthesis occured it would change the preliminary installingstress distribution in the upper femur which would lead to fatigue fracture. Ths experimental data and clinical observation would provide scientific basis forthe prevention of fracture of prosthetic stem following prosthetic replacement of femoral head.
Objective To re-estimate price elasticity of different income groups’ demand for cigarette in terms of the lastest national tobacco consumption data and provide policy-makers with evidence to make decision on public policy of tobacco control. Methods A total of 16 056 adults of different income were surveyed in 27 provinces in 2002 and the data analyzed by using two-part model (logistic and log-linear model). Results We found that the demand elasticities were -0.589, -0.234, -0.017 and 0.247 for the poor group, low income group, middle income group and high income group, respectively. Conclusions Increasing tobacco tax will result in decreasing more cigarette consumption of lower income groups than higher groups, bearing more taxation of higher income groups than lower income groups, therefore tobacco taxation is not regressive.
摘要:目的:研究老年患者动脉弹性功能与围术期血压变化的关系。方法:随机选择68例ASA分级Ⅰ－Ⅱ级行全麻手术的老年患者,根据检查所得动脉弹性的结果分为四组,分别是A组(C1、C2均正常),B组(C1异常,C2正常),C组(C1正常,C2异常),D组(C1、C2均异常)。测量其术前血压及全麻诱导8分钟后的血压水平。结果:〓动脉弹性功能不良的患者其术前MAP较高,且全麻诱导以后血压波动的比例较大。结论:高血压病的老年患者动脉弹性功能普遍降低;动脉弹性下降的老年病人全麻诱导后血压波动较大。Abstract: Objective:To investigate the relationship between the function of arterial elasticity and BP changes during perioperation in senile patients.Methods: 68 senile patients ASA class Ⅰor Ⅱ undergoing elective surgery under general anesthestia, were divided into four groups by evaluation of arterial elasticity (C1 was for large arterial elastic index and C2 for small. C1 and C2 were normal in group A, only C2 normal in group B, only C1 normal in group C, neither was normal in group D). Arterial blood pressure (BP) before operation and 8 min after induction were monitored and recorded. Results: Patients with dysfunction of arterial elasticity presented higher MAP during preoperation and significant BP changes after induction. Conclusion: Hypertension plays a key role in arterial elasticity.Arterial Blood Pressure of the senile patients with decreased arterial elasticity changes significantly after general anesthesia induction.
We applied Demons and accelerated Demons elastic registration algorithm in radiotherapy cone beam CT (CBCT) images, We provided software support for real-time understanding of organ changes during radiotherapy. We wrote a 3D CBCT image elastic registration program using Matlab software, and we tested and verified the images of two patients with cervical cancer 3D CBCT images for elastic registration, based on the classic Demons algorithm, minimum mean square error (MSE) decreased 59.7%, correlation coefficient (CC) increased 11.0%. While for the accelerated demons algorithm, MSE decreased 40.1%, CC increased 7.2%. The experimental verification with two methods of demons algorithm obtained the desired results, but the small difference appeared to be lack of precision, and the total registration time was a little long. All these problems need to be further improved for accuracy and reducing of time.
Polydimethylsiloxane (PDMS) and hydroxyapatite (HA) were combined in our laboratory to fabricate an elastic porous cell scaffold with pore-forming agent, and then the scaffold was used as culture media for rat bone marrow derived mesenchymal stem cells (rBMSCs). Different porous materials (square and circular in shape) were prepared by different pore-forming agents (NaCl or paraffin spheres) with adjustable porosity (62%-76%). The HA crystals grew on the wall of hole when the material was exposed to SBF solutions, showing its biocompatibility and ability to support the cells to attach on the materials.
Mitral valve disease is one of the most popular heart valve diseases. Precise positioning and displaying of the valve characteristics is necessary for the minimally invasive mitral valve repairing procedures. This paper presents a multi-resolution elastic registration method to compute the deformation functions constructed from cubic B-splines in three dimensional ultrasound images, in which the objective functional to be optimized was generated by maximum likelihood method based on the probabilistic distribution of the ultrasound speckle noise. The algorithm was then applied to register the mitral valve voxels. Numerical results proved the effectiveness of the algorithm.
In the process of positron emission tomography (PET) data acquiring, respiratory motion reduces the quality of PET imaging. In this paper, we present a correction method using three level grids B-spline elastic method to correct denoised and reorganized sinograms for respiratory motion correction. Using GATE simulates NCAT respiratory motion model to generate raw data which are used in experiment, the experiment results showed a significantly improved respiratory image with higher quality of PET, and the motion blur and structural information were fixed. The results proved the method of this paper would be effective for the elastic registration.
Due to lack of the practical technique to measure the biomechanical properties of the ocular cornea in vivo, clinical ophthalmologists have some difficulties in understanding the deformation mechanism of the cornea under the action of physiological intraocular pressures. Using Young's theory analysis of the corneal deformation during applanation tonometry, the relation between the elasticity moduli of the cornea and the applanated corneal area and the measured and true intraocular pressures can be obtained. A new applanation technique has been developed for measuring the biomechanical properties of the ocular cornea tissue in vivo, which can simultaneously acquire the data of the applanation area and displacement of the corneal deformation as well as the exerted applanation force on the cornea. Experimental results on a rabbit's eyeball demonstrated that the present technique could be used to measure the elasticity moduli and creep properties of the ocular cornea nondestructively in vivo.