Biological clock rhythm disorder and hypertension / 国际脑血管病杂志

Biological clock proteins are involved in the regulation of many important physiological processes, including blood pressure. The deletion or mutation of core circadian clock genes may cause elevated blood pressure levels and disrupted blood pressure rhythms, exacerbating vascular function damage, and ultimately leading to the occurrence, development and poor outcome of ischemic stroke. This article reviews the molecular mechanism of biological clock rhythm, the relationship between biological clock gene and blood pressure regulation mechanism, the mechanism of circadian rhythm disorder in the occurrence and development of hypertension, and the relationship between blood pressure rhythm disorder and stroke.

Comparison of curative effects between percutaneous curved vertebroplasty and unilateral percutaneous kyphoplasty in the treatment of osteoporotic thoracolumbar compression fracture / 中华创伤杂志

Objective:To compare the clinical effects of percutaneous curved vertebroplasty (PCVP) and unilateral percutaneous kyphoplasty (PKP) in the treatment of osteoporotic vertebral compression fracture (OVCF).Methods:A retrospective cohort study was used to analyze the clinical data of 104 patients with single vertebral OVCF treated in Tianjin Hospital from September 2019 to September 2020, including 21 males and 83 females; aged 50-91 years [(70.3±7.7)years]. AO classification of the fracture was type A1 in 65 patients and type A2 in 39. The patients received PCVP (PCVP group, n=51) or unilateral PKP surgery (unilateral PKP group, n=53). The operation time, bone cement injection volume, intraoperative fluoroscopy frequency, effective dispersion times of bone cement and excellent rate of bone cement distribution were compared between the two groups. In evaluation of the therapeutic effects of the two groups, visual analogue scale (VAS) and Oswestry dysfunction index (ODI) were measured preoperatively and at postoperative 24 hours, 3 months and 6 months; Beck index was measured preoperatively and at postoperative 24 hours and 3 months. The rate of bone cement leakage and rate of refracture of adjacent vertebral bodies were compared between the two groups. Results:All patients were followed up for 6-8 months [(6.4±0.7)months]. The operation time, bone cement injection volume and intraoperative fluoroscopy frequency in PCVP group was (12.15±1.63)minutes, (2.13±0.28)ml and (24.74±1.71)times, shorter or less than (22.09±1.62)minutes, (5.30±0.52)ml and (30.09±1.86)times in unilateral PKP group (all P<0.01). The effective dispersion times of bone cement in PCVP group was (1.42±0.04)times, higher than (1.18±0.02)times in unilateral PKP group ( P<0.01). The excellent rate of bone cement distribution in PCVP group was 94%, higher than 70% in unilateral PKP group ( P<0.01). There were no significant differences in VAS, ODI and Beck index between the two groups before operation and at 24 hours and 3 months after operation (all P>0.05). VAS and ODI in PCVP group were (1.20±0.49)points and 16.52±5.22 at 6 months after operation, lower than (1.49±0.58)points and 20.16±5.16 in unilateral PKP group (all P<0.01). VAS and ODI in the two groups were significantly improved at 24 hours, 3 months and 6 months after operation when compared with those before operation (all P<0.05). Beck index in the two groups detected at 24 hours and 3 months after operation was improved from that before operation (all P<0.05). Unilateral PKP group showed Beck index was 0.75±0.07 at 3 months after operation, significantly lower than 0.79±0.07 at 24 hours after operation ( P<0.05), but there was no significant change in PCVP group ( P>0.05). The leakage rate of bone cement in PCVP group was 16% (8/51), lower than 47% (25/53) in unilateral PKP group ( P<0.01). There was no significant difference in the incidence of refracture of adjacent vertebral bodies between the two groups during follow-up ( P>0.05). Conclusion:For OVCF, PCVP is superior to unilateral PKP in terms of operation time, amount of bone cement injection, intraoperative fluoroscopy frequency, dispersion effect of bone cement in vertebral body, pain, function improvement, maintenance of injured vertebral height and incidence of bone cement leakage.

Application of scalp electroencephalogram in treatment of refractory epilepsy with vagus nerve stimulation / 生物医学工程学杂志

Electroencephalogram (EEG) has been an important tool for scientists to study epilepsy and evaluate the treatment of epilepsy for half a century, since epilepsy seizures are caused by the diffusion of excessive discharge of brain neurons. This paper reviews the clinical application of scalp EEG in the treatment of intractable epilepsy with vagus nerve stimulation (VNS) in the past 30 years. It mainly introduces the prediction of the therapeutic effect of VNS on intractable epilepsy based on EEG characteristics and the effect of VNS on EEG of patients with intractable epilepsy, and expounds some therapeutic mechanisms of VNS. For predicting the efficacy of VNS based on EEG characteristics, EEG characteristics such as epileptiform discharge, polarity of slow cortical potential changes, changes of EEG symmetry level and changes of EEG power spectrum are described. In view of the influence of VNS treatment on patients' EEG characteristics, the change of epileptiform discharge, power spectrum, synchrony, brain network and amplitude of event-related potential P300 are described. Although no representative EEG markers have been identified for clinical promotion, this review paves the way for prospective studies of larger patient populations in the future to better apply EEG to the clinical treatment of VNS, and provides ideas for predicting VNS efficacy, assessing VNS efficacy, and understanding VNS treatment mechanisms, with broad medical and scientific implications.

Interpretation of the International Standard 2017 Version of Implantable Neurostimulators / 中国医疗器械杂志

ISO 14708-3 "Implants for surgery-active implantable medical devices-Part 3:implantable neurostimulators" 2017 version and 2008 version are compared, and changes in the standard are interpreted combined with the characteristics of the neurostimulator. The new version of the standard for the first time in the introduction mentioned a new type of non-electrode or extension's neurostimulator. Key issues that have significant impact on safety concerns such as wireless charging temperature rise, MRI acceptance criteria, etc., are given for the first time in the new version. New requirements to the wireless communication section are added, and the electromagnetic compatibility part is greatly adjusted. With more miniature non-electrode or extension's neurostimulator entering the market, standards such as electromagnetic compatibility and MRI, there will be greater adjustments.

Test-retest Reliability of Isokinetic Test for Hip Concentric Flexion and Extension / 中国康复理论与实践

@#Objective To investigate the reliability of isokinetic test for concentric flexion and extension of hip joint. Methods From September, 2014 to June, 2015, 30 healthy young people accepted isokinetic test for concentric flexion and extension of hip twice with the same procedure and method within a week. The intra-class correlation coefficient (ICC) of peak torque, peak torque to body weight, total work, total work to body weight and average power between the two tests was calculated. Results The ICCs were above 0.70 in all the parameters on both sides at 60°/s (P < 0.01). Meanwhile they were above 0.61 of right hip at 180°/s (P < 0.05), but below 0.55 on left (P > 0.05). Conclusion The isokinetic test for hip is reliable for clinical assessment.

Batteries Used in Active Implantable Medical Devices / 中国医疗器械杂志

In recent years active implantable medical devices(AIMD) are being developed rapidly. Many battery systems have been developed for different AIMD applications. These batteries have the same requirements which include high safety, reliability, energy density and long service life, discharge indication. History, present and future of batteries used in AIMD are introduced in the article.

Clinical study on risk factors correlated with senile degenerative aortic valve calcification by color Doppler echocardiograph / 国际生物医学工程杂志

Objective To investigate the value of the senile degenerative aortic valve calcification (AVC) and to analyze the correlative risk factors by color Doppler echocardiograph.Methods Aortic valves of 110 cases with AVC (study group) and 110 cases without AVC (control group) were observed by color Doppler echocardiograph.All the patients with AVC have been excluded of congenital and other acquired valves' diseases.The aortic valve' s shape and the diameters of aortic root were measured.At the same time,the peak systolic and diastolic velocities of aorta were detected.The different features were compared between the two groups.Results Test results showed significant differences in study group:Anteroposterior diameter of aortic annulus and the area of aortic valve were decreased by calcification; The anteroposterior diameter of aortic sinus increased and aorta transvalvular pressure gradient augmented; Detection rate of atherosclerosis (AS) of aorta and the peripheral artery stenosis of the study group were higher than that of control group; The AS increased pulse pressure and aggravated AVC; Correlative risk factors,in addition to age,included hypertension,hypercholesterolemia,osteoporosis,and so on.The correct diagnosis of the correlated diseases were on the basis of clinical examines.The rate of AVC with multi-factor was higher than that with single-factor.In addition,gender difference and the diameters of ascending aortic showed no significant difference in two groups.Relationship between diabetes of correlative factors and the rate of AVC showed no significant difference in two groups.Conclusion Morphologic abnormality and malfunction of aortic valve and the large artery in elder patients were caused by senile degenerative AVC.The more correlative risk factors,the worse showed.

Study of Implantable Single-point Electrical Stimulation System / 医疗卫生装备

Obiective To descript the method and the equipment of implantable single-point electric stimulation which is designed to continionsly and effectively treat the chronic diseases that harm the people's health. Methods The system is constructed with two parts, outside power transfer and implanted power receiver. The bypass capacitor of transistor and transformer inductor make up of power transmitter, which is half series resonant. With using transeutaneous power transform, the efficiency of this transform is studied. Experiments choose proper transmitting parameters: transformer winding is a 20 turns hollow coil of 35mm diameter, and the frequency is 150-200 kHz; the receiver winding is a 100 turns hollow coil of 10ram diameter. Results Finally the completed prototype of the system and the receiver can generate about 5-10 mA current to stimulation tissue with 5mm gap between receiver and radiator, which meets the requirement of application.ConclusionThis instrument can be used in all kinds of single-point stimulation experiment.

Design of Programmable Transcutaneous Neuromuscular Electrical Stimulation System and Its Primary Experimental Study / 航天医学与医学工程

Objective To develop a programmable neuromuscular electrical stimulation system as a potential countermeasure for muscle atrophy in long-term microgravity.Methods The system was mainly composed of a controllable constant current pulse generator,wires and skin electrodes.To meet the requirements of stimulating recipes selection,the stimulating parameters could be adjusted independently and the combinatorial output of different stimulating phases should also be achieved.Results The system worked well with high accuracy outputs.The sensation,contraction,tetany and pain thresholds of all the 5 waveforms stimulating signals were measured.For different stimulating waveforms,thresholds of each state were different and the subjective sensations induced by same stimulating amplitude were dissimilar.Conclusion The developed system providing powerful programmable and accurate stimulating signals,is convenient for the selection and verification of stimulating recipes and can be used as an instrument platform for study of electrical stimulation to prevent muscle atrophy in microgravity.Volunteer experiments have proved its validation for function of muscle contraction and provide primary basses for the optimization of stimulating recipes.

Study of Transcutaneous Wireless Bidirectional Communication System Based on Pulse Position Modulation / 航天医学与医学工程

Objective To find out a PPM-based transcutaneous wireless bidirectional communication system for implantable medical device.Methods The wireless communication system included device implanted in the body,controller and PDA outside the body.Pulse position modulation(PPM) was used for the wireless bidirectional communication between device implanted in the body and controller outside the body.Results A PPM-based transcutaneous wireless communication system was realized.Its wireless bidirectional communication distance between device implanted in the body with titanium container and controller outside the body was over two inches.This system was with good position availability.Conclusion Pulse position modulation is successfully used for transcutaneous wireless communication system,and average power consumption for communication device implanted in the body is lowered greatly compared with ASK modulation method.At the same time,the volume of communication device implanted in the body is decreased for antenna common-using idea.

Determination of copper,zinc and maganese in Ejiao by derivative flame atomic absorption spectrometry / 中国药学杂志

OBJECTIVE:To determine the contents of Cu,Zn and Mn in Ejiao,a kind of Chinese traditional medicine.METHOD:The contents of Cu,Zn and Mn were determined by derivative flame atomic absorption spectrometry (DFAAS) after digested by HNO3-HClO4.RESULTS:The contents of Cu,Zn and Mn were 10.48,12.38 and 18.09μg.g-1 respectively.CONCLUSIONS:The DFAAS possesses higher sensitivities,lower detection limits and better precision.