1.Application of linear and nonlinear characteristics of heart rate variability in assessment of autonomic nervous system activity.
Journal of Biomedical Engineering 2014;31(2):302-307
Calculation of linear parameters, such as time-domain and frequency-domain analysis of heart rate variability (HRV), is a conventional method for assessment of autonomic nervous system activity. Nonlinear phenomena are certainly involved in the genesis of HRV. In a seemingly random signal the Poincaré plot can easily demonstrate whether there is an underlying determinism in the signal. Linear and nonlinear analysis methods were applied in the computer words inputting experiments in this study for physiological measurement. This study therefore demonstrated that Poincaré plot was a simple but powerful graphical tool to describe the dynamics of a system.
Autonomic Nervous System
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physiology
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Heart Rate
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Humans
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Linear Models
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Nonlinear Dynamics
2.Effects of different bladder infusion rates on bladder responses in healthy and complete spinal cord injury rats
Chinese Journal of Physical Medicine and Rehabilitation 2014;36(5):321-324
Objective To investigate the bladder responses to different rates of bladder infusion in healthy and spinal cord injured rats.Methods Fourteen adult female Sprague-Dawley rats were used and divided into two groups:healthy group (n =7) and spinal transection injury group (n =7).The intravesical pressures induced by continuous infusion of saline with different rates under general anesthesia were recorded and compared between the two groups.Results In healthy group the responses of bladder contraction were dependent upon the rate of bladder infusion,and contraction time became shorter while increasing the infusion rate (P < 0.05),i.e.contraction time was (401.0±132.4),(215.7 ±95.9),(108.3 ±59.1) and (52.5 ±32.8)s,respectively,when the infusion rate was 0.05,0.1,0.2 and 0.5 mL/min.Compared with healthy group,spinal transection injury group had significantly shorter bladder contraction time (P < 0.05),however the relationship between bladder contraction time and infusion rate was much weakened.Spinal transaction injury rats had significantly lower peak of bladder pressure (P < 0.05) compared with healthy rats.There was no significant difference for contraction durations between the two groups.Conclusions The infusion rates influenced the contraction periods for both healthy and spinal cord injured rats.During bladder infusions with a same rate,the contraction time and the peak of bladder pressure were determined by bladder conditions,i.e.healthy or neurogenic with spinal cord injury.
3.Real-time and retrospective analyze of cardiac remote monitoring based on differential threshold method
Chuntao DONG ; Wei SUI ; Hongliu YU
China Medical Equipment 2014;(11):52-54
Objective:To observe the effects of real-time and retrospective analyze of cardiac remote monitoring based on differential threshold method.Methods: Xin An Bao XAB - M3AG ECG remote monitoring system which based on the differential threshold method of improvement being used to determine the parameters of electro cardio signal was installed in 8957 patients.Results: We had collected all 46967 ECG real-time data, including 9564 manual transmission, 25830 timing transmitting and 11573 automatically transmission. 5728 of automatically transmission was with arrhythmia (49.5%) and the others of automatically transmission was attribute to inference.Conclusion: The results showed that algorithm complexity based on the improved differential threshold method is low, the precision is high and it has a good real-time performance. It realized the real-time monitoring of ECG.
4.Crosslinking process optimization of collagen sponge
Heng WANG ; Hongliu YU ; Jinting LU ; Ying ZHAO
Chinese Journal of Tissue Engineering Research 2015;19(16):2567-2572
BACKGROUND:Colagen materials have good biocompatibility and biodegradability, but also had some problems such as low mechanical strength, poor resistance to degradation exposed in the process of clinical application. Numerous studies have reported that proper crosslinking could improve the disadvantage of colagen materials, regulate porous network structure, sweling and degradation of colagen materials. OBJECTIVE: To optimize carbodimide crosslinking process of colagen sponge and determine the best process conditions. METHODS:Colagen sponge was cross-linked by carbodimide for the preparation of loose and porous colagen sponge. Meanwhile, we optimized the conditions of cross-linking, in which the selected concentration of carbodimide was 5, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100 mmol/L, linking time was 2, 4, 6, 8, 12, 16, 20, 24 hours, and linking temperature was 5, 10, 15, 20, 25, 30, 35℃. We evaluated the best process conditions of colagen sponge through the aperture, porosity, water absorption, and degradation rate. RESULTS AND CONCLUSION:The optimal conditions were carbodimide concentration 50 mmol/L, crosslinking temperature 20℃,crosslinking time 6 hours. At this point, the average pore diameter of colagen sponge was 105 μm, the porosity was 79.45%, water absorption was 287.14%, and the degradation rate was 15.04% (2 days). The crosslinking of colagen sponge significantly improved its water absorption and degradation resistance.
5.Design of electronically controlled hydraulic damper for prosthetic knee
Hongliu YU ; Ling SHEN ; Jiahua HU ; Xingsan QIAN
Chinese Journal of Tissue Engineering Research 2009;13(39):7635-7638
OBJECTIVE: To design an electronically controlled hydraulic damper cylinder as a key part of the computer-controlled intelligent knee joint.METHODS: According to the characteristics of hydraulic fluids and processing technology, new type of micro-structure of the digital throttle and unique structure of the two-cylinder piston had been applied to the damper. It could control extension and flexion of the knee joint in two-way automatically, which improved the gait symmetry of artificial limb. Finally, a special self-made testing device was used to evaluate the performance of the hydraulic damper. The damping force adjustment was simulated in test by controlling the two needle valves with micro-computer. The kinematics speed was detected under different state of simulating the driving moment of hip joint and the damping moment of knee joint. The testing results indirectly built the dynamics relationship among the inertial force, damping force and the swing speed of the knee joint. RESULTS: When the position value X of the needle valve was reduced by the step motor driving, the resistance of the hydraulic cylinder was increased which resulted in faster speed of the cylinder rod. The sensitivity of the speed to the driving force decreased with the opening of needle valve increasing. When the stepping motor controlled the needle valve closer, the damping moment increased which led to a faster swing speed.CONCLUSION: The design of hydraulic damper cylinder meets the requirements of prosthetic knee dynamics control.
6.Kinematics Modeling and Analysis of Central-driven Robot for Upper Limb Rehabilitation after Stroke.
Jinhua YI ; Hongliu YU ; Ying ZHANG ; Xin HU ; Ping SHI
Journal of Biomedical Engineering 2015;32(6):1196-1201
The present paper proposed a central-driven structure of upper limb rehabilitation robot in order to reduce the volume of the robotic arm in the structure, and also to reduce the influence of motor noise, radiation and other adverse factors on upper limb dysfunction patient. The forward and inverse kinematics equations have been obtained with using the Denavit-Hartenberg (D-H) parameter method. The motion simulation has been done to obtain the angle-time curve of each joint and the position-time curve of handle under setting rehabilitation path by using Solid Works software. Experimental results showed that the rationality with the central-driven structure design had been verified by the fact that the handle could move under setting rehabilitation path. The effectiveness of kinematics equations had been proved, and the error was less than 3° by comparing the angle-time curves obtained from calculation with those from motion simulation.
Biomechanical Phenomena
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Humans
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Models, Biological
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Robotics
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Stroke Rehabilitation
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Upper Extremity
7.Research on Barrier-free Home Environment System Based on Speech Recognition.
Husheng ZHU ; Hongliu YU ; Ping SHI ; Youfang FANG ; Zhuo JIAN
Journal of Biomedical Engineering 2015;32(5):1019-1025
The number of people with physical disabilities is increasing year by year, and the trend of population aging is more and more serious. In order to improve the quality of the life, a control system of accessible home environment for the patients with serious disabilities was developed to control the home electrical devices with the voice of the patients. The control system includes a central control platform, a speech recognition module, a terminal operation module, etc. The system combines the speech recognition control technology and wireless information transmission technology with the embedded mobile computing technology, and interconnects the lamp, electronic locks, alarms, TV and other electrical devices in the home environment as a whole system through a wireless network node. The experimental results showed that speech recognition success rate was more than 84% in the home environment.
Computers
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Disabled Persons
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Humans
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Speech Recognition Software
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Wireless Technology
8.3 Degrees of Freedom Cabel Control Robot for Upper Limbs Rehabilitation
Zhuo JIAN ; Jinhua YI ; Yuhui GU ; Hongliu YU
Chinese Journal of Rehabilitation Theory and Practice 2013;19(1):82-85
Objective To design upper limbs rehabilitation training system. Methods The system consisted of 3 dimension of freedom robotic arm, cable transmission component and central drive and control component. The central drive and control system were posed at the base and the movements were transmitted from the base to the upper 3 DOF robotic arm by the cable transmission component. 3 dimensional model of the device were developed and the kinematic was simulated in SolidWorks. The first prototype was made and tested. Results and Conclusion The device could execute the designing training steps exactly and meet the design requirements. The system could recognize the intent of users exactly and response well when the auto-movement trigger angle was more than 3.6°.
9.Structure Design of Exoskeleton Device for Rehabilitation of Hands
Jicai LI ; Long GUAN ; Xin HU ; Hongliu YU
Chinese Journal of Rehabilitation Theory and Practice 2013;19(5):412-415
Objective To design an exoskeleton mechanical device for hand dysfunction rehabilitation. Methods Based on the bionic principles of the motion and the structure of finger joints, a micro exoskeleton mechanical structure with multi-joint fingers and multi-DOF motion was established, which included wearable finger exoskeleton and micro-motor drive mechanism. With the motion analysis software,the motion simulation analysis of the design was carried out on the basis of the three-dimensional model of the mechanical device. Results and Conclusion The structure of training device is compact and light, and the exoskeleton finger mechanism can move normally in the range of 0~67° without interference. Simulation data show that the mechanical device can complete planning exercises, and meet the design requirements of kinematics and mechanical properties.
10.Progress and Prospects of Upper Limb Rehabilitation Robot for Stroke Patients (review)
Xin HU ; Zhenping WANG ; Jinchao WANG ; Hongliu YU
Chinese Journal of Rehabilitation Theory and Practice 2014;(10):901-904
In this paper, the classification of the upper limb rehabilitation robot was discussed and the research progress was overviewed.Finally, the prospects of upper limb rehabilitation robot were put forward.