Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 12 de 12
Filter
Add more filters










Publication year range
1.
Int J Biol Macromol ; 103: 385-394, 2017 Oct.
Article in English | MEDLINE | ID: mdl-28366859

ABSTRACT

Hydroxyapatite/Chitosan (HA/CS) composite have significant application in biomedical especially for bone replacement. Inorganic particle shape and size of composite affect the scaffold mechanical property, biological property, and degradation. The aim of this study was to fabricate HA/CS scaffold with good pore connectivity and analyze their biological, degradation properties. Microhydroxyapatite/chitosan (mHA/CS) and nanohydroxyapatite/chitosan (nHA/CS) composite scaffolds with interconnected spherical pore architectures were fabricated. Composite scaffolds structure parameters were analyzed using micro CT. Cell proliferation and morphology were tested and compared between two scaffolds using mouse osteoblastic cell line MC3T3-E1. To research the composite degradation in lysozyme PBS solution, degradation rate and reducing sugar content were tested, and scaffolds morphology were observed by SEM. The results showed that microHA and nanoHA were fabricated by being calcined and synthesis methods, and their infrared spectra are very similar. EDAX composition analysis demonstrated that both of microHA and nanoHA were calcium deficiency HA. Micro-CT results demonstrated the scaffolds had interconnected spherical pores, and the structure parameters were similar. Cell viabilities were significant increased with cultured time, but there were no significant difference between microHA/CS and nanoHA/CS scaffolds. Scaffold structure was gradually destroyed and inorganic composition HA particles are more prominent with degradation time. SIGNIFICANCE: (1) Inorganic particle shape and size of composite affect the scaffold mechanical property, biological property, and degradation. NanoHA/CS and microHA/CS scaffolds with good pore connectivity were fabricated and their biological, degradation properties were studied in this manuscript. (2) The scaffold with interconnected porosity construct provides the necessary support for cells to proliferate and maintain their differentiated function, and its architecture related to the structure and morphology of new bone. Polymer scaffolds were fabricated by the technique of compression molding and particulate leaching method, and paraffin microspheres were used as the porogen. (3) MicroHA/CS and nanoHA/CS composite scaffolds are potential materials for use in bone tissue engineering.


Subject(s)
Biocompatible Materials/chemistry , Biocompatible Materials/pharmacology , Chitosan/chemistry , Durapatite/chemistry , Nanostructures/chemistry , Tissue Scaffolds/chemistry , 3T3 Cells , Animals , Biocompatible Materials/metabolism , Cell Proliferation/drug effects , Hydrolysis , Mice , Muramidase/metabolism , Porosity , Swine , Tissue Engineering
2.
Article in Chinese | WPRIM (Western Pacific) | ID: wpr-510014

ABSTRACT

Objective To explore the application of unmanned aerial vehicles (UAVs) technology for casualty evacuation in disaster rescue.Methods The research status of casualty evacuation using unmanned aerial vehicles was described in the disaster medical rescue,and several UAVs involved in casualty evacuation were introduced.According to different dynamic structures,casualty evacuation UAVs were divided into four types,such as traditional rotor helicopter,multi-rotor aircraft,ducted fan aircraft,compound aircraft.Meanwhile,the load capacity and flight speed of involved UAVs were analyzed.Results The advantages of casualty evacuation UAVs in the previous researches related were summarized,with the problems and technical difficulty discussed.Furthermore,the development tendencies of casualty evacuation UAVs were predicted.Conclusion Casualty evacuation UAVs can transport the wounded to the professional medical institutions outside of the disaster scene instead of rescue crews,to reduce the casualty rate of rescuers and avoid secondary damage of the injured personnel,with accurate point to point casualty evacuation.

3.
Article in Chinese | WPRIM (Western Pacific) | ID: wpr-510013

ABSTRACT

Objective To realize SLAM and path planning of mobile robot to solve the problem of real-time data association in the process of moving and to update the computational complexity of the state covariance matrix.Methods The mathematical model of SLAM was built,and FastSlam algorithm based on particle filter,A* and dynamic window approach (DWA) were used to prepare gmapping function package in the ROS framework.Results The motion simulation,path planning and dynamic obstacle avoidance of mobile robot in the ROS framework were realized.Conclusion By using ROS platform,mobile robots can execute path planning efficiently while completing self-localization and map building.

4.
Article in Chinese | WPRIM (Western Pacific) | ID: wpr-509919

ABSTRACT

Objective To design a vision-based detection method for rotated human bodies to fulfill unmanned wounded search in the rescue operation.Methods HOG (histogram of oriented gradient) which was the most successful visual feature in pedestrian detection was involved in,and the human detection in the wounded search task was realized by multi-directional detection.Furthermore,two human bodies datasets were established by imitating the views of unmanned ground vehicle (UGV)and unmanned aerial vehicle (UAV).Results The application to the two datasets proved the method's feasibility in UGV and UAV.Conclusion The method is robust to the in-plane rotations and out-plane rotations of human bodies,which is of vital significance to promote the efficiency of the wounded searching and rescuing.

5.
Chinese Medical Equipment Journal ; (6): 114-117,121, 2017.
Article in Chinese | WPRIM (Western Pacific) | ID: wpr-606342

ABSTRACT

Objective To design a visual terrain classification algorithm to facilitate the robot to make appropriate movement strategy by perceiving the surrounding environment.Methods Bag of words (BOW) and support vector machine (SVM) were used to develop a simple and effective terrain classification algorithm.The BOW model involved in feature extraction,codebook generation and feature coding.The mid-level feature developed by BOW model was then fed into SVM classifier to obtain the terrain classification result.Results The quadruped robot platform was applied to performing visual terrain classification experiment in the natural environment.The test environment included floor,asphalt,sand and grass.Good experimental results were achieved,and the classification accuracy was above 90% (the beat was 97.54% for grass).Conclusion The algorithm can effectively and accurately distinguish all kinds of terrains,with high accuracy and good stability.The key frame selection method needs researching in the future.

6.
Chinese Medical Equipment Journal ; (6): 122-126,130, 2017.
Article in Chinese | WPRIM (Western Pacific) | ID: wpr-606341

ABSTRACT

Objective To propose a grasp torque control based on experimental learning and haptic feedback to facilitate the manipulator in dexterous manipulation.Methods An experience database was built firstly,and then the object was recognized by tactile feedback in the grasp task.If the object had been experitentially grasped,the torque was output based on the database.In case a new object was grasped,the optimal output torque was calculated by iterative learning.Results The experiment showed that the robot hand could find the experiential output torque quickly when encountering the object in database and calculate the torque by iterative learning to achieve grasp task.Conclusion The experiential database grows up when the robot hand learns more and more experience.It can fast output torque like human in the grasp task.

7.
Biomed Eng Online ; 15: 12, 2016 Feb 02.
Article in English | MEDLINE | ID: mdl-26831146

ABSTRACT

BACKGROUND: In the process of bone defective reparation and engineered bone tissue construction, osteoblasts are adhered to the surface of the scaffold materials and impart the external mechanical load to the osteoblasts. So, the dynamic mechanical property of the scaffolds play an important role in the bone tissue repair and it is valuable to research. Material type and the architectural design of scaffolds are also important to facilitate cell and tissue growth. The aim of this study was to prepare a kind of material with good pore connectivity and analyze its dynamic mechanical property. METHODS: Fabrication and characterization of micro-hydroxyapatite(m-HA)/chitosan(CS) polymer composite scaffolds with well interconnected spherical pore architectures were reports. Micro-HA was prepared by being calcined and ball milled. Paraffin spheres in the range of 160-330 µm were fabricated with a dispersion method and used as the porogen in the fabrication of the scaffolds. Polymer scaffolds were fabricated by the technique of compression molding and particulate leaching method. The effects of the porogen content on the properties of the scaffolds were studied. RESULTS: With the increase of porogen, the pore of the scaffolds increased and became interconnected. Cyclic loading of three scaffolds were tested with 10 % strain under four levels of loading frequency, 0.1, 0.5, 1 and 1.5 Hz. The porous composite scaffolds exhibited a viscosity-elastic behaviour with a maximum stress of 3-4 kPa. At each frequency, modulus value is decreased with the paraffin microspheres content, but there was no significance difference in the peak stress of the three samples. All the samples tested displayed clear hysteresis loops. There was no significance difference in the peak hysteresis of the three samples, and the hysteresis difference values between the sixth compression cycle and the initial cycle for three samples was similar, with no statistically significant differences. CONCLUSIONS: Micro-HA/CS composite scaffolds with interconnected spherical macropores were fabricated using pherical paraffin as porogen. The porous composite scaffolds exhibited a viscosity-elastic behaviour with good repeatability. It is benefit to study the influence of the mechanical load on the cell of the scaffold.


Subject(s)
Biocompatible Materials/chemistry , Chitosan/chemistry , Durapatite/chemistry , Mechanical Phenomena , Tissue Scaffolds/chemistry , Paraffin/chemistry , Particle Size , Porosity , Water/chemistry
8.
Military Medical Sciences ; (12): 56-59,63, 2015.
Article in Chinese | WPRIM (Western Pacific) | ID: wpr-600626

ABSTRACT

ObjectiveTo realize the information integration of medical devices with different interfaces and nonstandard communication protocols in the mobile operating room .Methods There were three steps involved in the procedure:classi-fied the common medical equipment , designed three communication methods for different interfaces and developed an infor -mation collection system for mobile operating room .Results This system can acquire information from various medical de-vices and display the data and waveforms in real time .Conclusion The solution in the paper can facilitate the information acquisition for doctors during the operation and improve the efficiency and informationization level of the operating room .

9.
Military Medical Sciences ; (12): 981-985, 2014.
Article in Chinese | WPRIM (Western Pacific) | ID: wpr-462371

ABSTRACT

During rescue operations in case of armed conflicts in cities , terrorist attacks and public health emergencies , rescuers are always in danger .For this reason, search for and rescue robots have been used to search and evacuate the wounded .They have also become a hot issue in current robotics technology research ,promising a wide range of applications in civilian and military fields .This paper outlines the origin of rescue robot research ,course of development and classifica-tion, focuses on the developments of and future research of the U .S army on evacuation and rescue robots ,and finally pres-ents the problems and key technical difficulties facing the development of such robots .This paper is interded to improve re-search methods and design theories of rescue robotics .

10.
Military Medical Sciences ; (12): 704-707,713, 2014.
Article in Chinese | WPRIM (Western Pacific) | ID: wpr-600198

ABSTRACT

Plateau environment has a wide range of diurnal temperatures and thin air. The surgical shelter needs to resist the huge temperature shock and work in harsh environments, placing higher noise immunity requirements on the microenvironment temperature control system. The traditional microenvironment control of surgical treatment shelters mostly use instrument display and switch control, with a high failure rate and functional dispersion. We have designed a plateau microenvironment temperature control system with PLC as the control center and the touch screen as the Human Machine Interface so that real-time monitoring and control of temperature is achieved and the plateau temperature shock is resisted while the heater fuel ratio can be adjusted properly to adapt to plateau environment. This paper describes the control system hardware, software and algorithm design in detail.

11.
Article in Chinese | WPRIM (Western Pacific) | ID: wpr-583403

ABSTRACT

Based on the structure characteristics of the stretcher base of WCY2000field ambulance,this paper sets up a finite element analysis model with twotypes of beam elements.The accuracies under twotypes of elements are discussed and model method of the same structure is presented.

12.
Article in Chinese | WPRIM (Western Pacific) | ID: wpr-584757

ABSTRACT

To fulfill the plane-beam junction, this paper applies the simplified finite element modeling to the plane-beam composite structures. The finite element modeling of the teleconsulting vehicle compartment and its model analysis are performed. The results show that the finite element model can improve the design of the compartment and lays a foundation for the realization of the engineerization and sequencing of compartment dynamic strength design.

SELECTION OF CITATIONS
SEARCH DETAIL
...