Objective: Several generations of ultrasound contrast agents have been developed. Now the application of targeted microbubble is an important research field. Methods: Ultrasound microbubble contrast agents can be divided into two types: ordinary and special ones. First generation microbubble products are air bubbles. They lack a stabilizing shell and have large size. The second ones are stabilized by a sheU and have a smaller size ,instable gas cores consisting of air. The third ones have a stable shell and gas cores with perfiuorocarbons. Researches on new applications of targeted microbubble involve the targeted molecular imaging such as thrombus and inflammation imaging, thrombolytic therapy, drug/gene therapy and so on. Results: The stability of microbubble is increased gradually. Microbubble is injected intravenously and reaches the targeted tissue. At low ultrasound beam power imaging contrast can be improved. Low frequency ultrasound (1 MHz) can cause transient perfora-tion of cell membrane by cavitation effects and thereby improve drug/gene delivery efficiency. Conclusions: Ultrasound-target-ed microbubble has shown its advantages over other methods in the clinical diagnosis and treatment. While the bio-effects are not fully understood. And physical parameters affecting drug or gene delivery efficiency should be optimized.

BACKGROUND:Orthodontic tooth movement is based on the periodontal tissue remodeling. In the exogenous factors accelerating orthodontic tooth movement, Chinese herbal medicine has become a research hotspot because of its wide resources, low cost, easy to extract, mild effect, smal toxic, less side effects and drug resistance. OBJECTIVE: To summarize the role of Chinese herbal medicine in the periodontal tissue remodeling during orthodontic tooth movement. METHODS:A computer-based retrieval of CNKI, Wanfang and PubMed databases was performed for articles related to Chinese herbal medicine for improving orthodontic tooth movement published before 2014. The keywords were “Chinese herbal medicine, orthodontic tooth movement, periodontal tissue remodeling” in Chinese and English, respectively. RESULTS AND CONCLUSION:Erigeron breviscapus, Salvia, teasel, Drynaria, baicalin, evening primrose oil as Chinese herbs are most widely used in the promotion of periodontal tissue remodeling, characterized as wide resources, low cost, easy to extract, mild effect, low toxicity, less drug resistance. In the clinical orthodontic treatment, it is hoped to accelerate orthodontic tooth movement and shorten the treatment time. Therefore, under the appropriate corrective force, Chinese herbs can be used properly to improve periodontal tissue repair and remodeling, which can improve the microcirculation of periodontal tissue, increase the local blood flow, promote bone formation and repress bone resorption.

Objective To register pre-operative MRI/CT images with intra-operative ultrasound images based on vessels visible in both of the modalities. Method A non-rigid registration method of multimodal medical images based on Free Form Deformation(FFD) was proposed. When the images were aligned, the centerline points of the vessels in one image aligned with the intensity ridge points in the other image. Rigid transformation was adopted in global registration while local deformation was described by a Free Form Deformation based on a modally controlled B-spline. The method applied an optimization strategy combining the genetic algorithm with the conjugated gradients algorithm to minimize the objective function. Result Two experiments were designed on phantom and clinical data to evaluate the method. The results demonstrated that the registration method was consistent accurate. The average standard deviation of the final transformation parameters was sub-voxel, sub-millimeter, and within 0.010 radians. Conclusion The results show that the method has good registration accuracy and convergence rate. It can be applied efficiently in the ultrasound-image-guided surgery system.

Radio frequency ablation has become a valuable method in treating cancers or tumors for its wide adaptability, better efficacy, convenience and safety. This paper introduces the research and development of a multipolar RF tumor therapy system based on the technology of destroying hypoxic cell. This is an intellectualized tumor curing system.
Animals ; Catheter Ablation ; instrumentation ; methods ; Electrodes ; Equipment Design ; Mice ; Mice, Nude ; Neoplasms, Experimental ; therapy ; Software Design

Tumor combined therapeutic system, a kind of medical instrument to restrain and kill tumor, is based on radio frequency heating technique and biological heating effect theory. It can be used solely or in combination with chemotherapy and actinotherapy for tumor hyperthermia. Combined with hardware measurement and adjustment, as well as application of the improved PID algorithm to the system of temperature control, the required accurate temperature control which directly influences the curative effect is realized. The experimental results presented in this paper demonstrated that the equipment works stably and reliably, and it is of good usefulness.
Algorithms ; Combined Modality Therapy ; Equipment Design ; Humans ; Hyperthermia, Induced ; instrumentation ; methods ; In Vitro Techniques ; Neoplasms ; therapy ; Temperature

Trabecular microstructure is an important factor that influences the bone biomechanical properties. In this paper, studies on digital image analysis of trabecular microstructure are reviewed with special emphases on the serials parameters as well as on the measurement methods of trabecular microstructure characteristic. The future researches and advances are also prospected.
Algorithms ; Bone and Bones ; anatomy & histology ; ultrastructure ; Computer Simulation ; Finite Element Analysis ; Humans ; Image Enhancement ; methods ; Image Interpretation, Computer-Assisted ; methods ; Imaging, Three-Dimensional ; Magnetic Resonance Imaging ; Tomography, X-Ray Computed

Small-scale intellectualized medical instrument has attracted great attention in the field of biomedical engineering, and LabVIEW (Laboratory Virtual Instrument Engineering Workbench) provides a convenient environment for this application due to its inherent advantages. The principle and system structure of the hyperthermia instrument are presented. Type T thermocouples are employed as thermotransducers, whose amplifier consists of two stages, providing built-in ice point compensation and thus improving work stability over temperature. Control signals produced by specially designed circuit drive the programmable counter/timer 8254 chip to generate PWM (Pulse width modulation) wave, which is used as ultrasound radiation energy control signal. Subroutine design topics such as inner-tissue real time feedback temperature control algorithm, water temperature control in the ultrasound applicator are also described. In the cancer tissue temperature control subroutine, the authors exert new improvments to PID (Proportional Integral Differential) algorithm according to the specific demands of the system and achieve strict temperature control to the target tissue region. The system design and PID algorithm improvement have experimentally proved to be reliable and excellent, meeting the requirements of the hyperthermia system.
Algorithms ; Computer Simulation ; Hyperthermia, Induced ; instrumentation ; Neoplasms ; therapy ; Software Design ; Ultrasonic Therapy ; instrumentation ; methods

A detailed review is given in this paper on various current 3D display methods for sequential 2D medical images and the new development in 3D medical image display. True 3D display, surface rendering, volume rendering, 3D texture mapping and distributed collaborative rendering are discussed in depth. For two kinds of medical applications: Real-time navigation system and high-fidelity diagnosis in computer aided surgery, different 3D display methods are presented.
Algorithms ; Image Processing, Computer-Assisted ; methods ; Imaging, Three-Dimensional ; methods

The development of a multi-functional tumor combined therapeutic instrument based on improved PID algorithm is introduced. It is based on the theory of 1 + 1 = 3 or 1 + 1 + 1 > 3 curative effect enhancement by tumor combined therapy, and it can be used solely, or with the combination of chemotherapy or actinotheraphy or both for tumor hyperthermia. By adopting improved PID temperature control algorithm, the problem of temperature control precision reduction due to process characteristics changing with different heaters was solved, thus ensuring homogeneous and smooth radio frequency heating by different heaters to intracavity tumor foci. These experiments demonstrated that the new algorithm has strong adaptability and anti-disturbance capability, the equipment works stably and reliably, and it can control therapeutic temperature precisely (+/- 0.1 degree C), which indicates a good value in clinical application.
Algorithms ; Combined Modality Therapy ; Equipment Design ; Hyperthermia, Induced ; instrumentation ; Neoplasms ; therapy ; Temperature

Objective To determine the power-time-ablation scope correlogram of a water-cooled single needle electrode radiofrequency (RF) ablation system and to establish a theoretical basis for its practical application.Methods RF ablations were performed using a water-cooled single needle electrode radiofrequency ablation system developed by the authors using fresh ox liver as well as liver and muscles of healthy adult New Zealand white rabbits.The temperature of the ablation area was monitored using a multichannel thermometric system.The maximum ablation scope was determined by detecting the rim at which the temperature was no less than 50 °C.The specific absorption rate (SAR) of the isolated liver tissue was calculated.Results In the treatment voltage range of 100-130V,the process was smooth and steady.No impedance variation was obvious.The maximum diameter of a single ablation was 51 cm.With the treatment voltage at 140-170 V,a larger ablation area could be reached in less time,but eventually the impedance began to increase while the ablation area was no longer expanded.When the treatment voltage reached the range of 180-200 V the impedance almost always increased rapidly out of limits,and the treatment system stopped automatically.The measured SAR value was consistent with the theoretical value.Pathology confirmed that both liver tissue and muscle tissue manifested typical coagulative necrosis.Conclusions The power amplifier,cooling,thermometric and control sections of the RF ablation system worked stably,and the practical ablation effect met the design and clinical treatment requirements.