自治式水下机器人回收系统的研究与设计

本文介绍了我们承担研制的国家“８６３”计划１０００ｍ及６０００ｍ无缆水下机器人的回收系统．回收系统在４级海况下不用专用母船能够成功地回收水下机器人，依据母船、海况、水下机器人及其他具体情况，介绍了两种不同的回收方案和回收器，经海上试验证明是有效和可行的。

冠状动脉旁路移植术后抑郁焦虑状态随访和分析

To explore the presence of depression, anxiety and cardiac events after coronary artery bypass grafting (CABG) prospectively and comparably. To analysis influential factors of depression and anxiety ( peri-operation and 1 year after operation ), and the effection on cardiac events in the year after operation. We followed the patients who underwent scheduled consecutive CABG. We interviewed patients to assess depression, anxiety symptoms using self-rating depression scale( SDS) and self-rating anxiety scale（SAS）before operation , before discharge and 1 year after operation. And cardiac events were also identified. All patients were divided into the group with depression and/or anxiety symptoms or the other group without depression and/or anxiety symptoms 3 times according to depression and anxiety symptoms before operation , before discharge and 1 year after operation. 69 patients completed the follow-up.24 patients (34.8%) had depression and/or anxiety symptoms before CABG, 31 patients (44.9%) had depression and/or anxiety symptoms before discharge, and 10 patients (14.5%) had depression and/or anxiety symptoms 1 year after operation. 6 patients(8.7%) had cardiac events, and 5 patients were re-admitted. Arhythmia before and after operation, the quantity of blood vessel grafted, length of stay , depression and anxiety symptoms before operation, cardiac events may lead to depression and anxiety symptoms 1 year after operation. The use of cardiopulmonary bypass grafting (CPB), Arhythmia after operation, the prolonged length of stay are influential factors of cardiac events. Though the incidence of depression and/or anxiety symptoms 1 year after operation is lower than before operation and before discharge, it is high still. Arhythmia before and after operation, the more blood vessels grafted, the prolonged length of stay , depression and anxiety symptoms before operation and cardiac events could be risk factors of depression and anxiety symptoms 1 year after operation. Much attention must be paid to this phenomenon. Heavy patient's condition, complicated surgery are risk factors of cardiac events, and bad emotion before operation and before discharge are independent to cardiac events. Key words： perspective research; depression；anxiety; coronary artery bypass grafting; follow up

Automated Quality Assurance Applied to Mammographic Imaging

L. Blot, A. Davis, M. Holubinka, R. Marti and R. Zwiggelaar, 'Automated quality assurance applied to mammographic imaging', EURASIP Journal of Applied Signal Processing 2002 (7), 736-745 (2002)

Integracja szlaków sygnalizacyjnych interferonu gamma i receptora TLR4 w procesie zapalnym naczyń krwionośnych, warunkowana czynnikami transkrypcyjnymi STAT1 i IRF

Wydział Biologii: Instytut Biologii Molekularnej i Biotechnologii Zakład Genetyki Molekularnej Człowieka

INVESTIGATION OF BUBBLE DYNAMICS AND HEATING DURING FOCUSED ULTRASOUND INSONATION IN TISSUE-MIMICKING MATERIALS

The deposition of ultrasonic energy in tissue can cause tissue damage due to local heating. For pressures above a critical threshold, cavitation will occur in tissue and bubbles will be created. These oscillating bubbles can induce a much larger thermal energy deposition in the local region. Traditionally, clinicians and researchers have not exploited this bubble-enhanced heating since cavitation behavior is erratic and very difficult to control. The present work is an attempt to control and utilize this bubble-enhanced heating. First, by applying appropriate bubble dynamic models, limits on the asymptotic bubble size distribution are obtained for different driving pressures at 1 MHz. The size distributions are bounded by two thresholds: the bubble shape instability threshold and the rectified diffusion threshold. The growth rate of bubbles in this region is also given, and the resulting time evolution of the heating in a given insonation scenario is modeled. In addition, some experimental results have been obtained to investigate the bubble-enhanced heating in an agar and graphite based tissue- mimicking material. Heating as a function of dissolved gas concentrations in the tissue phantom is investigated. Bubble-based contrast agents are introduced to investigate the effect on the bubble-enhanced heating, and to control the initial bubble size distribution. The mechanisms of cavitation-related bubble heating are investigated, and a heating model is established using our understanding of the bubble dynamics. By fitting appropriate bubble densities in the ultrasound field, the peak temperature changes are simulated. The results for required bubble density are given. Finally, a simple bubbly liquid model is presented to estimate the shielding effects which may be important even for low void fraction during high intensity focused ultrasound (HIFU) treatment.

HEATING IN VASCULAR TISSUE AND FLOW-THROUGH TISSUE PHANTOMS INDUCED BY FOCUSED ULTRASOUND

High intensity focused ultrasound (HIFU) can be used to control bleeding, both from individual blood vessels as well as from gross damage to the capillary bed. This process, called acoustic hemostasis, is being studied in the hope that such a method would ultimately provide a lifesaving treatment during the so-called "golden hour", a brief grace period after a severe trauma in which prompt therapy can save the life of an injured person. Thermal effects play a major role in occlusion of small vessels and also appear to contribute to the sealing of punctures in major blood vessels. However, aggressive ultrasound-induced tissue heating can also impact healthy tissue and can lead to deleterious mechanical bioeffects. Moreover, the presence of vascularity can limit one’s ability to elevate the temperature of blood vessel walls owing to convective heat transport. In an effort to better understand the heating process in tissues with vascular structure we have developed a numerical simulation that couples models for ultrasound propagation, acoustic streaming, ultrasound heating and blood cooling in Newtonian viscous media. The 3-D simulation allows for the study of complicated biological structures and insonation geometries. We have also undertaken a series of in vitro experiments, in non-uniform flow-through tissue phantoms, designed to provide a ground truth verification of the model predictions. The calculated and measured results were compared over a range of values for insonation pressure, insonation time, and flow rate; we show good agreement between predictions and measurements. We then conducted a series of simulations that address two limiting problems of interest: hemostasis in small and large vessels. We employed realistic human tissue properties and considered more complex geometries. Results show that the heating pattern in and around a blood vessel is different for different vessel sizes, flow rates and for varying beam orientations relative to the flow axis. Complete occlusion and wall- puncture sealing are both possible depending on the exposure conditions. These results concur with prior clinical observations and may prove useful for planning of a more effective procedure in HIFU treatments.