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【medical-news】低频超声帮助腿部皮肤移植物”成
ScienceDaily (Dec. 10, 2007) — For skin transplants to “take root”, it needs to be ensured that the patient’s tissue is properly irrigated with blood. Low-frequency ultrasound can promote this effect. Researchers have developed the first device that permits variable control of the ultrasound frequency.
Minor skin wounds might hurt a lot, but they usually heal within a matter of days. For diabetics, the slightest scratch can have more serious consequences. In many cases the wound takes a long time to heal and spreads to the entire lower leg: Specialists refer to this as an “open leg ulcer”. The main reason is poor circulation, which causes insufficient oxygen and other nutrients to be transported to the wound. In many cases, the only solution is a skin transplant of healthy tissue.
To ensure that the transplant is accepted, the surgeon has to clean the wound and artificially stimulate the blood flow in the surrounding tissue – often using low-frequency ultrasound. Unlike the ultrasound used in prenatal examinations, which operates at frequencies of several hundred kilohertz, the frequencies used here are measured in tens of kilohertz. Devices operating at fixed frequencies are already available. But what effect does the treatment have on the patient’s circulation? The only empirical data that exists at present is based on patient surveys.
Researchers at the Fraunhofer Institute for Machine Tools and Forming Technology IWU in Dresden teamed up with colleagues from IMM Ingenieurbüro Mittweida and Smart Material GmbH Dresden to carry out a systematic study of this method. How often, for how long, and at what frequencies do wounds have to be treated to prepare them optimally for transplantation?
“We have developed a device that permits the frequency of the ultrasound waves to be varied between 20 and 120 kilohertz, and also has an output regulator,” says IWU team leader Dr. Gunther Naumann. “To stimulate the blood flow in the deeper epidermal layers, we need a lower frequency than that required to clean the wound in the subcutaneous zone.”
Another unique feature of the new ultrasound device is that it is equipped with a measuring system that directs light into the wound using special probes. The red region of the color spectrum of the reflected light indicates the concentration of oxygen in the blood – which in turn reveals how efficiently the tissue is being irrigated.
“Our observations have shown that the oxygen concentration continues to rise for 30 minutes after treatment. But we need to conduct further investigations to determine whether a sustained higher level can be reached after repeated treatment,” Naumann reports.
A prototype of the new device has been installed for use in clinical trials in the Department of Dermatology and Allergology at the academic teaching hospital in Dresden-Friedrichstadt. Ten patients have been treated so far. The study is to be continued in 2008.
Adapted from materials provided by Fraunhofer-Gesellschaft.
http://www.sciencedaily.com/releases/2007/12/071206232133.htm 本人已认领该文编译，48小时后若未提交译文，请其他战友自由认领。 看题目很有意思，随便翻译了一下，本拟在“谍影重重”翻译后向其学习。
先把我的贴上，等待“谍影重重”指正。
题目：超声帮助开放性腿部溃疡的皮肤移植物“成活研究
ScienceDaily (2007,12,10) — 为了皮肤移植物“成活”，需要保证病人的（移植）组织获得有效的血液灌注。低频超声能够促进该作用。研究人员已经研制出了可以调控超声频率的第一代设备。
轻微的皮肤伤口可能很痛，但通常在数天内愈合。对于糖尿病患者，最轻微的抓挠也能导致更严重的后果。大部分病例的愈合需要很长时间，会播散至整个下肢；专家称之为“开放性腿部溃疡”。主要原因是循环不良，导致转运至伤口处的氧气和其他营养物缺乏。对许多病例而言，唯一的处理方法是移植健康的皮肤。
为了保证移植物被接受，外科医师必须清创和人为刺激周围组织的血流量 – 通常采用低频超声。和产前检查使用超声的几百千赫兹（khz）操作频率不同，这里使用频率经测定为数十khz。（市场）已有可以使用固定频率的设备。但这种治疗对患者的循环起了什么作用？目前存在的唯一经验数据来源于对患者的检测。
德累斯顿Fraunhofer研究所的机床和成型工艺IWU研究人员和来自IMM Ingenieurbüro Mittweida和精细材料股份有限公司的同事合作，对该方法进行了系统的研究。多少次、多久以及何种频率治疗伤口才能获得最好的移植准备？
“我们已经研制出了一种装置，可让超声波频率在20－120khz区间变动，同时具备输出调节器，”IWU小组领导Gunther Naumann博士说。“为了刺激深部表皮层的血流量，我们需要一个比清理皮下区域伤口所需频率低的频段。”
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作者:admin@医学,生命科学 2011-02-20 05:11
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