Control system for an MRI compatible intracavitary ultrasound array for thermal treatment of prostate disease
Control system for an MRI compatible intracavitary ultrasound array for thermal treatment of prostate disease
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DOI：
10.1080/02656730010025841
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发表时间：
2001-05-01
影响因子：
3.1
通讯作者：
Hynynen, K
中科院分区：
文献类型：
--
作者：
Smith, NB;Merrilees, NK;Hynynen, K
16通道超声腔内阵列目前正用于前列腺肿瘤的局部热疗治疗的临床环境中。目前，基于临床医生对在侵入式热电偶探头的位置处测量的温度的判断来调整每个阵列元件的单独功率。MRI导出的温度测量可用于反馈控制系统，该反馈控制系统通过调节到阵列的元件的功率来非侵入性地调节温度分布。MRI已被证明可以提供准确、高分辨率、非侵入性的温度测量。设计了一个比例积分、单输入、单输出控制器，以评估MRI导出的温度反馈与该施加器的可行性。控制器的输入参数通过对来自阵列的加热的组织响应进行建模来确定。离体和体内实验评估了基于MRI的温度反馈控制系统在与临床高温治疗相似的持续时间内实现和维持目标温度的能力。将控制器设定为43 ℃的参考温度和6分钟的上升时间，离体组织（n = 6）内的温度在达到参考温度后为43.1 +/- 0.3 ℃，上升时间为9.5 +/- 0.3 min。使用家兔大腿肌肉（n = 7）的体内结果表明，稳态温度在+/-0.3 ℃范围内。-1 ℃的目标温度。这些结果证明了基于来自MR图像的温度信息的温度反馈用于控制来自腔内经直肠阵列的加热的可行性。
A 16-channel ultrasound intracavitary array is currently being used in a clinical setting for localized hyperthermia treatment of prostate tumours. Currently, the individual power to each array element is adjusted based on the clinician's judgement of the temperature measured at the locations of invasive thermocouple probes. MRI-derived temperature measurements may be useful for a feedback control system that non-invasively regulates the temperature distribution by adjusting the power to the elements of the array. MRI has been shown to provide accurate, high resolution, non-invasive thermometry. A proportional-plus-integral, single-input, single-output controller was designed to evaluate the feasibility of MRI-derived temperature feedback with this applicator. Input parameters for the controller were determined by modelling the tissue response to the heating from the array. Ex vivo and in vivo experiments evaluated the ability of the MRI-based temperature feedback control system to achieve and maintain a target temperature for a sustained period similar to that of a clinical hyperthermia treatment. With the controller set to a reference temperature of 43 degreesC and a rise time of 6 min, the temperatures within the ex vivo tissue (n = 6) were 43.1 +/- 0.3 degreesC after reaching the reference temperature and had a rise time of 9.5 +/- 0.3 min. In vivo results using rabbit thigh muscle (n = 7) showed that the steady state temperatures were within +/- 1 degreesC of their target temperatures. These results demonstrated the feasibility of a temperature feedback for controlling the heating from an intracavitary transrectal array based on temperature information from MR images.