Cushing Neuromonitoring Laboratory, Feinstein Institute for Medical Research, North Shore Long Island Jewish Health System, Manhasset, NY 11030, USA.
Biomed Microdevices. 2012 Aug;14(4):759-68. doi: 10.1007/s10544-012-9646-7.
This work describes the development of a micromachined lab-on-a-tube device for simultaneous measurement of brain temperature and regional cerebral blood flow. The device consists of two micromachined gold resistance temperature detectors with a 4-wire configuration. One is used as a temperature sensor and the other as a flow sensor. The temperature sensor operates with AC excitation current of 500 μA and updates its outputs at a rate of 5 Hz. The flow sensor employs a periodic heating and cooling technique under constant-temperature mode and updates its outputs at a rate of 0.1 Hz. The temperature sensor is also used to compensate for temperature changes during the heating period of the flow sensor to improve the accuracy of flow measurements. To prevent thermal and electronic crosstalk between the sensors, the temperature sensor is located outside the "thermal influence" region of the flow sensor and the sensors are separated into two different layers with a thin-film Copper shield. We evaluated the sensors for accuracy, crosstalk and long-term drift in human blood-stained cerebrospinal fluid. These in vitro experiments showed that simultaneous temperature and flow measurements with a single lab-on-a-tube device are accurate and reliable over the course of 5 days. It has a resolution of 0.013 °C and 0.18 ml/100 g/min; and achieves an accuracy of 0.1 °C and 5 ml/100 g/min for temperature and flow sensors respectively. The prototype device and techniques developed here establish a foundation for a multi-sensor lab-on-a-tube, enabling versatile multimodality monitoring applications.
这项工作描述了一种用于同时测量脑温与局部脑血流的微加工管上实验室设备的开发。该设备由两个具有四线配置的微加工金电阻温度探测器组成。一个用作温度传感器，另一个用作流量传感器。温度传感器采用 500 μA 的交流激励电流工作，以 5 Hz 的速率更新其输出。流量传感器采用恒温模式下的周期性加热和冷却技术，以 0.1 Hz 的速率更新其输出。温度传感器还用于补偿流量传感器加热期间的温度变化，以提高流量测量的准确性。为了防止传感器之间的热和电子串扰，温度传感器位于流量传感器的“热影响”区域之外，并且传感器被分成两个不同的层，中间夹有一层薄膜铜屏蔽。我们在人血污染的脑脊液中评估了传感器的准确性、串扰和长期漂移。这些体外实验表明，使用单个管上实验室设备进行同时的温度和流量测量在 5 天的时间内是准确可靠的。它的分辨率为 0.013°C 和 0.18 ml/100 g/min；温度和流量传感器的精度分别达到 0.1°C 和 5 ml/100 g/min。这里开发的原型设备和技术为多传感器管上实验室奠定了基础，实现了多功能多模态监测应用。
