Faculty of Engineering, Kyushu University, Fukuoka 819-0395, Japan.
Research Center for Ubiquitous MEMS and Micro Engineering (UMEMSME), Advanced Industrial Science and Technology (AIST), Tukuba 305-8564, Japan.
Sensors (Basel). 2017 Mar 27;17(4):687. doi: 10.3390/s17040687.
Monitoring rumen conditions in cows is important because a dysfunctional rumen system may cause death. Sub-acute ruminal acidosis (SARA) is a typical disease in cows, and is characterized by repeated periods of low ruminal pH. SARA is regarded as a trigger for rumen atony, rumenitis, and abomasal displacement, which may cause death. In previous studies, rumen conditions were evaluated by wireless sensor nodes with pH measurement capability. The primary advantage of the pH sensor is its ability to continuously measure ruminal pH. However, these sensor nodes have short lifetimes since they are limited by the finite volume of the internal liquid of the reference electrode. Mimicking rumen atony, we attempt to evaluate the rumen condition using wireless sensor nodes with three-axis accelerometers. The theoretical life span of such sensor nodes depends mainly on the transmission frequency of acceleration data and the size of the battery, and the proposed sensor nodes are 30.0 mm in diameter and 70.0 mm in length and have a life span of over 600 days. Using the sensor nodes, we compare the rumen motility of the force transducer measurement with the three-axis accelerometer data. As a result, we can detect discriminative movement of rumen atony.
监测奶牛的瘤胃状况很重要，因为功能失调的瘤胃系统可能导致死亡。亚急性瘤胃酸中毒（SARA）是奶牛的一种典型疾病，其特征是反复出现低瘤胃 pH 值。SARA 被认为是瘤胃酸中毒、瘤胃炎和真胃移位的触发因素，这些疾病可能导致死亡。在以前的研究中，通过具有 pH 测量能力的无线传感器节点来评估瘤胃状况。pH 传感器的主要优点是能够连续测量瘤胃 pH 值。然而，由于参考电极内部液体的有限体积，这些传感器节点的寿命很短。为了模拟瘤胃酸中毒，我们尝试使用具有三轴加速度计的无线传感器节点来评估瘤胃状况。这种传感器节点的理论寿命主要取决于加速度数据的传输频率和电池的大小，而提出的传感器节点直径为 30.0 毫米，长度为 70.0 毫米，寿命超过 600 天。使用传感器节点，我们将力传感器测量的瘤胃运动与三轴加速度计数据进行了比较。结果表明，我们可以检测到瘤胃酸中毒的有区别的运动。
