Development and in-vitro characterization of an implantable flow sensing transducer for hydrocephalus
Development and in-vitro characterization of an implantable flow sensing transducer for hydrocephalus
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DOI：
10.1007/s10544-010-9413-6
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发表时间：
2010-08-01
影响因子：
2.8
通讯作者：
Burger, Juergen
中科院分区：
文献类型：
--
作者：
Bork, Toralf;Hogg, Andreas;Burger, Juergen
一种用于监测脑脊髓液（CSF）流量以治疗脑积水的植入式传感器已经开发出来，该传感器基于测量局部热源的散热。传感器采用13.56 MHz的无源遥测技术供电，并读取测得的流速。使用蛋白浓度增加的人工脑脊液（CSF）和含10%新鲜血液的人工CSF表征了换能器的体外性能。将新鲜血液添加到人工CSF后，如果流量传感器的敏感表面靠近沉淀的红细胞，则观察到流速降低。在敏感表面与沉积物上方的剩余血浆/人工CSF混合物接触的情况下，已经观察到流速增加，这可以通过与人工CSF相比粘度增加的红细胞沉积引起的不对称流动曲线来解释。从人工CSF中去除血液后，在传感器测量中未观察到漂移，这可能与包装流量传感器敏感表面壁处的蛋白质沉积有关。流量传感器规格要求为流量范围在2 ml/h和40 ml/h之间的+-10%。可以在37 A摄氏度的测试条件下得到证实。
An implantable transducer for monitoring the flow of Cerebrospinal fluid (CSF) for the treatment of hydrocephalus has been developed which is based on measuring the heat dissipation of a local thermal source. The transducer uses passive telemetry at 13.56 MHz for power supply and read out of the measured flow rate. The in vitro performance of the transducer has been characterized using artificial Cerebrospinal Fluid (CSF) with increased protein concentration and artificial CSF with 10% fresh blood. After fresh blood was added to the artificial CSF a reduction of flow rate has been observed in case that the sensitive surface of the flow sensor is close to the sedimented erythrocytes. An increase of flow rate has been observed in case that the sensitive surface is in contact with the remaining plasma/artificial CSF mix above the sediment which can be explained by an asymmetric flow profile caused by the sedimentation of erythrocythes having increased viscosity compared to artificial CSF. After removal of blood from artificial CSF, no drift could be observed in the transducer measurement which could be associated to a deposition of proteins at the sensitive surface walls of the packaged flow transducer. The flow sensor specification requirement of +-10% for a flow range between 2 ml/h and 40 ml/h. could be confirmed at test conditions of 37A degrees C.