Schley D, Billingham J, Marchbanks R J
Department of Medical Physics and Bioengineering, Southampton General Hospital, Southampton, Hampshire. SO16 6YD, UK.
Math Med Biol. 2004 Dec;21(4):347-68. doi: 10.1093/imammb21.4.347.
The accumulation of excess cerebrospinal fluid in the ventricles of the brain results in hydrocephalus, a condition that is fatal if left untreated. The usual remedy is to insert a shunt into the ventricles of the brain, which drains excess fluid away, moderated by a pressure dependent valve. It is important that the system functions properly so that a reasonable intracranial pressure is maintained. Unfortunately, pressure measurements in the ventricles are highly invasive, while pressure measurements in the shunt outside the skull may not detect any blockage in the catheter inside. Here we develop a model primarily aimed at detecting in vivo a blockage and other shunt malfunction using non-invasive measurements, so that shunt valves can be adjusted accordingly. The system offers a clear insight into how currently available clinical measurements may be utilized. We then extend this to investigate the phenomenon of 'chatter' (rapid opening and closing) and other mechanisms including intracranial pressure pulsatility. Although simple, the model offers a clear indication of what is required for successful regulation of both intracranial pressure and shunt flow.
脑脊液在脑室中过度积聚导致脑积水，这种情况若不治疗会致命。通常的治疗方法是在脑室中插入分流管，通过一个依赖压力的阀门将多余的液体引流出去。确保该系统正常运行以维持合理的颅内压非常重要。不幸的是，脑室中的压力测量具有高度侵入性，而颅骨外分流管中的压力测量可能无法检测到导管内部的任何堵塞。在此，我们开发了一个模型，主要目的是利用非侵入性测量在体内检测堵塞和其他分流故障，以便相应地调整分流阀。该系统清晰地展示了如何利用当前可用的临床测量方法。然后我们将此扩展以研究“颤动”（快速开合）现象以及包括颅内压搏动性在内的其他机制。尽管该模型很简单，但它明确指出了成功调节颅内压和分流流量所需的条件。
