Using small pressure transducers to measure the cerebral perfusion pressure of conscious rats

Cerebral perfusion pressure (CPP) is the net pressure gradient causing blood flow to the brain. It must be maintained within narrow limits because minute fluctuations in pressure could cause brain tissue to become ischemic or could raise intracranial pressure (ICP). In this paper, two types of transducers were proposed to measure the CPP from conscious rats. One transducer was manufactured with a pressure sensor within a screw cylindrical shell; it was made with stainless steel to allow for easier insertion of the sensor into the skull. For another type, a tube with screw-shaped outside feature that was inserted in skull and connected to the pressure sensor, the sensor was placed on the rat head. The two types of transducers were not intruded into the brain tissue. A digital physiograph system was used to acquire and analyze the CPP value. The results of the experiments showed that both types of transducers were able to measure the CPP effectively in normal conscious rats.