On The Experimental Apparatus For Ultrasonic Disruption In The Treatment Of Intracerebral Hematoma

Intracerebral hemarrhage, a main disease among acute cerebrovascular ones, has very high disability rate and mortality. With the aging of the population in China, its disease rate and the absolute number of patients are increasing. The space occupying effect of intracerebral hematoma is the main reason leading the death of the hemarrhage patient. So it is important to work out the high-performance and safety apparatus in its treatment. There are some disadvantages in present stereotaxic hemorrhage aspiration such as the difficulty of the drainage cruor and the repeat of the punctures. In order to resolve these problems, the author develops a set of experimental facility-ultrasonic evacuation of brain hematoma, which is based on such basic theories as applied acoustics, electronics, microchip techniques, cerebrovascular studies and neurosurgery. Then the effect of ultrasonic power and cure time on hematoma liquation is researched while taking the rabbit cruor as the object. The apparatus includes ultrasonic vibration system and ultrasonic control system. The former makes use of PLL (phase-locked loop) to realize zero phase difference frequency tracing which ranges from 38.8KHZ to 57.6KHZ and can improve the transducer's output efficiency and work stability. To enlarge ultrasonic work score, a new design highlight of hemispherical radiation whose maximum angle can extend to 140 degree is brought up and realized. Taking advantage of the PIC microchip, the latter, ultrasonic control system can control ultrasonic power and input the cure time from 0 to 99 second each time and display it real-timely. In the experiment of ultrasonic disruption, the interrelation of ultrasonic output power, ultrasonic work time and the volume of liquefied hematoma is preliminarily researched. First of all, in the condition of the same ultrasonic output power, more hematomas are evacuated while more time spent with t<10s whereas the volume of liquefied hematoma hardly changes with t>10s. Second, under the condition of the same work time, output power is proportional to the volume of the hematoma, that is, it takes less time under the higher power to evacuate the same-size hematoma.This study shows that the ultrasonic can quickly and effectively evacuate hematoma and this newmethod can deal with the difficulty of drainage cruor better because it is easier to punch the liquefied hematoma...