| Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 1989: ¥300,000 (Direct Cost: ¥300,000)
Fiscal Year 1988: ¥300,000 (Direct Cost: ¥300,000)
Fiscal Year 1987: ¥3,000,000 (Direct Cost: ¥3,000,000)
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| Research Abstract |
With recent advances in neonatal intensive care, the prognosis of high risk infants has improved. However, neonatal asphyxia is still associated with neurological handicap. In the pathogenesis of this brain damage, alteration in cerebral circulation is an important etiological factor. Especially, hemodynamic changes shortly after birth seen to be closely related to the occurrence of hypoxic-ischemic brain damage.
The measurement of the blood flow velocity by the Doppler ultrasonic technique has great advantages, because it is technically easy and noninvasive. Recently, there have been several reports of continuous waveform Doppler ultrasonography used to measure relative changes of blood flow velocity in human newborn cerebral circulation system, using the pulsatility index (PI), ratio of systolic to diastolic velocity.
However, if there is a more modern and continuously measuring instrument by transcranial Doppler method, it will be more useful to obtain the information on the intracranial circulation. The purpose of our research is to make up a new type of continuously measuring instrument.
We tried several methods for this purpose; (1) using multiple probes to detect Doppler signals without technician's searching, (2) using electric scanning to catch by the maximum sensitivity, (3) using transverse direction of supersonic wave beam by PZT, (4) using high molecular jelly between the beans and scalp skin for detecting signals with higher sensitivity. However, it was difficult to get the Doppler signals continuously and half-automatically with long hours by these trials. We feel now there is more still room to investigate on the method of measurement, especially in a test of angular scanning method.
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