Transcranial Doppler(TCD) Model:EMS-9U Feature: I. Ease of use and flexibility, one machine for two purposes: Compact EMS-9U main unit, connected to table top or lap top computer through USB interface, can be used as a table top or portable TCD. For spot check, it can be packed in a lap top computer bag, so it is easy to carry. II. 32 depth M- wave: Displays transducer beam directions up to 32 continuous depth of Doppler power signal and clearly records the embolus trace under monitoring mode. M wave can measure the neck artery diameter. III. Specialized embolus detection technology, dynamic continuous monitoring system: Incorporated multi-depth and M-mode technology; an advanced embolus detection system is formed. Through large amount of clinical tests, it is a reliable embolus detection technique. It can perform long-term dynamic monitoring without limit of time. IV. Audio, spectrum synchronous storage and playback: Full digital design enables the synchronous playback, demonstration of the sound and spectrum on any computer, which is extremely convenient to scientific research and education. V. Four-channel, eight-depth Up to 4 channel and 8 depth configuration meets the highest clinical requirements.