The Triton Technology Model 100 Pulsed Doppler Flowmeter Module is a precision instrument designed to measure blood flow velocity in experimental preparations. As a stand-alone instrument it operates individually or in conjunction with other external synchronized instruments. The Pulsed Doppler Flowmeter is a state-of-the-art system for measuring blood flow velocity. The low-mass, inexpensive transducers are ideal for long term, chronic implantation, particularly when compared to the bulky, heavy transducers required for other technologies. These transducers use lightweight, non-shielded PVC-insulated wire.
Blood flow velocity is measured by projecting bursts of high frequency ultrasound diagonally across the blood vessel. Sound is backscattered from blood cells and the frequency of the scattered sound is shifted in proportion to the velocity of the cells. The scattered signal is detected and a voltage proportional to the velocity of the blood flow is developed for recording. A variable range gate control allows the user to measure blood flow velocity at many points across a blood vessel.
This module incorporates a number of unique features not found in other designs: A patented noise reduction circuit, Dynamic Noise Reduction, improves the signal-to-noise ratio by as much as 10 dB compared to other pulsed Doppler flowmeter designs. Range information is presented on a front panel LED display in 0.5 mm increments and as a proportional DC voltage at the back panel. The instantaneous flow velocity and direction sense is displayed on a dynamic LED bar graph display also on the front panel.
The most unique feature of the Model 100 is its internal calibration circuitry. The calibration is a true end-to-end calibration using a family of frequencies developed from the main quartz crystal clock. These stable, accurate frequencies are determined from the Doppler equation, the operating frequency and the transducer geometry. Other commercial pulsed Doppler designs utilize a simple voltage divider across the power supply as a calibration.
The pulsed Doppler Flow Module is available in 20 and 10 MHz versions for use on small and medium blood vessels. Many different implantable transducers are available to suit specific applications.
Model 100-20 (20 MHz) Model 100-10 (10 MHz)
Model 100-5 (5 MHz)
The Model 100 is a state-of-the-art Pulsed Doppler Flowmeter. Designed by a cardiovascular research group, this flowmeter is made to satisfy the most exacting requirements of researchers. Models are available in 20, 10 and 5
MHz for small, medium and large vessels. Each functional block of the electronic circuitry has been refined to provide optimal performance. The units function with implanted flow cuffs, transcutaneous flow probes and the 20 MHz system can be used with commercially available Doppler flow catheters. The Model 100 will function as a stand-alone unit, and will also synchronize with other pulsed Doppler flowmeters and with Sonomicrometers.
•Patented noise reduction circuitry for optimal signal-to-noise ratios
•Pulse repetition frequency internally by switch selectable to 125 KHz, 100KHz, 62.5 KHz and other rates
•Front panel range gate adjustment; range position is indicated on front panel LED bargraph display; DC voltage proportional to range is available at back panel
•Simultaneous phasic and mean output signals
•Audio output to front panel speaker is combined toward and away signals (up & down Doppler); back panel stereo phone jack provides directional flow signals separated for up Doppler to one ear and down Doppler to other ear; inserting phone jack breaks speaker connection
•Internal calibration is derived from quartz crystal oscillator; normal factory calibration frequency steps to velocities of 100, 50, 20 and 10cm/sec respectively, using 45-degree transducer; the angle coefficient is switch selectable internally for use with different transducer geometries.