| Term | Definition |
|---|
| Pulse u/s | produced from electric pulses in a short burst of acoustic energy, determines depth of interface |
| DMS 2D pulse has how many cycles? | 1-3 |
| Doppler pulses has how many cycles? | 5-20 |
| Pulse | a collection of cycles with a beginning and end |
| Two components of a pulse | cycles & deadtime |
| cycles | on, transmitting, sending time |
| deadtime | off, listening time, receiving |
| 5 descriptors of a pulse | PD, SPL, PRP, PRF, DF |
| Pulse Duration | time from the start of a pulse to the end of "that" pulse |
| Counterpart to SPL | pulse duration (can't be changed by operator) |
| PD (equation)= | # of cycles x T or # of cycles/F |
| Spatial Pulse Length | length/distance that a pulse occupies in space, determines axial resolution |
| SPL | determined by source & medium (like wavelength) |
| Pulse Repetition Period | the time from the start of the one pulse to the start of the next |
| PRP | aka: the time-of- flight of a sound pulse btwn xdcr and botton of image |
| Pulse Repetition Frequency | the number of pulses that occur in 1 sec. |
| Typical PRP frequency range | 1-10 kHz (1,000-10,000 Hz) |
| Duty Factor | fraction/% of time that a pulsed u/s is on or transmitting (unitless) |
| DF | determined by source and can't be changed by the operator (inversely related to image depth |
| Amplitude | the magnitude/strength of a sound beam, the difference btwn min value and avg value |
| Amp. | It's units depend on the acoustic variable (decreases exponentially as sound propagates thru body |
| Power | the rate at which work is done/energy is transferred from one area to another; the measure of total energy transmitted/unit time (work/time) |
| Directly proportional to Amp squared | power |
| dB | measures the power change in tissue |
| BUC | aka SP/SA factor, related to space (unitless); describes the spread of a beam in space |
| TP | (temporal peak) max. I found in the pulse @ an instance in time |
| PA | (pulse avg) avg. I during PD includes beginning (increased value) & near end (decreased value) |
| TA | (temporal avg) avg. I during PRP (transmit and receive times) related to DF |
| SPTA | the official output intensity labeling use to clarify bioeffect |
Combine with other sets
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