UMS Software Acoustic Parameters
The UMS software has been used to make FDA 510(k) submissions. It calculates the following acoustic parameters at a single hydrophone position. This requires that a calibrated hydrophone be used and we can supply a calibrated needle or membrane hydrophone for this purpose. All calculations are carried out according to the relevant international standards.
Acoustic Parameter | Description |
pr | Peak rarefactional pressure |
pc | Peak compressional pressure |
pr.3 | Derated peak rarefactional pressure |
pc.3 | Derated peak compressional pressure |
Isppa | Spatial-peak pulse-average intensity |
Isppa.3 | Derated spatial-peak pulse-average intensity |
MI | Mechanical index |
AWF | Acoustic working frequency |
Depth | Distance to start of pulse |
PD | Pulse duration |
PII | Pulse-intensity integral |
PII.3 | Derated pulse-intensity integral |
Other acoustic parameters can be derived from the above, including (but not restricted to) the following:
Acoustic Parameter | Description |
IOB (Output Beam intensity) | Power divided by beam width measured from planar or orthogonal cross scan |
Focal volume | Combination of beam widths from transverse and axial scans |
ISPTA (Spatial-peak temporal-average intensity) | For a single-element transducer, PII divided by pulse repetition interval |
ERA (Effective radiating area) | The area close to the transducer through which most of the acoustic power passes |
BNR (Beam non-uniformity ratio) | The ratio of the spatial-peak temporal-average intensity to the spatial-average intensity, averaged over the effective radiating area |
