. Author manuscript; available in PMC: 2013 Aug 19.

Published in final edited form as: IEEE Trans Ultrason Ferroelectr Freq Control. 2012 Jun;59(6):1167–1181. doi: 10.1109/tuffc.2012.2307

TABLE I.

Pulse Parameters for Acoustic Radiation Force Generation Under Free-Field Conditions.

	Push beam 1	Push beam 2	Push beam 3
Focal location (z, mm)	125	120	115
Lateral/axial (−6 db) beamwidth^* on P− pressure profile (mm)	3.5/38	3.2/36	3.0/35
Lateral/axial (−6 db) beamwidth^* on P+ pressure profile	2.3/34	2.1/32	2.0/28
P−/P+ Pressure^** (MPa)
Phantom	−5/14	−5/15	−5/16
Ex vivo tissue	−6/30	−6/34	−7/36
Pulse duration (μs)
Phantom	133	133	133
Ex vivo tissue	200	200	200
I_SPPA^*** (kW/cm²)
Phantom	1.3	1.5	1.6
Ex vivo tissue	2.3	2.5	2.8

Note that the beamwidth was narrower for shorter focal length (or smaller f-number).

^**

The pressures at the treatment locations were expected to be lower than these measurements because of sound attenuation. Given a mean propagation distance of 3 cm and attenuation coefficients of 0.1 dB/cm/MHz in the agar-graphite phantoms [54], and 1 dB/cm/MHz in the kidneys [55], the P− pressures were estimated to be ~5 MPa both in the phantom and the ex vivo experiments.

^***

I_SPPA = spatial peak pulse average intensity.