What intensity is measured at the location of maximum average over transmit time or pulse duration?

The intensity measured at the location of maximum average over transmit time or pulse duration refers to the Spatial Peak Pulse Average (SPPA) intensity. SPPA specifically indicates the highest intensity at a singular spatial point, averaged over the pulse duration. This means it represents the maximum intensity that one would experience at that peak location across the duration of the transmitted pulse.

This concept is crucial in ultrasound physics because different intensity metrics give specific insights into the behavior and safety of ultrasound energy in tissues. SPPA is particularly important in evaluating the effectiveness and safety of ultrasound applications, ensuring that exposures stay within acceptable limits.

Other measures relate to different aspects of ultrasound intensity. For instance, the Spatial Peak Temporal Average (SPTA) considers average intensity over time, which incorporates the duty cycle of the ultrasound pulse. SATA measures intensity averaged over time and space but does not reflect the peak values. Then, Spatial Peak Temporal Peak (SPTP) captures the highest intensity at a spatial point at the instant the pulse is at its maximum, not accounting for average. Each type serves a unique purpose in assessing ultrasound applications, but in the context of the maximum average over the pulse duration, SPPA is the correct identification.