“…Sparse arrays have been proposed in the field of ultrasonics for both active (Turnbull & Foster, 1991; Davidsen & Smith, 1993; Lockwood & Foster, 1996) and passive (Coviello, et al, 2012) (O'Reilly, et al, 2014; Jones, et al, 2015) imaging, as well as for FUS therapy (Hynynen & Jones, 2016). In the current device, the transducer elements were randomly placed on a hemispherical shell in a configuration that was optimized through numerical simulations (Jones, et al, 2013), since grating lobes (on both transmit and receive) resulting from periodic, sparse arrangements can be suppressed by using an irregular layout (Goss, et al, 1996; Hutchinson, et al, 1996; Hand, et al, 2009).…”