2B-1 Solutions for Reconfigurable Arrays in Ultrasound

A reconfigurable array may involve a relatively large 2D array of transducer sub-elements and a layer of electronics which uses switches to connect certain sub-elements together, to a single system channel [Fischer et al., 2005 and Thomenius et al., 2005]. An annular array pattern, consisting of ring-shaped element groups, may be electronically scanned, or stepped, across the surface of such a reconfigurable array. The array could use 20 to 32 system channels and provide image quality comparable to a 128 channel linear array [Hazard et al., 2003 amd Dietz et al., 1979], This paper discusses some of the unique challenges and solutions pertaining to reconfigurable two-dimensional ultrasound arrays. Size constraints of the electronics result in some non-ideal aspects to the switch array; namely, there are constraints on the distribution of system channel access points across the array, and that these switches have a certain on-resistance which introduces non-ideal signal propagation delays. Some solutions will be discussed in this paper which aim to reduce the effect of these non-ideal constraints, and may suggest certain design tradeoffs which can be made in the design of future reconfigurable switch arrays