  Images typically are represented as uniformly sampled data in the form of
matrix of pixels/voxels. Therefore, matrix multiply-and-accumulate (MAC) forms
the core of most state-of-the-art image analysis algorithms. While digital
implementation of MAC has generally been the preferred approach, high power
consumption is an impediment to adopting it for medical image analysis. In this
work, we present a time-domain signal processing architecture which performs
MAC operations with 7bit accuracy while consuming 400X lower energy than
digital implementation. The proposed architecture performs analog computation
using mostly digital circuits and is suitable for scaled CMOS technologies. The
proposed time-domain MAC architecture is expected to play a central role in
empowering the advancement of various on-chip image analysis operations.
