{"id":5432,"date":"2012-07-18T22:28:42","date_gmt":"2012-07-18T22:28:42","guid":{"rendered":"https:\/\/mtlsites.mit.edu\/annual_reports\/2012\/?p=5432"},"modified":"2012-07-18T22:28:42","modified_gmt":"2012-07-18T22:28:42","slug":"a-scalable-beamforming-architecture-for-portablewearable-ultrasound-imaging","status":"publish","type":"post","link":"https:\/\/mtlsites.mit.edu\/annual_reports\/2012\/a-scalable-beamforming-architecture-for-portablewearable-ultrasound-imaging\/","title":{"rendered":"A Scalable Beamforming Architecture for Portable\/Wearable Ultrasound Imaging"},"content":{"rendered":"

An ultrasound image is formed from a collection of ultrasonic beams transmitted and received by an array of transducer elements.\u00a0 As the resolution of an image and the range over which an image is to be formed increase, so do the number of these transducer elements and the corresponding digital processing units.\u00a0 The intensive signal processing power required for ultrasound imaging [1<\/a>] <\/sup>means that conventional ultrasound systems are often large and expensive, and this demand for processing power can only worsen as more transducers and signal channels are implemented.\u00a0 In applications such as point-of-care diagnostics in rural areas, the movement to a portable and low-power ultrasound imaging system is warranted.<\/p>\n

Beamforming, which in its simplest form involves delaying, scaling, and summing to produce a coherent signal from the collection of received beams, has been identified as an area for algorithmic research and development [2<\/a>] <\/sup>.\u00a0\u00a0In this work, an 8-channel wide, scalable digital beamformer is implemented with feedback for power reduction.\u00a0 Two modes of operation are available: coarse and fine beamforming.\u00a0 In the coarse beamforming mode, digitized data from an evenly spaced subset of transducer elements are processed, providing a low-quality image of the full region of interest, which yields power savings by turning off the analog front end electronics and analog-to-digital converters corresponding to the unused 50% or 75% of array channels (schematically shown in Figure 1).\u00a0 Figures 2a and b show the coarse images for quarter and half resolution coarse beamforming modes.\u00a0 Next, the user can specify a smaller region in which a higher quality image is desired, which is then beamformed by the same 8-channel wide processing unit using all available channels (an example of the full region full resolution image is shown in Figure 2c).<\/p>\n\n\t\t