A RDMA Interface for Ultra-Fast Ultrasound Data-Streaming over an Optical Link
Andrea Cossettini1, Konstantin Taranov2, Christian Vogt3, Michele Magno3, Torsten Hoefler2 and Luca Benini1,4
1Integrated Systems Laboratory, ETH Zürich, Zürich, Switzerland
2Scalable Parallel Computing Laboratory, ETH Zürich, Zürich, Switzerland
3Center for Project Based Learning, ETH Zürich, Zürich, Switzerland
4DEI, University of Bologna, Bologna, Italy
ABSTRACT
Digital ultrasound (US) probes integrate the analogto- digital conversion directly on the probe and can be conveniently connected to commodity devices. Existing digital probes are however limited to a relatively small number of channels, do not guarantee access to the raw US data, or cannot operate at very high frame rates (e.g., due to exhaustion of computing and storage units on the receiving device). In this work, we present an open, compact, power-efficient, 192-channels digital US data acquisition system capable of streaming US data at transfer rates greater than 80 Gbps towards a host PC for ultra-high frame rate imaging (in the multi-kHz range). Our US probe is equipped with two power-efficient Field Programmable Gate Arrays (FPGAs) and is interfaced to the host PC with two opticallink 100G Ethernet connections. The high-speed performance is enabled by implementing a Remote Direct Memory Access (RDMA) communication protocol between the probe and the controlling PC, that utilizes a high-performance Non-Volatile Memory Express (NVMe) interface to store the streamed data. To the best of our knowledge, thanks to the achieved datarates, this is the first high-channel-count compact digital US platform capable of raw data streaming at frame rates of 20 kHz (for imaging at 3.5 cm depths), without the need for sparse sampling, consuming less than 40 W.
Keywords: Ultrafast, Ultrasound, FPGA, RDMA, NVMe.
