[1] [1] Chen Xiaodong, Li Ming, Yu Feng, et al.. Technology of digital endoscopic ultrasonic imaging [J]. Chinese J Lasers, 2009, 36(10): 2557-2560.

[2] [2] A C Sobusiak, A Sowier, P Skrzywanek. Application of combined methods of imaging in minimally invasive surgery [C]. 25th Annual International Conference of IEEE-EMBS, 2003, 2: 1043-1046.

[3] [3] A C Sobusiak, A Sowier, P Skrzywanek. Utilization of miniprobes in modern endoscopic ultrasonography [J]. IEEE Sensors Journal, 2006, 6(5): 1323-1330.

[4] [4] Yu Daoyin, Li Ming, Li Yan, et al.. Research on synthetic aperture technique for endoscopic ultrasound imaging [J]. Chinese J Lasers, 2010, 37(11): 2693-2697.

[5] [5] Wang Lutao. Research on Beam Steering Techniques for Phased Medical Ultrasound Imaging [D]. Chengdu: University of Electronic Science and Technology of China, 2012. 2-3.

[6] [6] M Karaman, P-C Li, M O′Donnell. Synthetic aperture imaging for small scale systems [J]. IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control, 1995, 42(3): 429-442.

[7] [7] J Kortbek, J A Jensen, K L Gammelmark. Sequential beamforming synthetic aperture imaging [J]. Ultrasonics, 2013, 53(1): 1-16.

[8] [8] M Bae, M Jeong. A study of synthetic-aperture imaging with virtual source elements in B-mode ultrasound imaging systems [J]. IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control, 2000, 47(6): 1510-1519.

[9] [9] Zhang Chuang, Chen Xiaodong, Wang Yi, et al.. A fast synthetic aperture technology for ultrasound imaging [J]. Chinese J Lasers, 2013, 40(s1): s104003.

[10] [10] J A Jensen, N B Svendsen. Calculation of pressure fields from arbitrarily shaped, apodized, and excited ultrasound transducers [J]. IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control, 1992, 39(2): 262-267.

[11] [11] J A Jensen. FIELD: A program for simulating ultrasound systems [C]. 10th Nordic-Baltic Conference on Biomedical Imaging, 1996, 4(s1): 351-353.