2D array based on fermat spiral

Martínez-Graullera, Óscar; Martín, Carlos Javier Blanco; Godoy, Gregorio; Ullate, L.G.

doi:10.1016/j.phpro.2010.01.052

Cited by 2 publications

(2 citation statements)

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“…Much of the work on ultrasound 2D array design has come from the volumetric imaging community, where large-aperture 2D arrays are needed for quality image resolution at depth. To achieve 1° or better angular resolution, a 60λ aperture is needed, but to avoid large grating lobes element spacing must be less than λ/2, necessitating a prohibitively large number (~10 4 ) of elements to fill the aperture (Martínez et al 2010). Subsequent research into sparse 2D array configurations that minimize grating lobes has led to a variety of fruitful results, such as Vernier arrays that use two different sets of elements for transmit and receive that are spatially periodic and offset, Fermat spirals, and randomized arrays (Lockwood et al 1996;Martínez et al 2010).…”

Section: Introductionmentioning

confidence: 99%

“…To achieve 1˚ or better angular resolution, a 60λ aperture is needed, but to avoid large grating lobes element spacing must be less than λ/2, necessitating a prohibitively large number (~10 4 ) of elements to fill the aperture (Martínez et al 2010). Subsequent research into sparse 2D array configurations that minimize grating lobes has led to a variety of fruitful results, such as Vernier arrays that use two different sets of elements for transmit and receive that are spatially periodic and offset, Fermat spirals, and randomized arrays (Lockwood et al 1996;Martínez et al 2010). These studies focus on factors affecting image quality such as side lobe and grating lobe levels, and azimuthal beam symmetry.…”

Section: Introductionmentioning

confidence: 99%

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A random phased-array for MR-guided transcranial ultrasound neuromodulation in non-human primates

2018

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Transcranial focused ultrasound (FUS) is a non-invasive technique for therapy and study of brain neural activation. Here we report on the design and characterization of a new MR-guided FUS transducer for neuromodulation in non-human primates at 650 kHz. The array is randomized with 128 elements 6.6 mm in diameter, radius of curvature 7.2 cm, opening diameter 10.3 cm (focal ratio 0.7), and 46% coverage. Simulations were used to optimize transducer geometry with respect to focus size, grating lobes, and directivity. Focus size and grating lobes during electronic steering were quantified using hydrophone measurements in water and a three-axis stage. A novel combination of optical tracking and acoustic mapping enabled measurement of the 3D pressure distribution in the cortical region of an ex vivo skull to within ~3.5 mm of the surface, and allowed accurate modelling of the experiment via non-homogeneous 3D acoustic simulations. The data demonstrates acoustic focusing beyond the skull bone, with the focus slightly broadened and shifted proximal to the skull. The fabricated design is capable of targeting regions within the S1 sensorimotor cortex of macaques.

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Section: Introductionmentioning

confidence: 99%