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1.
Artigo em Inglês | MEDLINE | ID: mdl-31567082

RESUMO

Tiled modular 2-D ultrasound arrays have the potential for realizing large apertures for novel diagnostic applications. This work presents an architecture for fabrication of tileable 2-D array modules implemented using 1-3 composites of high-bandwidth (BW) PIN-PMN-PT single-crystal piezoelectric material closely coupled with high-voltage CMOS application-specific integrated circuit (ASIC) electronics for buffering and multiplexing functions. The module, which is designed to be operated as a λ -pitch 1.75-D array, benefits from an improved electromechanical coupling coefficient and increased Curie temperature and is assembled directly on top of the ASIC silicon substrate using an interposer backing. The interposer consists of a novel 3-D printed acrylic frame that is filled with conducting and acoustically absorbing silver epoxy material. The ASIC comprises a high-voltage switching matrix with locally integrated buffering and is interfaced to a Verasonics Vantage 128, using a local field programmable gate array (FPGA) controller. Multiple prototype 5 ×6 element array modules have been fabricated by this process. The combined acoustic array and ASIC module was configured electronically by programming the switches to operate as a 1-D array with elements grouped in elevation for imaging and pulse-echo testing. The resulting array configuration had an average center frequency of 4.55 MHz, azimuthal element pitch of [Formula: see text], and exhibited average -20-dB pulsewidth of 592 ns and average -6-dB fractional BW of 77%.

2.
J Am Acad Dermatol ; 55(2): 245-50, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16844506

RESUMO

BACKGROUND: Monthly skin self-examination (SSE) is associated with reduced incidence of advanced melanoma, but SSE is prone to error in detecting early changes of melanoma. OBJECTIVE: We sought to improve SSE accuracy by requiring participants to complete a mole-mapping diagram. METHODS: After completing a baseline survey, participants received SSE instruction, had their backs digitally photographed, and half were randomized to complete a mole-mapping diagram. Some photographs were altered by adding an image of a 5-mm pigmented lesion. At follow-up, participants were asked to identify any changes introduced to their photographs. RESULTS: A total of 88 participants completed the study. In all, 33% (n = 15) of the control group (no diagram) and 52% (n = 22) of the intervention group (mole-mapping diagram) (P = .06) gave accurate assessments. Analysis of only altered images indicated that the intervention group gave more accurate assessments (60% vs 33%, P = .01). LIMITATIONS: This study was limited by sample size, only addressed lesions on the back, and did not involve actual melanomas in study participants. CONCLUSIONS: Mole-mapping diagrams may improve SSE accuracy, and may be useful as a simple, cost-effective intervention in reducing melanoma mortality.


Assuntos
Melanoma/diagnóstico , Autoexame/normas , Neoplasias Cutâneas/diagnóstico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Educação de Pacientes como Assunto , Fotografação , Sensibilidade e Especificidade
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