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外文会议>Ultrasonics Symposium (IUS), 2009
>In situ measurements of attenuation coefficient for evaluating the hardness of cataract lens by a high frequency ultrasonic needle transducer
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In situ measurements of attenuation coefficient for evaluating the hardness of cataract lens by a high frequency ultrasonic needle transducer
A cataract is a clouding of the lens in the eye that affects vision. Phacoemulsification is the mostly common surgical method for treating cataracts, and determining the optimal phacoemulsification energy is dependent on measuring the hardness of the lens. This study explored the use of an ultrasound needle transducer for in situ minimally invasive measurements of ultrasound attenuation coefficient to evaluate the hardness of cataract lens. A 47 MHz high frequency needle transducer with a diameter of 0.9 mm was fabricated by a polarized PMN-33%PT single crystal in the present study. The attenuation coefficients at different stages of artificial porcine cataract lens were measured using the spectral shift approach. The hardness of the cataract lens was also evaluated by mechanical measurement of its elastic properties. The results demonstrated that the ultrasonic attenuation coefficient was increased from 0.048 ÃÂñ 0.02 to 0.520 ÃÂñ 0.06 dB/mm-MHz corresponding to an increase of Young's modulus from 6 to 96 kPa as the cataract further developed. In order to evaluate the feasibility of combining needle transducer and phacoemulsification probe for real time measurement during cataract surgery, the needle transducer was mounted on the phacoemulsification probe for vibration test. The results indicated that there was no apparent damage to the tip of needle transducer and the pulse-echo test showed a good performance in sensitivity was maintained after the vibration test.
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机译：白内障是指眼内晶状体混浊，影响视力。超声乳化术是治疗白内障的最常见手术方法，确定最佳超声乳化能取决于测量晶状体的硬度。这项研究探索了超声针换能器在超声衰减系数的原位微创测量中的应用，以评估白内障晶状体的硬度。在本研究中，由极化的PMN-33％PT单晶制造了直径为0.9 mm的47 MHz高频针式换能器。使用光谱位移法测量了人工猪白内障晶状体在不同阶段的衰减系数。白内障晶状体的硬度也通过对其弹性性能的机械测量来评估。结果表明，超声衰减系数从0.048×0.02增加到0.520×0.06 dB / mm-MHz，对应于杨氏模量从6增加到96 kPa。白内障进一步发展。为了评估在白内障手术期间将针式换能器与超声乳化探头结合进行实时测量的可行性，将针式换能器安装在超声乳化探头上进行振动测试。结果表明，针式换能器的尖端没有明显损坏，并且脉冲回波测试表明，振动测试后，在灵敏度方面保持了良好的性能。
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