Multiple frequencies from single crystal
Patent 4872346 Issued on October 10, 1989. Estimated Expiration Date: 
June 30, 2008. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
June 30, 2008. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 2769158 3233450 3309914 3898840 3924454 Selectable delay system Patent #: 4257271 InventorsAssigneeApplicationNo. 214847 filed on 06/30/1988US Classes:73/627By reflected waveExaminersPrimary: Levy, Stuart S.Assistant: Arana, Louis Attorney, Agent or FirmInternational ClassG01N 029/00AbstractA method and an apparatus for ultrasound imaging at different frequencies using a single ultrasound transducer. The transducer has a single characteristic frequency. The method and apparatus involve driving the transducer with pulses having different rise times through different coupling circuits having different impedance characteristics. Between pulses, the same transducer and coupling circuit which were used during the pulse transmission "listen" for echoes from the structure being ultrasonically investigated. It is believed that the combination of different pulses having different rise times and different coupling circuits having different characteristics enhances different ones of the frequencies contained in the Fourier spectrum of the driving pulse and suppresses others. This enables the operator to investigate a structure ultrasonically with a single transducer at different frequencies which illuminate different characteristics of the structure to greatest advantage. | |
