| 摘要 |
Figure 2 shows an ultra-sonic probe having a ultra-sonic waveguide(10) coupled to a mechanical connection(12) and a probe head(2). This probe is contained in a sealed thin walled catheter(36). The catheter is used to separate the probe from the arterial wall and to protect it against the intense resonant vibrations of the probe and also to permit other inputs(37). The tubular waveguide(10) is a tube made from thin wall inoxyable steel. The external diameter of the guide is less than 4mm. The thickness of the wall from one to several dozen mm. Its length is dimensioned so that it is compatible both with the resonant frequency of the formed probe and with the useful length of the probe. The probe head(2) is coupled to the tubular waveguide(1) and has is a cylinder of length 3 to 5mm. Its exterior diameter is less than 5mm. It contains an axial hole(6) whose interior diameter must permit its fitting to the waveguide. The fitting can be by clamping, brazing, welding or gluing. The axial hole(6) is also the orifice through which passes the metallic guide(35) and the radio-active opaqueness forming liquid. The mechanical connection permits coupling various sorts of probes
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