| 摘要 |
<p>An elongate tubular body (12) extends between a rotatable cutter (22), and a control (18). The cutter (22) is connected to the control (18) with a rotation element (24). A vacuum (86) is applied through an annular passage defined between the tubular body (12), and the rotatable element (24). The control (18) has an indicator that reveals resistance to rotation, and/or reduction in flow.</p> |
