| 摘要 |
A method of relieving vacuum of in a biopsy apparatus that comprises an outer cannula defining a first inner lumen therethrough and a tissue-receiving opening in communication with the first inner lumen; an inner cannula slidably disposed in the first inner lumen of the outer cannula, wherein the inner cannula defines a second inner lumen therethrough, at least one motor for moving the inner cannula relative to the outer cannula, and a vacuum source in fluid communication with the second inner lumen of the inner cannula, is disclosed. The method comprises applying vacuum from the vacuum source to the second inner lumen of the inner cannula; providing a leak path that permits fluid communication between the first inner lumen of the outer cannula and the atmosphere at a proximal end of the outer cannula; retracting the inner cannula away from a distal end of the outer cannula so as to permit tissue to prolapse into the tissue receiving opening due to the vacuum created through the second inner lumen of the inner cannula; translating the inner cannula toward the distal end of the outer cannula to sever the tissue that has prolapsed into the tissue receiving opening; aspirating the severed tissue through the second inner lumen of the inner cannula; and selectively relieving vacuum distally of the severed and aspirating tissue. The vacuum relief is achieved by retracting the inner cannula away from the distal end of said outer cannula thereby permitting the second inner lumen to communicate with the first inner lumen and the leak path while a portion of the biopsy apparatus, including the tissue receiving opening, is positioned within tissue.
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