| 摘要 |
<p>Procedures have long been known involving the introduction or removal of fluids into or from the vascular system or body cavities of a patient. For the introduction of fluids, these have developed to a point of employing a source of fluid (110) for intravenous procedures and connecting such source, via a pump (120), through a needle or catheter (N) in the vascular system. The pump (120) itself has been developed to a point that when connecting catheters (114, 118) are accidentally opened to ambient atmosphere, the pumping operation is terminated thereby to reduce the possibilities of air being introduced into the vascular system. Nevertheless, the use of such a pump (120) is not always effective to prevent accidents of this type. The methods of this invention advantageously utilize a catheter (126) that includes an elongated body portion (N) for insertion into a patient; at least one integral hub portion adjacent to the body portion; and at least one fluid flow control means (128) located in the body or hub portion or adjacent to the hub portion. The fluid flow control means (128) remains competent in response to ambient air pressure but opens in response to a positive fluid pressure above that of ambient air, and may be either integral with or releasably secured to the hub portion.</p> |
