Vessel cannulation device and method of use

Abstract

Devices and methods are provided for automatic vascular access. An automatic vessel cannulation device, mechanical or electronic, has a sensor configured to detect a physiologic parameter of a needle tip, and a blunting device advancing member released in response to the sensor. The sensor may measure pressure or any other physiological parameter. A processor is configured to analyze data sent by the sensor and is pre-set to identify parameters unique to arteries, veins, or other body cavities or organs. A method may include comparing a physiologic parameter with pre-determined parameters to deploy a blunting element if the physiologic parameter is within a range of the pre-determined parameters. An expandable sheath may be included. A device can be provided having a motor controlling the cannulation device orientation to scan tissue with the tip of the needle by moving the cannulation device through the ultrasound transducer.

1 - 41 . (canceled) 
     
     
         42 . An expandable sheath system comprising:
 an expandable outer layer sheath comprising longitudinal beams and a step, and   an inner rigid layer comprises a bulb and a shoulder which engages with a step of the outer layer sheath.   
     
     
         43 . The expandable sheath system of  claim 42 , wherein the inner rigid layer sheath is configured to fit over a needle shaft; and wherein after removal of the needle, the bulb is collapsed and the inner rigid layer sheath is removed from the outer layer sheath, while leaving the outer layer sheath in its position within a vessel. 
     
     
         44 . The expandable sheath system of  claim 42 , wherein the inner rigid layer is an integral part of a needle. 
     
     
         45 . An expandable sheath configured to be inserted into a patient's body over a needle, comprising rigid longitudinal beams and an expandable elastic layer, wherein the longitudinal beams are bridged by connections creating a spiral pattern along and around the sheath. 
     
     
         46 . The expandable sheath of  claim 45 , further comprising an external sheath slideably positioned over the expandable sheath. 
     
     
         47 . The expandable sheath of  claim 46 , wherein the external sheath comprises a handle and a support element connecting to the expandable sheath, wherein the external sheath is tearable. 
     
     
         48 . The expandable sheath of  claim 46 , further comprising a rigid large diameter sheath that is configured to be inserted into the expandable sheath, to maintain and expand the expandable sheath. 
     
     
         49 . An expandable sheath configured to be inserted into a patient's body over a needle, comprising: a sheath having a single substantially inelastic layer and an inner diameter, and wherein in a crimped state, a sheath inner diameter is in a tight fit with a needle, and wherein in an expanded state, the sheath inner diameter is at least double the sheath inner diameter in the crimped state. 
     
     
         50 . The expandable sheath of  claim 49 , wherein the inelastic layer has multiple micro-corrugations. 
     
     
         51 . The expandable sheath of  claim 49 , wherein the inelastic layer has between 2 and 6 large corrugations folded around the sheath. 
     
     
         52 . The expandable sheath of  claim 49 , further comprising a hub configured to overlap with a needle hub. 
     
     
         53 . The expandable sheath of  claim 49 , wherein the expandable sheath has one corrugation, and wherein this corrugation is folded around the sheath at least once. 
     
     
         54 . The expandable sheath of  claim 53 , wherein a distal end of the inelastic layer comprises a part that is perpendicular to a longitudinal axis of the sheath, and a part that is at an angle relative to the longitudinal axis of the sheath, configured to create a smooth distal taper for the sheath in its crimped state. 
     
     
         55 . The expandable sheath of  claim 53 , further comprising a hub configured to overlap with a needle hub. 
     
     
         56 - 76 . (canceled)