Retractable Centesis Needle
First Claim
1. A retractable centesis needle comprising:
- a housing having a cavity;
a hollow outer cannula extending distally from the housing, said outer cannula being open at both ends and defining a channel therethrough;
an inner cannula slidably disposed within the channel, wherein said inner cannula is adapted to slide between a fully extended state and a fully retracted state;
a first biasing member disposed in the housing cavity, said first biasing member associated with the inner cannula and biasing the inner cannula distally;
a second biasing member disposed in the housing cavity, said second biasing member variably associated with the inner cannula wherein the second biasing member distally biases the inner cannula when in the fully retracted state, and wherein the second biasing member does not bias the inner cannula when in the fully extended state.
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Accused Products
Abstract
A retractable centesis needle comprises a hollow, sharp tipped outer cannula extending from a housing. The outer cannula is generally tube-like and open at both ends to form a channel into a cavity in the housing. A blunt tipped inner cannula is disposed within the channel and capable of sliding away from the housing to an extended state and toward the housing to a refracted state. The inner cannula is biased toward the extended state by a first spring disposed in the housing. A second spring also disposed in the housing acts in the same direction as the first spring when the inner cannula is in a fully retracted state. However, the second spring does not bias the inner cannula in any direction when the inner cannula is in a fully extended state.
12 Citations
20 Claims
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1. A retractable centesis needle comprising:
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a housing having a cavity; a hollow outer cannula extending distally from the housing, said outer cannula being open at both ends and defining a channel therethrough; an inner cannula slidably disposed within the channel, wherein said inner cannula is adapted to slide between a fully extended state and a fully retracted state; a first biasing member disposed in the housing cavity, said first biasing member associated with the inner cannula and biasing the inner cannula distally; a second biasing member disposed in the housing cavity, said second biasing member variably associated with the inner cannula wherein the second biasing member distally biases the inner cannula when in the fully retracted state, and wherein the second biasing member does not bias the inner cannula when in the fully extended state. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
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19. A retractable centesis needle comprising:
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a housing having a cavity; an indicator disposed in one end of the cavity; a hollow outer cannula extending from the housing, said outer cannula being open at both ends and defining a channel therethrough; an inner cannula slidably disposed within the channel, said inner cannula having a hub adapted to cover the indicator; a first biasing member disposed in the housing cavity, said first biasing member associated with the hub and having a force to bias the hub in a direction toward the indicator; a second biasing member disposed in the housing cavity, said second biasing member having a force in the same direction as the first biasing member and adapted to act on the inner cannula when the indicator is not covered by the hub.
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20. A drainage system for centesis procedures comprising:
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a catheter having a distal end and a proximal end; a stopcock coupled to the proximal end of the catheter; a check valve coupled to the stopcock; and a retractable centesis needle comprising;
a housing having a cavity;
a hollow outer cannula extending distally from the housing, said outer cannula being open at both ends and defining a channel therethrough;
an inner cannula slidably disposed within the channel, wherein said inner cannula is adapted to slide between a fully extended state and a fully retracted state;
a first biasing member disposed in the housing cavity, said first biasing member associated with the inner cannula and biasing the inner cannula distally;
a second biasing member disposed in the housing cavity, said second biasing member variably associated with the inner cannula wherein the second biasing member distally biases the inner cannula when in the fully retracted state, and wherein the second biasing member does not bias the inner cannula when in the fully extended state, said retractable centesis needle adapted to be inserted through the check valve, the stopcock, and the catheter.
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Specification