| 摘要 |
In one aspect, a dual action syringe includes an external body having a distal end defining an anesthetic gel receptive concavity surrounding a needle passage through the distal end. The external body also includes a proximal end defining a plunger receptive passage. An internal body is slidably disposed in the external body. The internal body receives a needle in a distal end of the internal body and an anesthetic carpule to provide fluid flow communication between the carpule and the needle in response to pressure on the plunger. A biasing member is disposed in the external body, between the external body and the internal body, biasing a distal end of the needle away from the distal end of the external body into the external body; whereby, pressure on the plunger first moves the needle through the needle passage and subsequently provides fluid flow communication between the carpule and the needle.
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