Aspiration syringe
First Claim
1. An aspiration syringe suitable for one-handed operation, comprising;
- a barrel defining a bore,a plunger comprising a small cross-section plunger shaft extending into the bore, and a first seal member within the bore, carried by the distal end of the shaft for axial movement within the bore, andmeans for generating a syringe-actuating vacuum condition, comprising;
said first seal member, a stationary end closure across the bore, proximal of the first seal member, the plunger shaft extending in sliding, sealed engagement therethrough, the first seal member sized and constructed, relative to the wall defining the bore, to engage said wall in vacuum-tight sealing engagement, and the transverse cross-sectional area of the shaft being much less than the transverse cross-sectional area of the bore to provide a syringe-actuating vacuum chamber of substantial volume within the bore between said seal and said closure,whereby movement of the plunger shaft to carry the first seal member distally, from a first position, away from the end closure, creates a vacuum condition within said vacuum chamber sufficient that when the plunger shaft is released, the first seal member is propelled by pressure differential acting across said first seal member, while the distal end of the syringe is exposed to fluid, to automatically move the plunger proximally toward the end closure and cause entry of fluid into the portion of the bore distal of said first seal.
5 Assignments
0 Petitions
Accused Products
Abstract
An aspiration syringe suitable for one-handed operation has a barrel defining a bore, a plunger consisting of a small cross-section plunger shaft extending into the bore and a first seal within the bore, carried by the distal end of the shaft for axial movement within the bore, and an end closure across the bore proximal of the first seal, the plunger shaft extending in sliding, sealed engagement therethrough. The first seal engages the wall defining the bore in vacuum-tight sealing engagement. The transverse cross-sectional area of the shaft is much less than the transverse cross-sectional area of the bore to provide a syringe-actuating vacuum chamber of substantial volume within the bore between the seal and the end closure. Movement of the plunger shaft to carry the first seal distally, from a first position, away from the end closure, creates a vacuum condition within the vacuum chamber sufficient that when the plunger shaft is released, the first seal is propelled by pressure differential acting across the first seal, while the distal end of the syringe is exposed to fluid, to automatically move the plunger proximally toward the end closure and cause entry of fluid into the distal portion of the bore distal of the first seal. A method of drawing fluid samples is also described.
79 Citations
13 Claims
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1. An aspiration syringe suitable for one-handed operation, comprising;
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a barrel defining a bore, a plunger comprising a small cross-section plunger shaft extending into the bore, and a first seal member within the bore, carried by the distal end of the shaft for axial movement within the bore, and means for generating a syringe-actuating vacuum condition, comprising;
said first seal member, a stationary end closure across the bore, proximal of the first seal member, the plunger shaft extending in sliding, sealed engagement therethrough, the first seal member sized and constructed, relative to the wall defining the bore, to engage said wall in vacuum-tight sealing engagement, and the transverse cross-sectional area of the shaft being much less than the transverse cross-sectional area of the bore to provide a syringe-actuating vacuum chamber of substantial volume within the bore between said seal and said closure,whereby movement of the plunger shaft to carry the first seal member distally, from a first position, away from the end closure, creates a vacuum condition within said vacuum chamber sufficient that when the plunger shaft is released, the first seal member is propelled by pressure differential acting across said first seal member, while the distal end of the syringe is exposed to fluid, to automatically move the plunger proximally toward the end closure and cause entry of fluid into the portion of the bore distal of said first seal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A method for obtaining a fluid sample from a body by aspiration, said method comprising the steps of:
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providing an aspiration syringe comprising a barrel defining a bore, a plunger comprising a small cross-section plunger shaft extending into the bore, and a first seal member within the bore, carried by the distal end of shaft for axial movement within the bore, an end closure across the bore proximal of the first seal member, the plunger shaft extending in sliding, sealed engagement therethrough, the first seal member sized and constructed, relative to the wall defining the bore, to engage said wall in vacuum-tight sealing engagement, and the transverse cross-sectional area of the shaft being much less than the transverse cross-sectional area of the bore to provide a syringe-actuating vacuum chamber of substantial volume within the bore between said seal and said closure, with the distal end of the syringe free to release air, pressing the plunger to move the first seal member away from the end closure to create a vacuum condition within said vacuum chamber, exposing the distal end of the syringe to fluid, and releasing the plunger, the vacuum condition within said vacuum chamber being sufficient when said plunger is released to cause said plunger to automatically move proximally while drawing fluid into the bore distal of said first seal member. - View Dependent Claims (13)
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Specification