Patent Description:
Medical treatments often include the infusion of a medical fluid (e.g., a saline solution or a liquid medication) to patients using an intravenous (IV) catheter that is connected though an arrangement of flexible tubing and fittings, commonly referred to as an "IV set," to a source of fluid, for example, a syringe. Certain configurations of IV sets may have extended lengths of tubing, for example, in excess of <NUM> feet. Additionally, tubing may be primed with saline prior to the infusion of a liquid medication.

Document <CIT> discloses a device for a medical device. The medical device comprises a body and a container containing medicament and comprising an expelling passage. The medical device further comprises delivery drive means for expelling said medicament and mechanical priming drive means and mechanical priming activation means which are arranged and designed such that said mechanical priming activation means is capable of permitting activation of said mechanical priming drive means only when the medical device is substantially vertical with the expelling passage into an specific direction.

Document <CIT> discloses an automatic accurate dose syringe that includes a barrel, a plunger seal, a barrel adapter assembly having a barrel tip and a needle. A dose control mechanism has a plunger having a coarse pitch screw on its exterior surface. A housing has a corresponding coarse pitch guide along the interior surface of the housing, and a screw has a fine pitch screw which interfaces with a fine pitch nut of an adapter. The plunger has an internal annular space within which screw at least partially resides.

Document <CIT> discloses an assembly for a drug delivery device. The assembly comprises a housing body having a longitudinal axis and a drive assembly having a drive member. The drive member is configured to be axially displaced with respect to the housing body during operation of the drive assembly for setting and/or dispensing a dose of the drug.

In some applications, during the use of IV catheters, saline from the priming process may be delivered to patient before the liquid medication is delivered to the patient.

The disclosed subject matter relates to a syringe. In certain embodiments, a syringe is disclosed that comprises a syringe body defining a syringe cavity, a syringe port, and an indicator window, wherein the syringe port is in fluid communication with the syringe cavity; a first plunger comprising a first plunger shaft extending from the first plunger, the first plunger disposed within the syringe cavity and defining a first chamber in the syringe cavity, wherein the first chamber is in fluid communication with the syringe port; a biasing member coupled to the first plunger shaft, wherein the biasing member urges the first plunger from an unprimed position to a primed position toward the syringe port; and a priming indicator comprising a first indicator portion and a second indicator portion, the priming indicator coupled to the first plunger shaft, wherein the priming indicator presents the first indicator portion through the indicator window in the unprimed position and presents the second indicator portion through the indicator window in the primed position.

In certain embodiments, a medication delivery system is disclosed that comprises a syringe, comprising: a syringe body defining a syringe cavity, a syringe port, and an indicator window, wherein the syringe port is in fluid communication with the syringe cavity; a first plunger comprising a first plunger shaft extending from the first plunger, the first plunger disposed within the syringe cavity and defining a first chamber in the syringe cavity, wherein the first chamber is in fluid communication with the syringe port; a biasing member coupled to the first plunger shaft, wherein the biasing member urges the first plunger from an unprimed position to a primed position toward the syringe port; and a priming indicator comprising a first indicator portion and a second indicator portion, the priming indicator coupled to the first plunger shaft, wherein the priming indicator presents the first indicator portion through the indicator window in the unprimed position and presents the second indicator portion through the indicator window in the primed position; and a tubing in fluid communication with the syringe port and a catheter.

In certain embodiments, a method to deliver medication is disclosed that comprises advancing a plunger disposed within a syringe via a biasing member, wherein the plunger defines a chamber within the syringe; directing medication from the chamber into a tubing, wherein the tubing extends from the syringe to a catheter and defining a tubing volume; and presenting a first indicator portion of a priming indicator through an indicator window formed in the syringe.

The disclosed syringe incorporates a priming indicator to signal when a medication delivery system is primed with medical fluids. The priming indicator can be coupled to the priming mechanism. By indicating the priming status via the priming indicator, a clinician can be informed when priming is complete.

The detailed description set forth below is intended as a description of various configurations of the subject technology and is not intended to represent the only configurations in which the subject technology may be practiced. Like components are labeled with identical element numbers for ease of understanding. Reference numbers may have letter suffixes appended to indicate separate instances of a common element while being referred to generically by the same number without a suffix letter.

While the following description is directed to the administration of medical fluid using the disclosed syringe, it is to be understood that this description is only an example of usage and does not limit the scope of the claims. Various aspects of the disclosed syringe may be used in any application where it is desirable to indicate the status of a syringe.

The disclosed syringe overcomes several challenges discovered with respect to certain conventional syringes. One challenge with certain conventional syringes is that syringes may deliver excess medical fluid, such as saline, to patients. Further, conventional syringes may not indicate if priming is in process. Because excess medical fluid may delay the delivery of medical fluids, alter dosage of medication, and may not be tolerated by fluid restricted patients, such as premature babies the use conventional syringes is undesirable.

Therefore, in accordance with the present disclosure, it is advantageous to provide a syringe as described herein that simplifies the administration of medical fluids during priming and eliminates or substantially reduces delivering excess medical fluid to a patient. The disclosed syringe provides a priming indicator that provides a status to a clinician while minimizing excess fluid delivered to a patient.

An example of a syringe that indicates priming status and prevents delivery of excess medical fluid is now described.

<FIG> is a perspective view of a medication delivery system <NUM>, in accordance with various aspects of the present disclosure. In the illustrated example, the medication delivery system <NUM> delivers medication from the syringe <NUM> to the patient via a catheter <NUM> without delivering excess fluid, such as saline, used to prime the medication delivery system <NUM>.

In some embodiments, a medication flow path within a dual lumen tubing <NUM> can be primed with saline to remove any air or trapped gasses within the medication flow path of the dual lumen tubing <NUM>. Saline can be advanced from a proximal end <NUM> of the syringe <NUM>, through the medication flow path of the dual lumen tubing <NUM> and to the valve <NUM>.

The saline from the medication flow path of the dual lumen tubing <NUM> can be received by the medication flow path <NUM> of the valve <NUM>. In a priming configuration, a valve element <NUM> can prevent saline from the medication flow path <NUM> from entering the patient catheter <NUM> and can instead direct the saline toward the return flow path <NUM> of the valve <NUM> to allow primed saline to be returned to the syringe <NUM> via the return flow path of the dual lumen tubing <NUM>.

<FIG> is a perspective view of the medication delivery system <NUM> of <FIG> with the priming trigger <NUM> removed, in accordance with various aspects of the present disclosure. In the illustrated example, the syringe <NUM> advances medication within the medication flow path of the dual lumen tubing <NUM> to prime the medication flow path of the dual lumen tubing <NUM>. Advantageously, by priming the medication flow path with medication, the medication can be delivered to the patient via the catheter <NUM> proximal to the patient with less delay and without delivering the saline used to prime the medication flow path of the dual lumen tubing <NUM>.

To introduce medication into the medication flow path of the dual lumen tubing <NUM>, the medication plunger within the syringe <NUM> can be advanced or otherwise displaced to introduce a volume of medication into the medication flow path of the dual lumen tubing <NUM>. Optionally, the medication plunger of the syringe <NUM> can be configured to be advanced or displaced a desired amount to dispense a volume of medication into the medication flow path of the dual lumen tubing <NUM> that is equivalent to the volume of the medication flow path of the dual lumen tubing <NUM>. In other words, medication plunger of the syringe <NUM> can be advanced to fill the volume of the medication flow path of the dual lumen tubing <NUM> up to the valve element <NUM> to prime the medication for administration via the catheter <NUM>.

In some embodiments, the priming of medication into the medication flow path of the dual lumen tubing <NUM> can be automated or otherwise simplified. For example, the medication plunger can be biased to be advanced to introduce medication into the medication flow path of the dual lumen tubing <NUM>. The biasing member of the priming mechanism within the syringe <NUM> can be released by removing the priming trigger <NUM>. By removing the priming trigger <NUM>, the biasing member can advance the medication plunger to prime the medication within the medication delivery system <NUM>. Optionally, the priming travel of the medication plunger can be stopped or limited by a priming stop <NUM>. By limiting the travel of the medication plunger during priming, a desired volume of medication can be introduced into the medication flow path of the dual lumen tubing <NUM>, for example, sufficient medication volume to fill the medication flow path of the dual lumen tubing <NUM>.

As illustrated, as the medication is introduced into the medication flow path of the dual lumen tubing <NUM>, the saline previously primed through the dual lumen tubing <NUM> is displaced. The displaced saline is directed by the valve element <NUM> through the return flow path <NUM> of the valve <NUM> and into the return flow path of the dual lumen tubing <NUM>.

Medical fluid from the return flow path of the dual lumen tubing <NUM> can be returned into the syringe <NUM>. Returned medical fluid such as saline can be introduced into a return or saline chamber of the syringe <NUM>.

<FIG> is a perspective view of the medication delivery system <NUM> of <FIG> with the syringe <NUM> actuated, in accordance with various aspects of the present disclosure. In the illustrated example, the syringe <NUM> is actuated to dispense medication to the patient through the catheter <NUM>.

As illustrated, the distal end <NUM> of the syringe <NUM> can be advanced toward the proximal end <NUM> of the syringe <NUM> to actuate the medication plunger within the syringe <NUM>. By actuating the syringe <NUM>, the medication plunger can be advanced to deliver medication from the syringe <NUM> into the medication flow path of the dual lumen tubing <NUM>. In some embodiments, the syringe <NUM> can be actuated by a syringe pump to control the flow of medication to the patient.

During operation, the valve <NUM> is actuated to permit the flow of medication from the medication flow path <NUM> of the valve <NUM> to the patient via the catheter <NUM>. In some embodiments, the valve element <NUM> is actuated to permit fluid communication between the medication flow path <NUM> and the catheter <NUM> to allow medication to flow to the patient. Optionally, the valve <NUM> can be located proximal to the patient to minimize the length of the catheter <NUM>, reduce the amount of saline administered to the patient, and reduce the delivery time for the medication.

<FIG> is a perspective view of the medication delivery system <NUM> of <FIG> with the syringe <NUM> actuated, in accordance with various aspects of the present disclosure. In the illustrated example, the syringe <NUM> advances saline through the medication flow path of the dual lumen tubing <NUM> to advance the remaining medication to the patient via the catheter <NUM>.

As illustrated, after the medication is expelled from the syringe <NUM>, medication may remain in the volume of the medication flow path of the dual lumen tubing <NUM>. To ensure that the medication is fully delivered to the patient, the syringe <NUM> can be utilized to administer a saline "push" to continue to advance the medication through the medication flow path of the dual lumen tubing <NUM> after the medication within the syringe <NUM> is exhausted. Optionally, saline can be administered through the medication flow path until the medication is fully administered to the patient.

<FIG> is an elevation view of a syringe <NUM> with the syringe body hidden, in accordance with various aspects of the present disclosure. In the figures, similar features may be referred to with similar reference numerals. In the depicted example, the syringe <NUM> can be utilized to dispense medication and/or saline through a tubing coupled to the syringe port <NUM> of the syringe <NUM>. As illustrated, the syringe <NUM> can receive, store, and/or dispense medication and/or saline in chambers defined therein.

As illustrated, the proximal syringe portion <NUM> of the syringe <NUM> can store medical fluids such as medication and saline in a syringe cavity <NUM>. In the illustrated embodiment, the medication plunger <NUM> is movable within the syringe cavity <NUM> to define a medication chamber <NUM> within the proximal syringe portion <NUM>. Optionally, the volume of the medication chamber <NUM> is defined by the position of the medication plunger <NUM> relative to the proximal end <NUM> of the syringe <NUM>. In the depicted example, the medication chamber <NUM> can store medication.

In some embodiments, the medication chamber <NUM> is in fluid communication with the syringe port <NUM> of the syringe <NUM>. Optionally, the medication plunger <NUM> can include one or more seals <NUM> to seal against the walls of the syringe cavity <NUM> to prevent unintended fluid migration or mixing.

Further, the medication plunger <NUM> can be moved by the medication plunger shaft <NUM>. In some embodiments, the medication plunger <NUM> can be drawn distally to expand the medication chamber <NUM> and draw in more medication or medical fluid through the syringe port <NUM>. In some embodiments, the medication plunger <NUM> can be advanced proximally to contract the medication chamber <NUM> and expel medication or medical fluid from the medication chamber <NUM> through the syringe port <NUM>.

In the illustrated embodiment, the saline plunger <NUM> is movable within the syringe cavity <NUM> to define a saline chamber <NUM> within the proximal syringe portion <NUM>. In some embodiments, the saline plunger <NUM> and the medication plunger <NUM> cooperatively define the saline chamber <NUM> within the syringe cavity <NUM>. Optionally, the volume of the saline chamber <NUM> is defined by the position of the medication plunger <NUM> and the saline plunger <NUM>. In the depicted example, the saline chamber <NUM> can store saline or other medical fluids.

Optionally, the saline plunger <NUM> can include one or more seals <NUM> to seal against the walls of the syringe cavity <NUM> to prevent unintended fluid migration or mixing.

Further, the saline plunger <NUM> can be moved by the saline plunger shaft <NUM>. In some embodiments, the saline plunger <NUM> can be drawn distally to expand the saline chamber <NUM> and draw in more saline or medical fluid. In some embodiments, the saline plunger <NUM> can be advanced proximally to contract the saline chamber <NUM> and expel saline or medical fluid from the saline chamber <NUM>.

As previously described, during the administration of medication to patients, for example, fluid restricted patients, medication can be dispensed from the medication chamber <NUM> and then saline can be dispensed from the saline chamber <NUM> to advance the medication remaining in the tubing.

In the depicted example, medication can be dispensed from the syringe <NUM> by advancing the medication plunger <NUM> within the syringe cavity <NUM>. As a result, medication can be delivered from the syringe <NUM> through the syringe port <NUM>.

In some embodiments, the syringe <NUM> can include a priming mechanism or actuation mechanism <NUM> to automate, control, or otherwise simplify advancement of the medication plunger <NUM> to facilitate the priming of medication into an IV tubing. Optionally, the actuation mechanism <NUM> can be configured to introduce a sufficient volume of medication from the medication chamber <NUM> into the IV tubing to fully fill or prime the IV line prior to administration of the medication to the patient.

In the illustrated embodiment, the actuation mechanism <NUM> can utilize a biasing member such as a tension spring <NUM> to advance the medication plunger <NUM> within the syringe cavity <NUM>.

Optionally, the tension spring <NUM> can be coupled to the proximal syringe portion <NUM> at the proximal end <NUM> of the tension spring <NUM> and coupled to the actuation mechanism <NUM> at the distal end <NUM> of the tension spring <NUM>. In some embodiments, the actuation mechanism <NUM> extends from, or is generally coupled to the medication plunger shaft <NUM>. Further, the tension spring <NUM> can be disposed around the medication plunger shaft <NUM>.

As illustrated, the tension spring <NUM> can be preloaded or biased to facilitate advancement of the medication plunger <NUM> upon release or activation of the tension spring <NUM>. In the depicted example, the tension spring <NUM> can be extended or biased from a resting length to an elongated tensioned length. In some embodiments, a biasing member can be compressed from a resting length to a shortened compressed length.

As illustrated, the tension spring <NUM> can be preloaded or elongated by retracting the actuation mechanism <NUM>, which extends the tension spring <NUM>. In some embodiments, the actuation mechanism <NUM> can be locked or retained in place, preventing the medication plunger <NUM> from being advanced prior to priming by a retention mechanism. In the illustrated embodiment, the retention mechanism includes a priming trigger <NUM> with a shaft <NUM> that extends through the distal syringe portion <NUM> and through the through hole <NUM> of the actuation mechanism <NUM>, releasably coupling the actuation mechanism <NUM> to the distal syringe portion <NUM>. The priming trigger <NUM> can extend through slot <NUM> of the distal syringe portion <NUM>.

Optionally, the tension applied to the tension spring <NUM> can be adjusted by altering the position of the actuation mechanism <NUM> relative to the distal syringe portion <NUM> and inserting the priming trigger <NUM> through a slot <NUM> aligned with the through hole <NUM> of the actuation mechanism <NUM>.

<FIG> is an elevation view of the syringe <NUM> of <FIG> with the syringe body hidden and the priming trigger <NUM> removed, in accordance with various aspects of the present disclosure. As illustrated, the priming mechanism of the syringe <NUM> can be activated by removing the priming trigger <NUM> from the syringe <NUM>.

By removing the priming trigger <NUM>, the tension spring <NUM> is allowed to contract to advance the medication plunger shaft <NUM> and in turn, the medication plunger <NUM>. By advancing the medication plunger <NUM>, medication within the medication chamber <NUM> can advance through the IV tubing and prime the IV tubing. As described herein, the medication plunger <NUM> can be advanced by a desired or predetermined amount corresponding to the IV tubing volume during the priming process.

<FIG> is an elevation view of the syringe <NUM> of <FIG> with the syringe body hidden and the priming mechanism actuated, in accordance with various aspects of the present disclosure. In the illustrated embodiment, the medication plunger <NUM> can be further actuated to administer any remaining medication in the medication chamber <NUM> into the IV tubing and to the patient. In some embodiments, the medication plunger shaft <NUM> can be actuated to advance the medication plunger <NUM>. For example, the distal end <NUM> of the distal syringe portion <NUM> can be advanced toward the proximal end <NUM> to advance the medication plunger <NUM>. In some embodiments, the extensions <NUM> of the proximal syringe portion <NUM> can allow a clinician or a syringe pump to advance the distal syringe portion <NUM> relative to the proximal syringe portion <NUM>.

<FIG> is an elevation view of the syringe <NUM> of <FIG> with the syringe body hidden and the syringe actuated, in accordance with various aspects of the present disclosure. In the illustrated embodiment, the saline plunger <NUM> can be actuated to administer saline from the saline chamber <NUM> into the IV tubing to "push" or deliver any remaining medication in the IV tubing to the patient. In some embodiments, the saline plunger shaft <NUM> can be actuated to advance the saline plunger <NUM>. In some embodiments, the same actuation method for the medication plunger <NUM> can be utilized for actuating the saline plunger <NUM>.

For example, the distal end <NUM> of the distal syringe portion <NUM> can be advanced toward the proximal end <NUM> to advance the saline plunger <NUM>. In some embodiments, the extensions <NUM> of the proximal syringe portion <NUM> can allow a clinician or a syringe pump to advance the distal syringe portion <NUM> relative to the proximal syringe portion <NUM>.

In some embodiments, saline from the saline chamber <NUM> can be advanced through or around the medication chamber <NUM> to exit the syringe <NUM> via the syringe port <NUM>.

<FIG> is a perspective view of an actuation lever <NUM> of a syringe <NUM> with the syringe body hidden, in accordance with various aspects of the present disclosure. In the illustrated embodiment, the syringe <NUM> includes an actuation lever <NUM> to control the energizing and activation of the priming mechanism of the syringe <NUM>.

Similar to syringe <NUM>, in the illustrated embodiment, the actuation mechanism <NUM> can utilize a biasing member such as a tension spring <NUM> to advance the medication plunger within the syringe <NUM>. In the depicted example, the tension spring <NUM> can be coupled to the actuation mechanism <NUM> at the distal end of the tension spring <NUM>.

In the depicted example, the actuation lever <NUM> provides an interface to preload or bias the tension spring <NUM>. As illustrated, the actuation lever <NUM> is coupled to the actuation mechanism <NUM> and the actuation body <NUM>. Therefore, the actuation lever <NUM> can be retracted distally within the priming slot <NUM> to extend or bias the tension spring <NUM>.

Optionally, the actuation mechanism <NUM> can be locked to prevent the medication plunger from being advanced prior to priming. In the illustrated embodiment, the actuation mechanism <NUM> is retained by rotating the actuation lever <NUM> into the retention slot <NUM>. By rotating the actuation lever <NUM> into the retention slot <NUM>, the proximal edge of the of the retention slot <NUM> prevents the actuation lever <NUM>, and in turn the actuation mechanism <NUM> from advancing proximally and dispensing medication. In the illustrated embodiment, the retention slot <NUM> is generally perpendicular to the priming slot <NUM>.

In some embodiments, the amount of tension applied to the tension spring <NUM> can be adjusted by including multiple retention slots <NUM>. The actuation lever <NUM> may be rotated into one of multiple retention slots <NUM> to adjust the preload exerted upon the tension spring <NUM>.

<FIG> is a perspective view of the syringe <NUM> of <FIG> with the syringe body hidden and the actuation lever <NUM> in a released position. As illustrated, the priming mechanism of the syringe <NUM> can be activated by rotating the actuation lever <NUM> out of the retention slot <NUM> and into the priming slot <NUM>. By rotating the actuation lever <NUM> into the priming slot <NUM>, the tension spring <NUM> is allowed to advance the medication plunger to prime the IV tubing.

Optionally, the displacement of the medication plunger during priming may be limited by adjusting the length of the priming slot <NUM>. The proximal edge of the priming slot <NUM> creates a barrier preventing the actuation lever <NUM> from advancing proximally further than desired, limiting the advancement of the medication plunger. The position of the proximal edge of the priming slot <NUM>, and therefore the fluid displacement during priming, can be adjusted as desired.

<FIG> is a perspective view of a syringe <NUM> with an unprimed indicator 683a, in accordance with various aspects of the present disclosure. In the illustrated embodiments, the syringe <NUM> can include a priming indicator configured to signal to a clinician if priming is in process or if priming has been completed.

In the depicted example, the priming indicator can be used with any priming mechanism described herein, including, but not limited to the actuation mechanism <NUM> described herein. In the illustrated embodiment, the priming indicator can present an unprimed indicator 683a when the priming mechanism is in an unprimed position or if priming is in process, and a primed indicator 683b when the priming mechanism when the priming mechanism is in a primed position. In some applications, the priming indicator can indicate to a clinician if the priming mechanism is malfunctioning, for example if the priming indicator reflects a status different than the expected status of the priming mechanism.

In some embodiments, the unprimed indicator 683a and the primed indicator 683b can provide visual signals such as colors, patterns, or words. For example, the unprimed indicator 683a can present a red color and the primed indicator 683b can present a green color. Optionally, the unprimed indicator 683a and the primed indicator 683b can present audible or tactile signals, such as mechanism to create clicks or pops, or various textures on the surface of the indicator.

In the depicted example, the priming indicator can be coupled to move with the actuation lever <NUM> or other portions of the actuation mechanism to reflect the status of the actuation mechanism or priming mechanism. For example, when the actuation lever <NUM> is in a retained position, the priming mechanism has not been activated and the biasing member within the syringe <NUM> cannot advance the medication plunger. Prior to activation of the priming mechanism, the unprimed indicator 683a may be hidden by the distal syringe portion <NUM>.

During operation, the actuation lever <NUM> may be rotated to a released position to initiate priming and allow the biasing member to advance the medication plunger. After rotating the actuation lever <NUM> into the priming slot <NUM>, the unprimed indicator 683a can be presented in the retention slot <NUM>, also functioning as an indicator window. Therefore, the indicator window can present unprimed indicator 683a when priming begins.

<FIG> is a perspective view of the syringe <NUM> of <FIG>, in accordance with various aspects of the present disclosure. As illustrated, as priming is in process and the medication plunger is advancing, the actuation lever <NUM> can move proximally toward the proximal edge of the priming slot <NUM>. In the depicted example, the unprimed indicator 683a can be configured to be presented in the indicator window. In some embodiments, the length of the unprimed indicator 683a can correspond to the travel of the priming mechanism or the length of the priming slot <NUM> and may therefore present the unprimed indicator 683a until the actuation lever <NUM> has traveled to the end of the priming slot <NUM>.

<FIG> is a perspective view of the syringe <NUM> of <FIG> with a primed indicator 683b, in accordance with various aspects of the present disclosure. As illustrated, as the priming process is completed, the actuation lever <NUM> may rest against the proximal edge of the priming slot <NUM>. In the depicted example, the primed indicator 683b can be presented via the indicator window to signal to a clinician that the IV tubing is primed with medication. In some embodiments, the primed indicator 683b can be positioned to correspond with the end of the travel of the priming mechanism or the end of the priming slot to allow the primed indicator 683b to be presented when the actuation lever <NUM> has traveled to the end of the priming slot <NUM>.

Terms such as "top," "bottom," "front," "rear" and the like if used in this disclosure should be understood as referring to an arbitrary frame of reference, rather than to the ordinary gravitational frame of reference. Thus, a top surface, a bottom surface, a front surface, and a rear surface may extend upwardly, downwardly, diagonally, or horizontally in a gravitational frame of reference.

Various items may be arranged differently (e.g., arranged in a different order, or partitioned in a different way) all without departing from the scope of the subject technology.

Claim 1:
A syringe (<NUM>), comprising: a syringe body defining a syringe cavity (<NUM>), a syringe port (<NUM>), and an indicator window (<NUM>), wherein the syringe port is in fluid communication with the syringe cavity; a first plunger (<NUM>) comprising a first plunger shaft (<NUM>) extending from the first plunger, the first plunger disposed within the syringe cavity and defining a first chamber (<NUM>) in the syringe cavity, wherein the first chamber is in fluid communication with the syringe port;
a biasing member (<NUM>) coupled to the first plunger shaft, wherein the biasing member urges the first plunger from an unprimed position to a primed position toward the syringe port; a priming indicator(683a, 683b) comprising a first indicator portion (683a) and a second indicator portion (683b), the priming indicator coupled to the first plunger shaft, wherein the priming indicator presents the first indicator portion through the indicator window in the unprimed position and presents the second indicator portion through the indicator window in the primed position; and characterized by:
a retention mechanism releasably coupling the plunger shaft to the syringe body, wherein the retention mechanism prevents the biasing member from advancing the plunger in an engaged position and permits the biasing member to advance the plunger in a released position, the retention mechanism comprising:
a priming slot (<NUM>) formed in the syringe body and extending along the plunger shaft, wherein the indicator window defines a retention slot extending generally perpendicular from the priming slot; and
an actuation lever (<NUM>) coupled to the plunger shaft, the actuation lever extending through the priming slot and rotatable into the retention slot, wherein the actuation lever prevents the biasing member from advancing the plunger when rotated into the retention slot and permits the biasing member to advance the plunger when rotated into the priming slot.