MECHANICALLY ASSISTED INFLATION DEVICE HANDLE AND METHOD OF USE

An inflation device including a handle mechanism configured to selectively engage and disengage threads within the device. In some instances, the threads are configured to couple a plunger to a syringe body. The handle mechanism may be configured to (1) provide a mechanical advantage and (2) change the location and direction of the input force.

TECHNICAL FIELD

The present disclosure relates generally to devices used to pressurize, depressurize, or otherwise displace fluid, particularly in medical devices. More specifically, the present disclosure relates to devices used to pressurize, depressurize, or otherwise displace fluid along a line in order to inflate or deflate a medical device, such as a balloon.

DETAILED DESCRIPTION

An inflation device may include a syringe that utilizes threads to advance or retract a plunger by rotating the plunger handle relative to the body of the syringe such that the threads cause longitudinal displacement of the plunger relative to the body. In some instances, an inflation syringe may further include retractable threads, enabling a practitioner to disengage the threads and displace the plunger by simply pushing or pulling the plunger.

Certain inflation devices, such as those described in U.S. Pat. Nos. 5,047,015; 5,057,078; 5,163,904; and 5,209,732 include a mechanism in the handle of the device that allows the practitioner to disengage the threads by manipulating the mechanism. For example, in some instances the handle of such a device may include a “trigger” portion that may be configured to retract threads positioned on the plunger when the trigger is actuated.

An inflation device may further be configured such that the thread retraction mechanism includes elements that provide mechanical advantage, allowing a user to more easily manipulate the mechanism. Moreover, a mechanism may be configured to alter the location of an input force, which may provide flexibility and ease of operation to the device.

The directional terms “distal” and “proximal” are given their ordinary meaning in the art. That is, the distal end of a medical device means the end of the device furthest from the practitioner during use. The proximal end refers to the opposite end, or the end nearest the practitioner during use. As specifically applied to the syringe portion of an inflation device, the proximal end of the syringe refers to the end nearest the handle and the distal end refers to the opposite end, the end nearest the inlet/outlet port of the syringe. Thus, if at one or more points in a procedure a physician changes the orientation of a syringe, as used herein, the term “proximal end” always refers to the handle end of the syringe (even if the distal end is temporarily closer to the physician).

“Fluid” is used in its broadest sense, to refer to any fluid, including both liquids and gasses as well as solutions, compounds, suspensions, etc., that generally behave as a fluid.

FIGS. 1-9illustrate different views of an inflation device. In certain views the device may be coupled to, or shown with, additional components not included in every view. Further, in some views only selected components are illustrated, to provide detail into the relationship of the components. Some components may be shown in multiple views but not discussed in connection with every view. Disclosure provided in connection with any figure is relevant and applicable to disclosure provided in connection with any other figure.

FIG. 1is a perspective view of an inflation device100. In the illustrated embodiment, the inflation device100is partially comprised of a syringe110. The inflation device100includes three broad groups of components; each group may have numerous subcomponents and parts. The three broad component groups are: a body component such as syringe body112, a pressurization component such as plunger120, and a handle130.

The syringe body112may be formed of a generally cylindrical hollow tube configured to receive the plunger120. The syringe body112may include an inlet/outlet port115located adjacent a distal end114of the syringe body112. In some embodiments, a nut118may be coupled to the syringe body112adjacent a proximal end113of the syringe body112. The nut118may include a center hole configured to allow the plunger120to pass through the nut118into the syringe body112. Further, the nut118may include internal nut threads119(FIG. 2) configured to selectively couple the nut118to the plunger120in some embodiments.

The plunger120may be configured to be longitudinally displaceable within the syringe body112. The plunger120may be comprised of a plunger shaft121coupled to a plunger seal122at the distal end of the plunger shaft121. The plunger shaft121may also be coupled to the handle130at the proximal end of the plunger shaft121, the plunger shaft121spanning the distance between the plunger seal122and the handle130.

The handle130broadly refers to the group of components coupled to the proximal end of the plunger120, some of which may be configured to be graspable by a user. In certain embodiments, the handle130may be configured such that the user may manipulate the position of the plunger120by manipulating the handle130. Further, in some embodiments the handle130may be an actuator mechanism, configured to manipulate components of the inflation device100. In further embodiments, the actuator mechanism may include a lever mechanism.

Any and every component disclosed in connection with any of the exemplary handle configurations herein may be optional. That is, though the handle130broadly refers to the components coupled to the proximal end of the plunger shaft121that may be configured to be graspable by a user, use of the term “handle” is not meant to indicate that every disclosed handle component is always present. Rather, the term is used broadly, referring to the collection of components, but not specifically referring to or requiring the inclusion of any particular component. Likewise, other broad groupings of components disclosed herein, such as the syringe110or syringe body112and the plunger120, may also refer to collections of individual subcomponents. Use of these terms should also be considered non-limiting, as each subcomponent may or may not be present in every embodiment.

As shown inFIG. 1, a fluid reservoir116may be defined by the space enclosed by the inside walls of the syringe body112between the plunger seal122and the distal end114of the syringe body112. Accordingly, movement of the plunger seal122with respect to the syringe body112will alter the size and volume of the reservoir116. Advancing the plunger120(displacing in the distal direction) may reduce the volume and/or increase the pressure within the syringe body112. Similarly, retracting the plunger120may increase the volume and/or decrease the pressure within the syringe body112.

As shown inFIGS. 1 and 2, in some embodiments, the syringe110may include a nut118, coupled to the proximal end113of the syringe body112. The nut118may utilize threads or other coupling mechanisms to couple the nut118to the syringe body112. The nut118may additionally include internal nut threads119configured to couple the nut118to a portion of the plunger120. The plunger120may also include external plunger threads125configured to couple the plunger120to the nut118. The plunger120may thus be translated longitudinally with respect to the syringe body112by rotating the plunger120such that the interaction of the nut threads119and the plunger threads125results in the longitudinal translation of the plunger120. Thus, when the plunger threads125and the nut threads119are engaged, movement of the plunger120is constrained with respect to the syringe body112, though the plunger120is not necessarily fixed with respect to the syringe body112. For example, the plunger120may be rotatable, but not directly translatable, when the threads125,119are engaged.

The plunger threads125may be configured such that they may be retracted within the plunger shaft121. As shown inFIGS. 3 and 4, in some embodiments, the plunger threads125do not extend 360 degrees around the axis of the plunger shaft121. Furthermore, as shown inFIGS. 1-4, the plunger threads125may be formed on a thread rail124that may be disposed within a groove123in the plunger shaft121.

The thread rail124may be configured such that interaction between angled surfaces126on the thread rail124and the angled surfaces127(FIG. 5) within the groove123interact such that the plunger threads125may be retractable within the plunger shaft121. The relationship between the angled surfaces126on the thread rail124and the angled surfaces127within the groove123(FIG. 4) is shown inFIGS. 5, 8A, and 8B. Translation of the thread rail124in the proximal direction simultaneously causes the thread rail124to retract toward the center axis of the plunger shaft121due to the interaction of the angled surfaces126on the thread rail124with the angled surfaces127in the groove123. Similarly, translation of the thread rail124in the proximal direction causes the thread rail124to move away from the center axis of the plunger shaft121. In the illustrated embodiment, a distally oriented biasing force acting on the thread rail124may bias the plunger threads125to the non-retracted position. As such, a singular proximally oriented force applied to the handle130(specifically the trigger member133) may decouple the threads125,119. It will be appreciated by one of ordinary skill in the art having the benefit of this disclosure that it is within the scope of this disclosure to modify the angles and interfaces such that a distally oriented biasing force on the thread rail124would bias the plunger threads125in the retracted position. As mentioned above, analogous mechanisms are disclosed in U.S. Pat. Nos. 5,047,015; 5,057,078; 5,163,904; and 5,209,732.

FIGS. 8A and 8Billustrate two positions of the thread rail124with respect to the internal nut threads119and the plunger shaft121.FIG. 8Ashows thread rail124disposed in a non-retracted position, such that the plunger threads125are engaged with the internal nut threads119.FIG. 8Bshows the thread rail124sufficiently retracted into the plunger shaft121such that the plunger threads125are not engaged with the internal nut threads119.

Embodiments that utilize retractable threads may allow a user to displace the plunger shaft121relative to the syringe body112either through rotation of the plunger shaft121(and the subsequent interaction of threads), or by retracting the plunger threads125and displacing the plunger shaft121by applying opposing forces on the plunger shaft121and the syringe body112. (The forces, in turn, may move the plunger shaft121distally or proximally with respect to the syringe body112.) Both methods of displacement may be utilized during the course of a single therapy.

FIG. 6is a cross-sectional view of the inflation device ofFIG. 1with fluid50disposed within the reservoir116.FIGS. 2 and 6illustrate the inflation device ofFIG. 1in a first configuration, with the handle released and the threads engaged (FIG. 2) and a second configuration, with the handle actuated and the threads disengaged (FIG. 6). These configurations are also shown in additional detail inFIGS. 7A-8Bas described below. When comparing these configurations, it may be noted that, in the illustrated embodiment, when the handle is actuated and the threads disengaged, the trigger member133is laterally displaced (as well as axially displaced), as shown inFIG. 6as compared toFIG. 2. With continued reference toFIG. 6, in some instances, a practitioner may desire to quickly displace the plunger shaft121, for instance, while priming the inflation device or while priming or deflating an attached medical device such as a balloon. Quick displacement of the plunger shaft121may be accomplished by retracting the plunger threads125and sliding the plunger shaft121relative to the syringe body112. For example, a practitioner may quickly fill the reservoir116with the fluid50by disengaging the plunger threads125and pulling the plunger shaft121in a proximal direction with respect to the syringe body112. Further, a practitioner may quickly force the fluid50into lines leading to other devices or quickly expel unwanted air bubbles from the reservoir116by retracting the plunger threads125and advancing the plunger shaft121.

In other instances, the practitioner may desire more precise control over the position of the plunger shaft121(for example when displacing the plunger shaft121in order to adjust the fluid pressure within the reservoir116) or it may simply be difficult or impossible without a mechanical advantage to displace the plunger shaft121due to high fluid pressure within the reservoir116. In these instances, the practitioner may opt to displace the plunger shaft121by rotation of the plunger shaft121.

Referring back toFIG. 4, the handle130of the inflation device100(FIG. 1) may include components that enable a practitioner to retract the thread rail124of the plunger120. In some embodiments, the plunger shaft121may be fixed to a first member such as the inner member131of the handle130. The thread rail124may be fixed to a trigger133component of the handle130. Further, a biasing component135may be configured to bias the trigger133in a distal direction relative to the plunger shaft121. Because the trigger133is fixed to the thread rail124, a distally oriented force on the trigger133will result in a distally oriented force on the thread rail124as well. The force provided by the biasing component135(hereafter also referred to as the biasing force) may thus bias the thread rail124in a non-retracted position as described above. Conversely, overcoming the biasing force and translating the trigger133in a proximal direction with respect to the plunger shaft121and the inner member131may retract the plunger threads125. In some embodiments, the biasing force135may be greater than a force required to proximally displace the plunger130within the syringe body112.

In some embodiments, the handle130may further include a second member such as the outer sleeve136and one or more levers140,141. The levers140,141may be disposed such that they provide mechanical advantage, enabling the user to more easily overcome the biasing force and displace the trigger133toward the inner member131.

Referring particularly toFIGS. 4, 6, 7A, and 7B, portions of the handle130that interact with the lever140may be the mirror image of the portions of the handle130that interact with the lever141. Thus, in some embodiments, disclosure provided in connection with one lever is equally applicable to the other lever. Furthermore, it is within the scope of this disclosure to include levers on each side of the handle that are not identical or to include a single lever.

FIG. 7Ais a detail view of a portion of the handle of the inflation device, in the configuration shown inFIG. 2.FIG. 7Bis a detail view of the same portion of the handle of the inflation device, in the configuration shown inFIG. 6. As shown in the detail views ofFIGS. 7A and 7B, the outer sleeve136contacts a first lever arm146of the lever140at point A. The outer sleeve136may include a first lever contact surface139configured to contact the first lever arm146. A distally oriented force manually applied to the outer sleeve136will thus exert a distally oriented force on the first lever arm146at point A through contact of the first lever contact surface139with the first lever arm146. The lever140may be coupled to the plunger shaft121via pivot point B. A cross bar142disposed on a second lever arm147of the lever140may thus exert a proximally oriented force on a second lever contact surface145included on a top member134of the trigger133at point C. Thus, a manually applied force that acts distally on the outer sleeve136is transferred by the levers140,141and results in the cross bars142,143applying a proximal force on the trigger133. As discussed above, in the illustrated embodiment, a proximal force on the trigger133causes the thread rail124to retract, disposing the plunger120in a decoupled state.

It is within the scope of this disclosure to alter the shape or form of the levers140,141. For instance, the lever140is shown with an inside radius near the pivot point B that mates with an outside radius formed on a portion of the inner member131. It is within the scope of this disclosure to alter the design such that the outside radius is formed on the lever140and the inside radius is formed on the inner member131. The first lever arm146and the second lever arm147may also be curved or angled in one or more directions. Similar design modifications to the levers or any other component are equally within the scope of this disclosure. In the illustrated embodiment, the length of the first lever arm146is greater than the length of the second lever arm147, meaning the distance from the pivot point B to the end of the first lever arm146is greater than the distance from the pivot point B to the end of the second lever arm146. In other embodiments, the design could be modified such that the length of the second lever arm147is greater than the length of the first lever arm146. Moreover, the levers140,141may be modified such that the pivot point B is located at one end of each lever, rather than the pivot point located between the force transferring contact points A, C as in the illustrated embodiment. Furthermore, any combination of these alternative designs is within the scope of this disclosure, including designs where each of two levers has a different design, the handle includes a single lever, or compliant mechanisms are utilized to transfer force and/or provide mechanical advantage.

FIG. 7Aillustrates the lever mechanism of the handle130with the plunger (120ofFIG. 2) in a coupled state, i.e., when the plunger120is coupled to the syringe body112via the threads125,119. As noted above, in the illustrated embodiment, this configuration correlates to the configuration wherein the handle130is released and the threads125,119are engaged. In the configuration ofFIG. 7A, external forces are not constraining or compressing the trigger133or the outer sleeve136. (As discussed below,FIG. 7Adoes include indicia showing where forces may be applied to actuate the handle to displace the elements into the configuration ofFIGS. 6, 7B and 8B.)

FIG. 7Aalso indicates a transverse distance (perpendicular to a longitudinal axis of the plunger120) between point A and point B defining a first moment arm length152. Also shown is a transverse distance between point C and point B defining a second moment arm length151. As can be seen in the figure, these moment arms correlate with the first lever arm146and second lever arm147. In the illustrated embodiment, the first moment arm length152is longer than the second moment arm length151. In other embodiments, the first moment arm length152may be equal to or shorter than the second moment arm length151. In the illustrated embodiment, a distal displacement distance of the outer sleeve136with respect to the plunger shaft121is thus converted by the lever140to a shorter proximal displacement distance of the trigger133with respect to the plunger shaft121, creating a mechanical advantage (due to the difference between the first moment length152and the second moment arm length151). The mechanical advantage may thus be understood as converting a force X applied to the outer sleeve136in a distal direction into a proximally applied force acting on the thread rail (124ofFIG. 5) via the trigger133. In other words, application of force X may result in a force, acting on point C, that tends to displace the trigger133in the same manner as a force applied directly to the trigger133, such as that illustrated as force Y. (As discussed below, in certain uses, forces X and Y may also be simultaneously applied by external elements, e.g. portions of a practitioner's hand, though force Y would be supplemented by the force exerted at point C due to application of force X). Force on the thread rail124(whether due to application at point C due to input by force X alone, or by a combination of forces X and Y) may thus be directed to counter and overcome the force exerted by the biasing member135, compress the biasing member135, and displace the thread rail124. Hence, the lever140provides a mechanical advantage in decoupling the plunger120from the syringe body112when a single force is externally applied to the handle130in a distal direction.

Furthermore, application of distal force X results in a reactionary force Z (assuming that the inflation device100is constrained such that force X does not simply displace the entire inflation device100). In some instances, a proximal force manually applied to the syringe body112in opposition to the manually applied distal force to the outer sleeve136may be transferred to the plunger shaft121when the thread rail124is engaged, and result in at least a portion of the reactionary force Z. When force X is sufficient to compress the biasing member135and displace the thread rail124, reactionary force Z will no longer have a component supplied by engagement of the thread rail124with the syringe body112. At that point, the reaction force Z may only result from the friction force between the plunger seal122and the syringe body112(assuming there is no pressure in the reservoir of the syringe body112). Accordingly, when force X is also sufficient to overcome force Z (as supplied by such friction) the plunger122may be advanced within the syringe body112due to application of force X. However, when force Z is only supplied by such friction, force Z may not be sufficient to compress the biasing member135, resulting in expansion of the biasing member135, displacement of the thread rail124in a distal direction, and, thus, reengagement of the thread rail124with the syringe body112. This reengagement again allows force on the syringe body112to be transferred to the plunger shaft121, such that force Z again has a component supplied by forces exerted on the syringe body112. This, in turn, may increase force Z, again compressing the biasing member135, and cause displacement and retraction of the thread rail124. Hence, advancement of the plunger120in response to a distally oriented force applied to the handle130(absent a proximal force externally applied to the trigger133) may result in repeated disengagement and re-engagement of the thread rail124as the plunger120is advanced, causing a discontinuous pattern of engagement/disengagement and a “rough” feel or sound as the threads repeatedly engage/disengage. As further detailed below, in some embodiments, the lever mechanism may be configured to inhibit re-engagement of the thread rail124during advancement of the plunger120when the distally oriented force is manually applied to the handle130absent a proximal force manually applied to the trigger133.

In some embodiments, the mechanical advantage may be configured (due to lever140size, relative displacement of the outer sleeve136and trigger133, stiffness of the biasing member135, and the ratio of the first moment arm length152over the second moment arm length151) such that a distally directed force X on the outer sleeve136to decouple the plunger120is less than the friction force between the plunger seal122and the syringe body112. In other words, the inflation device100may be configured such that the magnitude of the distally directed force X applied on the outer sleeve136required to decouple the plunger120from the syringe body112is less than the force required to advance the plunger120after the plunger120is decoupled from the syringe body112. In such embodiments, frictional resistance to advancement of the plunger120is thus sufficient to keep the biasing member135compressed such that the threads do not discontinuously engage/disengage as the plunger120is advanced due to application of force X. Such embodiments may be configured such that application of force X allows for smooth and/or continuous advancement of the plunger120without application of an external force on the trigger133(such as force Y). In this configuration, the handle mechanism may thus supply the mechanical advantage at a first magnitude or supply a first factor of the mechanical advantage. As detailed below, during actuation of the handle, the magnitude of the mechanical advantage may change.

FIG. 7Billustrates the lever mechanism of the handle130with the plunger120in a decoupled state, i.e., when the plunger120is decoupled from the syringe body112due to actuation of the handle and retraction of the thread rail124. In this configuration, the outer sleeve136is displaced distally relative to the position shown inFIG. 7Aand the trigger133is displaced proximally relative to the position shown inFIG. 7A. As noted above, displacement of the trigger133may be due to external application of force X (and the transfer of that force at point C), external application of force Y, or a combination thereof. In the illustrated configuration, point C of lever arm147is displaced in the transverse direction toward the pivot point B. As such, the second moment arm length151′ inFIG. 7Bis shorter than the second moment arm length151inFIG. 7A, resulting in a second magnitude for the mechanical advantage greater than the first magnitude discussed in connection withFIG. 7A. In other words, the magnitude of the mechanical advantage in the configuration shown inFIG. 7B(the second factor of the mechanical advantage, or the mechanical advantage generated by the configuration ofFIG. 7B) may be greater than the magnitude of the mechanical advantage in the configuration shown inFIG. 7A(the first factor of the mechanical advantage, or the mechanical advantage generated by the configuration ofFIG. 7A). As such, the required amount of distally directed force X on the outer sleeve136to overcome the biasing force in opposition to the reaction force Z is greater when the plunger120is in the coupled state than when the plunger120is in the decoupled state. Hence, the lever mechanism provides for a lower required amount of distally directed force X to be applied to the outer sleeve136, to maintain the plunger120in the decoupled state after the plunger120is decoupled from the syringe body112. Said another way, the amount of externally applied distal force X on the outer sleeve136required to distally displace the outer sleeve136with respect to the plunger shaft121at a first position of the outer sleeve136may be greater than the amount of manually applied distal force X on the outer sleeve136required to distally displace the outer sleeve136with respect to the plunger shaft121at a second position of the outer sleeve136wherein the second position of the outer sleeve136is distal of the first position. In some embodiments, the second factor of the mechanical advantage (in combination with the biasing force) may provide for a lower amount of distally directed force X (applied to the outer sleeve136) required to maintain decoupling of the plunger120when the plunger120is being displaced within the syringe body112. As the amount of force X in such instances is less than the friction force between the plunger seal122and the syringe body112, the plunger may be advanced in a continuous manner (without engaging/disengaging threads) when a distally oriented force is externally applied to the outer sleeve136. Again, this may be stated as, in accordance with the second factor of the mechanical advantage, a distally directed manual force X on the sleeve136required to maintain decoupling of the plunger120from the syringe body112may be less than a distally directed manual force X on the sleeve136required to distally displace the plunger120within the syringe body112to decouple the plunger120from the syringe body112.

In some embodiments, the friction force between the plunger seal122and the syringe body112may at least partially define the reaction force Z on the plunger shaft121. In some embodiments, the friction force may substantially define the complete reaction force Z on the plunger shaft121. Further, the friction force may be different when the plunger120is stationary with respect to the syringe body112than when the plunger120is moving. In other words, the static friction force between the plunger seal122and the syringe body112may be different than the dynamic friction force. In some instances, the dynamic friction force may be less than the static friction force. In some embodiments, the first factor of the mechanical advantage may provide for a single required force X (required to decouple the plunger120) externally applied to the handle in the distal direction to be less than the dynamic friction force. In other embodiments, the first factor of the mechanical advantage may provide for the single required force X externally applied to the handle to be less than the static friction force and greater than the dynamic friction force. Similarly, the second factor of the mechanical advantage may provide for the single required force X to be less than the dynamic friction force. In some embodiments, a pressure within the syringe body112may also at least partially define the reaction force Z on the plunger shaft121.

It will be appreciated by one of ordinary skill in the art having the benefit of this disclosure that, in many instances, a proximal force may be manually applied to the trigger133at the same time a distal force is manually applied to the outer sleeve136. For example, when the handle130is grasped by a user, the user may actuate the handle130by squeezing the trigger133with his or her fingers. This action may coincide with a distally oriented force exerted on the outer sleeve136by the palm of the user's hand. Accordingly, the forces applied in this manner may be understood as a proximal force on the trigger133and a distal force on the outer sleeve136. The mechanism of the levers140,141converts the distally oriented force exerted on the outer sleeve136in combination with the manually applied proximal force on the trigger133into a combined proximal force on the trigger133to overcome the biasing force and retract the thread rail124. In such an instance, the combination of the manually applied distal force on the outer sleeve136and the manually applied proximal force on the trigger133may also provide a mechanical advantage in decoupling the plunger120from the syringe body112.

In the illustrated embodiment, a single force applied to the handle130in the distal direction exceeding a first specified amount may decouple the plunger120from the syringe body112. A single force applied to the handle130in the distal direction exceeding a second specified amount may maintain decoupling the plunger120from the syringe body112. A single force applied to the handle130in the distal direction exceeding a third specified amount may overcome a static friction between the plunger seal122and the syringe body112and initiate advancement of the plunger120. A single force applied to the handle130in the distal direction exceeding a fourth specified amount may overcome a dynamic friction between the plunger seal122and the syringe body112and maintain advancement of the plunger120. The first specified amount may be greater than the second specified amount and less than the third specified amount and/or the fourth specified amount. The second specified amount may be less than the third specified amount and/or the fourth specified amount.

In some embodiments, friction forces may further inhibit re-engagement of the thread rail124. For example, a friction force between the first lever contact surface139and the first lever arm146at point A and/or a friction force between the cross bar142and the second lever contact surface145at point C may provide for a force X required to prevent proximal displacement of the outer sleeve136away from the position as shown inFIG. 7Bto be less, and in some instances substantially less, than a force X required to distally displace the sleeve into the position as shown inFIG. 7B. As such, the friction force between the first lever contact surface139and the first lever arm146at point A and/or the friction force between the cross bar142and the second lever contact surface145at point C may further inhibit re-engagement of the thread rail124during advancement of the plunger120when the distally oriented force is manually applied to the handle130absent a proximal force manually applied to the trigger133.

In the illustrated embodiment, a single force applied to the outer sleeve136in the distal direction may be transferred to the plunger shaft121indirectly via the lever mechanism and the biasing component135. In some instances, the single force applied to the outer sleeve136in the distal direction may distally displace the outer sleeve136relative to the plunger shaft121such that the outer sleeve136bottoms-out on the plunger shaft121and the single force is transferred rigidly to the plunger shaft121.

A handle configured to provide a mechanical advantage when retracting a thread rail may be desirable for certain therapies that require large syringes or high pressure. Such therapies may also require a larger biasing force due to the size of the device or the pressure within the device. A handle providing a mechanical advantage may make devices configured for such therapies easier to use.

As described above, and illustrated in the figures, in some embodiments, the levers140,141may not be pinned or otherwise mechanically coupled to any of the other parts. In some embodiments, the levers140,141may be only be constrained due to contact with other components of the device. Likewise, the outer sleeve136may not be mechanically fastened to any other component, though—like the levers140,141—contact between portions of the outer sleeve136and other components may be utilized to secure the position of the outer sleeve136with respect to the other components. Thus, in some embodiments the levers140,141and the outer sleeve136may be allowed to “float” with respect to the other parts. A floating assembly as described above may allow certain components multiple degrees of freedom with respect to the other parts. For example, as explained below, in some embodiments the trigger133may be displaced in both the longitudinal and transverse directions (with respect to the outer sleeve136) when the trigger133is actuated.

As shown inFIGS. 3 and 4, the outer sleeve136may also include slots137configured to mate with ridges132formed on the outer surface of the inner member131. The interaction between these slots137and ridges132constrains the movement of the outer sleeve136with respect to the inner member131; that is, the two components may only travel (with respect to each other) in a single direction, parallel to the longitudinal axis of the syringe body112. As mentioned above, in the illustrated embodiment, the trigger133travels in a direction transverse to the longitudinal axis of the syringe body112(in addition to travel along the longitudinal axis) when it is compressed, due to the interaction of the angled surfaces126,127of the thread rail124and the plunger shaft121. Ridges and slots, such as those of the illustrated embodiment (132,137), may provide a degree of usability and comfort to the device, as the portion of the outer sleeve136—which may be in contact with the palm of the user in some instances—does not slide in a transverse direction.

Many design modifications relating to the outer sleeve136are within the scope of the current disclosure. For example, in the illustrated embodiments, the outer sleeve136has a cap-like shape, fitting over the inner member131. In other embodiments, the outer sleeve136may instead be designed as a button that slides into the inner member131when it is compressed. Likewise, any other longitudinally actuatable component may be utilized in place of the outer sleeve136.

The handle mechanism described above, and shown in each ofFIGS. 1-9, may also be utilized to change the location and direction of an input force required to retract the plunger threads125. The mechanism may allow a user to draw the trigger133toward the inner member131(and thus retract the plunger threads125) solely by applying a distally oriented force to a top surface138of the outer sleeve136. As outlined above, the levers140,141transfer this force to the trigger133, which retracts the plunger threads125.

In some instances, a user such as a medical practitioner, may desire to displace the plunger120in a distal direction with only one hand. This may be accomplished by grasping the syringe body112and using a surface, for example a table top, to apply a distally oriented force on the top surface138of the outer sleeve136. In this manner, a mechanism such as that described above may enable a practitioner to displace the plunger in a one-handed fashion.

FIG. 9is a perspective view of the inflation device100ofFIG. 1with fluid50disposed within the device and a balloon105coupled to the inflation device100via a delivery line104. Referring now to components shown inFIG. 9as well as the other figures, in some instances it may be desirable to operate the syringe110“one-handed” as described above in order to prime the system. For example, a practitioner may utilize the inflation device100in connection with a therapy that includes the balloon105, such as an angioplasty. The practitioner may initially fill the syringe body112with the fluid50, such as a contrast fluid, by drawing the plunger120back in the proximal direction. In some instances, the practitioner will do so by grasping the handle130of the inflation device100with a first hand, while grasping the syringe body112with a second hand. The practitioner may then retract the plunger threads125by squeezing the trigger133and the outer sleeve136together with his or her first hand, then drawing the plunger120back in the proximal direction.

After a desired amount of fluid50is disposed within the syringe body112, the practitioner may orient the syringe body112such that the distal end114of the syringe body112is above the handle130, so any air bubbles in the fluid50will tend to rise to the distal end114of the syringe body112. The practitioner may also shake, tap, or otherwise disturb the syringe110in order to facilitate movement of any air bubbles in the fluid50. The practitioner may then prime the syringe110by displacing the plunger120in a distal direction with respect to the syringe body112, thereby forcing the air bubbles from the syringe body112.

In some instances, the practitioner will displace the plunger120as described after first retracting the plunger threads125. This may be accomplished in any manner disclosed herein, including the one-handed operation described above. That is, the practitioner may prime the inflation device100simply by grasping the syringe body112with one hand and using a static object or surface, such as a table top, to exert a distally directed force on the top surface138of the outer sleeve136. The force on the outer sleeve136will both (1) retract the plunger threads125via the handle130mechanism and (2) act to displace the plunger120in a distal direction with respect to the syringe body112. This orientation positions the syringe body112in a potentially desirable position to allow air to travel to the distal end114of the syringe body112while simultaneously orienting the handle130such that the top surface138of the outer sleeve136directly faces a horizontal surface such as a table. Thus, in some instances a physician may desire to prime the syringe110in this way due to the orientation of the syringe110as well as the ability to do so with one hand.

There may be other instances during therapy in which the practitioner desires to displace the plunger120distally using only one hand. In addition to priming the inflation device100as described above, this method of advancing the plunger120may also be employed to prime a device connected to the syringe110, such as a balloon105.

Without further elaboration, it is believed that one skilled in the art can use the preceding description to utilize the present disclosure to its fullest extent. The examples and embodiments disclosed herein are to be construed as merely illustrative and exemplary, and not a limitation of the scope of the present disclosure in any way. It will be apparent to those having skill in the art that changes may be made to the details of the above-described embodiments without departing from the underlying principles of the disclosure herein. It is intended that the scope of the invention be defined by the claims appended hereto and their equivalents.