Detachable plunger rod attached to the plunger head of the pump device

Abstract

The pump device mechanism includes a rotatable cam body axially fixed to the distal end of a plunger rod receivable within the pump device and rotatable around the plunger rod. The cam body has a cam surface that cooperates with a fixed cam pin in a plunger head in a camming action. Cooperation between the cam surface of the cam body and the cam pin causes the cam body to rotate within the plunger head through a series of push-pull angular positions configured to alternately push and pull the plunger head within the syringe, from an engagement angular position where the cam body and the plunger head are engaged to a disengagement angular position where the cam body and the plunger head are not engaged. Rotation of the cam body from one angular position to another is achieved by axially reciprocating the plunger rod.

Description

[Technical Field]

[0001] This application claims priority to and benefits from U.S. Provisional Patent Application No. 63 / 429,781, filed December 2, 2022, entitled "Plunger rod detachable from plunger head of pump device," the disclosure of which is incorporated herein by reference in its entirety.

[0002] The present invention relates generally to systems and methods for coupling a disposable reservoir (e.g., a syringe) of a medication delivery device (e.g., a pump device) to a reusable portion (RP) of the medication delivery device. More specifically, the present invention relates to a mechanism, plunger rod, and plunger head structure that releasably engages a plunger rod with a plunger head to provide a series of alternating push-pull angular positions between engagement and disengagement of the plunger rod and plunger head for alternately pushing and pulling the plunger head within the disposable reservoir. [Background technology]

[0003] Some liquid drug delivery systems are two-part systems. Such systems typically include a reusable part and a disposable part (e.g., a disposable syringe). The reusable part typically includes, among other things, an electric motor and a gear system driven by the electric motor. The disposable part typically includes a reservoir (e.g., a syringe) and a gear-driven plunger means for expelling the drug from the drug reservoir.

[0004] In conventional drug delivery systems, the plunger means includes a plunger rod (a type of lead screw) and a plunger head (a type of piston), and the plunger rod is usually inseparable from the plunger head. Furthermore, such plunger means are usually inseparable from the reservoir itself, and the use of such plunger means has drawbacks. For example, disposable reservoirs, along with the plunger rod and plunger head, are discarded after use. This is wasteful and uneconomical. Furthermore, because the plunger rod (lead screw) is traditionally integral with the disposable reservoir, combining the disposable reservoir with the reusable portion often leads to a decrease in the accuracy of the delivered drug due to uncertainty regarding the exact position, i.e., the axial position, of the plunger rod within the reservoir / syringe. Furthermore, the assembly process for disposable reservoirs, including plunger rods, is relatively complex and time-consuming due to the multiple steps involved in the assembly process. Furthermore, the inseparable attachment of the plunger rod to the disposable reservoir precludes the disposable reservoir from being stockpiled, dispensed, or otherwise treated as a prefilled device. As a result, conventional disposable reservoirs are typically filled from a vial immediately prior to use. Summary of the Invention [Means for solving the problem]

[0005] The pump device for delivering a medication includes a disposable reservoir (e.g., a disposable syringe) and a reusable part that is removably connectable to the disposable reservoir. The disposable reservoir includes, among other things, a plunger head (piston) that is bidirectionally movable within the disposable reservoir, for example, between a proximal end of the disposable reservoir and a distal end of the disposable reservoir. The reusable part includes, among other things, a plunger rod (lead screw). The plunger head and plunger rod are designed such that the plunger rod can be releasably engaged with the plunger head when the disposable reservoir and the reusable part are connected to each other, such that the plunger rod moves linearly and bidirectionally (back and forth) within the disposable reservoir together with the plunger head.

[0006] The plunger rod and plunger head collectively comprise a quick-coupling / release cam mechanism that allows the plunger rod to be quickly engaged and released from the plunger head. The cam mechanism includes a rotatable, cylindrical cam body axially secured to the distal end of the plunger rod and linearly movable between a retracted (home) position and a fully extended position in the reusable portion of the pump device. The cam mechanism rotatably cams about the plunger rod. The cam body has a cam surface that cams with a fixed cam pin in the plunger head to rotate within the plunger head from an engagement angular position where the cam body and plunger head engage with each other to a disengagement angular position where the cam body and plunger head are disengageable. Rotation of the cam body within the plunger head between the engagement and disengagement angular positions is achieved through a series of alternating push / pull angular positions to alternately push and pull the plunger head within the disposable reservoir. Rotation of the cam body within the plunger head from one angular position to another is accomplished by reciprocating the plunger rod axially (linearly) using, for example, an electric motor, causing the cam pins on the plunger head to alternately cam into engagement with the cam surfaces of the cam body, thereby alternately pushing and pulling the plunger rod, and thus the plunger head, within the disposable reservoir. [Brief explanation of the drawings]

[0007] The accompanying drawings illustrate various exemplary embodiments and aspects, but these examples are not intended to be limiting of the present invention. It should be understood that for simplicity and clarity of illustration, elements shown in the figures referenced below have not necessarily been drawn to scale. Further, where considered appropriate, reference numerals repeated among the figures indicate like, corresponding, or similar elements.

[0008] 1A-1C show a pump device according to one embodiment.

[0009] 2A-2C show the plunger rod of FIG. 1 whose rotational movement is restricted by a rotation restriction portion.

[0010] FIG. 3 illustrates a lead screw type plunger rod according to one embodiment.

[0011] FIG. 4 shows a plunger head according to one embodiment.

[0012] 5A-5B show an exemplary cylindrical cam body according to one embodiment.

[0013] FIG. 6 shows the cylindrical cam body of FIG. 2C and FIGS. 5A to 5B assembled to the plunger rod of FIG. 3 before being inserted into the plunger head of FIG.

[0014] FIG. 7 illustrates a zigzag route for a cylindrical cam body according to one embodiment.

[0015] FIG. 8 is a development view that schematically illustrates an example of a tension member of a cylindrical cam body according to one embodiment.

[0016] Figures 9A to 9L are schematic diagrams that sequentially explain the state in which the cam surfaces of the cylindrical cam body in Figures 5A to 5D are alternately engaged with the fixed cam pin in Figure 4 by causing the plunger rod in Figure 3 to move back and forth in the axial direction by the electric motor in Figure 2C so that the plunger rod, and therefore the plunger head, is alternately pushed and pulled.

[0017] 10A-10I illustrate typical operation of a four-stroke cycle pump device according to an exemplary embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0018] The following description provides various details of embodiments. However, this description is not intended to limit the scope of the claims, but rather to illustrate various principles of the present invention and exemplary methods for implementing the same. FIGS. 1A, 1B, and 1C respectively show an exploded view, a cross-sectional view, and an assembled view of a pump device (100) according to an exemplary embodiment. The pump device 100 includes a disposable drug reservoir (e.g., in the form of a disposable syringe 101) and a reusable portion 116. The syringe 101 includes a syringe housing 102, a syringe inlet / outlet port 104 for filling and expelling a liquid drug from the syringe housing 102, a plunger head 106 with two annular grooves (108, 110), and two O-rings 112 for the two annular grooves 108 and 110. The plunger head 106 is movable bidirectionally within the syringe housing 102 between a first axial (proximal) position 103 on the longitudinal axis 107 of the syringe 101 and a second axial (distal) position 105 on the longitudinal axis 107.

[0019] The reusable portion 116 includes an electric motor 118, a gear train 120, a gear drive shaft 122, a plunger rod 124 (lead screw), a plunger rod rotation constraint 126, a syringe adapter 128 with a handgrip surface (160 in FIG. 1C), a cylindrical cam body 130, and two flat retaining E-clip rings 132 and 134 (snap rings). The cylindrical cam body 130 has a concentric through-hole through which the plunger rod 124 is inserted during the pump device assembly process. (The concentric through-hole of the plunger rod 124 is shown at 572 in FIGS. 5A and 5B.)

[0020] Gear drive shaft 122 has an elongated, hollow, cylindrical body 136 having a proximal portion 138 and a distal end including a gear wheel 142. Gear wheel 142 is operatively coupled to and driven by gear train 120. Proximal portion 138 of cylindrical body 136 is reduced in diameter relative to the diameter of the body of gear drive shaft 122, thereby forming a circumferential ledge 140 at proximal end 138 of gear drive shaft 122. Circumferential ledge 140 is used to retain gear drive shaft 122 within pump housing 114, as shown in FIG. 1B. Gear drive shaft 122 includes a nut portion (not shown in FIG. 1A but shown as 156 in FIG. 1B) and a bore or sleeve with an opening shown as 144. The bore or sleeve may be a through bore or through sleeve, meaning that it may have a second opening on the opposite side of opening 144.

[0021] Plunger rod 124 has two threaded surfaces, one of which is shown as 146. (Because the two threaded surfaces 146 are located opposite each other, the other threaded surface is not shown in FIG. 1A.) Plunger rod 124 also has two circumferential grooves 148 and 150 recessed into the cylindrical body of plunger rod 124, which receive retaining E-clip rings 132 and 134, respectively.

[0022] Reusable portion 116 also includes housing 114. Housing 114 includes a throughbore 152 that allows electric motor 118 (in conjunction with gear train 120 and gear wheel 142) to move plunger rod 124 axially (linearly) in both directions, extending plunger rod 124 from housing 114 through throughbore 152 and fully retracting plunger rod 124 to a stored position within housing 114. Throughbore 152 abuts bore / sleeve opening 144. Space 154 provides for removably and securely mounting syringe 101 and syringe adapter 128 to housing 114.

[0023] 1B shows the assembled pump device 100 with the cylindrical cam body 130 axially secured to the distal end of the plunger rod 124 by (between) retaining E-clip rings 132 and 134. This means that the cylindrical cam body 130 cannot move axially (along axis 107) along the length of the plunger rod 124. However, the cylindrical cam body 130 is free to rotate about the plunger rod 124. The mechanism by which the cylindrical cam body 130 rotates about the plunger rod 124 will be described below. FIG. 1B also shows the plunger rod (lead screw) 124 partially seated within the bore / sleeve of the gear drive shaft 122, with its two threaded surfaces 146 threadedly engaging a nut portion 156 of the gear drive shaft 122.

[0024] 1B also shows that the reusable portion 116 and the disposable syringe 101 can be releasably coupled to one another using, for example, a magnet (i.e., magnetic attraction), a snap-fit ​​connector, a bayonet connector, or the like. For example, a permanent magnet can be fixedly embedded in the reusable portion 116 or the disposable syringe 101, and a metal plate that is magnetically attractable to the magnet can be fixedly embedded in the other portion (e.g., the disposable syringe 101 or the reusable portion 116). In this way, when the reusable portion 116 and the disposable syringe 101 are brought close to one another, the permanent magnet magnetically attracts the metal plate. FIG. 1B also shows a cylindrical cam body 130 housed within the plunger head 106.

[0025] 1B , when motor 118 is activated, gear train 120 rotates, causing gear wheel 142, and thus the entire gear drive shaft 122, to rotate about longitudinal axis 107 of plunger head 106, cylindrical cam body 130, gear drive shaft 122, and plunger rod 124. Because nut portion 156 is part of or formed within cylindrical body 136 of gear drive shaft 122, nut portion 156 and gear drive shaft 122 can rotate together about rotation axis 107. Because gear drive shaft 122 (and thus nut portion 156) is axially constrained at reusable portion 116 and plunger rod 124 is rotationally constrained by plunger rod rotation constraint 126, rotation of nut portion 156 causes plunger rod 124 to move axially (linearly) along longitudinal axis 107. The direction in which plunger rod 124 moves along axis 107 depends on the direction of rotation (clockwise or counterclockwise) of gear wheel 142, which in turn depends on the direction of rotation of electric motor 118. That is, changing the direction of rotation of electric motor 118 changes the direction of rotation of gear wheel 142, and therefore the direction of rotation of nut portion 156, and the linear direction in which plunger rod 124 moves.

[0026] 2A-2C show that plunger rod 124 is constrained against rotational movement by plunger rod rotation constraint 126, while plunger rod 124 is able to move, or slide, linearly along longitudinal axis 107 of plunger rod 124. Referring to FIG. 2A, plunger rod 124 has two flat cut surfaces, one of which is designated 210. (The other flat cut surface 212 of plunger rod 124 is opposite flat cut surface 210 and is shown in FIG. 2B.) Plunger rod rotation constraint 126 is a generally circular object containing a concentric through-hole 220 through which plunger rod 124 can move linearly (axially) along longitudinal axis 107 (e.g., by electric motor 118). To constrain rotational movement of plunger rod 124 within plunger rod rotation constraint 126, throughbore 220 of plunger rod rotation constraint 126 has two constraint planes (230, 232) that abut cut surfaces 210 and 212 of plunger rod 124, respectively. (Constraint plane 230 is shown in FIG. 2A , and both constraint planes 230 and 232 are shown in FIG. 2B .) Plunger rod rotation constraint 126 also includes two peripheral flat cut surfaces (240, 250) to prevent plunger rod rotation constraint 126 from rotating within housing 114, for example, as a result of rotation of nut portion 156 of gear drive shaft 122 during normal operation of the pump device. FIG. 2B is a plan view of plunger rod 124 and plunger rod rotation constraint 126.

[0027] FIG. 2C shows cylindrical cam body 130 axially secured to the distal end of plunger rod 124 by (and between) flat retaining E-clip rings 132 and 134 (E-clip ring 132 is not shown in FIG. 2C). FIG. 2C shows E-clip ring 134 seated in annular groove 150. The use of retaining E-clip rings 132 and 134 prevents cylindrical cam body 130 from moving axially (along axis 107) on and along the length of plunger rod 124. However, cylindrical cam body 130 can rotate about plunger rod 124 between E-clip rings 132 and 134 by providing cam surfaces, as shown in FIG. 2C and as further described below in connection with, for example, FIGS. 5A-5B.

[0028] FIG. 2C also shows a plunger rod rotation constraint 126 fixedly mounted within the housing 114 of the reusable portion 116 of the pump device 100. Also shown in FIG. 2C is a portion of the power transmission system of the pump 100, which linearly moves the plunger rod 124 along the longitudinal axis 107. The power transmission system may include, among other things, an electric motor 118, a gear train 120, a gear wheel 142, and control circuitry or systems capable of controlling the operation of the power transmission system. The electric motor 118 is selectively controlled to bidirectionally rotate (260) the gear drive shaft 122 (FIGS. 1A and 1B) clockwise or counterclockwise, thereby selectively moving the plunger rod 124 forward or backward (270). Also shown in FIG. 2C are annular (circumferential) grooves 108 and 110.

[0029] Figure 3 more clearly shows plunger rod 124. Plunger rod 124 has a proximal end 310 and a distal end 320. Plunger rod 124 has two threaded surfaces 146 separated by two flat cut surfaces 210 and 212. (Only flat cut surface 210 is shown in Figure 3.) Distal end 320 of plunger rod 124 has two axially spaced annular (circumferential) grooves 148 and 150 for receiving two flat retaining E-clip rings 132 and 134, respectively.

[0030] Figure 4 illustrates a cylindrical plunger head 106 according to one embodiment. The plunger head 106 has a cylindrical chamber 410 that is open on one side and concentrically defined within the plunger head 106 by a cylindrical wall 420. The plunger head 106 also has a plurality of cam pins that are equiangularly spaced about the axis 107 of the plunger head 106, equiradially spaced from the axis 107, and that project radially from the cylindrical wall 420 toward the axis 107. (The longitudinal axis 107 is not shown in Figure 4.) Four cam pins (e.g., cam pins 430, 440, 450, and 460) are shown in Figure 4 by way of example. Plunger head 106 is linearly movable bidirectionally within syringe housing 102 along longitudinal axis 107 (e.g., using electric motor 118), but friction between two O-rings (112), typically rubber, and the inner wall of syringe housing 102 prevents rotation of plunger head 106 within syringe housing 102 about axis 107. Cam pins 430, 440, 450, and 460 cam against cam surfaces on cylindrical cam body 130 to rotate cylindrical cam body 130 within plunger head 106 about longitudinal axis 107 and to various operational angular positions of plunger head 106. This method of operation is described herein, for example, in connection with FIGS. 5A-5B, 6, 7, and 9A-9L. Cylindrical cam body 130 may include multiple cam surfaces spaced about the circumference of cylindrical cam body 130.

[0031] Tensioning member: "U" shaped tensioning recess and cam surface The cylindrical cam body may include a plurality of tension members disposed at the distal end of the cylindrical cam body, equiangularly spaced about axis 107 of cylindrical cam body 130 and equiradially spaced from axis 107 along its entire length. Each tension member includes a U-shaped tension recess. The number of tension members is equal to the number of cam pins. Each U-shaped tension recess is configured to receive, tensionally engage, and tension a respective one of the cam pins. (All cam pins have the same size and shape, and all U-shaped tension recesses also have the same size and shape. This means that any cam pin can engage any U-shaped tension recess, and any U-shaped tension recess can engage any cam pin, during axial reciprocation of plunger rod 124.) The U-shaped tension recesses are collectively used to axially tension the cam pins within syringe housing 102, and thus plunger head 106, when plunger rod 124 is moved rearward (backward) within syringe housing 102, for example, by electric motor 118.

[0032] 5A-5B show an exemplary cylindrical cam body (130) including four exemplary tension members, designated P1, P2, P3, and P4, each having one tension recess. However, the cylindrical cam body can include any number of tension members that is mechanically useful, such as fewer than four (e.g., three) or more than four (e.g., five). Furthermore, the tension members can include more than two tension recesses, such as two, three, etc. (An example tension member with three tension recesses is shown in FIG. 8). The number of tension members included in the cylindrical cam body and the number of tension recesses included in each tension member depend, among other factors, on the mechanical aspects of the cylindrical cam body, plunger head, cam pin, and syringe (e.g., overall dimensions, cam surface slope, diameter, shape, friction, materials used, etc.). Subject to mechanical feasibility, any number of tension members and tension recesses can be used.

[0033] 5A-5B, tension members P1, P2, P3, and P4 are identical in size, shape, and spatial orientation (e.g., relative position to longitudinal axis 107 of cylindrical cam body 130). Tension members P1, P2, P3, and P4 have cam surfaces configured to operate in conjunction with fixed cam pins 430, 440, 450, and 460 to functionally rotate cylindrical cam body 130 to a desired angular position within cylindrical chamber 416 of plunger head 106 upon reciprocating axial movement of plunger rod 124, and thus cylindrical cam body 130 within plunger head 106.

[0034] Each tension member P1, P2, P3, and P4 also has a tension recess that, when abutted against cam pins 430, 440, 450, and 460, is capable of tension engagement with cam pins 430, 440, 450, and 460, respectively, causing plunger rod 124 to pull cylindrical cam body 130 linearly (longitudinal, axially) in direction 526. Tension member P1 has an exemplary tension recess 504, and tension member P2 has an exemplary tension recess 506. (The tension recesses of tension members P3 and P4 are not shown in FIGS. 5A-5B but are identical to tension members P1 and P2 in shape, size, spatial orientation, and function, as described herein.) Each U-shaped tension recess is generally open toward the proximal end 508 of the cylindrical cam body 130 at an acute angle to a line parallel to the longitudinal axis 107 of the cylindrical cam body 130. (All U-shaped tension recesses taper toward the distal end 502 of the cylindrical cam body 130, parallel to the axis 107.

[0035] Each tension member Pi has a first protrusion and a second protrusion, and a U-shaped tension recess corresponding to tension member Pi is formed by and between the first and second protrusions. For example, tension member P1 (FIGS. 5A-5B) has a first protrusion (designated 510) and a second protrusion (designated 512). Protrusion 510 has a cam surface 514, and protrusion 512 has a stop surface 516. The U-shaped tension recess in (associated with) tension member P1 is formed by tension member P1's cam surface 514 and stop surface 516 and a bottom surface (e.g., an arcuate surface as shown at 504) that interconnects (bridges) cam surface 514 and stop surface 516.

[0036] Similarly, tension member P2 has a first protrusion 518 identical in structure, shape, orientation, and function to protrusion 510 of tension member P1, and a second protrusion 520 (FIG. 5B) identical in structure, shape, orientation, and function to protrusion 512 of tension member P1. Protrusion 518 has a cam surface (522) identical to cam surface 514 of protrusion 510, and protrusion 520 has a stop surface (524) similar to stop surface 516 of protrusion 512. Similar to U-shaped tension recess 504 formed by tension member P1, the U-shaped tension recess of tension member P2 (and associated with tension member P2) is formed by cam surface 522 and stop 524 of tension member P2 and a bottom surface (e.g., an arcuate surface as shown at 506) that interconnects (bridges) cam surface 522 and stop surface 524. The U-shaped tension recesses of all other tension members are formed by similar protrusions in the same manner as shown and described in relation to tension members P1 and P2.

[0037] The cam surfaces of the first protrusions of the tension members (e.g., cam surface 514 of first protrusion 510 of tension member P1, cam surface 522 of first protrusion 518 of tension member P2, etc.) cooperate with cam pins 430, 440, 450, and 460, respectively, to rotate cylindrical cam body 130 within cylindrical chamber 410 of plunger head 106. Cylindrical cam body 130 rotates within cylindrical chamber 410 until cam pins 430, 440, 450, and 460 tensilely engage tension recesses (e.g., tension recesses 504, 506) of tension members P1, P2, P3, P4, respectively. When the cam pins 430, 440, 450, and 460 are respectively tension-engaged with the tension recesses of the tension members P1, P2, P3, and P4, the electric motor 118 controllably retracts (moves rearward) the plunger rod 124 within the syringe housing 102, pulling the cylindrical cam body 130 and thus the plunger head 106 within the syringe housing 102 rearward (direction 526), ​​for example, to fill the syringe housing 102 with a medicament.

[0038] Each tension member has three additional cam surfaces (for a total of four cam surfaces in the example described herein). As an example, tension member P1 has cam surfaces 528, 530, and 532, and tension member P2 has cam surfaces 534, 536, and 538.

[0039] With respect to tension member P1, each of cam surfaces 528 and 530 (in cooperation with corresponding cam surfaces of the other tension members) can cooperate with one of cam pins 430, 440, 450, and 460 to rotate cylindrical cam body 130 within cylindrical chamber 410 through a predetermined angle at which cylindrical cam body 130 can receive all of cam pins 430, 440, 450, and 460 and cooperate with those cam pins to rotate cylindrical cam body 130 to various operating angular positions. The various angular operating positions of the cylindrical cam body 130 relative to the cam pin, and thus the plunger head, correspond to various phases of the reciprocating motion of the plunger rod 124, including engagement of the plunger rod 124 with the plunger head 106 (by the cylindrical cam body 130), alternate pushing and pulling of the plunger head 106 (by the cylindrical cam body 130) within the syringe housing 102, and finally, release of the plunger rod 124 from the cylindrical cam body 130, thereby releasing (disengaging) the plunger rod 124 from the plunger head 106. The various angular operating positions corresponding to various movements of the plunger rod 124 are described further herein, for example, below.

[0040] With respect to tension member P2, cam surfaces 534 and 536 function similarly to cam surfaces 528 and 530 of tension member P1 by cooperating with a different one of cam pins 430, 440, 450, and 460. All other tension members similarly have two cam surfaces of the same type, e.g., cam surfaces 528 and 530. All cam and stop surfaces of cylindrical cam body 130 are equiangularly spaced about axis 107 of cylindrical cam body 130 and equiradially spaced from axis 107 along its entire length.

[0041] 5A and 5B illustrate an exemplary cylindrical cam body 130 including four exemplary tension members designated P1, P2, P3, and P4, each having one tension recess. By way of example, each of tension members P1, P2, P3, and P4 has one tension recess.

[0042] Tensile member - penetration route: entrance and exit funnels Two adjacent tension members (Pi, Pi+1) jointly define a through-route therebetween through which each of cam pins 430, 440, 450, and 460 can enter and exit cylindrical cam body 130. (During axial reciprocating motion of plunger rod 124, cam pins do not enter and exit cylindrical cam body 130 through the same through-route. That is, if a cam pin (e.g., cam pin 430) enters cylindrical cam body 130 through a particular through-route, it will exit cylindrical cam body 130 only through another, subsequent through-route.)

[0043] The through channels have an inlet funnel and an outlet funnel. The number of through channels is the same as the number of cam pins. The through channels and cam pins are configured so that as the plunger rod 124 moves the cylindrical cam body 130 forward (544) into the chamber 410 of the plunger head 106, each particular cam pin abuts against an inlet funnel of a particular through channel and inserts (i.e., engages) into the cylindrical cam body 130, and as the plunger rod 124 moves the cylindrical cam body 130 backward (526) from the chamber 410 of the plunger head 106, each cam pin abuts against an outlet funnel of another through channel and withdraws (removes) it from the cylindrical cam body 130. (The inlet funnel axially precedes the outlet funnel into the cylindrical cam body 130.)

[0044] The inlet funnel F i is formed by a pair of conjugated axially forward camming surfaces, including the forward camming surface of a particular tension member P i and the forward camming surface of the tension member P i+1 adjacent to the particular tension member P i . The outlet funnel E i is formed by a pair of conjugated axially forward camming surfaces, including the rearward camming surface of a particular tension member P i and the rearward camming surface of the adjacent tension member P i+1 . For example (see FIG. 5B), the inlet funnel F i is formed by a pair of conjugated axially forward camming surfaces, including the forward camming surface 530 of tension member P i and the forward camming surface 534 of tension member P 2 adjacent to tension member P i . Similarly (see FIGS. 5A-5B), the inlet funnel F 4 is formed by a pair of conjugated axially forward camming surfaces, including the forward camming surface 574 of tension member P 4 and the forward camming surface 528 of tension member P 1 adjacent to tension member P 4 .

[0045] For example (see again FIG. 5B), exit funnel E1 is formed by a pair of conjugated axially rearward surfaces, including rearward cam surface 532 of tension member P1 and rearward stop surface 542 of tension member P2 adjacent tension member P1. (As used herein, forward and rearward refer to axial positions relative to cylindrical cam body 130. For example, when axially forward, cam surface 530 of tension member P1 and cam surface 534 of tension member P2 lead cam surface 532 of tension member P1 and surface 542 of tension member P2 within cylindrical cam body 130.)

[0046] Each inlet funnel is configured to rotatably receive a respective one of the cam pins and guide the cam pin to an engaged angular position upon linear insertion of cylindrical cam body 130 into chamber 410 of plunger head 106 by plunger rod 124. As cylindrical cam body 130 is linearly (axially 107) and non-rotationally moved in direction 544 into chamber 410 of plunger head 106, corresponding cam surfaces of cylindrical cam body 130 cooperate with cam pins 430, 440, 450, and 460 to rotate cylindrical cam body 130 about longitudinal axis 107 to an angular position within chamber 410 at which the cam pins engage their respective ejection recesses and at which plunger rod 124 can simultaneously eject cam pins 430, 440, 450, and 460, and thus plunger head 106, within syringe housing 102.

[0047] Conversely, when cylindrical cam body 130 moves axially (107) and non-rotationally rearward (rearward) in direction 526 within chamber 410 of plunger head 106, corresponding cam surfaces (e.g., other cam surfaces) of cylindrical cam body 130 cooperate with cam pins 430, 440, 450, and 460 to rotate cylindrical cam body 130 about longitudinal axis 107 to angular positions within chamber 410 where the cam pins each engage with the pulling recesses, allowing plunger rod 124 to simultaneously pull cam pins 430, 440, 450, and 460, and thus plunger head 106, into syringe housing 102.

[0048] As shown in Figures 5A-5B, inlet funnel F1 is configured to rotatably receive and guide each of cam pins 430, 440, 450, and 460 into an engaged angular position within cylindrical cam body 130 as plunger rod 124 linearly inserts cylindrical cam body 130 into chamber 410. (Linear movement of cylindrical cam body 130 relative to the cam pins in direction 544 causes cylindrical cam body 130 to rotate about axis 107.) Figures 5A-5B show an example of a cylindrical cam body (130) with four extrusion members, thus providing a total of four through-holes, each with an opening similar to opening 540. FIG. 5B shows three other inlet funnels: F2 (coexisting with and between tension members P2 and P3), F3 (coexisting with and between tension members P3 and P4), and F4 (coexisting with and between tension members P4 and P1).

[0049] 5B, exit funnel E1 is configured so that cylindrical cam body 130 rotatably receives and guides each of cam pins 430, 440, 450, and 460 into a disengagement angular position within cylindrical cam body 130 as cam body 130 linearly retracts from chamber 410 of plunger head 106. (As cylindrical cam body 130 moves linearly away from the cam pins, cylindrical cam body 130 rotates about axis 107 until the cam pins are each released from cylindrical cam body 130 through the exit funnel.)

[0050] Each inlet funnel (e.g., inlet funnel F1) has a large opening at the distal end 502 of the cylindrical cam body 130 and tapers (narrows) from the distal end 502 toward the proximal end 508 of the cylindrical cam body 130. Each outlet funnel (e.g., outlet funnel E1) has a large opening that opens toward the proximal end 508 of the cylindrical cam body 130 and tapers (narrows) toward the distal end 502 of the cylindrical cam body 130. Therefore, the inlet funnel (F1 in FIG. 5B) and outlet funnel (E1 in FIG. 5B) of each penetration route are arranged back-to-back in the longitudinal direction so that the narrow opening of the inlet funnel coincides with the narrow opening of the outlet funnel. Referring to FIG. 5B, the inlet funnel F1 and the outlet funnel E1 are arranged back-to-back in the longitudinal direction so that the narrow opening of the inlet funnel coincides with the narrow opening of the outlet funnel as opening 540.

[0051] Tooth-cam surface and extrusion recess Cylindrical cam body 130 has n teeth that are circumferentially spaced at equal angular intervals around axis 107 and that are spaced at equal radial intervals from axis 107 along the entire periphery of cylindrical cam body 130, forming n cam surfaces and n stop surfaces at the proximal end of the cylindrical cam body. The n cam surfaces and the n stop surfaces provided by the n teeth collectively form n U-shaped pushing recesses that allow plunger rod 124 to push plunger head 106 through the cam pin, thereby expelling, for example, a medication contained within syringe housing 102. (Expulsion of a medication from the syringe housing is performed, for example, to prepare an infusion tubing set for operation and / or to deliver a medication to a patient (e.g., subcutaneous administration).)

[0052] By way of example, the cylindrical cam body 130 has eight (n=8) circumferential teeth, designated sequentially as T1, T2, T3, T4, T5, T6, T7, and T8. Teeth T1-T8 are circumferentially, equiangularly, and equiradially spaced on the proximal end 508 of the cylindrical cam body 130 around the longitudinal axis 107 of the cylindrical cam body 130. (FIG. 5A illustrates teeth T1, T2, T3, T4, and T8. FIG. 5B illustrates teeth T1, T2, T3, T4, and T5.) The circumferential teeth T1, T2, T3, T4, T5, T6, T7, and T8 collectively form a sawtooth crown 578 at the proximal end 508 of the cylindrical cam body 130, with each tooth of the sawtooth crown 578 being a right triangle including a cam surface and a stop surface.

[0053] Teeth T1, T2, T3, T4, T5, T6, T7, and T8 form eight structurally identical U-shaped extrusion recesses between them. Each U-shaped extrusion recess is formed by the cam surface of a particular tooth (Ti) and the stop surface of the subsequent tooth (Ti+1), as well as a bottom surface that interconnects the cam surface of the particular tooth (Ti) and the stop surface of the subsequent (consecutive) tooth (Ti+1) to form a single continuous surface. As an example (see FIG. 5B ), U-shaped extrusion recess 546 is formed between teeth T2 and T3 by cam surface 548 of tooth T2, stop surface 550 of tooth T3, and bottom surface 552 that interconnects cam surface 548 and stop surface 550. (Cam surface 548, stop surface 550, and bottom surface 552 form a single continuous surface.)

[0054] Similarly, between teeth T3 and T4, a U-shaped extrusion recess 554 is formed by cam surface 556 of tooth T3, stopper surface 558 of tooth T4, and a bottom surface (560) that interconnects cam surface 556 and stopper surface 558 and forms a single continuous surface with them. (Cam surface 556, stopper surface 558, and bottom surface 560 form a single continuous surface.) Similarly, between teeth T1 and T2, a U-shaped extrusion recess 562 is formed by cam surface 564 of tooth T1 (FIG. 5A), stopper surface 566 of tooth T2 (FIG. 5A), and a bottom surface (568) that interconnects cam surface 564 and stopper surface 566 and forms a single continuous surface with them. The remaining U-shaped extrusion recesses are similarly formed between teeth T4 and T5, between teeth T5 and T6, between teeth T6 and T7, between teeth T7 and T8, and between teeth T8 and T1. (The cam surface 564, the stopper surface 566, and the bottom surface 568 form one continuous surface.)

[0055] The cam surfaces of the teeth (e.g., cam surface 564 of tooth T1, cam surface 548 of tooth T2, cam surface 556 of tooth T3, etc.) cooperate with cam pins 430, 440, 450, and 460, respectively, to rotate cylindrical cam body 130 within cylindrical chamber 410 of plunger head 106. Cylindrical cam body 130 rotates within cylindrical chamber 410 until cam pins 430, 440, 450, and 460, respectively, engage extrusion recesses (e.g., extrusion recesses 562, 546, 554, etc.). When the cam pins 430, 440, 450, and 460 each engage with the ejection recesses, the electric motor 118 controllably pushes (moves forward) the plunger rod 124 within the syringe housing 102, pushing the cylindrical cam body 130 and thus the plunger head 106 within the syringe housing 102 forward (direction 544), e.g., to expel medication from the syringe housing 102, e.g., to prime an infusion tubing set and / or deliver medication to a patient.

[0056] The cam surface of the cylindrical cam body 30 is formed, for example, in a 30° spiral around the cylindrical cam body 130, and is configured to impart unidirectional rotational motion to the cylindrical cam body 130 when the cylindrical cam body 130 is moved axially back and forth relative to the rotating fixed cam pin of the plunger head 106 by the plunger rod 124. (The plunger rod 124 repeatedly moves axially back and forth to alternately align the cam surface with the fixed cam pin, thereby maintaining the cam body 130 in an alternate plunger head extension position and a plunger head extension position.)

[0057] One-way rotation of cylindrical cam body Generally, the orientation of the tension members and cam surfaces of the teeth of the cylindrical cam body 130 is such that reciprocation of the cylindrical cam body 130 within the chamber 410 of the plunger head 106 by the plunger rod 124 along the axis of rotation 107 imparts unidirectional rotational motion (576, FIG. 5A) and longitudinal reciprocating motion to the cylindrical cam body 130 within the chamber 410. (This unidirectional rotational direction, rotational direction 576 in this example, is referred to herein as the primary rotational direction.) However, there is one qualified exception to this concept, which is related to the inlet funnel, as described below.

[0058] Before plunger rod 124 engages plunger head 106 via cylindrical cam body 130 and cam pins (i.e., before cylindrical cam body 130 is forced by plunger rod 124 into chamber 410 of plunger head 106), cylindrical cam body 130 rotates freely on plunger rod 124 between two retaining E-clip rings 132 and 134. This means that the initial angular orientation of inlet funnels F1, F2, F3, and F4 of cylindrical cam body 130 relative to the angularly fixed cam pins of chamber 410 is random. Furthermore, the angular orientation of chamber 410, and therefore the cam pins, relative to the syringe housing can vary from syringe to syringe (e.g., during syringe assembly), which adds another factor to the randomness of the inlet funnel and cam pin alignment.

[0059] Thus, although the inlet funnel's front cam surface can potentially rotate the cylindrical cam body 130 in the same primary rotational direction 576 as the other cam surfaces of the cylindrical cam body 130 (potentially, when these cam surfaces cooperate with the cam pins), the other cam surfaces of the cylindrical cam body 130 are not necessarily angularly aligned with the cam pins when the cylindrical cam body 130 engages the cam pins. The inlet funnel's front cam surface that cams with the cam pins and maintains the primary rotational direction 576 is referred to herein as the "primary cam surface." (Inlet funnel cam surfaces 530, 536, and 574 are examples of primary cam surfaces.) However, the funnel's front cam surface that could potentially rotate the cylindrical cam body 130 in the primary rotational direction 576 may be angularly offset relative to the cam pins. That is, the front cam surface may be angularly offset relative to the cam pins when the cylindrical cam body 130 engages the cam pins. Thus, if there is an angular offset between the primary cam surface and the cam pin, the cam surface that coincides with the cam pin is the inlet funnel's other, forward cam surface, referred to herein as the auxiliary cam surface. (Inlet funnel cam surfaces 528 and 534 are examples of auxiliary cam surfaces.) In this case, cooperation between the auxiliary cam surface and the cam pin causes cylindrical cam body 130 to rotate in the opposite direction to primary rotation direction 576. However, a third option is to align the cam pin with through-channel opening 540. In this case, the cam pin reaches the cam surface of each tooth that abuts the through-channel without rotating cylindrical cam body 130 in either direction.

[0060] The U-shaped extrusion recess is configured to synchronize the cam pins (e.g., cam pins 330, 340, 350, and 360) and thus push the plunger head 106 axially forward (in direction 544) within the syringe housing 102 when the plunger rod 124 is moved forward, e.g., by the electric motor 118, causing the cylindrical cam body 130 to move in direction 544, e.g., expelling the medication from the syringe housing 102.

[0061] In one embodiment, the number of teeth (n) may be twice the number of tension members k (e.g., k=n / 2). Continuing with this example, as shown in FIGS. 5A-5B, the number of tension members is four (k=4), and FIGS. 5A-5B show example tension members P1, P2, P3, and P4. Each U-shaped extrusion recess generally opens toward the distal end 502 of the cylindrical cam body 130 at an acute angle relative to a line parallel to the longitudinal axis of the cam body 130. (All U-shaped extrusion recesses taper toward the proximal end 508 of the cylindrical cam body 130, parallel to the axis 107.)

[0062] The n circumferential teeth and n / 2 tension members are alternately arranged around the periphery of the cylindrical cam body, with every odd-numbered tooth T2i+1 (e.g., teeth T1, T3, T5, etc.) structurally abutting (located on the opposite side of) the through-hole formed by two adjacent tension members Pi and Pi+1, and every even-numbered tooth T2i (e.g., teeth T2, T4, T6, etc.) structurally abutting (located on the opposite side of) the U-shaped tension recess of a particular tension member (Pi+1). For example, teeth T1, T2, T3, T4, T5, T6, T7, and T8 and tension members P1, P2, P3, and P4 are alternately arranged around the periphery of the cylindrical cam body 130, and the following relationship holds: Tooth T1 abuts the penetration route formed by adjacent tension members P1 and P4. Tooth T2 abuts against U-shaped tension recess 570 of tension member P1. Tooth T3 abuts the through-route formed by adjacent tension members P1 and P2. Tooth T4 abuts U-shaped tension recess 580 (FIG. 5A) of tension member P2, and so on.

[0063] 6 shows the cylindrical cam body 130 and plunger rod 124 assembled together, and shows the cylindrical cam body 130 in a state before being inserted into the plunger head 106 by the plunger rod 124. Cam pin 430 (not shown in FIG. 6), located radially opposite cam pin 450, abuts (610) the through route formed between tension members P1 and P2. Cam pin 460 of plunger head 106 abuts (620) against a through-route formed between tension members P2 and P3 (tension member P3 is not shown in FIG. 6). Cam pin 450 of plunger head 106 abuts against a through-route formed between tension members P3 and P4 (tension member P3 is not shown in FIG. 6). Cam pin 440 (not shown in FIG. 6), located radially opposite cam pin 460, abuts (630) the through route formed between tension members P4 and P1.

[0064] 6, the cam surface of the cylindrical cam body 130 that abuts the cam pin is the rotation-retaining cam surface. Thus, when the plunger rod 124 is moved linearly (axially) forward (544) along the longitudinal axis 107, for example by the electric motor 118, the forward cam surface of the cylindrical cam body 130 cams against the cam pin of the plunger head 106, causing the cylindrical cam body 130 to rotate in the direction 576.

[0065] The n / 2 tension members are positioned axially spaced apart from the n teeth of the sawtooth crown and form guide zigzag routes along which the cam pins move as the plunger rod reciprocates, from an engagement angular position where the cam pins each abut against the through-holes to a disengagement angular position (where the cam pins each abut against the through-holes) as the cylindrical cam body rotates within the plunger head. (The guide zigzag routes guide the cam pins in the cylindrical cam body from one recess to another and, correspondingly, from one operating angular position of the cylindrical cam body to another operating angular position.)

[0066] 7, tension members P1, P2, P3, and P4 (tension member P3 is not shown in FIG. 7) are positioned axially apart from sawtooth crown 578 and together form a guide zigzag route indicated in FIG. 7 by dotted (dashed) line 710. (The five arrows on dotted line 710 indicate the direction that the cam pin moves relative to zigzag route 710 as cylindrical cam body 130 rotates in direction 576 and reciprocates within plunger head 106.)

[0067] Guide zigzag route 710 surrounds surface 720 of cylindrical cam body 130, and each cam pin of plunger head 106 enters or accesses guide zigzag route 710 through a corresponding through route opening (e.g., 540, FIG. 5B ). (Each through route opening is sometimes referred to as an access point for zigzag route 710.) The width of guide zigzag route 710 varies along the length of the route, but its minimum value is set to allow cam pins 430, 440, 450, and 460 to pass through the route as cylindrical cam body 130 rotates within plunger head 106.

[0068] A rotational cycle of the cylindrical cam body 130 within the plunger head 106 involves rotation of the cylindrical cam body 130 from an engagement angular position, in which the cam pins of the plunger head 106 each abut an inlet funnel, to a disengagement angular position, in which the cam pins each abut an outlet funnel and each cam pin abuts an outlet funnel of the penetration route next in the penetration route that includes the inlet funnel of that particular cam pin. Rotation of the cylindrical cam body 130 from the engagement angular position to the disengagement angular position occurs through a continuous series of alternating push-pull angular positions upon axial reciprocation of the plunger rod 124, as described herein, for example, below.

[0069] For simplicity, Figure 7 shows one example cam pin (e.g., cam pin 440) traversing zigzag route 710. (Other cam pins on the plunger head enter zigzag route 710 at different access points and traverse different portions of zigzag route 710.) When cylindrical cam body 130 is forced into plunger head 106 by plunger rod 124 (as shown at 544 in Figure 6), cam pin 440 enters cylindrical cam body 130 (730), enters inlet funnel 740, and travels along the inlet through path 750 to access zigzag route 710. Although cam pin 440 is fixed, axial reciprocation of cylindrical cam body 130 within plunger head 106 by reciprocating plunger rod 124 causes cam pin 440 (and other cam pins on the plunger head) to rotate cylindrical cam body 130 from one angular position to another.

[0070] When cam pin 440 enters entrance funnel 740 through landmark A1 (by forcing cylindrical cam body 130 against cam pin 440), cam pin 440 rotates cylindrical cam body 130 in direction 576 or the opposite direction, depending on which forward cam surface (rotation-retaining cam surface or counter-rotation cam surface) cam pin 440 interacts with. If none of these cam surfaces interacts with cam pin 440, cam pin 440 accesses zigzag route 710 along entrance path 750 without rotating cylindrical cam body 130.

[0071] 7 illustrates five different points and landmarks (designated A1, A2, A3, A4, and A5) along the path of the cam pin 440 relative to the cylindrical cam body 130, indicating various angular positions at which the cylindrical cam body 130 is rotated by and relative to the fixed cam pin 440. Landmark A1 corresponds to the engagement angular position (relative to the cam pin 440) of the cylindrical cam body 130, where moving the cylindrical cam body 130 forward 544 relative to the fixed plunger head 106 enables the cylindrical cam body 130 to engage with the plunger head 106. Landmarks A2 through A4 indicate successive, alternating push / pull angular positions of the cylindrical cam body 130 relative to the cam pin 440. Landmark A5 corresponds to the angular position (relative to cam pin 440) at which cylindrical cam body 130 disengages from plunger head 106 by moving cylindrical cam body 130 away from fixed plunger head 106.

[0072] With respect to landmarks A2 to A4, landmark A2 indicates a first U-shaped push recess corresponding to a first push angle position where the plunger rod 124 can push the plunger head 106 forward, landmark A3 indicates a U-shaped pull recess corresponding to a pull angle position where the plunger rod 124 can pull the plunger head 106 backward, and landmark A4 indicates a second U-shaped push recess corresponding to a second push angle position where the plunger rod 124 can push the plunger head 106 forward again, thus alternating between the "nature" of a push recess and a pull recess.

[0073] When cam pin 440 is at landmark A4 (after zig-zag movement along zig-zag route 710), cylindrical cam body 130 is first pushed forward (544) by plunger rod 124 (e.g., to expel medication from syringe housing 102). Cylindrical cam body 130 is then pulled by plunger rod 124 to disengage cylindrical cam body 130 from cam pin 440. Cam pin 440 is disengaged from cylindrical cam body 130 by pulling cylindrical cam body 130 rearward, such that cam pin 440 exits zig-zag route 710, enters exit funnel 760, and generally exits cylindrical cam body 130 along exit through-path 780 (770).

[0074] The example shown in FIG. 7 illustrates a cylindrical cam body with a particular design, in which each tension member P1, P2, P3, and P4 has one tension recess. This design (i.e., one tension recess per tension member) provides each cam pin with three alternating push / pull angular positions, for a total of five angular positions, including an engagement angular position (A1), three alternating push / pull angular positions (A2-A4), and a disengagement angular position (A5). However, in other embodiments, the cylindrical cam body is designed to provide a different number of pull and push angular positions, as described below in connection with FIG. 8. A zigzag route formed in the cylindrical cam body (e.g., the zigzag route in FIG. 8) guides the cam pin in the cylindrical cam body from one recess to another and, correspondingly, from one operating angular position of the cylindrical cam body to another operating angular position.

[0075] FIG. 8 schematically illustrates an expanded cylindrical cam body 800 according to another embodiment. Similar to cylindrical cam body 130, cylindrical cam body 800 includes four tension members, designated P1′, P2′, P3′, and P4′. However, unlike cylindrical cam body 130, each of tension members P1′, P2′, P3′, and P4′ has (provides) three tension recesses. For example, tension member P1′ has tension recesses 810, 820, and 830. Thus, cylindrical cam body 800 has a total of 12 tension recesses. The four tension members P1′, P2′, P3′, and P4′ form four through-holes between them. Therefore, cylindrical cam body 800 is also designed to cooperate with a plunger head similar to plunger head 106, which includes four cam pins. Cam body 800 also has 16 teeth designated T1', T2', T3', ..., T16', with 16 extrusion recesses formed therebetween similar to teeth T1, T2, T3, ..., T8 of cylindrical cam body 130.

[0076] As described in connection with cylindrical cam body 130, a cam pin (e.g., cam pin 440) enters cylindrical cam body 130 via a particular through-route and exits cam body 130 via a subsequent (successive) through-route. Similarly, cam pin 840 enters cylindrical cam body 800 (850) via through-route 860 and exits cylindrical cam body 800 (870) via a subsequent (successive) through-route 880.

[0077] FIG. 8 illustrates the cam pin 840 at nine different times and landmarks (designated B1, B2, B3, B4, B5, B6, B7, B8, and B9) along a zigzag path 890 relative to the cylindrical cam body 800. The nine landmarks indicate various angular positions to which the cylindrical cam body 800 is sequentially rotated by and relative to the fixed cam pin 840. Landmark B1 corresponds to the engagement angular position (relative to the cam pin 840) of the cylindrical cam body 800, at which the cylindrical cam body 800 can engage with the fixed plunger head by moving the cylindrical cam body 800 forward relative to the plunger head. Landmarks B2 through B8 indicate sequential, alternating push / pull angular positions of the cylindrical cam body 800 relative to the cam pin 840. Landmark B9 corresponds to a disengagement angular position (relative angle with respect to cam pin 840) at which cylindrical cam body 800 can be disengaged from the plunger head by separating cylindrical cam body 800 from the fixed plunger head.

[0078] With respect to landmarks B2 to B8, landmark B2 indicates a first U-shaped push recess corresponding to a first push angle position where the plunger rod can push the plunger head forward. Landmark B3 indicates a U-shaped pull recess corresponding to a first pull angle position where the plunger rod can pull the plunger head backward. Landmark B4 indicates a second U-shaped push recess corresponding to a second push angle position where the plunger rod can push the plunger head forward again. Landmark B5 indicates a U-shaped pull recess corresponding to a second pull angle position where the plunger rod can pull the plunger head backward. Landmark B6 indicates a third U-shaped push recess corresponding to a third push angle position where the plunger rod can push the plunger head forward again. Landmark B7 indicates a U-shaped pull recess corresponding to a third pull angle position where the plunger rod can pull the plunger head backward. Landmark B8 indicates a fourth U-shaped push recess corresponding to a fourth push angle position where the plunger rod can push the plunger head forward again, thus alternating the "nature" of push recess and pull recess.

[0079] 9A-9L are exploded views of an example cylindrical cam body, illustrating step-by-step how the cam surface of the cylindrical cam body engages with an example cam pin to alternately push and pull the cylindrical cam body, and thus the syringe plunger head. Cylindrical cam body 910 (in this example, similar to cylindrical cam body 130) is axially fixed to the distal end of plunger rod 920 (in this example, similar to plunger rod 124), but is bidirectionally rotatable about the plunger rod. Tension members P1", P2", P3", and P4" are similar to tension members P1, P2, P3, and P4, respectively, of cylindrical cam body 130. Reference line 970 indicates the rest angular position of cam pin 930 relative to cylindrical cam body 910.

[0080] 9A shows cylindrical cam body 910 prior to engagement with cam pin 930 (in this example, similar to cam pins 430, 440, 450, and 460). Cam body 910 provides a five-position cycle that rotates cylindrical cam body 910 from an engagement angular position (position A1) in which cam pin 930 abuts an inlet funnel 960 to a disengagement angular position (position A5) in which cam pin 930 abuts an outlet funnel 962 of a through passage subsequent to the through passage containing inlet funnel 960. Rotation of cylindrical cam body 910 from engagement angular position A1 to disengagement angular position A5 occurs through a series of alternating push-pull angular positions during reciprocating axial movement (942) of plunger rod 920, as described herein, e.g., below. The successive alternating push-pull angular positions in this example include two push angular positions (angular positions A2 and A4) and one pull angular position (angular position A3) that angularly follows push angular position A2 and angularly precedes push angular position A4.

[0081] Referring to FIG. 9A, as plunger rod 920 moves cylindrical cam body 910 forward (in direction 940) toward the plunger head (not shown in FIG. 9A), this movement causes fixed cam pin 930 to enter (950) an entrance funnel 960 formed by and between tension members P1″ and P2″. ​​As cylindrical cam body 910 continues to move in direction 940, cam pin 930 continues to enter cylindrical cam body 910 through entrance funnel 960, and a forward cam surface 980 of tension member P1″ cams into engagement with cam pin 930. Reference numerals 990, 992, 994, and 996 indicate successive legs of the zigzag groove traversed by cam pin 930 as plunger rod 920 moves reciprocally along longitudinal axis 107 (e.g., up and down in FIGS. 9A-9L).

[0082] Figure 9B shows the front cam surface 980 being cammed by the cam pin 930. As the cylindrical cam body 910 continues to move in the direction 940, the cam surface 980 cams into engagement with the cam pin 930, causing the cylindrical cam body 910 to rotate on the plunger rod 920 in the direction 982 about the rotation axis 107 until the cylindrical cam body 910 reaches the engagement angular position A1, as shown in Figure 9C. As the cylindrical cam body 910 continues to move in the direction 940, the cam pin 930 continues to penetrate deeper into the cylindrical cam body 910 along the zigzag groove leg 990 from the engagement angular position A1 toward the push-out angular position A2. More specifically, to move the cam pin 930 to the push-out angular position A2, the cylindrical cam body 910 is first moved in direction 940 (equivalent to moving the cam pin 930 downward along the reference line 970 relative to the cam body 910) until the cam surface 984 of tooth T3" is cammed by the cam pin 930, as shown in FIG. 9D. (FIG. 9D shows the cam surface 934 of tooth T3" being cammed by the cam pin 930.) Next (see FIG. 9D), as the cylindrical cam body 910 is further advanced in direction 940, the cam surface 984 cams into engagement with the cam pin 930 and the cylindrical cam body 910 rotates further in direction 982, until the cylindrical cam body 910 reaches the push-out angular position A2, as shown in FIG. 9E.

[0083] 9B , the longitudinal (axial) spacing 946 between the tension and push recesses is the axial distance that the cylindrical cam body 910 must move in order for the cam pin to switch from engagement with the push recess to engagement with the tension recess, or vice versa. Because the plunger rod is an integral part of the reusable portion of the pump device, the exact axial position of the plunger rod and the spacing between the tension and push recesses (spacing 946) are always known to the pump device's controller. Therefore, because spacing 946 is a known element to the pump device's controller, the controller always knows the exact axial position of the plunger head 106 within the syringe housing 102. As a result, the pump device can precisely control the flow rate of the medication as well as the dosage of the medication delivered to a patient using the pump device.

[0084] Referring again to FIG. 9B, line 928 is parallel to longitudinal axis 107. Midline 934 of tooth T8″, i.e., the entire tooth, is inclined at angle α relative to line 928. For example, angle α can be 30° to 50° (e.g., α=45°). All teeth in the sawtooth crown are inclined at the same angle and in the same direction in the developed view. (Teeth T1″-T8″ in FIGS. 9A-9L are inclined approximately 30° to the right in the developed view.)

[0085] 9E, when cam pin 930 is in angular position A2, as plunger rod 920 moves forward (direction 940), the pushing recess corresponding to angular position A2 pushes cylindrical cam body 910, i.e., plunger head (106 in FIG. 1A), forward. For example, by moving the syringe from proximal end 103 (FIG. 1A) of syringe housing 102 to distal end 105 (FIG. 1A) of syringe housing 102, air within the syringe housing can be expelled in preparation for filling the syringe with medication. After the plunger head reaches the distal end of the syringe housing, or at any time before the plunger head reaches the distal end of the syringe housing, the direction of axial movement of plunger rod 920 can be reversed, i.e., plunger rod 920 can be moved backward (direction 944) (e.g., by electric motor 118).

[0086] Referring to FIG. 9E, as the cylindrical cam body 910 is moved rearward (direction 944) by the plunger rod 920, the cam pin 930 continues to move within the cylindrical cam body 910 along the zigzag groove leg 992 from the push angle position A2 toward the pull angle position A3. More specifically, to move cam pin 930 to tension angle position A3, cylindrical cam 910 first moves in direction 944 (equivalent to moving cam pin 930 upward relative to cam body 910 along reference line 970) until cam surface 986 of tension member P2″ is cammed by cam pin 930, as shown in FIG. 9F. (FIG. 9F shows cam surface 986 of tension member P2″ being cammed by cam pin 930.) Next (see FIG. 9F), further rearward movement of cylindrical cam body 910 in direction 944 cams cam surface 986 into camming engagement with cam pin 930, again rotating cylindrical cam body 910 in direction 982 until cylindrical cam body 910 reaches tension angle position A3, as shown in FIG. 9G.

[0087] 9G, when cam pin 930 is in angular position A3, as plunger rod 920 moves rearward (direction 944), the pulling recess corresponding to angular position A3 pulls cylindrical cam body 910. This causes the plunger head (106 in FIG. 1A) to move rearward within the syringe, e.g., from distal end 105 (FIG. 1A) of syringe housing 102 to proximal end 103 (FIG. 1A) of syringe housing 102, e.g., to fill the syringe housing with medication. At any time after or before the plunger head reaches the proximal end of the syringe housing, the direction of axial movement of plunger rod 920 can be reversed, i.e., plunger rod 920 can be advanced again in direction 940 (e.g., by electric motor 118).

[0088] Referring to FIG. 9G, as the cylindrical cam body 910 again moves in the direction 940, the cam pin 930 continues to move within the cylindrical cam body 910 along the zigzag groove leg 994 from the pulling angular position A3 toward the pushing angular position A4. More specifically, to position cam pin 930 at push-out angular position A4, cylindrical cam body 910 is moved in direction 940 (which is equivalent to moving cam pin 930 downward relative to cam body 910 along reference line 970) until cam surface 988 of tooth T4" is cammed by cam pin 930, as shown in FIG. 9H. (FIG. 9H shows cam surface 988 of tooth T4" being cammed by cam pin 930.) Next (see FIG. 9H), if cylindrical cam body 910 is moved further forward (in direction 940), cam surface 988 cams into engagement with cam pin 930 and cylindrical cam body 910 again rotates in direction 982 until cylindrical cam body 910 reaches push-out angular position A4, as shown in FIG. 9I.

[0089] 9I , when cam pin 930 is in angular position A4, as plunger rod 920 moves forward (direction 940), the push-out recess associated with angular position A4 again pushes against cylindrical cam body 910, thus pushing the plunger head (106 in FIG. 1A) forward within the syringe, e.g., from proximal end 103 (FIG. 1A) of syringe housing 102 to distal end 105 (FIG. 1A) of syringe housing 102, e.g., delivering a medication loaded in the syringe housing to a patient. After the plunger head reaches the distal end of the syringe housing, or at any time before the plunger head reaches the distal end of the syringe housing, the direction of axial movement of plunger rod 920 can be reversed, i.e., plunger rod 920 can be moved backward in direction 944 (e.g., by electric motor 118), to release plunger rod 920 from the plunger head. This allows, for example, replacing a used (empty) disposable syringe (102) with a new disposable syringe.

[0090] As the cylindrical cam body 910 moves rearward (direction 944), the cam pin 930 continues its relative movement along the zigzag groove leg 996 through (guided by) the exit funnel 962 from the push-out angular position A4 towards the release angular position A5. More specifically, to move the cam pin 930 to the release angular position A5, the cylindrical cam body 910 is moved axially in direction 944 (which is equivalent to moving the cam pin 930 upwardly relative to the cam body 910 along reference line 970) until the cam surface 997 of the tension member P2" is cammed by the cam pin 930, as shown in FIG. 9J. (FIG. 9J shows that the cam surface 997 of the tension member P2" is cammed by the cam pin 930.) Next (see FIG. 9J), further movement of the cylindrical cam body 910 rearward in direction 944 causes the cam surface 997 to cam against the cam pin 930, again rotating the cylindrical cam body 910 in direction 982 about the rotation axis 107 until the cylindrical cam body 910 reaches the release angular position A5, as shown in FIG. 9K. Referring to FIG. 9K, when the cam pin 930 is in the disengagement angular position A5, if the plunger rod 920 moves further rearward (in the direction 944), the cylindrical cam body 910 disengages from the cam pin 930, as shown in FIG. 9I.

[0091] Forward cam surface 980 of tension member P1", cam surface 984 of tooth T3", rearward cam surface 986 of tension member P2", cam surface 988 of tooth T4", and rearward cam surface 997 of tension member P2" are angled such that reciprocating axial movement of plunger rod 920 (942 in FIG. 9A ) causes these cam surfaces to cooperate with cam pin 930 sequentially (i.e., first forward cam surface 980, then cam surface 984, and so on) to rotate cylindrical cam body 910 unidirectionally in direction 576. Cam pin 931 is one cam pin described as rotating cylindrical cam body 910 unidirectionally in direction 576. However, as described herein and shown, for example, in FIG. As shown in FIG. 4, the plunger head has multiple cam pins, all of which synchronously rotate the cylindrical cam body 910 in one direction, 576. The synchronous movement of the cam pins means that all of the cam pins simultaneously enter (engage) the cylindrical cam body through different penetration routes (entrance funnels), then pass through similar zigzag legs, and finally simultaneously exit (disengage) the cylindrical cam body through different penetration routes (exit funnels). The entrance penetration route of a particular cam point is the exit penetration route of another cam point. Similarly, the exit penetration route of a particular cam point is the entrance penetration route of another cam point.

[0092] 9L also shows two of the four cam pins, one designated 930 and the other designated 932. As cam pin 930 rotates cylindrical cam body 910 and enters cylindrical cam body 910 through inlet funnel 960 at engagement angular position (A1), cam pin 932 simultaneously rotates cylindrical cam body 910 and simultaneously enters cylindrical cam body 910 through inlet funnel 964 at engagement angular position (A1') (the other cam pins similarly move through other inlet funnels). The other cam pins simultaneously move along similar paths to their engagement angular positions. In this manner, all cam pins simultaneously enter cylindrical cam body 910.

[0093] When the cam pin 930 rotates the cylindrical cam body 910 to the first push-out angular position (A2), as the cam pin 932 moves to this position via the guide zigzag groove legs 990, it cams the cylindrical cam body 910 to rotate to its first push-out angular position (A2') as it moves to this position via the zigzag groove legs 990. The other cam pins move simultaneously (zigzag) via similar paths to their respective push-out angular positions. In this way, all of the cam pins can be pushed simultaneously by the cylindrical cam body 910, thereby pushing out the plunger head 106.

[0094] As cam pin 930 moves to the pulling angular position (A3) via leg 992 of the zigzag path, it rotates cylindrical cam body 910 to its pulling angular position (A3); as cam pin 932 moves to the pulling angular position (A3') via leg 992' of the zigzag path, it rotates cylindrical cam body 910 to its pulling angular position (A3'). The other two cam pins simultaneously move to their pulling angular positions via similar paths. In this way, all of the cam pins are simultaneously pulled by cylindrical cam body 910, thereby pulling plunger head 106.

[0095] When the cam pin 930 moves to the second push-out angle position via the leg 994 of the guide zigzag groove, the cam pin 930 rotates the cylindrical cam body 910 to its second push-out angle position (A4). When the cam pin 932 moves to the second push-out angle position (A4') via the leg 994' of the zigzag groove, the cam pin 932 rotates the cylindrical cam body 910 to its second push-out angle position (A4'). The other two cam pins also move to their push-out angle positions simultaneously via a similar path. In this way, all of the cam pins are pushed out simultaneously by the cylindrical cam body 910, thereby pushing the plunger head 106 twice.

[0096] As cam pin 930 moves through zigzag groove leg 996 to its take-off angular position (A5), it rotates cylindrical cam body 910 to its take-off angular position A5. As cam pin 932 moves through zigzag groove leg 996' to its take-off angular position (A5'), it rotates cylindrical cam body 910 to its take-off angular position (A5'). The other cam pins simultaneously move to their take-off angular positions via similar paths. In this manner, all cam pins simultaneously disengage from cylindrical cam body 910, releasing plunger rod 910 from plunger head 106. Thus, as cam pin 930 enters cylindrical cam body 910 through entrance funnel 960, moves along a zigzag route including legs 990, 992, 994, and 998, and exits cylindrical cam body 910 through exit funnel 962, all other cam pins simultaneously follow. For example, cam pin 932 enters cylindrical cam body 910 through entrance funnel 964, travels a similar zigzag route including legs 990', 992', 994', and 996', and exits cylindrical cam body 910 via exit funnel 966.

[0097] Referring again to FIG. 9A, tension member P3″ has a first (outer) stop surface 912, and tooth T6″ has a stop surface 914. Stop surfaces 912 and 914 are laterally spaced (916) apart such that stop surface 912 leads stop surface 914 relative to the direction of rotation (576) of cylindrical cam body 910. Spacing 916 is selected to allow a cam pin entering cylindrical cam body 910 through the through route between tension members P2″ and P3″ to engage and cam together with the cam surface of tooth T5″. Spacing 916 is also selected to allow a cam pin located in the extrusion recess between teeth T5″ and T6″ to engage and cam together with the inner cam surface 924 of tension member P3″.

[0098] Similarly, tension member P3" has a second (inner) stop surface 918, and tooth T7" has a stop surface 920. Stop surfaces 918 and 920 are laterally spaced apart (922) such that stop surface 918 leads stop surface 920 relative to the direction of rotation (576) of cylindrical cam body 910. Spacing 922 may be the same as spacing 916, but is selected so that a cam pin housed in a tension recess of tension member P3" can engage and cam together with the cam surface of tooth T6". Spacing 922 is also selected so that the cam pin can engage and cam together with an outer cam surface 926 of tension member P3". Similarly, spacings identical to spacings 916 and 922 exist between the two stop surfaces of tension member Pi" and the stop surfaces of their respective teeth. The spacing between the stop faces allows all cam pins to pass smoothly through the guide zigzag route (eg, guide zigzag route 710).

[0099] As an example, the pump device 100 is a four-stroke cycle pump that performs four different plunger rod (plunger head) strokes: 1. Engagement and Air Expulsion Stroke (First Stroke): The plunger rod 124 is moved linearly from a stored (home) position in the reusable portion 116 of the pump device 100, e.g., by the electric motor 118, to engage the plunger head 106 at the bottom (proximal end 103) of the syringe housing 102 and continue to push the plunger head 106 toward the distal end 105 of the syringe housing 102, expelling (for example) any air within the syringe 101. 2. Filling stroke (second stroke): The plunger rod 124 moves linearly backward from the distal end 105 of the syringe housing 102 to the bottom (proximal end 102) of the syringe housing 102 to fill the syringe housing 102 with a medication (for example). 3. Delivery stroke (third stroke): The plunger rod 124 moves linearly backward from the proximal end 103 of the syringe housing 102 to the distal end 105 of the syringe housing 102 to expel the medicament (for example) from the syringe housing 102. 4. Disengagement and Retraction Stroke (Fourth Stroke): The plunger rod 124 moves linearly rearward from the distal end 105 of the syringe housing 102 to disengage from the plunger head 106 and continues rearward to a retracted position within the reusable portion 116 of the pump device 100.

[0100] That is, the plunger rod 124 (and thus the plunger head 106) passes through the syringe 101 four times to complete one full operating cycle of the pump device 100, from when the plunger rod 124 engages the plunger head 106 until when the plunger rod 124 disengages from the plunger head 106. As used herein, stroke is the maximum axial distance that the plunger rod (and thus the cylindrical cam body and plunger head) can travel as the plunger rod moves within the cylindrical syringe housing from one predetermined axial position along the longitudinal axis of the cylindrical syringe housing to another predetermined axial position. In the example shown in FIGS. 10A-10I, the stroke distance of the plunger rod 124 is the distance traveled by the plunger rod 124 between the proximal end 103 of the syringe housing 102 (or the retracted / home position of the cylindrical cam body 130) and the distal end 105 of the syringe housing 102. Depending on the application of the pump device, the operating cycle of the pump device may be less than four strokes or more than four strokes, and the number of serrated crown teeth (and therefore the number of extrusion recesses), the number of tension members, and the number of tension recesses per tension member can be set to suit the selected operating cycle of the pump device.

[0101] 10A-10I illustrate an example nine-step process for operating pump device 100 according to an exemplary embodiment. (Some of the nine steps may be combined into a single step.) The nine-step process generally includes operatively engaging disposable syringe 101 with reusable portion 116 of pump device 100, engaging plunger rod 124 of pump device 100 with plunger head 106 of disposable syringe 101, operating the pump device with the disposable syringe and reusable portion of the pump device engaged, and finally, disengaging plunger rod 124 from plunger head 106 to separate disposable syringe 101 from reusable portion 116 of the pump device. The nine-step process for operating the pump device illustrates (and includes) a four-stroke operating cycle of pump device 100.

[0102] 10A shows the first step of a nine-step process for operating the pump device. (This step of the nine-step process for operating the pump device corresponds to FIG. 9A, which shows the cylindrical cam body prior to engagement with the plunger head.) In this step, the syringe 101 is attached to the reusable portion 116 of the pump device 100, and the cylindrical cam body 130 is in a retracted / home position within the reusable portion 116 of the pump device 100 and disengaged from the plunger head 106.

[0103] FIG. 10B illustrates a second step in the nine-step process for operating the pump device. (This step corresponds to FIG. 9E, which shows the cylindrical cam body aligning itself with the cam pin by camming (and rotating) to the first thrust angular position of the plunger head.) In this step, plunger rod 124 extends axially (longitudinally) partially forward in direction 940, engaging cylindrical cam body 130 with the plunger head's cam pin, thereby locking it into the plunger head 106. One of the four cam pins (e.g., cam pin 430) is shown seated in the first thrust recess of cylindrical cam body 130, which corresponds to the first thrust angular position of cylindrical cam body 130. At this stage, plunger rod 124 is positioned at the proximal end 103 of syringe 101, ready to expel air from syringe 101, for example.

[0104] 10C illustrates a third step in the nine-step process for operating the pump device. (This step in the nine-step process for operating the pump device also corresponds to FIG. 9E, which shows the cylindrical cam body still in the extended angular position within the plunger head.) At this step, plunger rod 124 is fully extended within syringe 101 (cam body 130 is at distal end 105 of syringe 101) and, following its first stroke within syringe 101, moves (e.g., from proximal end 103 of syringe 101 to distal end 105 of syringe 101) to expel, e.g., air, from syringe 101. At this stage, plunger rod 124 is nearly ready for a second stroke to fill syringe 101 with medicament, e.g., by moving plunger rod 124, and thus plunger head 106, rearward (rearward) in direction 944. To retract the plunger head 106 in direction 944 with the plunger rod 124, the plunger rod 124 must first be moved rearward (944) the distance (distance 946) required to guide the cam pin 430 into the tension recess in the cam body 130. This causes the cylindrical cam body 130 to cam against the cam pin and rotationally align with the tension angular position of the plunger head 106.

[0105] Figure 10D shows the fourth step of the nine-step process for operating the pump device. (This step of the nine-step process for operating the pump device corresponds to Figure 9G, which shows the cylindrical cam body aligned with the cam pin by camming (and rotational) action to the plunger head's pulled angular position.) At this step, the plunger head 106 is ready to be moved rearwardly by the plunger rod 124 in direction 944 (from the distal end 105 of the syringe 101 to the proximal end 103 of the syringe 101) to complete a second stroke (e.g., a fill stroke) of the plunger rod 124 and retract the plunger head 106, e.g., to fill the syringe 101 with a medication.

[0106] FIG. 10E illustrates a fifth step in a nine-step process for operating the pump device. (This step in the nine-step process for operating the pump device corresponds to FIG. 9G, showing the cylindrical cam body still in the extended angle position within the plunger head.) FIG. 10E illustrates the plunger rod 124 after completing a second stroke (e.g., a fill stroke). At this stage, the plunger rod 124 is nearly ready for a third stroke (e.g., a drug delivery stroke) by moving the plunger rod 124, and thus the plunger head 106, forward in direction 940 to, for example, expel a medication from the syringe 101 or prepare an infusion set (tubing system) for operation. To move the plunger head 106 forward (in direction 940) by the plunger rod 124, the plunger rod 124 must first be moved forward (940) a distance (distance 946) required to guide the cam pin 430 into the second (subsequent) ejection recess in the cam body 130. This causes the cylindrical cam body 130 to cam against the cam pin and rotationally align with the subsequent thrust angular position of the plunger head 106 .

[0107] FIG. 10F illustrates a sixth step in a nine-step process for operating the pump device. (This step in the nine-step process corresponds to FIG. 9E and shows the cylindrical cam body aligned with the cam pins by camming (and rotation) to the plunger head's thrust angular position.) One of the four cam pins (e.g., cam pin 430) is seated in the second (subsequent) thrust recess of the cylindrical cam body 130, as shown in FIG. 10F. This corresponds to the second thrust angular position of the cylindrical cam body 130. At this stage, the plunger head 106 is still engaged with the cam body 130 and is moved forward in direction 940 by the plunger rod 124, ready to initiate a third stroke (e.g., fill, prime, etc.) of the plunger rod 124 to expel medication from the syringe 101 or prime the infusion set.

[0108] Figure 10G illustrates the seventh step in the nine-step process for operating the pump device. (This step in the nine-step process for operating the pump device also corresponds to Figure 9E, with the cylindrical cam body still in the extended angular position within the plunger head.) At this stage, the plunger rod 124 is fully extended within the syringe 101 (with the cam body 130 at the distal end 105 of the syringe 101) and has traveled from the proximal end 103 of the syringe 101 to the distal end 105 of the syringe 101 to complete a third stroke (e.g., a drug delivery stroke) within the syringe 101, delivering (for example) a drug from the syringe 101.

[0109] After moving the third stroke, the plunger rod 124 disengages from the plunger head 106 and is ready to be stored in the pump device. To disengage the plunger rod 124 from the plunger head 106, the plunger rod 124 is moved rearward in the direction of 944. As the plunger rod 124 is moved in the direction of 944, the cylindrical cam body 130 cams against the cam pin of the plunger head 106, causing the cylindrical cam body 130 to rotate. As a result, the cylindrical cam body 130 is rotatably positioned in the disengagement angular position of the plunger head 106, as shown in FIG. 9K. Once the cylindrical cam body 130 is rotatably positioned in the disengagement angular position of the plunger head 106, further movement of the plunger rod 124 rearward in the direction of 944 disengages the plunger rod 124 from the plunger head 106, as shown in FIG. 9L.

[0110] Figure 10H illustrates the ninth step of the nine-step process for operating the pump device (this step corresponds to Figure 9L, which shows the cylindrical cam body disengaged from the example cam pin of the plunger head). At this stage, the plunger rod 124 has been fully withdrawn and has completed a fourth stroke (e.g., a retraction stroke) before being returned to a retracted position within the reusable portion 116 of the pump device 100.

[0111] 10I illustrates the ninth step of the nine-step process for operating the pump device, which involves removing (948) the syringe 101 from the reusable portion 116 while the plunger rod 124 is in the retracted / home position of the reusable portion 116. If desired, the removed syringe can be replaced with a new, similar disposable syringe.

[0112] The advantages of the pump device of the present invention compared to conventional pumps include at least the following: 1. Flexibility to design quick-release cam mechanisms to suit your needs, including the ability to engage the plunger rod with the plunger head by simply moving the plunger rod forward, and disengage the plunger rod from the plunger head by simply moving the plunger rod backward. 2. Reduction in cost of goods sold (COGS) associated with the disposable component of the pump device (syringe). 3. Reduction of the number of parts individually assembled into disposable parts (syringes). 4. Improving product sustainability. 5. The plunger rod (lead screw) is part of the reusable part of the pump device, allowing for a high precision propulsion system, allowing for greater accuracy and smaller or tighter tolerances. 6. The ability to design round syringes rather than oval or other shaped syringes. 7. Simplification of the assembly process for disposable parts (syringes). 8. Support or promote the prefilled reservoir concept. 9.Improved lead screw positioning accuracy and position monitoring accuracy. 10. Improved efficiency of occlusion control by strengthening the position control of the lead screw (plunger rod). 11.Improved drug delivery system concept.

[0113] As used herein, the articles "a" and "an" are used to refer to one or to more than one (e.g., at least one) of the grammatical object of the article, depending on the context. For example, "an element" can mean one element or more than one element, depending on the context. The term "including" is used herein to mean "including but not limited to," and is used synonymously. As used herein, the terms "or" and "and" are used interchangeably with the term "and / or," unless the context clearly dictates otherwise. The term "such as" is used interchangeably with the phrase "such as, but not limited to."

[0114] Having thus described exemplary embodiments of the present invention, it will be apparent to those skilled in the art that modifications of the disclosed embodiments are within the scope of the present invention. Accordingly, alternative embodiments may include functionally equivalent objects / articles. For example, the plunger head and / or plunger rod and / or cylindrical cam body may have a different design (e.g., different shape, size, and / or material, different number of cam pins, different number of cam surfaces and / or stop surfaces, different number of pull recesses, different number of push recesses, etc.) than those described herein and shown in the drawings. Features of particular embodiments may be used in conjunction with other embodiments shown herein. The present disclosure has been described in the context of a pump device having a disposable reservoir (syringe) and a reusable part. However, the present disclosure may also relate to (e.g., implemented by, used in conjunction with, or for use with) other types of "two-part" devices, pumps, syringes, therapeutic drug delivery devices, etc. Accordingly, the scope of the claims is not necessarily limited by the present disclosure.

Claims

1. 1. A quick connect and release cam mechanism for a pump device including a reusable portion and a disposable portion, comprising: a rotating cam body having a plurality of cam surfaces axially secured to a distal end of the plunger rod and rotatable about the plunger rod, the plunger rod being movable between a retracted position and an extended position within the reusable portion; a plurality of cam pins within a plunger head of the disposable reservoir, the plunger head being bidirectionally movable linearly within the disposable reservoir; the plurality of cam surfaces and the plurality of cam pins are configured to cooperate by cam action to rotate the rotating cam body relative to the plunger head through a series of alternating push-pull angular positions for alternately pushing and pulling the plunger head within the disposable part, from an engagement angular position where the cam body and the plunger head are engaged to a disengagement angular position where the cam body and the plunger head are disengaged, and rotating the rotating cam body from one angular position to another angular position causes the plunger rod to reciprocate axially relative to the plunger head. Quick coupling and release cam mechanism for pump devices.

2. a mechanism for selecting an operational interaction between an axially reciprocating plunger rod of the pump device and a plunger head that is bidirectionally movable between first and second axial positions within the syringe and is restrained from rotational movement within the syringe, the mechanism comprising: a cylindrical cam body axially constrained to rotate about the axially reciprocating plunger rod and received by a single-sided open chamber concentrically defined within the plunger head by a cylindrical wall, the cylindrical cam body having a plurality of spaced cam surfaces disposed circumferentially of the cylindrical cam body; a plurality of cam pins projecting from the cylindrical wall at equal angles toward the longitudinal axis of the plunger head, the plurality of cam pins cooperating with the cylindrical cam body during reciprocating motion of the plunger rod to sequentially traverse the plurality of cam surfaces and rotate the cylindrical cam body within and relative to the chamber to successively different angular positions corresponding to different operational interactions between the plunger rod and the plunger head.

3. 3. The mechanism of claim 2, wherein the plurality of cam pins cooperate with the cam body as the cam body reciprocates axially within the chamber to sequentially traverse the plurality of cam surfaces and rotate the cam body in one direction relative to the chamber into successively different rotational operating positions upon successive movements of the reciprocating plunger rod.

4. The different operational interactions between the plunger rod and plunger head are: (i) When the cam body is moved axially by the plunger rod, the plunger rod engages with the plunger head and enters the chamber; (ii) alternately pushing and pulling the plunger head within the syringe by the plunger rod as the plunger rod reciprocates axially; and 3. The mechanism of claim 2, further comprising: (iii) disengaging the plunger rod from the plunger head and releasing it from said chamber when the cam body is moved axially by the plunger rod.

5. The successively different angular positions of the cam body within the chamber are an engagement angle position where the plunger rod engages with the plunger head as a result of the cam surface of the cam body moving forward in the axial direction relative to the cam pin by the plunger rod; a disengagement angular position where the cam body can be disengaged from the cam pin by moving the cam body axially rearward from the chamber by the plunger rod; 3. The mechanism of claim 2, further comprising a series of alternating push / pull angular positions between an engagement angular position and a disengagement angular position, wherein the cam body alternately pushes and pulls the plunger head within the syringe as the plunger rod continuously reciprocates axially.

6. A series of alternating push-pull angular positions are (i) a first angular position in which the cam body is positioned within the plunger head to urge the plunger head forward from a first axial position within the syringe to a second axial position within the syringe; (ii) a second angular position subsequent to the first angular position, in which the cam body is in a position pulling the plunger head rearward within the plunger head from a second axial position within the syringe to a first axial position within the syringe; and (iii) a third angular position after the second angular position at which the cam body again urges the plunger head forward from the first axial position within the syringe to a second axial position within the syringe.

7. 7. The mechanism of claim 6, wherein a first angular position is for expelling air from the syringe, a second angular position is for filling the syringe with medication, and a third angular position is for expelling medication from the syringe.

8. The cylindrical cam body is n circumferential teeth disposed at equal angular intervals on the proximal end of the cam body to form n U-shaped extrusion recesses for axially extruding the cam pin and, therefore, the plunger head within the syringe; 6. The mechanism of claim 5, further comprising n / 2 circumferential tensioning members equally angularly spaced about the distal end of the cam body, each tensioning member having a U-shaped tensioning recess, for axially tensioning the cam pin and, therefore, the plunger head within the syringe.

9. 9. The mechanism of claim 8, wherein each U-shaped extrusion recess generally opens toward the distal end of the cam body at an acute angle relative to a line parallel to the longitudinal axis of the cam body, and each U-shaped tension recess generally opens toward the proximal end of the cam body at an acute angle relative to a line parallel to the longitudinal axis of the cam body.

10. 9. The mechanism of claim 8, wherein the n teeth and the n / 2 tension members are alternately arranged on a cylindrical cam body, and the odd teeth (Ti) abut the through-holes formed by and between two adjacent tension members (Pi, Pi+1), and the even teeth (Ti+1) abut the U-shaped tension recess of a particular tension member (Pi+1).

11. The penetration route formed by and between two adjacent tension members is: an inlet funnel configured to rotatably receive and guide each of the plurality of cam pins into an engagement angular position when the cylindrical cam body is inserted into the chamber; an exit funnel configured to rotatably receive and guide each of the plurality of cam pins from the disengagement angular position when the cam body is withdrawn from the chamber; 11. The arrangement of claim 10, wherein the inlet and outlet funnels of each through-route are arranged back-to-back in the length direction such that the narrow opening of the inlet funnel coincides with the narrow opening of the outlet funnel.

12. The inlet funnel is formed by a pair of conjugated axially forward camming surfaces including a forward camming surface of a particular tension member (Pi) and a forward camming surface of a tension member (Pi+1) adjacent to the particular tension member (Pi); 12. The mechanism of claim 11, wherein the exit funnel is formed by a pair of axially rearward conjugated cam surfaces including the rearward cam surface of a particular tension member (Pi) and the rearward surface of an adjacent tension member (Pi+1).

13. 13. The mechanism of claim 12, wherein the number of through channels is the same as the number of cam pins, and each cam pin is configured to abut an inlet funnel of a particular through channel to insert a cam body into a chamber of the plunger head and to abut an outlet funnel of a different through channel to withdraw the cam body from the chamber of the plunger head.

14. 14. The mechanism of claim 13, wherein n=8 and the number of cam pins is four.

15. the n circumferential teeth form a sawtooth crown at the proximal end of the cam body, each tooth of the sawtooth crown being a right-angled triangular tooth including a cam surface and a stop surface among a plurality of cam surfaces, and each specific U-shaped extrusion recess is formed by connecting (bridging) the cam surface of a specific tooth (Ti) with the stop surface of a subsequent tooth (Ti+1) at its bottom; 9. The mechanism of claim 8, wherein each particular tension member (Pi) has a first protrusion and a second protrusion, the first protrusion having a cam surface of a plurality of cam surfaces, and the second protrusion having a stop surface, and the U-shaped tension recess of the particular tension member (Pi) is formed by connecting (bridging) the cam surface and the stop surface of the particular tension member (Pi) at a bottom surface.

16. 16. The mechanism of claim 15, wherein the n / 2 tension members are positioned axially spaced apart from the serrated crown and together with the serrated crown define a guide zigzag route through which the plurality of cam pins traverse as the cylindrical cam body rotates from the engagement angular position to the disengagement angular position through a series of alternating push-pull angular positions as the plunger rod reciprocates.

17. the sawtooth crown has a ring-shaped base at the proximal end of the cam barrel, with circumferential teeth extending longitudinally from said ring-shaped base perpendicular to the plane of the ring-shaped base, with all teeth facing toward the distal end of the cam body; 16. The mechanism of claim 15, wherein for each tooth, the cam surface is inclined relative to a line parallel to the longitudinal axis of the cam body and the stop surface is parallel to a line parallel to the longitudinal axis of the cam body.

18. 1. A pump device for delivering a medication, comprising: a disposable reservoir including a plunger head movable bidirectionally within the disposable reservoir between a first axial position and a second axial position, the plunger head having a single-sided open chamber concentrically defined within the plunger head by a cylindrical wall, and a plurality of cam pins projecting radially from the cylindrical wall at equal angles relative to a longitudinal axis of the plunger head; a reusable portion having a cylindrical cam body, the cylindrical cam body being axially constrained to and rotatable about the plunger rod and receivable by the one-sided open chamber, the cylindrical cam body having a plurality of cam surfaces circumferentially therearound, and a plurality of cam pins cooperating with the cylindrical cam body to sequentially traverse the plurality of cam surfaces as the plunger rod reciprocates axially, causing the cylindrical cam body to rotate to successively different angular positions within and relative to the one-sided open chamber corresponding to different operational interactions between the plunger rod and the plunger head.

19. 19. The mechanism of claim 18, wherein the cam pin traverses a plurality of cam surfaces on the cam body as the cam body reciprocates axially within the chamber, causing the cam body to rotate in one direction relative to the chamber and move to successively different rotational operating positions during successive reciprocating movements of the plunger rod.

20. 1. A method of operating a pump device having a plunger rod with a rotatable cam body, comprising: Engaging a disposable reservoir with a plunger head to a reusable portion of the pump device, and engaging the disposable reservoir with the reusable portion of the pump device; The method includes axially reciprocating a plunger rod within a disposable reservoir, causing a rotatable cam body to cam against a cam pin within a plunger head to rotate the rotatable cam body to an engagement angular position where the plunger rod engages with the plunger head, and then rotating the plunger rod through alternating push-pull angular positions corresponding to a series of alternately pushing and pulling the plunger head forward and backward within the disposable reservoir, to a disengagement angular position where the plunger rod can be disengaged from the plunger head.

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