Abstract:
A wearable infusion device prevents reservoir refilling. The device includes a base adapted to be adhered to a patient&#39;s skin, a reservoir that holds a liquid medicament, and a cannula that delivers liquid medicament from the reservoir to the patient. The device further includes a fill port communicating with the reservoir to permit the reservoir to be provided with the liquid medicament, and a lock-out that prevents the reservoir from being refilled through the fill port after the reservoir has been provided with the liquid medicament.

Description:
[0001]    The present application is a continuation of copending U.S. patent application Ser. No. 11/906,106, filed Sep. 28, 2007, which application is incorporated herein by reference in its entirety. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    The present invention relates to infusion devices and more particularly to such devices that enable liquid medicaments to be conveniently and safely self-administered by a patient. 
         [0003]    Tight control over the delivery of insulin in both type I diabetes (usually juvenile onset) and type II diabetes (usually late adult onset), has been shown to improve the quality of life as well as the general health of these patients. Insulin delivery has been dominated by subcutaneous injections of both long acting insulin to cover the basal needs of the patient and by short acting insulin to compensate for meals and snacks. Recently, the development of electronic, external insulin infusion pumps has allowed the continuous infusion of fast acting insulin for the maintenance of the basal needs as well as the compensatory doses (boluses) for meals and snacks. These infusion systems have shown to improve control of blood glucose levels. However, they suffer the drawbacks of size, cost, and complexity. For example, these pumps are electronically controlled and must be programmed to supply the desired amounts of basal and bolus insulin. This prevents many patients from accepting this technology over the standard subcutaneous injections. 
         [0004]    Hence, there is a need in the art for a convenient form of insulin treatment which does not require significant programming or technical skills to implement to service both basal and bolus needs. Preferably, such a treatment would be carried out by an infusion device that is simple to use and mechanically driven negating the need for batteries and the like. It would also be preferable if the infusion device could be directly attached to the body and not require any electronics to program the delivery rates. The insulin is preferably delivered through a small, thin-walled tubing (cannula) through the skin into the subcutaneous tissue similar to technologies in the prior art. 
         [0005]    While the idea of such a simple insulin delivery device is compelling, many obstacles must be overcome before such a device may become a practical realty. One problem resides in insulin supply. Patients vary greatly on the amount of insulin such a device must carry to provide treatment over a fixed time period of, for example, three days. This is one environment where one size does not fit all. Still further, such devices must be wearable with safety and not subject to possible accidental dosing. Still further, such devices must be capable of delivering an accurately controlled volume of medicament with reliability. While it is preferred that these devices include all of the forgoing features, it would be further preferred if the cost of manufacturing such a device would be economical enough so as to render the device disposable after use. As will be seen subsequently, the devices and methods described herein address these and other issues. 
       SUMMARY OF THE INVENTION 
       [0006]    The invention provides a wearable infusion device comprising a reservoir that holds a liquid medicament, an outlet port that delivers the liquid medicament to a patient [[,]] and a pump that displaces a volume of the liquid medicament to the outlet port when actuated. The device further comprises a control that actuates the pump, a fill port communicating with the reservoir to permit the reservoir to be filled with the liquid medicament, and a lock-out that prevents the reservoir from being refilled after the reservoir has been filled. 
         [0007]    The lock-out may be arranged to block the fill port. The lock-out may be configured to prevent the reservoir from being refilled after the reservoir has been once filled. The lock-out may be responsive to pressure to prevent the reservoir from being refilled after the reservoir has been filled. The lock-out may be responsive to pressure within the fill port. The device further comprises a chamber between the fill port and the reservoir, and the lock-out senses pressure within the chamber. The lock-out may include a diaphragm for sensing pressure within the chamber. The lock-out may alternatively be responsive to the reservoir being at a given level to prevent the reservoir from being refilled. 
         [0008]    In another embodiment, a wearable infusion device comprises a base adapted to be adhered to a patient&#39;s skin, a reservoir that holds a liquid medicament, a cannula that delivers the liquid medicament from the reservoir to the patient a fill port communicating with the reservoir to permit the reservoir to be provided with the liquid medicament, and a lock-out that prevents the reservoir from being filled through the fill port after the reservoir has been provided with the liquid medicament. 
         [0009]    The lock-out may be arranged to prevent the reservoir from being refilled after the reservoir has once been provided with the liquid medicament. The lock-out may be responsive to pressure to prevent the reservoir from being refilled through the fill port after the reservoir has once been provided with the liquid medicament. The lock-out may be arranged to be responsive to pressure within the fill port. 
         [0010]    The device may further comprises a chamber between the fill port and the reservoir, and the lock-out may be arranged to sense pressure within the chamber. The lock-out may include a diaphragm for sensing pressure within the chamber. 
         [0011]    The lock-out is may alternatively be responsive to the reservoir being at a given level to prevent the reservoir from being refilled. The lock-out may be configured to block the fill port. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]    The features of the present invention which are believed to be novel are set forth with particularity in the appended claims. The invention, together with further features and advantages thereof, may best be understood by making reference to the following description taken in conjunction with the accompanying drawings, in the several figures of which like reference numerals identify identical elements, and wherein: 
           [0013]      FIG. 1  is a perspective view of a first infusion device embodying certain aspects of the present invention; 
           [0014]      FIG. 2  is a schematic representation of the valves and pump of the device of  FIG. 1 ; 
           [0015]      FIG. 3  is an exploded perspective view of the device of  FIG. 1 ; 
           [0016]      FIG. 4  is a sectional view, in perspective, of the device of  FIG. 1  showing the pump of the device directly coupled to an actuator button; 
           [0017]      FIG. 5  is a sectional view, in perspective, of the device of  FIG. 1  showing the valves and the valve and actuation linkages prior to the delivery of a medicament dose; 
           [0018]      FIG. 6  is a sectional view, to an enlarged scale, illustrating the actuation linkages prior to the delivery of a medicament dose; 
           [0019]      FIG. 7  is a sectional view, like that of  FIG. 6 , illustrating the actuation linkages during the delivery of a medicament dose; 
           [0020]      FIG. 8  is a another sectional view, like that of  FIG. 5 , illustrating the actuation linkages just after the delivery of a medicament dose; 
           [0021]      FIG. 9  is a perspective view of another infusion device embodying various aspects of the present invention; 
           [0022]      FIG. 10  is a schematic representation of the valves and pump of the device of  FIG. 9  between medicament dosage delivery and for filling the pump with the medicament; 
           [0023]      FIG. 11  is a schematic representation of the valves and pump of the device of  FIG. 9  during medicament dosage delivery; 
           [0024]      FIG. 12  is an exploded perspective view of the device of  FIG. 9 ; 
           [0025]      FIG. 13  is a perspective view of one component of the device of  FIG. 9 ; 
           [0026]      FIG. 14  is a lengthwise sectional view in perspective of the device of  FIG. 9  and showing a cannula assembly for use therein in exploded view; 
           [0027]      FIG. 15  is a lengthwise sectional view in perspective of the device of  FIG. 9  similar to  FIG. 14  showing the cannula assembly in operative association with the device; 
           [0028]      FIG. 16  is a sectional plan view showing the valve configuration of the device of  FIG. 9  during pump filling; 
           [0029]      FIG. 17  is a sectional plan view showing the valve configuration of the device of  FIG. 9  during medicament delivery; 
           [0030]      FIG. 18  is a sectional view, in perspective, to an enlarged scale, showing the actuation linkages of the device of  FIG. 9  prior to medicament dosage delivery; 
           [0031]      FIG. 19  is a sectional view like that of  FIG. 18 , showing the actuation linkages of the device of  FIG. 9  during medicament dosage delivery; 
           [0032]      FIG. 20  is a sectional view like that of  FIG. 18 , showing the actuation linkages of the device of  FIG. 9  after medicament dosage delivery; 
           [0033]      FIG. 21  is a another sectional view, in perspective, to an enlarged scale, showing the operation of the actuation linkages; 
           [0034]      FIG. 22  is another sectional view like that of  FIG. 21 , in perspective, to an enlarged scale, showing the operation of the actuation linkages; 
           [0035]      FIG. 23  is still another sectional view showing the last dose lock-out and the device pump during normal medicament delivery actuation; 
           [0036]      FIG. 24  is a sectional view, like that of  FIG. 23 , showing the last dose lock-out and device pump after normal medicament delivery; 
           [0037]      FIG. 25  is a sectional view, like that of  FIG. 23 , showing the last dose lock-out being conditioned for disabling the actuator upon return of the device pump after a last normal medicament delivery; 
           [0038]      FIG. 26  is a sectional view, like that of  FIG. 23 , showing the last dose lock-out disabling the actuator upon a final medicament delivery; 
           [0039]      FIG. 27  is another sectional view, to an enlarged scale, showing the device pump and the fill port being blocked during actuation for delivery of medicament; and 
           [0040]      FIG. 28  is another sectional view, like that of  FIG. 22 , showing the device pump and the fill port being locked in a blocked condition by the last dose lock-out. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0041]    Referring now to  FIG. 1  it is a perspective view of a first infusion device embodying certain aspects of the present invention. The device  10  generally includes an enclosure  12 , a base  14 , a first actuator control button  16 , and a second actuator control button  18 . 
         [0042]    The enclosure  12 , as will be seen subsequently, is formed by virtue of multiple device layers being brought together. Each layer defines various components of the device such as, for example, a reservoir, fluid conduits, pump chambers, and valve chambers, for example. This form of device construction, in accordance with aspects of the present invention, enables manufacturing economy to an extent rendering the device disposable after use. 
         [0043]    The base  14  preferably includes an adhesive coating to permit the device to be adhered to a patient&#39;s skin. The adhesive coating may originally be covered with a releasable cover that may be pealed off of the base  14  when the patient endeavors to deploy the device  10 . Such arrangements are well known in the art. 
         [0044]    The device  10  may be mated with a previously deployed cannula assembly. However, it is contemplated herein that the various aspects of the present invention may be realized within a device that may be alternatively first adhered to the patient&#39;s skin followed by the deployment of a cannula thereafter. 
         [0045]    The actuator buttons  16  and  18  are placed on opposites sides of the device  10  and directly across from each other. This renders more convenient the concurrent depression of the buttons when the patient wishes to receive a dose of the liquid medicament contained within the device  10 . This arrangement also imposes substantially equal and opposite forces on the device during dosage delivery to prevent the device from being displaced and possibly stripped from the patient. As will be further seen hereinafter, the concurrent depression of the buttons is used to particular advantage. More specifically, the actuator button  16  may serve as a valve control which, when in a first position as shown, establishes a first fluid path between the device reservoir and the device pump to support pump filling, and then, when in a second or depressed position, establishes a second fluid path between the device pump and the device outlet or cannula to permit dosage delivery to the patient. As will be further seen, a linkage between the control actuator buttons  16  and  18  permits actuation of the device pump with the actuator control button  18  only when the second fluid path has been established by the first actuator control button  16 . Hence, the first actuator control button  16  may be considered a safety control. 
         [0046]    Referring now to  FIG. 2 , it is a schematic representation of the valves and pump of the device  10  of  FIG. 1 . As may be seen in  FIG. 2 , the device  10  further includes a fill port  20 , a reservoir  22 , a pump  24 , and the cannula  30 . The device further includes a first valve  32  and a second valve  34 . Fluid conduit  40  provides a fluid connection between the fill port  20  and the reservoir  22 , fluid conduit  42  provides a fluid connection between the reservoir  22  and the first valve  32 , fluid conduit  44  provides a fluid connection between the first valve  32  and the pump  24 , fluid conduit  46  provides a fluid connection between the pump  24  and the second valve  34 , and fluid conduit  48  provides a fluid connection between the second valve  34  and the device outlet  50 . The outlet  50  is arranged to communicate with the cannula  30 . 
         [0047]    It may also be noted that the actuator buttons  16  and  18  are spring loaded by springs  36  and  38 . The springs are provided for returning the actuator buttons to the first position after a dosage is administered. 
         [0048]    The pump  24  of the device  10  comprises a piston pump. The pump  24  includes a pump piston  26  and a pump chamber  28 . In accordance with this embodiment, the actuator control button  18  is directly coupled to and is an extension of the pump piston  26 . 
         [0049]    With further reference to  FIG. 2 , the device additionally includes a first linkage  52  and a second linkage  54 . The first linkage is a toggle linkage between the first valve  32  and the second valve  34 . It is arranged to assure that the second valve  34  does not open until after the first valve  32  is closed. The second linkage  54  is between the first actuator button  16  and the second actuator button  18 . It is arranged to assure that the pump does not pump until after the first valve is closed and the second valve is opened by the first actuator button  16 . 
         [0050]    Still further, the second valve  34  is a safety valve that closes tighter responsive to increased fluid pressure within fluid conduit  46 . This assures that the liquid medicament is not accidentally administered to the patient notwithstanding the inadvertent application of pressure to the reservoir, for example. In applications such as this, it is not uncommon for the reservoir to be formed of flexible material. While this has its advantages, it does present the risk that the reservoir may be accidentally squeezed as it is worn. Because the second valve only closes tighter under such conditions, it is assured that increased accidental reservoir pressure will not cause the fluid medicament to flow to the cannula. 
         [0051]    In operation, the reservoir is first filled through the fill port  20  to a desired level of medicament. In this state, the valves  32  and  34  will be as shown. The first valve  32  will be open and the second valve  34  will be closed. This permits the piston chamber  28  to be filled after the reservoir is filled. The cannula  30  may then be deployed followed by the deployment of the device  10 . In this state, the valves  32  and  34  will still be as shown. The first valve  32  will be open and the second valve  34  will be closed. This permits the pump chamber  28  to be filled through a first fluid path including conduits  42  and  44  as the piston  24  returns to its first position after each applied dose. 
         [0052]    When the patient wishes to receive a dose of medicament, the actuator buttons are concurrently pressed. In accordance with aspects of the present invention, the linkage  52  causes the first valve  32  to close and the second valve  34  to thereafter open. Meanwhile, the second linkage  54  precludes actuation of the pump  24  until the first valve  32  is closed and the second valve  34  is opened by the first actuator button  16 . At this point a second fluid path is established from the pump  24  to the cannula  30  through fluid conduits  46  and  48  and the outlet  50 . The medicament is then administered to the patient through cannula  30 . 
         [0053]    Once the medication dosage is administered, the piston  24 , and thus the actuator button  18 , is returned under the spring pressure of spring  38  to its initial position. During the travel of the piston back to its first position, a given volume of the liquid medicament for the next dosage delivery is drawn from the reservoir into the pump chamber  28  to ready the device for its next dosage delivery. 
         [0054]    Referring now to  FIG. 3 , it is an exploded perspective view of the device of  FIG. 1 . It shows the various component parts of the device. The main component parts include the aforementioned device layers including the base layer  60 , the reservoir membrane or intermediate layer  62 , and the top body layer  64 . The base layer is a substantially rigid unitary structure that defines a first reservoir portion  66 , the pump chamber  28 , and valve sockets  68  and  70  of the first and second valves respectively. The base layer  60  may be formed of plastic, for example. The reservoir membrane layer  62  is received over the reservoir portion  66  to form the reservoir  22  ( FIG. 2 ). A valve seat structure  72  is received over the valve sockets  68  and  70  to form the first and second valves  32  and  34  ( FIG. 2 ) respectively. A rocker  74  is placed over the valves seat structure  72  to open and close the valves as will be seen subsequently. The pump actuator button  18  carries the pump piston that is received within the pump chamber  28 . The pump actuator button  18  also carries a cam cylinder  76  with a lock tube  78  therein that form a portion of the second linkage  54  ( FIG. 2 ). The spring  38  returns the actuator button  18  to its first position after each dosage delivery. 
         [0055]    The first actuator control button carries a valve timing cam  80  that rocks the rocker  72 . The button  16  further carries a cam cylinder  82  and a cam pin  84  that is received into the cam cylinder  82 . The spring  36  returns the actuator button  16  to its first position after each dosage delivery. The top body layer  64  forms the top portion of the device enclosure. It receives a planar cap  86  that completes fluid paths  85  partially formed in the top layer  64 . Lastly, a needle  88  is provided that provides fluid coupling from the cannula (not shown) to the outlet of the device  10 . 
         [0056]      FIG. 4  shows a sectional view, in perspective, of the device of  FIG. 1 . More specifically, the figure shows details of the piston pump  24  within the device  10 . Here, it may be seen that the piston  26  of the piston pump  24  is received within the pump chamber  28  that is formed in the base layer  60  of the device. The piston  26  may further be seen to be an extension of the actuator button  18 . An O-ring  90  provides a seal between the pump chamber  28  and the piston  26 . The spring  38  returns the actuator button  18  to its shown first position after each dosage delivery. 
         [0057]      FIG. 5  is a sectional view, in perspective, of the device of  FIG. 1  showing the valves  32  and  34  and the valve and actuation linkages prior to the delivery of a medicament dose. The valves will first be described. First, it may be noted that the valve seat structure  72  is received within the valve sockets  68  and  70 . The valve seat structure  72  includes valve seats  92  and  94  that are received within the valve sockets  68  and  70  respectively. Each of the seats  92  and  94  has a widened portion  96  and  98 , respectively, that cause the seats to be more tightly seated within sockets  68  and  70  in response to increased fluid pressure in the downward direction. As previously described, this protects against the potential effects of accidental medication delivery due to external pressure being applied to the reservoir of the device. 
         [0058]    The rocker  74  opens and closes the valves  32  and  34 . It is under control of the timing cam  80  carried by the first actuator control button  16 . As the control button  16  is moved laterally, the cam  80  causes the rocker  74  to pivot and to apply pressure to one or the other of the valve seats  92  or  94 . The shape of the cam surfaces on the rocker  74  and the cam  80  assure that the valve  34  will not open until the valve  32  closes. The cam  80  and rocker  74  thus form the first linkage  52  shown in  FIG. 2 . 
         [0059]    While the cam  80  and rocker  74  are operating the valves  32  and  34  under timing control provided by the first linkage  52 , the second linkage  54  is controlling when the pump may displace liquid medicament form the pump chamber  28  to the device outlet and cannula.  FIGS. 5-8  show details of the second linkage. 
         [0060]    As may be seen in  FIGS. 5 and 6 , the second linkage includes the cam cylinder  76 , the lock tube  78 , the outer cam cylinder  82 , and the cam pin  84 . The cam cylinder is integral with the second actuator control button  18  and the outer cam cylinder  82  is integral with the first actuator control button. The second linkage  54  further includes a lock cylinder  100 . The foregoing are disposed in a bore  102  formed in the base layer  60  of the device. 
         [0061]    When the actuator buttons are in their first position as shown in  FIG. 6 , the end of the lock tube  78  abuts the end of the lock cylinder  100 . The lock cylinder includes ears  104 . When a dosage delivery is desired, the concurrent pushing of the buttons  16  and  18  causes the outer cam cylinder  82  to slide over the lock cylinder  100  first and then the cam cylinder  76  to slide over the lock tube  78 . The sliding of the outer cam cylinder  82  over the lock cylinder  100  causes the first valve to close and the second valve to open. When this is accomplished, the cam cylinder  76  is then permitted to slide over lock tube  78  to cause the piston  26  to move through the pump chamber  28 . This displaces the liquid medicament in the pump chamber  28  for delivering the medicament to the cannula  30  and the patient. 
         [0062]      FIG. 7  illustrates the manner in which the outer cam cylinder  82  slides along the lock cylinder  100 . It may first be noted that the cam pin  84  has a reduced diameter portion creating an annular space  106  between the pin  84  and the lock cylinder  100 . The outer cam cylinder  82  engages the pin at a flange  108  of the pin  84 . This engagement will cause the pin  84  to move with the outer cam cylinder  82 . The pushing of the first actuator button  16  will cause the outer cam cylinder  82  to engage the ears  104  of the lock cylinder  100  while at the same time, the end of the pin  84  moves into the lock tube  78 . Eventually, the ears  104  are depressed enough by the outer cam cylinder  82  as the end of the pin  84  clears the end of the depressed lock cylinder  100  to permit the ears  104  to enter space  106 . This occurs with a snap sound and feel as it occurs suddenly. The outer cam cylinder  82  is now free to slide its complete travel distance over the lock cylinder  100 . The valve  32  has now been closed and the valve  34  has been opened. 
         [0063]    The snap action of the actuator buttons  16  and  18  provides positive assurance to the patient that a dosage of medicament was delivered. Also, because the snap action only occurs when the pump actuator button  18  completes it full travel, the patient will also know that a full dosage was delivered. 
         [0064]    After the outer cam cylinder  82  has completed its travel over the lock cylinder  100 , the ears  104  will be displaced sufficiently into space  106  to permit the cam cylinder  76  to clear the end of the lock cylinder  100  and slide over the lock tube  78 . The condition of the second linkage  54  at this time is shown in  FIG. 8 . As previously described, as the cam cylinder  76  slides over the lock tube  78 , the pump  24  is actuated to deliver the medicament to the patient. 
         [0065]    Referring now to  FIG. 9 , it is a perspective view of another infusion device embodying various aspects of the present invention. The device  210  generally includes an enclosure  212 , a base  214 , a first actuator control button  216 , and a second actuator control button  218 . 
         [0066]    The enclosure  212  is formed by virtue of multiple device layers being brought together. Each layer defines various components of the device such as, for example, a reservoir, fluid conduits, pumps, and valve chambers, for example. This form of device construction, in accordance with aspects of the present invention, enables manufacturing economy to an extent rendering the device disposable after use. 
         [0067]    The base  214  preferably includes an adhesive coating to permit the device to be adhered to a patient&#39;s skin. The adhesive coating may originally be covered with a releasable cover that may be pealed off of the base  214  when the patient endeavors to deploy the device  210 . Such arrangements are well known in the art. 
         [0068]    As will also be seen subsequently, the device  210  may be mated with a previously deployed cannula assembly. However, it is contemplated herein that the various aspects of the present invention may be realized within a device that may be alternatively first adhered to the patient&#39;s skin followed by the deployment of a cannula thereafter. 
         [0069]    As in the previous embodiment, the actuator buttons  216  and  218  are placed on opposites sides of the device  210  and directly across from each other. This again renders more convenient the concurrent depression of the buttons when the patient wishes to receive a dose of the liquid medicament contained within the device  210 . This arrangement also imposes substantially equal and opposite forces on the device during dosage delivery to prevent the device from being displaced and possibly stripped from the patient. As will be further seen hereinafter, the concurrent depression of the buttons is used to particular advantage. More specifically, the actuator button  216  may serve as a valve control which, when in a first position as shown, establishes a first fluid path between the device reservoir and the device pump to support pump filling, and then, when in a second or depressed position, establishes a second fluid path between the device pump and the device outlet or cannula to permit dosage delivery to the patient. As will be further seen, a linkage between the control actuator buttons  216  and  218  permits actuation of the device pump with the actuator control button  218  only when the second fluid path has been established by the first actuator control button  216 . Hence, the first actuator control button  216  may be considered a safety control. 
         [0070]    With continued reference to  FIG. 9 , it may be further noted that the device  210  also includes a tactile indicator  260  that represents the volume of the liquid medicament delivered by the device with each actuation of the pump  224 . The tactile indicator is carried by the pump actuator button  218  and takes the form of a plurality of distinct raised features or bumps  262  and  264 . Alternatively, the tactile indicator may take the form of one or more distinct relieved portions. Each bump  262  and  264  may correspond to a single unit of medicament. Hence, in this embodiment, the bumps  262  and  264  indicate that the device delivers two units of medicament with each actuation of the pump. 
         [0071]    The tactile indicator  260  being carried on the pump actuator control button  218  provides a very significant feature and advantage. As will be seen subsequently, the pump actuator button  218  has an integral extension that forms the piston  226  of the piston pump  224  as represented in  FIG. 10  to be described hereinafter. It will also be seen that the piston chamber  228  is formed in a component of the device that may be used in devices delivering dosage amounts other than two units. The component may be common to all such devices because it would have a fixed piston chamber length and the dosage amount is determined by the throw of the pump piston  226 . Each piston throw is integral to the part and corresponds to a respective given dosage amount. Each pump actuator button for a given dosage amount may have then be provided with a corresponding tactile indicator. Hence, if a tactile indicator indicates a dosage amount of two units, for example, it is assured that that is the medicament amount delivered with that particular pump button. Further, this arrangement is advantageous from a manufacturing standpoint because the actuator buttons for the various dosage size devices cannot be confused with each other. 
         [0072]    Referring now to  FIGS. 10 and 11 , they are schematic representations of the valves and pump of the device of  FIG. 9  between medicament dosage filling ( FIG. 10 ) and medicament dosage delivery ( FIG. 11 ) As may be seen in  FIGS. 10 and 11 , the device  210  further includes a reservoir  222 , a pump  224 , and the cannula  230 . The device further includes a shuttle valve  231  forming a first valve  232  defined by O-rings  233  and  235  and a second valve  234  defined by O-rings  237  and  239 . Although O-rings are used herein to form seals, other types of valve construction may best employ forms of seals other than O-rings without departing from the invention. Fluid conduit  240  extends between the valves  232  and  234 . A fluid conduit  242  provides a fluid connection between the reservoir  222  and the shuttle valve  231  and fluid conduit  244  provides a fluid connection between the shuttle valve  231  and the pump  224 . A further fluid conduit  246  provides a fluid connection between the shuttle valve  231  and the device outlet  250 . The outlet  250 , in the form of a needle, is arranged to communicate with the cannula  230 . 
         [0073]    It may also be noted that the actuator buttons  216  and  218  are spring loaded by springs  236  and  238 . The springs are provided for returning the actuator buttons to the first position after a dosage is administered. 
         [0074]    The pump  224  of the device  210  comprises a piston pump. The pump  224  includes a pump piston  226  and a pump chamber  228 . In accordance with this embodiment, the actuator control button  218  is directly coupled to and is an extension of the pump piston  226 . 
         [0075]    With further reference to  FIGS. 10 and 11 , the device additionally includes a first linkage  252  and a second linkage  254 . The first linkage is formed by the shuttle bar  241  of the first valve  232  and the second valve  234 . It is arranged by separating the valves  232  and  234  be a distance that assures that the second valve  234  does not open until after the first valve  232  is closed. The second linkage  254  is between the first actuator button  216  and the second actuator button  218 . It is arranged to assure that the pump  224  does not pump until after the first valve  232  is closed and the second valve  234  is opened by the first actuator button  216 . 
         [0076]    Still further, the second valve  234  is a safety valve that assures that the liquid medicament is not accidentally administered to the patient notwithstanding the inadvertent application of pressure to the reservoir, for example. In applications such as this, it is not uncommon for the reservoir to be formed of flexible material. While this has its advantages, it does present the risk that the reservoir may be accidentally squeezed as it is worn. Because of the second valve  234 , it is assured that accidental reservoir pressure will not cause the fluid medicament to flow to the cannula. 
         [0077]    In operation, the pump chamber  228  is first filled as the actuator button  218  returns to the first position after having just delivered a medicament dosage. In this state, the shuttle valve  231  is set so that the first valve  232  will be open (the reservoir  222  communicates with the fluid conduit  240 ) and the second valve  234  will be closed (the conduit  246  is closed off from fluid conduit  240 ). This establishes a first fluid path from the reservoir  222  to the pump  224  through conduits  242 ,  240  and  244  that permits the piston chamber  228  to be filled by the reservoir as the actuator button is returned to its first position under the influence of the spring  238 . 
         [0078]    When the patient wishes to receive another dose of medicament, the actuator buttons are concurrently pressed. In accordance with aspects of the present invention, the linkage  252  causes the first valve  232  to close and the second valve  234  to thereafter open. Meanwhile, the second linkage  254  precludes actuation of the pump  224  until the first valve  332  is closed and the second valve  334  is opened by the first actuator button  216 . At this point a second fluid path is established from the pump  224  to the cannula  30  through fluid conduits  244 ,  240  and  246  and the outlet  250 . The medicament is then administered to the patient through cannula  30 . 
         [0079]    Once the medication dosage is administered, the piston  224 , and thus the actuator button  218 , is returned under the spring pressure of spring  238  to its initial position. During the travel of the piston back to its first position, a given volume of the liquid medicament for the next dosage delivery is drawn from the reservoir into the pump chamber  228  as described above to ready the device for its next dosage delivery. 
         [0080]    Referring now to  FIG. 12 , it is an exploded perspective view of the device of  FIG. 9 . It shows the various component parts of the device  210 . Like the device  10  of  FIG. 1 , the device  210  is constructed in device layers including a base layer  280 , an intermediate layer  282 , and the top body layer  284 . 
         [0081]    As may also be seen in  FIG. 13 , the base layer  280  is a substantially rigid unitary structure that defines a first reservoir portion  286 , the pump chamber  228 , and a valve chamber  290  for the first and second valves  232  and  234 . The base layer  280  may be formed of plastic, for example. 
         [0082]    The valve chamber  290  is arranged to receive the valve shuttle bar  241  carried by and extending from the first actuator button  216 . O-rings  233 ,  235 ,  237 , and  239  are arranged to be seated on the shuttle bar  241  to form the first and second valves  232  and  234  respectively ( FIG. 10 ). The actuator button  216  also carries a first portion  292  of the second linkage  254  ( FIG. 10 ). The second linkage is received within a suitably configured bore  295  formed in the base layer  280  and will be described subsequently. 
         [0083]    The pump actuator button  218  carries the pump piston  226  and a second portion  294  of the second linkage  254 . The pump piston  226  is arranged to be received within the pump chamber  228  and the second portion  294  of the second linkage  254  is arranged to be received within the bore  295  for interacting with the first portion  292 . O-rings  300  and  302  are arranged to be seated on the piston  226  to provide a seal against leakage and to prevent external contaminants from entering the piston chamber. The base layer  280  further includes fluid channels  304  that serve to form the fluid conduits illustrated in  FIG. 10 . Finally, springs  306  and  308  are arranged to spring load the actuator buttons  216  and  218 . 
         [0084]    The intermediate layer  282  is formed of flexible membrane material. A portion  296  of the intermediate layer is received over the reservoir portion  286  to form the reservoir  222  ( FIG. 10 ). A rigid plate  310  is arranged to be adhered to the portion  296  of the reservoir. Because the layer  282  is flexible membrane, it will move as the reservoir is filled and emptied. The rigid plate  310  will then move with it. The plate includes an eyelet  312  dimensioned to receive an elongated web  314  that forms a part of a medicament level indicator to be described hereinafter. The web  314  carries an indicator line or feature  316 . 
         [0085]    The top layer  284  is arranged to be received over the intermediate layer  282  and adhered to the base layer. It includes a panel  320  having a view window  318  through which the medicament level indicator line may be observed. 
         [0086]    Lastly with respect to  FIG. 12 , it may be noted the device  210  further includes a pin  322 . The pin  322  is a locking pin that is employed to lock the actuator buttons after a last medicament dose is delivered. It also serves to maintain the device fill port, to be described subsequently, in a blocked condition after a last medicament dose is delivered. 
         [0087]    Referring now to  FIGS. 14 and 15 , they are lengthwise sectional views, in perspective, of the device of  FIG. 9  along with a cannula assembly that may be deployed in the device.  FIG. 14  illustrates the previously described layered structure of the device  210  including device layers  280 ,  282 , and  284 . As may also be noted in  FIG. 14 , the device includes a port for receiving a cannula assembly  340 . The cannula assembly has a base  342 , a generally cylindrical docking structure  344 , and a cannula  346 . The docking structure  344  is arranged to be received by the port  330  ( FIG. 15 ) after the cannula assembly  340  is applied to the patient&#39;s skin with the cannula projecting beneath the patient&#39;s skin. The device includes a needle  348  that projects through a septum  350  of the device when the cannula assembly  340  is received by the port  330 . This completes the fluid path from the reservoir  222  to the cannula  346 . For a more detailed description of such a cannula assembly and the device that utilizes the same, reference may be had to co-pending U.S. application Ser. No. 11/803,007, filed May 11, 2007, and entitled INFUSION ASSEMBLY, which application is owned by the present assignee and incorporated herein by reference. 
         [0088]      FIGS. 14 and 15  also clearly illustrate a medicament level indicator embodying the present invention. The rigid plate  310  forms a moveable wall that moves as the medicament volume increases and decreases within the reservoir. The elongated web  316  is preferably formed from a non-elastic, non-compressible, elongated material. It has a first end  352  and a second end  354 . The web is fixed at the first end  352  with respect to the rigid plate  310  of the reservoir  222  and is arranged to move in a first plane generally perpendicular to the rigid plate  310  intermediate the first and second ends  352  and  354 . Because the web  316  is fixed at the first end  352  and free to move within the eyelet  312 , its second end  354  will move in linear movement in a second plane substantially parallel to the rigid member and transverse to the first plane. 
         [0089]    As previously mentioned, a panel  320  of the top layer  284  has a window opening  318  to render the medicament level indicia viewable. The cover panel  320  forms a guide channel  356  that receives and confines the web second end to guide the web for linear movement in the second plane substantially transverse to the first plane. As the reservoir is filled or emptied, a glance through the window  318  will provide an indication of the level of the medicament in the reservoir  222 . 
         [0090]    Referring now to  FIG. 16 , it is a sectional plan view showing the valve configuration of the device  210  of  FIG. 9  during medicament filling of the pump chamber  228  immediately after a dosage delivery. Here, it may be clearly seen that the first actuator button  216  has an extension comprising the shuttle bar  241  of the valves  232  and  234 . Above the valves are the conduits from the reservoir, from the pump, and to the cannula. More particularly, the conduit  242  is in fluid communication with the reservoir  222  ( FIG. 10 ), the conduit  244  is in fluid communication with the pump, and the conduit  246  is in fluid communication with the cannula. The valves are shown with the first valve  232  opened and not blocking the reservoir conduit  242 , and the second valve  234  closed and blocking the conduit  246  to the cannula. This permits medicament to flow from the reservoir through conduit  242  and to the pump chamber  228  through conduit  244  as the actuator button  216  returns to its first position. Hence, the pump chamber is filled and ready for the next dosage delivery. 
         [0091]    Referring now to  FIG. 17 , it is a sectional plan view showing the valve configuration of the device  210  of  FIG. 9  during medicament delivery. Here, the valves are shown with the first valve  232  closed and blocking the reservoir conduit  242 , and the second valve  234  open permitting medicament to flow from the pump through conduit  244  and to the cannula through conduit  246 . As previously mentioned, the first and second valves  232  and  234 , respectively, are spaced apart so that conduit  242  is blocked before conduit  246  is opened. 
         [0092]      FIGS. 18-22  show details of the operation of the second linkage  254  of the device  210 . Through this discussion, simultaneous reference to more than one drawing figure may be necessary. As may be seen  FIG. 18 , the first actuator button  216  has an extension  380  that terminates in a block  382  having a first ramp surface  384  and a second ramp surface  386 . When the device  210  is actuated, the button  216  is concurrently depressed with pump button  218 . It and its extension  380  and bloc  382  are free to move to the right. As seen in  FIGS. 18 and 21 , the pump actuator button  218  has parallel extensions  400  and  402  which are joined and separated be a rod member  404 . As seen in  FIG. 18 , the extension  400  abuts an abutment  388  which it must clear to be able to move to the left. As shown in  FIG. 21 , as the button  216  is depressed, its extension  380  moves to the right causing the first ramp surface to engage the rod member  404 . Continued movement of the button causes the rod member  404  to rise up under the first ramp surface  384  which in turn causes the extension  400  to begin to move slightly to the left and bend upward about rib  405 . Eventually, the rod member  404  rides up the length of the first ramp  384  causing the end  401  of extension  400  to clear the abutment  388  as shown in  FIG. 19 . The pump button  216  is now able to move freely to the left. When the end  401  of extension  400  totally clears the abutment  388 , it will snap behind the abutment  388  as shown in  FIG. 20  and become temporarily locked. Meanwhile, as shown in  FIG. 22 , the rod member  404  has traversed down the second ramp surface  386 . The buttons  216  and  218  are now fully depressed. 
         [0093]    Hence, from the above, it may be seen that the pump button  218  could not at first move freely while the first actuator button  216  which operates the valves could. As a result, the pump actuation lags behind the valve actuation causing the first valve  232  ( FIG. 10 ) to be closed and the second valve  234  to be opened, establishing a medicament delivery flow path to the cannula, before the pump is able to begin pumping the medicament to the patient. Because this operation occurs quickly, it appears to the patient that both actuator buttons are moving at the same rate. 
         [0094]    When the extension  400  of the pump button clears the abutment  388 , it becomes locked in a snap action. As in the previous embodiment, this provides positive feedback to the patient that a dosage of medicament was delivered as desired. It also causes a full dose to be delivered. By virtue of the snap action of the pump actuator, only full doses may be administered. 
         [0095]    When the medicament has been delivered, the spring loading of the actuator buttons returns the buttons to their first or initial position. During this time, the same timing provided by the block  382  is used for recharging the pump. More specifically, ramp  366  unlatches the end  401  of extension  400  by lifting rod member  404  so that  246  is closed and conduit  242  is opened before the pump is returned by the spring to its initial position. This assures that the pump does not pull medicament from the patient but only from the reservoir. As the piston  226  of the piston pump  224  returns, a full dose of the medicament is drawn up into the piston chamber  228  to ready the device for the next dosage delivery. 
         [0096]      FIGS. 23 and 24  show the operation of the piston pump  224  in greater detail. Also shown is a last dose lock-out  420  that will be described subsequently. Here it may be seen that the piston  226  of pump  224  is an extension of the pump actuator button  218 . Also, it may be seen that the O-rings  300  and  302  seal the piston  226  and the chamber  228 . The double O-rings both prevent leakage of medicament from the camber  228  and prevent outside contaminants from entering the chamber  228 . 
         [0097]    When the pump chamber is filled with medicament as the actuator button is returned from the second position shown in  FIG. 24  to the first or initial position shown in  FIG. 23  after a dosage delivery, medicament flows from the reservoir, through a conduit  307  ( FIG. 13 ), through a diaphragm chamber  424  and through the conduit  244  to the pump chamber  228 . The chamber  424  is defined by a diaphragm  422  formed of flexible membrane material. The diaphragm  422  includes an extension which captures the pin  322 , previously shown in the exploded view of  FIG. 12 . As long as the reservoir has medicament, and hence is not empty, the diaphragm  422  is not affected. In this state, the button  216  is free to be actuated. 
         [0098]    As may be noted, the pin is L-shaped at end  323  with an L-extension  428 . A capture ramp  430 , integral with the actuator button, passes adjacent to the pin  322  and over the L-extension  328 . This occurs when the actuator button is depressed as long as the reservoir has sufficient medicament to provide at least one more dosage delivery. 
         [0099]    Reference may now be had to  FIGS. 25 and 26  as the operation of the last dose lock-out  420  is described. When the reservoir has insufficient medicament to support delivery of another dose of medicament, and during the return of the actuator button  218  after what will be the last dose delivered, a negative pressure is created in the diaphragm chamber  424 . This causes the diaphragm  422  to be drawn into the chamber  424  due to the absence of liquid medicament in the chamber  424 . As the diaphragm  422  is drawn into the chamber  424 , the pin  322  is drawn upward with the diaphragm  422  where it engages an abutment  432  connected to the ramp extension  430 . The pin  322  is now caused to be captured between the ramp  430  and the abutment  432 . The button  216  is now only partially returned to its first position whereas the pump actuator button  218  is free to fully return to its initial position. Upon the next attempted actuation of the device, the L-extension will ride up the ramp  430  and fall into a locked position between the ramp  430  and a shoulder  434  formed in the actuator button  216 . The button is now locked and cannot be returned to its first position. The pump actuator button  218  will also be locked in its second position as shown in  FIG. 26 . This is due to the fact that the first button  216  is not able to return from its second position which, as shown in  FIG. 20 , causes the end  401  of the extension  400  of the pump actuator  218  be locked between the abutment  388  and actuator button  216 . Hence, the device  210  is now locked and cannot be reused. 
         [0100]    Referring now to  FIGS. 27 and 28 , they illustrate a further aspect of the last dose lock-out. Before the device  210  can be used to deliver a medicament, its reservoir must be filled with a medicament. To this end, the device  210  is provided with a fill port  440  that communicates with the reservoir. When the device  210  is filled with medicament, the actuator buttons  216  and  218  are in their initial positions. The first actuator button  216  further includes another extension  442  which does not cover the fill port  440  when the actuator button  216  is in its initial position. However, when the actuator button  216  is in its fully actuated second position, it does block the fill port  440  as seen in  FIG. 28 . When the last dose lock-out has the locked the device, the actuator button  216  is left in its fully actuated second position. As a result, the last dose lock-out not only locks both actuator buttons  216  and  218  to disable the device  210 , it also blocks the fill port  440  to further render the device disabled. 
         [0101]    While particular embodiments of the present invention have been shown and described, modifications may be made. For example, instead of manual actuation and spring loaded return of the valves used herein, constructions are possible which perform in a reversed manner by being spring actuated and manually returned. It is therefore intended in the appended claims to cover all such changes and modifications which fall within the true spirit and scope of the invention as defined by those claims.