[ 0091 ] fig1 a shows a schematic representation of a first embodiment of the invention . correspondingly , the configuration of the different structures as well as there relative dimensions and locations are intended to serve illustrative purposes only . more specifically , a drug delivery system ( here : infusion system ) 1 b comprises a reservoir unit 10 in combination with three different control units 20 , 30 , 40 , in which a combination of the reservoir unit and one of the control units provides an operative drug delivery device . the reservoir unit comprises a drug reservoir 11 and a pump 12 comprising an outlet means 13 and adapted for infusing a drug into a body of a user in accordance with instructions ( i . e . a local command ) received from a local processor 15 . the pump may be of the metering type , i . e . the amount of drug infused corresponds to the controlling signals received from the local processor or the infusion unit may be provided with detecting means for determining the amount of drug actually infused ( not shown ). the local processor is associated with a local receiving means 16 cooperating with the local processor means for receiving control commands from at least one of the control units . an energy source 19 is provided in the form of a battery . the three control units are in the form of a basic unit 20 , a standard unit 30 and an advanced unit 40 . the standard control unit comprises a control processor 35 associated with a transmitter 36 for wireless transmitting control commands to the local processor via the local receiving means . the control unit further comprises a display 31 associated with the control processor . the display may be used when the user enters information into the control unit via user - accessible input means ( not shown ), e . g . the desired size for a bolus command or program data changing the infusion rate or profile , the information being transferred via the transmitting means . an energy source 39 is provided in the form of a battery . the standard control unit 30 may be attached to the reservoir unit 10 by releasable means 14 , 34 . the first combination is based on one - way transmission of commands from the control unit to the reservoir unit , however , the reservoir unit comprises local transmission means 17 cooperating with the local processor means for transmitting data information to control receiving means 47 provided in the advanced control unit 40 . the data may comprise information as to the initial amount of drug in the reservoir , the current amount of drug in the reservoir , the infusion rate , information from a sensor element or id information identifying the given reservoir unit . the advanced control unit further comprises memory means 42 allowing transmitted and / or received commands / data to be stored and recalled . the memory means may be detachable , e . g . in the form of a memory stick or card . the first and second combinations are based on one - way transmission of commands from the control unit to the reservoir unit , however , the reservoir unit further comprises second local receiving means 18 adapted to cooperate mechanical command means 28 provided on the basic control unit 20 . more specifically , the basic control unit is provided with a protrusion 28 adapted to be received in the second local receiving means when the reservoir unit and the control unit are attached to each other by releasable or non - releasable means 14 , 24 . the reservoir unit may be adapted to provide a single basal infusion rate when combined with the basic control unit , or it may be adapted to provide a plurality of infusion rates which can be specifically activated by mechanical commands from a corresponding number of different basic control units . [ 0097 ] fig1 b shows a schematic representation of a further embodiment of the invention . correspondingly , the configuration of the different structures as well as there relative dimensions and locations are intended to serve illustrative purposes only . more specifically , a drug delivery system 1 b comprises two different reservoir units 110 , 150 in combination with a control unit 120 in which a combination one of the reservoir units and the control units provides an operative drug delivery device . in contrast to the control units of the first embodiment , the control unit 120 comprises an attachable subunit 130 and a remote subunit 140 , the subunits comprising transmission means and corresponding receiving means adapted for wireless transmission of commands or data information to and / or from the respective unit ( s ). for this reason the control unit 120 may be considered a control assembly . the reservoir units of the system and the attachable subunit comprise mating coupling means allowing the attachable subunit to be secured to a reservoir unit , the mating coupling means including communication means 131 , 132 allowing commands or data information to be transferred , whereby commands or data information to and / or from a reservoir unit can be transmitted wireless between the remote subunit and the reservoir unit via the attachable subunit . the remote subunit 140 generally corresponds to the advanced control unit of the first embodiment , i . e . comprising a control processor 145 associated with transmitting and receiving means 146 , 147 , a display 141 associated with the control processor , memory means 142 and an energy source 149 . the attachable subunit also comprises a processor 135 associated with receiving means and transmitting means 136 , 137 and an energy source 139 . in the shown embodiment the attachable subunit further comprises a mechanical pump actuator 131 serving as a mechanical means for transmitting commands to a corresponding pump in a reservoir unit , as well as electrical contact means 132 for receiving information from a reservoir unit , i . e . providing “ passive ” control commands allowing the sensor to be used . the reservoir unit and the attachable subunit are attached to each other by releasable means associated with the mating coupling means . the first reservoir unit 110 comprises a drug reservoir 111 and a pump 112 comprising an outlet means 113 and adapted for infusing a drug into a body of a user in accordance with commands received from the attachable subunit , as well as a sensor 114 in communication with electrical contact means 115 for transmitting information to the attachable subunit , the electrical contact means also providing the energy necessary for driving the sensor . the pump comprises a mechanical interface allowing the pump to be driven in a controlled manner via the command / actuator means 131 . in the shown embodiment the pump is in the form of a membrane pump driven by command actuators located in the attachable subunit , however , a variety of pump and command means may be utilized . for example , the pump may be of the bleeding hole type comprising valve means controlled by the control unit ( preferably in combination with flow control means ) or may essentially correspond to the above - described first embodiment in which the reservoir unit comprises a local processor which in this further embodiment would be controlled via the processor 135 and energized from the battery 139 . the sensor 114 is adapted for detecting a condition in the body of the user such as the blood glucose level . the detected glucose level may be transmitted to the remote subunit and displayed on the display or it may be utilized for controlling the delivery of the drug in response thereto in a closed loop arrangement . whereas a combination of the first reservoir unit and the control unit provides an advanced pump assembly based on two - way transmission of commands / data between the control unit and the reservoir unit and comprising an integrated sensor system , the second reservoir unit 150 is a basic unit merely providing a controllable pump 152 in combination with a drug reservoir 151 . [ 0103 ] fig2 a and 2b show a second embodiment of the invention . more specifically , a drug delivery ( here : infusion ) system 2 comprises a reservoir unit 200 in combination with two different control units 250 , 260 , in which a combination of the reservoir unit and one of the control units provides an operative drug delivery device . the reservoir unit comprises an outer housing defining the outer boundaries for the combined infusion device , the housing having an upper surface 201 , a rim portion 202 and a lower surface 203 adapted to be arranged towards a skin surface of a user . preferably the lower surface is provided with an adhesive ( not shown ) allowing the device to be attached directly to the skin surface . in the upper surface an opening 204 is provided adapted to receive a control unit , the reservoir unit and the control units including mating coupling means 205 , 255 , 265 so as to allow a control unit to be secured to the reservoir unit , the mating coupling means including electrical contacts 206 , 256 , 266 . the control unit 250 comprises a housing having an upper surface 251 , a rim portion 252 and a lower surface 253 , the control unit being adapted to be received in a corresponding opening in the reservoir unit 200 , the control unit including mating coupling means 255 so as to allow the control unit to be secured to the disposable unit . it is to be noted that the coupling means shown on the control units respectively the reservoir unit are not intended to engage each other but are merely arranged for illustrative purposes . in accordance with the actual design of the units , the electrical contacts may provide command / data transfer to and / or from the control unit as well as providing the control unit with energy from an energy source provided in the disposable unit or vice versa . the control unit 250 comprises a user interface having a user actuatable key 257 and a display 258 . in the shown embodiment only a single key is provided , for example in the form of an on - off switch or a bolus key . in accordance with the actual design of the control unit , the display may provide the user with different kinds of information , e . g . the actual infusion profile , the amount of drug infused ( e . g . for insulin a number of units ) for a given period , the amount of drug remaining in the disposable unit etc . as the basal infusion rate for any drug to be infused using the device of the invention will be dependent of the individual user , it could be possible to set such a basal rate using control means arranged on either of the two units . as this setting normally will not have to be changed on a regular basis , these control means may be provided on portions of the units which are hidden to the user when the two units are secured to each other , for example on the rear surface of the control module . the second control unit 260 essentially corresponds to the first control unit 250 , the differences being a group of user actuatable keys 267 , e . g . allowing the unit to be program med by the user , as well as another display 268 , e . g . having graphic and / or alpha - numeric capabilities . the second control unit further comprises a memory means as well as a back - up energy source therefore ( not shown ). in the shown embodiment all pump components in contact with the drug is contained in the disposable part , however , according to the actual type of pump , some components thereof may be provided in the control unit , for example a small electric motor actuating a valve pump comprised in the disposable unit . the memory means allows the control unit to be released from a first disposable unit and placed in a second disposable unit without loss of information contained in the control unit , e . g . specific program settings or information regarding the amount of drug infused for one or more periods . in a further embodiment ( not shown ), the disposable unit may comprise additional means providing a back - up memory function for the control unit , this allowing a new or pre - used control unit to be updated when inserted into such a disposable unit . [ 0110 ] fig2 b shows the reservoir unit 200 with the control unit 250 mounted . as can be seen , the control unit is fully embedded in the opening of the reservoir unit , the upper surfaces of the two units being arranged flush with each other . advantageously , such a design could be used in cases where the combined device is sold as a disposable single unit ( preferably with a basic control unit as described above ), the control unit being inserted into the opening before being sold . indeed , the shown flush configuration may also be used for control units intended for re - use . not to be seen , the reservoir unit comprises a reservoir , a pump means for pumping drug contained in the reservoir to an outlet opening ( not shown ) and an energy source for operating the pump and , if deemed appropriate , the control unit when attached . as described above with reference to the second control unit 260 , the pump means may serve fully or only partly as an operating pump , the remaining components being provided by the control unit . further , depending on the actual type and design of the pump , control means for operating the pump may be provided in either of the units or divided therebetween as discussed in greater detail in the introductory portion . [ 0112 ] fig3 a and 3b show a third embodiment of the invention . more specifically , a drug delivery ( here : infusion ) system 3 comprises a reservoir unit 300 in combination with three different control units 350 , 360 , 370 in which a combination of the reservoir unit and one of the control units provides an operative drug delivery device . the reservoir unit comprises an outer housing defining the outer boundaries for the combined infusion device , the housing having an upper surface 301 , a rim portion 302 and a lower surface 303 adapted to be arranged towards a skin surface of a user and preferably being provided with an adhesive . the reservoir unit is provided with a “ cut - out ” portion 304 adapted to receive a control unit , the reservoir unit and the control units including mating coupling means 305 , 355 , 365 , 375 so as to allow the control unit to be secured to the reservoir unit , the mating coupling means including electrical contacts . as can be seen , the lower portion comprises an extension in the form of a base plate portion which extends in a tongue - like fashion corresponding to the cut - out portion of the housing , the upper surface 307 of the base plate portion and the portion 312 of the rim facing towards the base plate portion providing mounting surfaces for a control unit and together defining a confinement for a control unit . as appears from the figure , the confinement 304 is provided within the outer boundaries of the disposable housing . the reservoir unit 300 comprises the same internal components as described for the second embodiment . the control unit 350 comprises a housing having an upper surface 351 , a rim 352 and a lower surface 353 , the rim comprising a connecting portion 354 . the control unit is adapted to be received in the corresponding confinement 304 in the reservoir unit 300 , the control unit including mating coupling means 355 on the connecting portion 354 and the lower surface ( not shown ) so as to allow the control unit to be secured to the corresponding portions 312 , 307 of the reservoir unit , the mating coupling means including electrical contacts . the coupling means may be of the same type as discussed above with reference to the fig2 a embodiment . the control unit 350 comprises a simple user interface having a single user actuatable key 357 , for example in the form of an on - off key or a bolus key , but no display . the second control unit 360 has the same dimensions as the first control unit 350 , but comprising two keys and a display 368 . the display may provide the user with information as to infusion settings and / or history , just as the display would allow the control unit to be menu - programmable using the two keys . the third control unit is somewhat larger ( and thus larger than the upper base plate surface 307 ) and comprises four keys and a larger display 378 . [ 0117 ] fig3 b shows the reservoir unit 300 with the control unit 350 mounted . as can be seen , the control unit fully occupy the confinement 304 defined within the outer boundaries of the disposable housing , the upper and outer rim surfaces of the two units being arranged flush with each other . the control unit may be attached in releasable or a non - releasable m anner . [ 0118 ] fig4 a and 4b show a fourth embodiment of the invention . more specifically , a drug delivery system 4 comprises two reservoir units 400 , 410 in combination with a control unit 450 in which a combination of one of the reservoir units and the control unit provides an operative drug delivery device . the first reservoir unit 400 has the same general outer configuration as in the second embodiment comprising an opening 404 adapted to receive a control unit , whereas the second reservoir unit 410 has the same general outer configuration as in the third embodiment comprising a cut - out portion 414 adapted to receive a control unit . fig4 b shows the reservoir unit 410 with the control unit 450 mounted . [ 0119 ] fig5 shows a fifth embodiment of the invention in which a drug delivery system 5 comprises two reservoir units 500 , 510 in combination with an advanced control unit 550 having a keyboard and a display , whereby a combination of one of the reservoir units and the control unit provides an operative drug delivery device . in contrast to the embodiments described with reference to fig2 - 4 , the units comprise wireless communication means 506 , 516 , 556 for transmission of commands / data and the units are not adapted to be connected to each other . the first reservoir unit 500 may represent a basic reservoir unit providing e . g . a single basal rate which can be activated by the control unit . the second reservoir unit 510 may represent an advanced reservoir unit being fully programmable by means of the control unit ( e . g . allowing the user to enter a desired infusion rate or profile or a bolus command ) as well as providing two - way exchange of command instructions and data information . [ 0120 ] fig6 shows a sixth embodiment of the invention in which a drug delivery system 6 comprises two control units 650 , 660 in combination with an advanced reservoir unit 600 whereby a combination of one of the control units and the reservoir unit provides an operative drug delivery device . in contrast to the embodiments described with reference to fig2 - 4 , the units comprise wireless communication means 606 , 556 , 566 for transmission of commands / data and the units are not adapted to be connected to each other . the first control unit 650 comprises a simple user interface having a single user actuatable key 657 , for example in the form of an on - off key or a bolus key , but no display . the second control unit 660 has an entirely different configuration comprising three keys 667 and a display 668 . the display may provide the user with information as to infusion settings and / or history , just as the display would allow the control unit to be menu - program mable using the two keys . [ 0122 ] fig7 a discloses a control unit 750 mounted in a reservoir unit 700 . apart from the outer form of the control unit and the corresponding confinement in the reservoir unit , the units are of the same general configuration as the embodiment shown in fig3 b to which reference is made . fig7 b shows the combined infusion device of fig7 a with a hollow infusion needle 701 attached in communication with an outlet from the pump or reservoir means and protruding from the lower surface of the reservoir unit . the lower surface is further provided with a peelable liner 702 covering an adhesive layer for attaching the device to the skin of the user . to facilitate introduction of the needle , the disposable device may be provided with user actuatable means for automatically advancing the needle into the skin after the device has been attached . fig7 c shows the infusion device of fig7 b with an infusion catheter attached in communication with an outlet from the pump means . the infusion catheter comprises an infusion line or tubing 710 communicating with an infusion needle 711 , a pad 712 being provided between the line and the needle , the pad allowing the catheter and needle to be gripped during the insertion procedure just as it allows the catheter to be properly secured to the skin of the user . the reservoir unit may be provided with an outlet opening in the vicinity of the lower surface thereof comprising a connector allowing either an infusion needle or an infusion catheter to be attached to the opening . such a connector may also serve as a port for filling the reservoir , either initially or during re - filling . while the present invention has been described in connection with the exemplary embodiments shown in the various figures , the delivery system according to the invention may be provided with additional features providing improved functionality , control and ease of use . for example , a sensor may be provided for continuously measuring the pressure in the infusion line or needle , this allowing the detection of a malfunctioning which could be used to initiate an alarm making the user aware of a problem . however , more advanced sensors may be incorporated in the units . for example , it may be desirable to automatically deliver certain drugs only when required by the subject , either by patient activation or passively , such as by a feedback mechanism . in such a case , the device further includes a sensor ( feedback ) for detecting a condition in the body of the subject and for controlling the delivery of the drug in response thereto . the sensor may be , for example , a temperature sensor , a pulse rate sensor , a blood glucose sensor , a blood pressure sensor or a ph sensor . the sensors may be formed integrally with the reservoir unit or attached separately . the sensor may rest against the skin , may be inserted through the skin , or may be within the device and separate from the skin . the reservoir unit may also include a plurality of drug reservoirs , each reservoir being independently controllable and communicating with an outlet with which a single infusion needle also communicates . for such a plurality of drug reservoirs , pump means integrally formed with the reservoir is preferred , for example in the form of individual gas generators . including a plurality of drug reservoirs provides for considerable variations in the amounts of drug which can be delivered , in the rates at which drug can be delivered and in the number of drugs which can be delivered by the same device . the reservoir unit may further be provided with a reservoir for a calibrating liquid in case the unit is provided with sensors requiring such a liquid . in the above description of the exemplary embodiments , the different structures providing mechanical , electrical and fluid contact and communication between the different components just as the means providing the described functionality for the different components ( i . e . pump , reservoir , energy source , memory , control , display etc .) have been described to a degree to which the concept of the present invention will be apparent to the skilled reader . the detailed construction and specification for the different components are considered the object of a normal design procedure performed by the skilled person along the lines set out in the present specification .
the invention relates to a modular drug delivery system , comprising a reservoir unit and a control unit in combination with at least one further reservoir or control unit , whereby each combination of a reservoir unit and a control provides different capabilities . more specifically , the present invention provides a system for delivering a drug to a user , comprising a reservoir unit , a control unit , and at least one further reservoir unit or control unit , wherein each reservoir unit is adapted to receive at least one command from a control unit and perform an action in response thereto , and comprises a reservoir adapted to contain a liquid drug and includes , in a situation of use , associated outlet means . the system further comprises expelling means for expelling a drug out of the reservoir through the outlet means . each control unit comprises control means providing one or more commands for controlling the operation of a reservoir unit , wherein each combination of a reservoir unit and a control unit is adapted to provide a system with different capabilities .