Abstract:
The present invention provides a device for administering an injectable product in doses, the device including a casing, a container accommodated by the casing, a delivering appliance for delivering the product from the container, a drive for the delivering appliance, and a means for determining a malfunction of the device, wherein a vibrator motor is accommodated by the casing, the vibrator motor being triggered by the means for determining a malfunction such that it generates a vibrating alarm signal when a malfunction is determined.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
         [0001]    This application is a continuation of International Patent Application PCT/CH00/00506, filed on Sep. 19, 2000, which claims priority to an earlier filed German Application Number DE 199 47 826 A1, filed on Oct. 5, 1999.  
         BACKGROUND  
         [0002]    The invention relates to a device for administering an injectable product in doses.  
           [0003]    Infusion devices, such as are used for example in diabetotherapy and such as the invention also relates to in particular, comprise at least the following components: a casing; a container, accommodated by the casing, containing the product; a delivering appliance for delivering the product from the container; and a drive means for the delivering appliance. The product is subcutaneously administered from the container through a catheter and an infusion needle connected to the catheter.  
           [0004]    For users who administer the product themselves in the context of a treatment or for other purposes, it is generally important to be able to use their infusion device discreetly and inconspicuously. Surety in handling the device should not, however, suffer as a result. Furthermore, when the device can be comfortably and simply handled, this contributes to surety in administering the product.  
         SUMMARY  
         [0005]    It is an object of the invention to provide a device for administering an injectable product in doses which can be handled securely and inconspicuously.  
           [0006]    The invention is based on a device for administering an injectable product which comprises at least the following components: a casing; a container, accommodated by the casing, for the product; a delivering appliance for delivering the product from the container; and a drive means for the delivering appliance.  
           [0007]    The drive means preferably comprises a drive motor. In a preferred exemplary embodiment, it further comprises a spindle drive acting on the delivering appliance. A catheter comprising an injection or infusion needle may be connected or is already connected to an outlet of the container. The container is preferably an ampoule, filled with the product, which may be inserted into a receptacle formed by the casing and which can be exchanged. The aforementioned components are preferably all accommodated in the casing, as is for example the case in known infusion pumps for diabetotherapy. This is not, however, absolutely essential for the purposes of the invention. The product is preferably a medicinal and/or cosmetic active solution, for example insulin. The delivering appliance is preferably a piston, but can also be a peristaltic pump or can be formed in another suitable way. The device is preferably constantly worn on the user&#39;s body or clothing.  
           [0008]    The device preferably comprises a means for determining a malfunction of the device. The term malfunction is intended to relate to operations, operational conditions, function and functional conditions of the device, including departures from normal, proper or correct operations, operational conditions, function and functional conditions. Such a malfunction can be due to an occlusion or leak along or on the product&#39;s path from the container to an outlet of the injection needle. Another example of a malfunction can be based in or relate to the drive means, for example a broken or defective drive motor for the delivering appliance or a broken or defective control and/or regulating system for a drive motor. Although the drive means preferably comprises a drive motor and a control system and/or regulating system for the drive motor, a non-motorized drive for the delivery means is also conceivable, for example by means of a pressure medium or a drive spring.  
           [0009]    The device is preferably equipped with an input means, formed for example by a keyboard or a touch screen. In principle, however, a different input appliances can be provided instead or in addition, for example a speech input. By means of the input means, the user himself in particular can bring an influence to bear on administering the product.  
           [0010]    In accordance with the invention, a vibrator motor is accommodated by the casing. The vibrator motor may be accommodated in the casing. In principle, however, it can also be fixed externally to the casing. In both cases, the vibrator motor is arranged such that a vibrating movement of the vibrator motor can be clearly and noticeably perceived by the user. Preferably, the vibrator motor causes the whole casing or a part of the casing to vibrate.  
           [0011]    In a first preferred function, the vibrator motor forms an alternative to an acoustic or other signal provider or, which is particularly preferred, an additional appliance for alerting. If a means for determining a malfunction of the device determines the malfunction in question, the vibrator motor emits a vibrating alarm or warning signal. In this case, a trigger for the vibrator motor is connected to the means for determining the malfunction. When the malfunction in question arises and is determined, the vibrator motor is triggered and generates the vibrating alarm signal.  
           [0012]    A vibrating alarm signal is definitely perceived by the user himself, but not by those around him. By means of the vibrator motor, therefore, a sure and at the same time discreet i.e. inconspicuous way of alerting the user is provided. If the vibrator motor is provided in addition to another alerting appliance, for example an acoustic alerting appliance, then the vibrator motor provides a redundancy with respect to the alerting appliance. If another alerting appliance is additionally provided, for example an acoustic signal provider, then a switch is preferably provided with which the user can optionally switch off one of the alerting appliances or select one of them as the alerting appliance. Advantageously, a common trigger can be provided for a number of redundant alerting appliances. The additional expense of triggering the vibrator motor can then be avoided.  
           [0013]    The means for determining a malfunction preferably comprises a sensor which detects an impermissibly large deviation from an ideal state. The sensor is preferably a component of a means for monitoring a pressure within the components of the device which guide the product, if the malfunction to be determined is an occlusion. The sensor for this is preferably a force sensor. In such cases, a force necessary to drive the delivering appliance is measured. Preferably, the reaction force exerted by the delivering appliance is directly measured. A force sensor is preferably also used to determine a leak. Advantageously, both an occlusion and a leak may be detected by the same force sensor.  
           [0014]    A malfunction of a drive motor and/or a malfunction of a control and/or regulating system for a drive motor is preferably detected by means of an angular position sensor for the motor. The angular position of the control system for the drive motor which the sensor detects is not adopted as a variable, but is only used for the purpose of determining the malfunction of the drive means and triggering the vibrator motor.  
           [0015]    The malfunction can also be an advance notice that the stored energy of an energy source for the drive means has been used up. If electrical energy is required for the drive motor, then the level of charge of a battery for the drive motor, for example, can be monitored. In this case, the vibrator motor is triggered by the trigger when the level of energy drops below a predetermined minimum energy reserve.  
           [0016]    If the device comprises an input device, a second function of the vibrator motor in accordance with the invention is to confirm inputs which have been inputted by means of the input means. Preferably, individual vibrating signals are allocated to selected input appliances or to all the input appliances of the input means. If, for example, the user inputs an extra bolus, then the individual inputs, inputted for example via a keyboard or a touch screen, are individually confirmed by a vibration. In this function of the vibrator motor, a trigger for the vibrator motor is connected to the input means.  
           [0017]    If the drive means comprises a control and/or regulating system for a drive motor, then the trigger for the vibrator motor is preferably formed by this control and/or regulating system.  
           [0018]    A drive motor for the delivering appliance can at the same time also form the vibrator motor. In another, different preferred exemplary embodiment, a separate vibrator motor for one of or a combination of the functions cited is provided in addition to a drive motor.  
           [0019]    In accordance with the invention, a third function of the vibrator motor is that it vibrates when the device is primed. This ensures that the product guiding system, from the container to the outlet of the injection or infusion needle, is smoothly and securely vented. In particular, the user does not have to shake or strike the device when priming it, so that any air bubbles from priming are definitely removed. Priming is finished when the product emerges at the injection or infusion needle. It serves to vent the product-guiding components.  
           [0020]    In a fourth function, the vibrator motor is periodically triggered in accordance with the invention, to indicate to the user tactilely that his device is functioning normally. This can be provided in addition to—or also as an alternative to—an alerting function. The positive indication that the device is functioning normally ensures particularly sure handling.  
           [0021]    The vibrator motor provided in accordance with the invention can fulfill one of the aforementioned four functions or any combination thereof. It preferably fulfills a number and, in one embodiment, all of the four aforementioned functions.  
           [0022]    If the vibrator motor fulfils a number of the functions cited, a characteristic vibration can be generated for each of the functions. If attention can be drawn to a number of different malfunctions using the vibrator motor, a characteristic vibrating signal is also advantageously provided for each malfunction. The vibrating signal of a malfunction differs in particular from a periodically generated signal to confirm that the device is operating normally. On the other hand, however, signals for confirming inputs can correspond to alerting signals. An individual vibration also need not be provided for priming.  
           [0023]    The vibrator motor advantageously exhibits a maximum length of at most 20 mm and a maximum width of at most 5 mm. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0024]    [0024]FIG. 1 is a longitudinal sectional view of an infusion pump comprising a pressure monitoring system and a vibrator motor;  
         [0025]    [0025]FIG. 2 depicts a force sensor for the pump according to FIG. 1; and  
         [0026]    [0026]FIG. 3 depicts a schematic wiring diagram, comprising the vibrator motor, an input means, a position sensor and the force sensor. 
     
    
     DETAILED DESCRIPTION  
       [0027]    [0027]FIG. 1 shows a portable infusion pump for insulin treatment. The pump, in particular its drive, is described in German patent application No. 197 17 107. Reference is additionally made to the teaching in said application, which is incorporated herein by reference.  
         [0028]    A container in the form of an ampoule  2  is accommodated in a pump casing  1 . The ampoule  2  is filled with insulin. A delivering appliance in the form of a piston  6  is accommodated in the ampoule  2  such that it is linearly slidable in a feed direction towards an outlet  3  of the ampoule. The piston  6  is advanced by a driven member  7 , formed as a threaded rod, pressing on a rear surface of the piston  6 . The driven member  7  is part of a spindle drive  8  which is formed with two telescopic stages. With respect to the piston drive, the invention is not however restricted to this.  
         [0029]    When the piston  6  is advanced along an sliding axis V, insulin is delivered via a catheter  4  connected to the outlet  3  and an infusion needle  5  fixed to the front free end of the catheter  4 . Together, the ampoule  2 , outlet  3 , catheter  4  and needle  5  may be thought of and referred to as comprising a fluid guiding system. In order to set a defined base pressure in the ampoule  2 , a valve  25  is arranged on the flow path of the insulin. Such a valve can be used not only to define base pressure which continuously prevails in the fluid guiding system, but also to prevent the ampoule  2  from emptying itself under the weight of the column of fluid in the fluid guiding system. The valve  25  is preferably designed such that the ampoule is definitely prevented from undesirably emptying itself, under the conditions arising in the practical use of the infusion pump. In the exemplary embodiment, the valve  25  is accommodated in a removable casing lid D which seals an ampoule compartment after an ampoule  2  has been inserted.  
         [0030]    The driven member  7  is driven by means of a drive motor  11 , via a reduction gear, onto the spindle drive  8  comprising the driven member  7 . With respect to the spindle drive and the reduction gear, reference is made to German patent application No. 197 17 107. At least the driven member  7  is guided linearly and non-rotationally in the casing  1 , such that the threaded rod  7  is advanced by rotary driving two preliminary drive members of the spindle drive which surround the driven member  7  like a sleeve.  
         [0031]    The spindle drive  8 , together with the gear and the motor  11 , is mounted on a sliding platform  10  which for its part is mounted as a whole in the casing  1 , non-rotationally but linearly slidable in and counter to the feed direction of the piston. It would also be possible in principle to arrange the motor  11  fixed to the casing; it would be equally possible to arrange the motor  11 , together with the gear, fixed to the casing. In this case, a sliding mesh—for example, a spur wheel toothing extending over a corresponding length along the feed direction—would have to be provided between the drive component fixed to the casing and the initial step of the spindle drive  8  which is then mounted on the sliding platform  10 .  
         [0032]    In order to be able to determine any malfunctions in the fluid guiding system or the components thereof, the pressure of the product fluid—in particular, for example, the fluid pressure in the ampoule  2 —is monitored. To monitor the pressure, a reaction force exerted by the piston  6  on the casing  1  is measured by means of force sensor  13  and compared with a predetermined index value for the reaction force. Calibrating the index value is described in German patent application No. 198 40 992, to which reference is made in this respect and which is incorporated herein by reference.  
         [0033]    The force exerted by the piston  6  onto the threaded rod  7  and via the spindle drive onto the sliding platform  10  and, as a result of its sliding capacity, onto the force sensor  13 , is measured as the reaction force by means of the force sensor  13 . For this purpose, the sliding platform  10  is mounted floating on the casing walls in the casing  1 . The sliding platform  10 , comprising a platform sleeve  10   a , is supported, longitudinally slidably, in a part of the casing sleeve surrounding this sleeve  10   a  by means of elastic mounting elements  10   b  in the form of a pair of O-rings, for example rubber rings. The platform sleeve  10   a  surrounds drive members of the spindle drive formed as drive sleeves. A contact is established between the sliding platform  10  and the casing  1  only via the O-rings  10   b . A sliding movement between the sliding platform  10  and the casing  1  along the sliding axis V takes place only within the context of elastic deformation of the O-rings  10   b . The O-rings  10   b  themselves slide neither with respect to the casing  1  or with respect to the sliding platform  10 , but only elastically deform. By forming this floating mounting, frictional forces are minimized and the force applied by sliding the piston  6  is transmitted as unaltered as possible onto the force sensor  13 . The O-rings  10   b  are accommodated in circumferential grooves of the platform sleeve  10   a  and in this way are fixed with respect to these two opposing surfaces of the casing  1  and the platform sleeve  10   a  by a positive lock on the one hand and a frictional lock on the other. They could, however, also be connected in a material bond to one of these two surfaces, and if appropriately assembled they could also be pressed together between the two oppositely moving surfaces and in this way held only in a frictional lock. In any event, it should nonetheless be ensured that no other frictional forces have an effect when sliding the sliding platform  20 , except the elastic deforming forces.  
         [0034]    The force sensor  13  is arranged between a rear facing surface of the sliding platform  10  and a wall of the casing  1  opposite the rear facing surface. It is furthermore arranged in the alignment of the sliding axis V of the piston  6 , such that the reaction force acting along the sliding axis V of the piston  6  acts directly on the force sensor  13 . The reaction force is introduced symmetrically with respect to the sliding axis V, and therefore cannot give rise to a substantial tilting moment.  
         [0035]    [0035]FIG. 2 shows the force sensor  13  on its own. It is formed by a bending beam  14  to which a thin-film strain measuring strip  15  is applied at least on one surface of the beam. Readings may be augmented by applying a strip to both opposing surfaces of the beam. Four lines of a bridge circuit are designated at  17 . In forming the bending beam, two stays  16   a  and  16   b  (FIG. 1) are indicated as linear supports at the platform end, spaced in parallel from each other on one surface of the beam, and between which the beam  14  comprising the strain measuring strip  15  is bent by the reaction force exerted by the piston  6 . To exactly define the site at which the reaction force is introduced, a further stay  16   c  (FIG. 1)—whose linear support is indicated in FIG. 2—projects from a base plate  1   b  of the under side of the casing  1  opposite the two stays  16   a  and  16   b , exactly in the middle between these two stays  16   a  and  16   b . The linear support of the third stay  16   c  lies in the alignment of the sliding axis V and parallel to the stays  16   a  and  16   b . The three stays  16   a ,  16   b  and  16   c  are cross-sectionally round in the support area, such that the reaction force is introduced along the stays  16   a  and  16   b  as exactly linear as possible and the load on the support at the stay  16   c  also acts linearly on the bending beam  14 . Other cross-sectional shapes which cause or approximate this are also suitable. Other sensors, for example piezo-resistive sensors, could equally be used instead of strain measuring strips in the context of a static measuring process.  
         [0036]    A reading representing the impressed reaction force, preferably proportional to the reaction force, is emitted from the force sensor  13 , via a line  17 , to the control system  20  for the motor  11 , preferably in the form of an electrical reading signal. The reading representing the reaction force currently being measured is permanently at an input I of the control system  20 . The control system  20  is connected to the motor  11  via an output O and a corresponding control line or control bus  18 . The motor  11  is positionally controlled.  
         [0037]    A vibrator motor  30  is arranged in the casing  1 . The vibrator motor  30  is rigidly fixed to the casing  1 . In the exemplary embodiment, it is fixed in a sealing stopper of the casing  1 , preferably rigidly so that the vibrations are transmitted to the casing  1 . The vibrator motor  30  is connected to the output O of the control system  20  via a line  18   a , i.e., it is triggered by the control system  20  via the line  18   a.    
         [0038]    If, with the aid of the force sensor  13 , an occlusion is determined by the control system  20  by comparing the measured reaction force with a maximum value, then the vibrator motor  30  is triggered by the control system  20  via the line  18   a  and emits a characteristic vibrating signal, indicating an occlusion, via the casing  1 .  
         [0039]    The drive motor  11  is a step or stepper motor with a physically predetermined start-stop frequency. This is a frequency and a corresponding motor speed, beyond which the motor torque decreases, which cuts off the motor  11  if it experiences comparatively little resistance in this state. Once it has been cut off, it no longer starts automatically, but merely oscillates back and forth until it is completely shut off. It is then re-started by a control command from the control system  20 .  
         [0040]    The position of the motor  11  is monitored by means of an impeller  12  fixed on the axis of the motor rotor and an optical sensor co-operating with the same, for which the impeller  12  serves as a light barrier interrupter. The control system  20  shuts off the motor  11  if a control impulse does not result in the motor turning. The position of the motor is known to the control system  20 , at least in the form of the number of completed revolutions from a reference position at any point in time. The position of the motor could also be ascertained by means of a counter connected to the optical sensor, which counts up the number of interruptions by the blades of the impeller  12 . From this, the control system  20  also knows the position of the driven member  7  relative to the sliding platform  10 , and ultimately also the position of the piston  6  in the ampoule  2 .  
         [0041]    The control system  20  comprises a micro-processor  21  having two non-volatile memories  22  and  23 . A standard index value distribution S for the reaction force is stored in the memory  22 . The other memory  23  is described in priming the infusion pump. The control system  20  is connected via an interface I/O to the motor  11 , the force sensor  13  and other components, in particular an energy source. The connection to the force sensor  13  is indicated by the reference numeral  17  and the connection to the motor  11  by the reference numeral  18 .  
         [0042]    [0042]FIG. 3 shows how the vibrator motor  30  is embedded in the pressure monitoring system and how the drive motor  11  is monitored. The vibrator motor  30  is further connected to an input means  40  via the control system  20 . The pressure is monitored by means of the force sensor  13 , whose reading signal passes to the control system  20  via the line  17 . If the control system  20  determines an occlusion by comparing the force measured by the force sensor  13  with a maximum value, it switches on the vibrator motor  30  via a line  18 . The user can manually switch the vibrator motor off via a line  31  by means of the input means  40 . If a malfunction of the motor  11  is determined with the aid of the sensor  12 , the vibrator motor  30  is likewise switched on by the control system  20 . In particular, it switches the vibrator motor  30  on when it switches off the motor  11 , as described above. The drive is monitored by means of the impeller and the optical sensor co-operating with the same, which in FIG. 3 are indicated together by the reference numeral  12 .  
         [0043]    The input means  40  is formed by a keyboard or a touch screen. The individual input appliances of the input means  40 , representing other such appliances, are indicated by the reference numerals  41 ,  42  and  43 , which are formed either by keys or keypads. Each of the input appliances of the input means  40  is electrically connected to the input I of the control system  20  via a line  45 . Only one line to the control system  20  is shown, as representative of the possible plurality of such lines  45 . The control system  20  emits an individual control signal via the connection line  18   a , depending on the input appliance of the input means  40  currently being operated, and the vibrator motor  30  generates a characteristic vibrating signal for each of the input appliances, depending on this control signal.  
         [0044]    When priming, the threaded rod  7  is driven towards the piston  6 , from a starting state in which the ampoule  2  has been inserted into the casing  1  and its sealing membrane at the outlet  3  has been pierced by a connection needle. The motor  11  moves in overdrive, significantly above the start-stop frequency, until it abuts the piston  6 . In overdrive, it is operated at a pulse frequency which is preferably at least twice as large as its start-stop frequency. As soon as the threaded rod  7  abuts the piston  6  with its pallet, the motor  11  is automatically cut off since its torque above the start-stop frequency is not sufficient to drive the threaded rod  7  and the piston  6 . The stopping position of the motor  11  is registered in the control system  20  and stored as a reference position for delivering the product. If a suitable reference value for a particular position of the piston  6  and the type of ampoule  2  being used is stored in the control system  20 , then the control system  20  can ascertain whether the ampoule  2  is a full or for example half-full ampoule from the actual position of the piston as determined when the threaded rod  7  moves up to it, by comparing this with said reference value.  
         [0045]    In the exemplary embodiment, the motor  11 —formed as a step or stepper motor with a settable start-stop frequency—is automatically re-started, once it has been cut off as described above, such that the piston  6  is then advanced in the ampoule  2 . In the course of priming, the piston  6  is advanced in the ampoule  2  towards the outlet  3  until insulin emerges at the delivery point of the infusion needle  5 . When the motor  11  is re-started, the vibrator motor  30  is triggered by the control system  20  and thus switched on. Gas bubbles stuck in the fluid guiding system of the device are released by the vibrations of the vibrator motor  30 , such that it is ensured that by the end of priming, the fluid guiding system has been thoroughly vented. As soon as it is definitely determined that fluid is emerging, the driven member  7  and therefore also the piston  6  is stopped in the sliding position along the common sliding axis V which it has just reached. It may be stopped manually if the emerging fluid is observed by the user, or also automatically by the control system  20 . When it is stopped, in particular by switching off the motor  11 , the vibrator motor  30  is simultaneously also stopped or switched off by the control system  20  via the line  18   a.    
         [0046]    The vibrator motor  30  is then once again ready to receive control signals, for example if an occlusion is determined, or to confirm inputs by means of the input means  40 .  
         [0047]    In the foregoing description preferred exemplary embodiments of the invention have been presented for the purpose of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise form disclosed. Obvious modifications or variations are possible in light of the above teachings. The embodiments were chosen and described to provide the best illustration of the principals of the invention and its practical application, and to enable one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. All such modifications and variations are within the scope of the invention as determined by the appended claims when interpreted in accordance with the breadth they are fairly, legally, and equitably entitled.