Abstract:
The present invention provides systems and methods for delivering medication with drug delivery devices such as drug pumps or the like. Drug delivery systems in accordance with the present invention include a remote controller that wirelessly communicates with a drug delivery device. The remote controller can control an infusion pump in such a way that provides the user with better control of the amount of medication dispensed.

Description:
TECHNICAL FIELD  
       [0001]     The present invention relates to systems and methods for delivering medication with drug delivery devices such as drug pumps or the like. More particularly, the present invention relates to drug delivery systems that include a remote controller that wirelessly communicates with a drug delivery device.  
       BACKGROUND  
       [0002]     The use of infusion pumps for various types of drug therapy is becoming more common, where these infusion pumps are used to automatically administer liquid medicant to a patient. The liquid medicant is supplied from a source of medicant and pumped into the patient via a catheter or other injection device. For example, diabetics can utilize external infusion therapy for delivering insulin using devices worn on a belt, in a pocket, or the like, with the insulin being delivered via a catheter with a percutaneous needle or cannula placed in the subcutaneous tissue. In addition, medication pump therapy is becoming more important for the treatment and control of other medical conditions, such as pulmonary hypertension, HIV and cancer. The manner in which the liquid is infused is controlled by the infusion pump, which may have various modes of infusion, such as a continuous mode in which the liquid medicant is continuously infused at a constant rate, or a ramp mode in which the rate of infusion gradually increases, then remains constant, and then gradually decreases.  
         [0003]     Typically, the monitoring of an infusion pump is performed by reviewing a visual display means incorporated in the infusion pump, and the control of the infusion pump is performed by activating an input device, such as a keypad, incorporated with the infusion pump. Consequently, the monitoring and/or control of an infusion pump are performed at the same location at which the infusion pump is disposed. One drawback of this type of drug therapy is the inability to conceal an external infusion pump and catheter tubing from view. Many users desire to hide the external pump under clothing so as keep their medical condition private. However, this can be inconvenient or impractical, especially for diseases such as diabetes, since a user must have ready access to the external pump for periodic monitoring or administering extra amounts of medication (i.e., boluses during the course of the day). If a user has concealed the external pump, the user often must partially undress or carefully maneuver the external pump to a location that permits access to the display and keypad.  
         [0004]     In response to these issues, systems have been developed to allow a user to control the infusion pump through a remote controller that communicates with the pump via a wireless communications link, for example. In this way, a user can dispense medications without needing to physically access the pump, thereby making infusion pump therapy more convenient for the user. Many times, the user can start a process of dispensing a dosage of medication by simply providing a small number of commands to the pump via the remote controller, which will dispense the entire desired volume of medication without interruption. Situations may occur, however, in which it may be desirable for a user to stop or start the dispensing process in an urgent manner to ensure that the proper therapeutic amount of the medication enters the body. For example, a user that mistakenly initiates the dispensing of a bolus of medication may wish to abruptly stop the dispensing of medication, such as in a situation where a user mistakenly sends a bolus command with an inadvertently large bolus quantity. If the medication to be dispensed were insulin, the user would need to quickly cancel the bolus command to prevent a potentially hypoglycemic event from occurring.  
         [0005]     In these types of urgent situations, the pump may be able to be stopped by pressing an appropriate navigation button on the pump or by removing the needle that dispenses the medication from the user&#39;s skin. One disadvantage to either of these approaches is that the navigation buttons and needle may be difficult to access due to the location of these items underneath a user&#39;s clothing, which can create a significant time delay. Removal of the needle is also inconvenient because the needle insertion process must then be repeated. In another alternative, the pump may be stopped by pressing a navigation button on the remote controller. However, under certain situations, wireless communication can be lost which would prevent a remote controller from being able to stop the pump. Thus, it is desirable to provide a medication dispensing system that allows for use of a remote controller to control an infusion pump in such a way that provides the user with better control of the amount of medication dispensed.  
       SUMMARY  
       [0006]     In an aspect of the present invention, a method of delivering a bolus of insulin using a remote controller is provided. The method comprises the steps of: establishing a communication link between the remote controller and an infusion pump that contains insulin; providing a bolus value to the pump with the remote controller, the bolus value indicating a total amount of insulin to be dispensed; dispensing a predetermined portion of the total amount of insulin from the pump; and dispensing an additional predetermined portion of the total amount of insulin from the pump based on information comprising receipt of a continue command from the remote controller.  
         [0007]     In another aspect of the present invention, a method of delivering a bolus of insulin using a remote controller and pump is provided where an alarm is triggered if a signal is not received by the pump within a predetermined period of time. The method comprises the steps of: establishing a communication link between the remote controller and an infusion pump that contains insulin; providing a bolus value to the pump with the remote controller, the bolus value indicating a total amount of insulin to be dispensed; dispensing a predetermined portion of the total amount of insulin from the pump; and triggering an alarm if a signal comprising a continue command is not received by the pump within a predetermined period of time.  
         [0008]     In another aspect of the present invention, a method of delivering a bolus of insulin using a remote controller and pump is provided where dispensing of medication is terminated if a signal is not received by the pump within a predetermined period of time. The method comprises the steps of: establishing a communication link between the remote controller and an infusion pump that contains medication; providing a bolus value to the pump with the remote controller, the bolus value indicating a total amount of medication to be dispensed; dispensing a predetermined portion of the total amount of medication from the pump; and terminating dispensing of medication from the pump if a signal comprising a continue command is not received by the pump within a predetermined period of time.  
         [0009]     In yet another aspect of the present invention, a method for dispensing a predetermined quantity of medication as a bolus is provided. The method comprises the steps of: inputting the predetermined quantity of medication into a remote controller; wirelessly transmitting information comprising the predetermined quantity of medication from the remote controller to a pump; dispensing a predetermined first portion of the quantity of medication from the pump; and dispensing an additional predetermined portion of the quantity of medication from the pump in response to receiving a wireless signal from the remote controller wherein the wireless signal comprises instructions to continue dispensing. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]     These and other features, aspects, and advantages of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings where:  
         [0011]      FIG. 1  is a plan view of an exemplary remote controller in accordance with the present invention;  
         [0012]      FIG. 2  is a perspective view of the remote controller of  FIG. 1 ;  
         [0013]      FIG. 3  is a plan view of an exemplary test strip that can be used with the remote controller shown in  FIGS. 1 and 2 ;  
         [0014]      FIG. 4  is a perspective view of a pump in accordance with the present invention;  
         [0015]      FIG. 5  is a schematic diagram showing certain functional aspects of the remote controller of  FIG. 1  and the pump of  FIG. 2  and showing in particular an aspect of wireless communication between the remote controller and pump;  
         [0016]      FIG. 6  is a schematic flow chart showing an exemplary method for dispensing a bolus of medication in accordance with the present invention;  
         [0017]      FIG. 7  is a schematic flow chart showing the method of  FIG. 6  and showing in particular steps for reestablishing a lost wireless signal in accordance with the present invention;  
         [0018]      FIG. 8  is a schematic diagram showing a sequence of commands and responses using a status request and continue command in accordance with the present invention; and  
         [0019]      FIG. 9  is a schematic diagram showing a sequence of commands and responses using only the continue command in accordance with the present invention. 
     
    
     DETAILED DESCRIPTION  
       [0020]      FIG. 1  is a plan view of an exemplary remote controller  200  in accordance with the present invention. Remote controller  200 , as shown, includes a first housing  201 , a display  202 , an OK button  204 , a down button  206 , back button  208 , an up button  210 , light emitting diode (LED)  212 , and strip port connector (SPC)  214 . Remote controller  200  is schematically shown in  FIG. 5  to further include functional components including navigational buttons (NAV)  216 , a radio frequency module (RF)  218 , a blood glucose measurement (BGM) module  220 , a battery (BAT)  222 , a wired communication port (COM), an alarm (AL)  226 , a microprocessor (MP)  228 , a memory portion (MEM)  230 , and a memory chip port (MCP). Preferably, first housing  201  is ergonomically designed to be handheld and to incorporate the functional circuitry required for measuring glucose episodically and provide wireless communication with pump  300 .  
         [0021]      FIG. 2  is a perspective view of remote controller  200  that further illustrates port cover  209 . Preferably, port cover  209  comprises an elastomeric material that covers a wired connection port (not shown) and a memory chip port (not shown). Examples of a wired connection port include a universal serial bus (USB) or IEEE RS  232 . Examples of memory suitable for insertion into a memory chip port include a flash memory such as a SIMM card, a SmartCard, Smart Media, and the like.  
         [0022]     Display  202  preferably comprises a liquid crystal display (LCD) to show both textual and graphical information to a user. A user interface (UI) may comprise a software driven menu that can be shown on display  202  that enables the user to operate remote controller  200 . A user can navigate through the UI using navigation buttons  216  which include up button  210 , down button  206 , OK button  204 , and back button  208 . Preferably, the UI allows a user to perform functions including operating pump  300 , querying the status of pump  300 , measuring glucose episodically, and displaying data on display  202  from remote controller  200  and/or pump  300  (e.g. glucose concentration versus time).  
         [0023]     Microprocessor  228  preferably controls display  202 , navigational buttons  216 , RF module  218 , blood glucose measurement module  220 , wired communication port  224 , first alarm  226 , and memory chip port  232 . Microprocessor  228  further preferably provides the capability to perform various algorithms for the management of a medical treatment. Examples of such algorithms include a predictive algorithm for a user&#39;s glucose concentrations (e.g. an algorithm that predicts a user&#39;s glucose concentration in the future) and a bolus calculator. A bolus is a predetermined amount of a medication that is dispensed over a relatively short time. In the case of a bolus calculator, microprocessor  228  preferably can process inputs such as food data (e.g. carbohydrates) that may be entered manually using first navigation buttons  216 , or via wired communication port from a personal computer or like device. Additionally, blood glucose data can be provided to microprocessor  228  directly from the blood glucose measurement module  220 . Using the inputted food data and glucose measurement data, a bolus of insulin can be determined, and shown on display  202 , and the bolus amount can be transmitted wirelessly from remote controller  200  to pump  300 . This enables pump  300  to dose an appropriate amount of insulin to a user while at the same time reducing the amount of user interactions with pump  300 .  
         [0024]     RF module  218  of remote controller  200  provides for bi-directional communication to pump  300  and potentially other devices such as a continuous glucose monitor, a personal computer, a personal digital assistant, a cell phone, insulin pen, or a second pump which may dispense glucose. Exemplary frequencies which may be suitable for use with RF module  218  are about 433 MHz, about 863 MHz, about 903 MHz, and about 2.47 GHz. RF module  218  may include a commercially available component such as a Chipcon CC 1000, an antenna, and a RF impedance matching network. RF module  218  may send commands to pump  300  such as a basal pumping rate, duration of pumping, and bolus amounts. In addition, RF module  218  may receive data from pump  300 . Such data can include information indicating an occlusion or other error condition, an amount of insulin in reservoir, battery lifetime status, and historical insulin delivery information.  
         [0025]     Wired communication port  224  provides the option of transferring data to or from an external device such as a personal computer. Wired communication port  224  may also be used to upgrade the software memory portion  230  of remote controller  200 . Memory portion  230  preferably comprises a volatile memory type such as, for example, flash memory. Memory portion  230  preferably contains the application and system software for operating remote controller  200 . Wired communication port  224  may then re-write memory portion  230  such that the entire application and system software is upgraded. This allows potential bugs in the software to be fixed and may be used to create added functionality in remote controller  200 . In addition, a flash memory card may be inserted into memory chip port  232  for upgrading remote controller  200  without connecting it to a personal computer.  
         [0026]     Remote controller  200  preferably includes alarm  226  which may be in a variety of forms to warn a user of various statuses that might need an actionable response. For example, alarm  226  may include an audio alarm (monophonic beeps or polyphonic tones), a vibratory alarm, or a LED  212  which may be a multi-colored LED that can illuminate red, yellow, and green lights. An alarm signal can be used to warn a user that there is a low glucose reading, a partially filled glucose test strip, a low reservoir of insulin, an occlusion in pump  300 , a low battery status for pump  300 , a low battery status for remote controller  200 , an improperly filled test strip, or the like. For the previously mentioned situations in which a user may need to intervene because of a potentially dangerous situation, the alarm may be a vibration, audio signal, and/or LED  212  switching from green to red or from green to yellow.  
         [0027]      FIG. 4  is a perspective view of a pump  300  in accordance with the present invention. Pump  300 , as shown, includes a housing  301 , a backlight button  302 , an up button  304 , a cartridge cap  306 , a bolus button  308 , a down button  310 , a battery cap  312 , an OK button  314 , and a display  316 . Pump  300  preferably comprises a pump suitable for use in dispensing medication such as insulin for improved diabetic therapies. For example, pump  300  may be similar to a commercially available pump from Animas, Corp. (Catalog No. IR  1200 ) except that pump  300  includes RF capabilities in accordance with the present invention. Housing  301  may comprise an RF transparent material and/or may be painted with an RF transparent paint. Pump  300  further preferably includes display (DIS)  316 , navigational buttons (NAV)  318 , a reservoir (RES)  320 , an infrared communication port (IR)  321 , a radio frequency module (RF)  322 , a battery (BAT)  324 , an alarm (AL)  326 , and a microprocessor (MP)  328  as shown in  FIG. 5 . Pump  300  and remote controller  200  preferably bi-directionally communicate using a wireless signal via RF module  218  and RF module  322 .  
         [0028]     Preferably, the antenna portion of RF module  218  is located within housing  201 . Similarly, RF module  322  is preferably located within housing  301 . In such a case, the material used for housing  201  and housing  301  is preferably RF transparent (i.e. does not absorb or interfere with RF signals). Further, if housing  201  or housing  301  is painted, the paint used is preferably RF transparent as well.  
         [0029]     RF module  218  and RF module  322  further preferably include a communication protocol that enables remote controller  200  to communicate with a particular pump  300 . Both remote controller  200  and pump  300  preferably have a unique identification code associated with their respective RF module  218  and RF module  322 . This is desirable because under certain conditions, a second user with a second pump  300  may be in close proximity to the first user. It would be undesirable for the first user&#39;s remote controller  200  to cross communicate with the second user&#39;s pump  300 . In order to avoid such cross communication, a remote controller  200  preferably initiates a pairing protocol before using pump  300  for the first time. When initiating the pairing protocol, remote controller  200  and pump  300  exchange their unique identification code (e.g. serial number). In all subsequent wireless communications, the correct unique identification code is preferably established before exchanging data.  
         [0030]     Remote controller  200  preferably comprises an integrated blood glucose meter that can measure glucose episodically using disposable test strips. An exemplary test strip  100  suitable for use in remote controller  200  is shown in  FIG. 3 . Test strip  100  includes a conductive layer printed onto a substrate  5 . The conductive layer includes a first contact  13 , a second contact  15 , a reference contact  11 , and a strip detection bar  17  that may be used to electrically connect to strip port connector  214 . The conductive layer further includes a first working electrode  12 , a second working electrode  14 , and a reference electrode  10  which are electrically connected, respectively, to first contact  13 , second contact  15 , and reference contact  11 . Test strip further includes a clear hydrophilic film  36  which is bound by an adhesive  60  that forms a sample receiving chamber that allows blood to be dosed at inlet  90 . An exemplary test strip is the commercially available OneTouch Ultra test strip from LifeScan, Inc. in Milpitas, Calif., U.S.A.  
         [0031]     A reagent layer (not shown) is provided on first working electrode  12 , second working electrode  14 , and reference electrode  10 . Reagent layer may include chemicals such as a redox enzyme and mediator which selectivity reacts with glucose. During this reaction, a proportional amount of a reduced mediator can be enzymatically generated which is measured electrochemically. This allows a current to be measured that is proportional to the glucose concentration. Examples of reagent formulations or inks suitable for use in making reagent layer  22  can be found in U.S. Pat. Nos. 5,708,247 and 6,046,051 and Published International Applications WO01/67099 and WO01/73124, all of which are fully incorporated by reference herein for all purposes.  
         [0032]     Preferably, in addition to measuring glucose episodically, remote controller  200  can also wirelessly communicate with pump  300 . In use, remote controller  200  sends commands to pump  300  to dispense a fluid or medication for a pre-determined time period, rate, and/or volume. Preferably, a user selects from a menu of basal programs that have been programmed on pump  300 . The user can also preferably set a basal rate, a bolus dose, and a combination thereof as commands to pump  300  from remote controller  200 . Remote controller  200  receives data from pump  300  such as the status of the dispensing of medication (e.g. the dispense rate, amount of medication remaining in pump  300 , or the proportion of medication delivered based on the amount programmed).  
         [0033]     During routine use, a user may send a bolus command from remote controller  200  to pump  300  to initiate the dispensing of an insulin bolus. However, under certain circumstances, a user may mistakenly send a bolus command where the bolus was inadvertently too large. For this case, the user would need to cancel the bolus command to prevent a potential hypo-glycemic event from occurring. Pump  300  can be stopped by pressing the appropriate navigation button  318  on pump  300 , removing the needle from the user&#39;s skin that dispenses insulin, or by pressing the appropriate navigation button  216  on remote controller  200 . Stopping pump  300  by using navigation button  318  may be inconvenient because pump  300  may be inconspicuously worn underneath a user&#39;s clothing. Removing the needle which dispenses insulin may be inconvenient because the needle may be difficult to access and because the insertion process must then be repeated. Stopping pump  300  by using remote controller  200  obviates the problems associated with using navigation buttons  318  or removing the needle from a user&#39;s skin. However, stopping pump  300  could be problematic if there is a loss of wireless communication.  
         [0034]     A typical bolus of insulin ranges from about 0.5 units to about 10 units and a typical bolus delivery period for a 10 unit bolus would be about 20 seconds. This provides a user with a relatively short time window of about 20 seconds or less to cancel an undesired bolus command. This further shows that pressing the appropriate navigation button  318  or removing the needle from the user&#39;s skin would be inconvenient because the user would have to act quickly. In such a situation, using remote controller  200  would be a more expedient way to cancel the bolus command.  
         [0035]      FIG. 6  shows an exemplary method  500  for dispensing a bolus of medication such as insulin in accordance with the present invention. As shown, method  500  includes a step  502  in which a user inputs a predetermined quantity or a bolus amount into remote controller  200  using navigation buttons  216 . Remote controller  200  then wirelessly transmits the bolus amount to pump  300  as shown in step  504 . Depending on the magnitude of the bolus amount, pump  300  assigns a pre-determined bolus delivery rate for insulin delivery that typically delivers a bolus in less than about 20 seconds as shown in step  505 . In addition, microprocessor  328  divides the bolus amount into a plurality of predetermined portions as shown in step  506 . Each of the plurality of predetermined portions are preferably sized so they range from about 0.10 units to about 1.0 units. Preferably, the predetermined portions are equally sized. For example, a bolus amount of 3.0 units can be divided into 3 portions of 1.0 unit each, 6 portions of 0.50 units each, 12 portions of 0.25 units each, etc. The plurality of predetermined portions do not need to be equally sized and may be different. For example, a bolus amount of 3.0 units can be divided in to 2 portions of 1.0 unit each and 2 portions of 0.50 units each.  
         [0036]     Pump  300  then dispenses a first predetermined portion of the bolus as shown in step  507 . Next, pump  300  waits for a wireless signal from remote controller  200  to continue dispensing as shown in step  510 . Once pump  300  receives wireless signal  400  to continue dispensing from remote controller  200 , pump  300  then dispenses a subsequent predetermined portion as shown in step  512 , which in this case is a second predetermined portion. If pump  300  does not receive a wireless signal to continue dispensing within a first predetermined waiting period, then display  202  preferably shows an error message to the user indicating that wireless communication has been lost and that the bolus has been terminated. The first pre-determined waiting period preferably ranges from about 10 seconds to about one minute.  
         [0037]     As shown in  FIG. 7 , if pump  300  does not receive a wireless signal to continue dispensing within the first predetermined waiting period, the user is preferably prompted to try to reestablish wireless communication in step  519 . In step  520 , the user preferably manipulates the position of remote controller  200  in an attempt to improve wireless transmission or to generally check the meter for problems. For example, a user may physically move remote controller  200  closer to pump  300  or move remote controller  200  such that large metal objects do not interfere with the wireless transmission. In step  522 , pump  300  waits for a wireless signal to continue dispensing within a second predetermined waiting period from remote controller  200 . Preferably, the second predetermined waiting period is about one minute or less. If the user&#39;s intervention sufficiently improved the wireless signal transmission so that a continue command can be received, pump  300  then dispenses the next predetermined portion of the bolus as shown in step  512 . If the wireless signal transmission is not sufficiently improved within the second predetermined waiting period, remote controller  200  preferably displays an error message and terminates the dispensing of the bolus as shown in step  524 .  
         [0038]     After pump  300  finishes dispensing a predetermined portion in step  512 , pump  300  determines whether all portions have been dispensed as shown in step  514  as shown in  FIGS. 6 and 7 . If there are still remaining predetermined portions to be pumped, then the next step would be step  508  in which pump  300  waits for a wireless signal to continue. If all of the predetermined portions have been dispensed, then method  500  for dispensing a bolus is finished as shown in step  516 . As illustrated, in method  500  a bolus is dispensed into the body only if wireless communication is maintained between remote controller  200  and pump  300  throughout the bolus process. Pump  300  must receive wireless commands to continue before dispensing a portion of the bolus. This method ensures that the bolus can be stopped quickly using remote controller  200 . If this is not possible because of a loss of wireless communication, then method  500  will stop the bolus process.  
         [0039]     Various modes can be used in accordance with the present invention for remote controller  200  to send continue commands. In a first exemplary mode that is described below in Example 1, remote controller  200  sends a recurring polling command interrogating pump  300  in regards to its status. Remote controller  200  may send the polling command in an asynchronous or synchronous manner. When pump  300  communicates to remote controller  200  that a predetermined portion of a bolus has been dispensed after receiving a polling command, remote controller  200  then sends the continue command. Remote controller  200  continually polls pump  300  to determine when another continue command needs to be sent to pump  300  so that all of the predetermined portions can be dispensed.  
         [0040]     In a second exemplary mode which is described below in Example 2, remote controller  200  does not send any polling commands, but instead continually sends out continue commands at a predetermined frequency until the bolus is complete or until the bolus is terminated by remote controller  200 . In this mode, if a continue command was sent to pump  300  before a predetermined portion has been dispensed, pump  300  ignores the continue command. Once pump  300  has finished dispensing a predetermined portion, it can then receive the continue command from remote controller  200 . This second mode is more simplistic than the first mode because it does not use the polling command. However, the second mode sends several continue commands some of which are ignored by pump  300  if it has not finished dispensing a predetermined portion at that point in time.  
       EXAMPLE 1  
       [0041]      FIG. 8  is a schematic showing a sequence of commands and responses using a status request (e.g. polling) and a continue command in accordance with the present invention. In step  800 , a 3.0 unit bolus of insulin is selected or input using the user interface on remote controller  200 . Remote controller  200  sends a command to the pump  300  via wireless signal  400 , which instructs pump  300  to start a bolus of 3.0 units. Pump  300  divides the bolus into three predetermined portions of one unit each. Pump  300  then begins delivering the first predetermined portion of the bolus into the user&#39;s body.  
         [0042]     In step  802 , remote controller  200  sends a command requesting the status of the bolus. In this example, the polling step is performed on a recurring basis. At step  804 , pump  300  has only delivered 0.5 units when the command is received causing pump  300  to send a response indicating that 0.5 of the requested 3.0 units has been delivered, and remote controller  200  updates the bolus delivery status information on first display  202 . In step  806 , pump  300  continues to deliver insulin until a total of 1.0 unit is delivered. At the end of step  806 , pump  300  waits to receive a continue command from remote controller  200 . In step  808 , remote controller  200  sends another command requesting the status of the bolus. In step  810 , pump  300  sends a response to the polling command indicating that 1.0 unit was delivered, and that it was now waiting for a continue command, and remote controller  200  updates the bolus delivery status information on first display  202 . In step  812 , remote controller  200  then sends a continue command to the pump  300 , which then allows pump  300  to continue delivering the second predetermined portion of the bolus. In summary, steps  802  to  812  cause the first predetermined portion of the bolus to be dispensed, ensures that remote controller  200  and pump  300  can still wirelessly communicate, and then initiates the dispensing of the next predetermined portion of the bolus.  
         [0043]     In Example 1, steps  814  to  834  enable all three predetermined portions to be delivered if wireless communication is not lost. In step  814 , remote controller  200  sends a command requesting the status of the bolus. At step  816 , pump  300  has delivered 1.5 units when the command is received causing pump  300  to send a response indicating that 1.5 of the requested 3.0 units has been delivered, and remote controller  200  updates the bolus delivery status information on first display  202 . In step  818 , pump  300  continues to deliver insulin until a total of 2.0 units have been delivered. At the end of step  818 , pump  300  waits to receive a continue command from remote controller  200 . In step  820 , remote controller  200  sends another command requesting the status of the bolus. In step  822 , pump  300  sends a response indicating that 2.0 units has been delivered, and that it is now waiting for a continue command, and remote controller  200  updates the bolus delivery status information on first display  202 . In step  824 , remote controller  200  then sends a continue command to the pump  300 , which then allows pump  300  to continue delivering the third predetermined portion of the bolus.  
         [0044]     In step  826 , remote controller  200  sends a command requesting the status of the bolus. At step  828 , pump  300  has delivered 2.5 units when the command was received causing pump  300  to send a response indicating that 2.5 of the requested 3.0 units has been delivered, and remote controller  200  updates the bolus delivery status information on first display  202 . In step  830 , pump  300  continues to deliver insulin until 3.0 units has been delivered. In step  832 , remote controller  200  sends another command requesting the status of the bolus. In step  834 , pump  300  sends a response indicating that 3.0 units has been delivered, and that it is now done delivering all pre-determined portions of the bolus.  
       EXAMPLE 2  
       [0045]      FIG. 9  is a schematic showing an exemplary sequence of commands and responses using only the continue command in accordance with the present invention. In this example, there is no polling command from remote controller  200  to pump  300  as in Example 1. In step  900 , a 3.0 unit bolus of insulin is selected using the user interface on remote controller  200 . Remote controller  200  sends a command to the pump  300  via wireless signal  400 , instructing pump  300  to start a bolus of 3.0 units. Pump  300  divides the bolus into three predetermined portions of one unit each. Pump  300  then begins delivering the first predetermined portion of the bolus into the user&#39;s body.  
         [0046]     In step  902 , remote controller  200  sends a continue command. In this example, the continue command may be performed either on a recurring basis or asynchronously. If a recurring signal is sent, it preferably has a frequency in the range of about 0.5 second to 1 second. For step  902 , the continue command is received by pump  300  which causes it to respond with an indication of how much of the bolus has been delivered. At step  904 , pump  300  sends a response indicating that 0.5 unit of the requested 3.0 units had been delivered, and remote controller  200  updates the bolus delivery status information on first display  202 . In step  906 , pump  300  continues to deliver insulin until a total of 1.0 unit has been delivered. At the end of step  906 , pump  300  waits to receive a continue command from remote controller  200 . In step  908 , remote controller  200  sends another continue command. Once pump  300  received the continue command in step  908 , it starts delivering the second predetermined portion of the bolus into the user&#39;s body. Next, pump  300  responds with an indication of how much of the bolus has been delivered in step  910  which in this case is 1.0 unit of the requested 3.0 units, and remote controller  200  updates the bolus delivery status information on first display  202 . For step  912 , the continue command is sent by remote controller  200  and received by pump  300 . In step  914 , pump  300  responds with an indication of how much of the bolus has been delivered which in this case was 1.5 units of the requested 3.0 units, and remote controller  200  updates the bolus delivery status information on first display  202 . In step  916 , pump  300  continues to deliver insulin until 2.0 units has been delivered and then waits for a continue command. For step  918 , the continue command is sent by remote controller  200  and received by pump  300 . Next, pump  300  responds with an indication of how much of the bolus had been delivered in step  920  which in this case was 2.0 units of the requested 3.0 units, and remote controller  200  updates the bolus delivery status information on first display  202 . For step  922 , the continue command is sent by remote controller  200  and received by pump  300 . Next, pump  300  responds with an indication of how much of the bolus has been delivered in step  924  which in this case is 2.5 units of the requested 3.0 units, and remote controller  200  updates the bolus delivery status information on first display  202 . In step  926 , pump  300  continues to deliver insulin until a total of 3.0 units have been delivered which is the end of the bolus. For step  928 , the continue command is sent by remote controller  200  and received by pump  300 . However, pump does not dispense any more insulin because the bolus has been completely delivered. Pump  300  responds with an indication that 3.0 units of the requested 3.0 units was dispensed indicating that the bolus was completely delivered, and remote controller  200  updates first display  202  with an indication that the bolus is complete.  
         [0047]     The present invention has now been described with reference to several embodiments thereof. The entire disclosure of any patent or patent application identified herein is hereby incorporated by reference. The foregoing detailed description and examples have been given for clarity of understanding only. No unnecessary limitations are to be understood therefrom. It will be apparent to those skilled in the art that many changes can be made in the embodiments described without departing from the scope of the invention. Thus, the scope of the present invention should not be limited to the structures described herein, but only by the structures described by the language of the claims and the equivalents of those structures.