Abstract:
A battery backup system is provided for use in a sedation and analgesia system. The battery backup system can include a battery, a power source, and a battery controller connected to power source and the battery. The power source can be connected to the battery controller unidirectional. In addition, the battery can be connected to the battery controller bidirectional. The battery controller can help determine whether the sedation and analgesia system should be run with the power source or the battery.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
       [0001]    This application claims the benefit and priority from U.S. provisional application Serial No. 60/411,079, filed on Sep. 16, 2002, which is incorporated by reference herein in its entirety. The present application cross references and incorporates by reference copending U.S. Ser. No. 09/324,759, filed Jun. 3, 1999. 
     
    
     
       FIELD OF THE INVENTION  
         [0002]    The present invention relates, in general, to battery backup systems and, more particularly, to battery backup systems integrated with medical devices.  
         BACKGROUND OF THE INVENTION  
         [0003]    It has long been recognized that continuous power delivery to medical devices, in particular, to systems related to anesthesia, is paramount in assuring patient safety. Patients under anesthesia count on the reliability of such systems to function properly in the event of a power outage, an accidental disruption of AC power, or any other episode that leads to disruption of AC power. To this effect, batteries have been used in cooperation with many medical devices so that in the event of AC power loss, those systems will function normally for a sufficient time to ensure patient safety.  
           [0004]    Batteries have also been used as a means to provide portability to medical systems where use of those systems is desired in places where AC power may be absent or inadequate, such as in ambulances, homes, and the like. Generally, these devices function in a monitoring capacity, whereby a patient may travel at will, regardless of limitations based on AC power availability. These systems allow patients and/or hospitals to monitor critical patient parameters in a non-intrusive way by eliminating the limitations associated with systems powered solely by AC.  
           [0005]    As the speed of medical device development increases, the need has arisen for battery systems that take into account the specific needs of new developments. In particular, sedation and analgesia systems comprising integrated drug delivery and patient monitoring require a battery backup system that accounts for idiosyncrasies related particularly to such a system. For example, a number of systems related to automatic drug infusion have a backup means capable of maintaining drug infusion in the event of an AC power failure. However, these backup means do not account for the integration of drug delivery with such features as, for example, oxygen delivery, associated with integrated sedation and analgesia systems. Existing battery systems are effective in their present capacities, however they fail to take into account the specific needs of sedation and analgesia systems.  
           [0006]    Sedation and analgesia systems that integrate patient monitoring systems and drug delivery systems rely on algorithms based on drug delivery and patient physiological response to drug delivery. Such algorithms are used to calibrate drug delivery to meet the specific needs of a patient undergoing sedation and/or analgesia. Procedures generally start by inputting a general drug delivery regimen into the sedation and analgesia system, where the regimen is automatically or manually altered based on the patient&#39;s response to the pre-determined regimen. In the event of an AC power loss, data related to patient response and corrections corresponding to the response may be lost. Losing such data often necessitates rebooting the system to re-establish a new drug regimen. The pre-determined drug regimen is often inferior to the altered regimen based on the response of the patient to drug delivery because the patient may be put in danger of over-medication or under-medication while under the pre-determined regimen and before enough patient data is again collected for calibration of the system and altering of the regimen. Though establishing a pre-determined drug regimen is effective at the beginning of a procedure, where a patient is in little danger, the risks of patient consciousness and/or patient over-sedation are far more critical after the procedure has progressed a while. Therefore, the need has arisen for a system and method for providing reliable maintenance of recorded patient response to variable parameters associated with a sedation and analgesia system.  
           [0007]    Rebooting a sedation and analgesia system due to an AC power loss may also result in a lag time, where monitoring and/or drug delivery are unavailable, due to necessary start-up times associated with software, hardware, and/or the testing of a fail-safe module. In order to ensure software functionality, sedation and analgesia systems generally provide testing program modules associated with the sedation and analgesia system that are performed before the drug delivery and/or patient monitoring systems are enabled. Though necessary to ensure patient safety, procedures associated with system start-up may endanger a patient if performed during critical times of a medical procedure. Time lapses in monitoring and/or drug delivery may result in patient under-medication and/or the physician missing a critical patient episode that otherwise would have been registered had the system been functioning fully the whole time. It would therefore be advantageous to provide a system and method for maintaining and/or monitoring drug delivery functionality in the event of a primary AC power loss.  
         BRIEF SUMMARY OF THE INVENTION  
         [0008]    The present invention provides a system and method for providing reliable maintenance of recorded patient response to variable parameters associated with a sedation and analgesia system. The invention further provides a system and method for maintaining and/or monitoring the drug delivery functionality associated with a sedation and analgesia system in the event of a primary AC power loss. More particularly, the invention provides a battery backup system integral with a sedation and analgesia system. The battery backup system according to the present invention is integral with a sedation and analgesia systems that accounts for particular idiosyncrasies associated with sedation and analgesia systems.  
           [0009]    The present invention also provides a sedation and analgesia system having an ambulatory capability irrespective of an AC power source. The invention further provides a system and method for providing reliable maintenance of recorded patient response to variable parameters associated with a sedation and analgesia system. 
       
    
    
     BRIEF DESCRIPTION OF THE FIGURES  
       [0010]    [0010]FIG. 1 illustrates one embodiment of a sedation and analgesia system having a battery backup system in accordance with the present invention.  
         [0011]    [0011]FIG. 2 illustrates a more detailed view of one embodiment of a battery backup system in accordance with the present invention.  
         [0012]    [0012]FIG. 3 illustrates one embodiment of a method for using a battery backup system integral with a sedation and analgesia system in accordance with the present invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0013]    Before explaining the present invention in detail, it should be noted that the invention is not limited in its application or use to the details of construction and arrangement of parts illustrated in the accompanying drawings and description. The illustrative embodiments of the invention may be implemented or incorporated in other embodiments, variations and modifications, and may be practiced or carried out in various ways. Furthermore, unless otherwise indicated, the terms and expressions employed herein have been chosen for the purpose of describing the illustrative embodiments of the present invention for the convenience of the reader and are not for the purpose of limiting the invention.  
         [0014]    [0014]FIG. 1 illustrates a block diagram depicting one embodiment of the present invention comprising a sedation and analgesia system  22  having user interface  12 , such as that described in U.S. Patent Application Serial No. 60/330,853 filed Nov. 1, 2001 by Hickle, et al, software controlled controller  14 , peripherals  15 , battery backup system  16 , external communications  10 , patient interface  17 , and drug delivery  19 , where sedation and analgesia system  22  is operated by user  13  in order to provide sedation and/or analgesia to patient  18 . An example of sedation and analgesia system  22  is disclosed and enabled by U.S. patent application Ser. No. 09/324,759, filed Jun. 3, 1999 which is herein incorporated by reference in its entirety.  
         [0015]    [0015]FIG. 2 illustrates one embodiment of battery backup system  16 , where battery backup system  16  comprises of power source  40 , which further includes AC power input  45  and AC/DC converter  71 , where AC input  45  power is delivered to AC/DC converter  71 . AC power input  45  may be, for example, a standard 120 volt wall outlet, however other power sources which produces AC voltages are consistent with the present invention. AC/DC converter  71  may convert for, for example, 120 volts AC to a 28 volt DC output, however other DC voltage outputs are consistent with the present invention. DC output from AC/DC converter  71  is herein referred to as first DC power supply  46 . Battery backup system  16  further comprises AC present output  60 , where AC present output  60  is a signal transmitted to controller  14  indicating that AC power input  45  is present and/or that AC power input  45  carries sufficient voltage to maintain full functionality of sedation and analgesia system  22 .  
         [0016]    Power source  40  further includes DC power supply  46 . DC power supply  46  is, in one embodiment of the present invention, supplied to battery controller  32 , where battery controller  32  comprises a DC/DC converter (not shown) as well as a battery charger (not shown). DC power supply  46  may be passed through the DC/DC converter, where the voltage is stepped down from, for example, the 28 volts associated with DC power supply  46  to 26.3 volts, where the stepped down voltage is used to charge battery  33  via the battery charger. The battery charger may be a current limiting power supply, where current is held constant by altering the voltage of the output of the DC/DC converter associated with battery controller  32 . Current delivered to battery  33  from the battery charger may be held constant until battery  33  is fully charged, where the voltage output associated with the DC/DC converter may then be held constant. Battery  33  may be a lithium ion battery, sealed lead battery, or other suitable means of providing a backup DC power source for sedation and analgesia system  22 . The present invention comprises modifying the DC/DC converter and/or the battery charger associated with battery controller  32  to account for the particular idiosyncrasies of a variety of batteries, where any suitable battery may be used with sedation and analgesia system  22 . Battery  33  further features any suitable charge life, where battery  33  may be configured differently for use with a portable or in-house sedation and analgesia system  22 .  
         [0017]    DC power may be output from battery  33  via second DC power supply  72 , where second DC power supply may be routed through battery controller  32  to first OR logic gate  61 . First OR logic gate  61  may be an OR logic gate, and oring diode pair, or other suitable electrical juncture. Battery controller  32 , in one embodiment of the present invention, comprises a current sensor, where the DC voltage used to charge battery  33  and the DC voltage output of battery  33  may be monitored. Data related to remaining battery  33  charge, battery  33  charging, battery  33  output, and/or estimated battery life may be output via battery controller output  73 , where battery controller output  73  transmits data to controller  14 . The present invention further comprises battery communications signal  44 , where battery communications signal  44  comprises inputting data to battery controller  32  related to battery profiles, calibration constants, or inputting other data necessary to properly charge and/or operate battery  33 .  
         [0018]    First OR logic gate  61 , in one embodiment of the present invention, allows for either first DC power supply  46  or second DC power supply  72  to deliver primary power to sedation and analgesia system  22 . If sufficient AC power is available from AC power input  45 , the voltage of first DC power supply  46  will be greater than that of second DC power supply  72 , and first DC power supply  46  will act as the primary power source for sedation and analgesia system  22 . If sufficient AC power is not available from AC power input  45 , second DC power supply  72  may act as the primary power supply for sedation and analgesia system  22 .  
         [0019]    Battery backup system  16  further comprises power supply  53 , where power supply  53  may be either power from first DC power supply  46  or second DC power supply  72 . Power supply  53  interfaces with on/off switch  67 , where on/off switch  67  allows the delivery of power from power supply  53  to power sedation and analgesia system  22  in the event that sedation and analgesia system  22  is operating properly, and to disallow the delivery of power from variable power supply  53  to sedation and analgesia system  22  in the event that sedation and analgesia system  22  is not functioning properly. On/off switch  67  may be a solid state switch, a relay, a solid state relay, a mosfet, or any other suitable means of controlling power delivery from variable power supply  53  to sedation and analgesia system  22 .  
         [0020]    On/off switch  67  may be turned off in the event that a software failure, hardware failure, or other potentially dangerous episode occurs or by the discretion of user  13 . Such a failure may be indicated to power on/off device  51  via signals  50  from a fail safe module, a software health check monitor, or from any other source monitoring the functionality of sedation and analgesia system  22  or via signal  54  from user interface  12  programmed by user  13 . Signals  50  may be binary transmissions, analog transmissions, or both. Power on/off device  51  may be a programmable controller, a microprocessor, a series of logic gates, or any other suitable means of receiving signals from sedation and analgesia system  22  and turning on/off switch  67  off in the event of a sedation and analgesia system malfunction. Power on/off device  51  may turn on/off switch  67  on or off via actuator signal  55 , where actuator signal  55  may be a transistor-transistor logic (TTL) signal and on/off switch  67  is a mosfet. At the beginning of a medical procedure, power supply  53  may pass through on/off switch  67 , where a TTL actuator signal  55  is normally present at startup in a properly functioning sedation and analgesia system. The interface of the TTL actuator signal  55  interfaced with on/off switch  67 , in the form of a mosfet, allows power from variable power supply  53  to pass through on/off switch  67  as long as the high TTL signal is present. In the event that signals  50  indicate a sedation and analgesia malfunction, power on/off device  51  may drop the voltage of actuator signal  55 , thereby disabling power delivery across the mosfet. Other embodiments and combinations of on/off switch  67  and actuator signal  55  are contemplated and are consistent with present invention.  
         [0021]    In one embodiment of the present invention, power supply  58  comprises current that has passed on/off switch  67 , where power supply  58  may flow to DC/DC converter  68  and/or to second OR logic gate  64 . DC/DC converter  68  may, for example, convert the 28 volt power associated with power supply  58  to 12 volts, 5 volts, or any other suitable voltage necessary to run hardware and/or software associated with sedation and analgesia system  22 . The present invention comprises a plurality of DC/DC converters, where the voltage of power supply  58  may be stepped down to a plurality of different voltages by the DC/DC converters, where output  65  is the appropriate voltage for one or a plurality of systems such as, for example, patient interface  17 , associated with sedation and analgesia system  22 .  
         [0022]    Second OR logic gate  64  is, in one embodiment of the present invention, an oring diode pair, where second OR logic gate  64  receives power supply  58  and power supply  46  as inputs. The power supply input having the highest voltage will, in one embodiment of the present invention, pass through second OR logic gate  64  to DC/DC converter  69 , where power supply  46  or power supply  58  originating from AC power input  45  will generally be dominant with respect to power supply  58  originating from battery  33 .  
         [0023]    The present invention further comprises DC/DC converter  69 , where DC/DC converter  69  may convert the DC power passing through second OR logic gate  64  to a suitable voltage needed to power user interface  12  via interface signal  59 . DC/DC converter  69  may also provide the necessary voltages for basic software and/or hardware functionality associated with a sedation and analgesia system  22  in standby mode via basic power signal  52 . In one embodiment of the present invention, when on/off switch  67  is turned off by power on/off device  51 , sedation and analgesia system  22  may still retain enough power in user interface  12  and/or other basic system functions in order to allow sedation and analgesia system  22  to be rebooted. DC/DC converter  69  may convert power supply  46  or power supply  58  to any suitable voltage such as, for example, 5 volts. The present invention further comprises a plurality of DC/DC converters, where the DC/DC converters may provide any suitable voltage to power any software and/or hardware associated with the standby or power down mode of sedation and analgesia system  22 . For example, in the event of a system malfunction, power on/off device  51  may disable the delivery of power from variable power supply  53  to sedation and analgesia system  22 , however software associated with sedation and analgesia system  22  may need a brief period of time while under power to properly shut down. Therefore, in one embodiment of the present invention, basic power signal  52  provides sufficient power to insure the safe power down of hardware and/or software associated with sedation and analgesia system  22 .  
         [0024]    [0024]FIG. 3 illustrates one embodiment of method  69  for employing battery integrated with sedation and analgesia system  22 . Method  69  comprises start step  70 , herein referred to as step  70 , where step  70  comprises providing a battery  33  integral with sedation and analgesia system  22 . In one embodiment of the present invention, step  72  of method  69  comprises delivering AC power input  45  to sedation and analgesia system  22 , where AC power input  45  may be, for example, a standard 120V wall outlet, however other AC power inputs are consistent with the present invention. The present invention further comprises charging battery  33  via battery controller  32  when AC power input  45  is present.  
         [0025]    Method  69  further comprises query  73 , where query  73  comprises ascertaining whether AC power input  45  is present throughout the duration of a medical procedure. If AC power input  45  is not disrupted, method  69  will proceed to step  72  and sedation and analgesia system  22  will continue to run on AC power input  45 . If AC power input  45  is disrupted, method  69  may proceed to step  76 , where step  76  comprises an alarm response to the power disruption. The alarm response of step  76  may be a visual indicator of an AC power input  45  disruption, an audio indicator of an AC power input  45  disruption, and/or any other suitable means of notifying user  13  of the power disruption. Alarm response  76  may be provided to user  13  via user interface  12 .  
         [0026]    If AC power input  45  is disrupted, method  69  may also proceed to query  74 , where query  74  comprises ascertaining whether DC power is available from battery  33 . If DC power is not available from battery  33  due to insufficient charge or malfunction, method  69  may proceed to finish step  78 . If sufficient DC power is present, method  69  may proceed to step  75 , where step  75  comprises maintaining the operability of sedation and analgesia system  22  with DC power from battery  33 . If DC power is available, the present invention further comprises alerting user  13  to the estimated charge life remaining in battery  33  and/or other factors relating to the functionality of battery  33 . Step  75  further comprises maintaining the functionality of sedation and analgesia system  22  in variable modes, where battery backup system  16  may be designed to provide user  13  with sufficient time to ensure patient  18  safety in the event of a disruption in AC power input  45 . For example battery  33  may have a full charge life of ten minutes, where battery  33  maintains full functionality of sedation and analgesia system  22  for five of the ten minutes. Following the initial five minute period, sedation and analgesia system  22  may have only moderate functionality such as, for example, patient monitoring, where drug delivery  19  has been disabled. Providing multiple battery modes allows battery  33  to be small in size while enabling user  13  to ensure patient  18  safety. The present invention comprises providing a plurality of modes of battery  33  operation, where battery  33  may be configured for use in portable sedation and analgesia systems, where the charge life of battery  33  must be substantially longer, or for in-house sedation and analgesia systems, where any suitable battery  33  with any suitable charge life may be provided.  
         [0027]    In one embodiment of the present invention, method  69  further comprises query  77 , where query  77  comprises ascertaining whether AC power input  45  has become available following at least one disruption of AC power input  45 . In one embodiment of the present invention, if AC power input  45  becomes available following a disruption in AC power input, method  69  will proceed to step  72 , where sedation and analgesia system  22  will run on AC power input  45 . If method  69  proceeds to step  72  from query  77 , AC power input  45  may also be used to charge battery  33  in the event a second power outage or other disruption in AC power input  45  occurs. If AC power input  45  is not available, method  69  may proceed to step  75 , where sedation and analgesia system  22  may be maintained for any suitable duration by battery  33  or any other suitable DC power source.  
         [0028]    In a further embodiment of the present invention, if AC power input  45  is disrupted, method  69  will not proceed to step  72 , where user  13  relies on the DC power from battery  33  to insure patient safety before the charge of battery  33  dissipates. Once the charge life of battery  33  has expired, method  69  may proceed to finish step  78 , where step  78  comprises the deactivation of all systems associated with sedation and analgesia system  22 .  
         [0029]    It is further contemplated that certain embodiments of sedation and analgesia system  22  may be used in a portable capacity, where sedation and analgesia system  22  may rely on solely on DC power to maintain system functionality. In such portable embodiments, the remaining charge life of battery  33  may be shown to user  13  throughout the duration of the procedure. Battery  33  may also be configured into a plurality of modes to insure patient  18  safety such as, for example, where battery backup system  16  displays critical warning alarms when the charge life of battery  33  drops below a critical level. Battery  33  of a portable sedation and analgesia system  22  may be recharged by AC power input  45 . Battery  33  may also or instead be replaceable.  
         [0030]    While the present invention has been illustrated by description of several embodiments, it is not the intention of the applicant to restrict or limit the spirit and scope of the appended claims to such detail. Numerous variations, changes, and substitutions will occur to those skilled in the art without departing from the scope of the invention. Moreover, the structure of each element associated with the present invention can be alternatively described as a means for providing the function performed by the element. Accordingly, it is intended that the invention be limited only by the spirit and scope of the appended claims.