Patent Publication Number: US-2022218338-A1

Title: Systems and methods for controlling a segmented circuit

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation application claiming priority under 35 U.S.C. § 120 to U.S. patent application Ser. No. 16/153,124, entitled SYSTEMS AND METHODS FOR CONTROLLING A SEGMENTED CIRCUIT, filed Oct. 5, 2018, now U.S. Patent Application Publication No. 2019/0105035, which is a continuation application claiming priority under 35 U.S.C. § 120 to U.S. patent application Ser. No. 15/727,316, entitled SYSTEMS AND METHODS FOR CONTROLLING A SEGMENTED CIRCUIT, filed Oct. 6, 2017, which issued on Nov. 27, 2018 as U.S. Pat. No. 10,136,889, which is a continuation application claiming priority under 35 U.S.C. § 120 to U.S. patent application Ser. No. 14/226,081, entitled SYSTEMS AND METHODS FOR CONTROLLING A SEGMENTED CIRCUIT, filed Mar. 26, 2014, which issued on Oct. 31, 2017 as U.S. Pat. No. 9,804,618, the entire disclosures of which are hereby incorporated by reference herein. 
    
    
     BACKGROUND 
     The present invention relates to surgical instruments and, in various circumstances, to surgical stapling and cutting instruments and staple cartridges therefor that are designed to staple and cut tissue. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention itself will be better understood by reference to the following description of instances of the invention taken in conjunction with the accompanying drawings, wherein: 
         FIG. 1  is a perspective view of a surgical instrument comprising a power assembly, a handle assembly, and an interchangeable shaft assembly; 
         FIG. 2  is perspective view of the surgical instrument of  FIG. 1  with the interchangeable shaft assembly separated from the handle assembly; 
         FIGS. 3A and 3B  illustrate a circuit diagram of the surgical instrument of  FIG. 1 ; 
         FIGS. 4A and 4B  illustrate one embodiment of a segmented circuit comprising a plurality of circuit segments configured to control a powered surgical instrument; 
         FIGS. 5A and 5B  illustrate a segmented circuit comprising a safety processor configured to implement a watchdog function; 
         FIG. 6  illustrates a block diagram of one embodiment of a segmented circuit comprising a safety processor configured to monitor and compare a first property and a second property of a surgical instrument; 
         FIG. 7  illustrates a block diagram illustrating a safety process configured to be implemented by a safety processor; 
         FIG. 8  illustrates one embodiment of a four by four switch bank comprising four input/output pins; 
         FIG. 9  illustrates one embodiment of a four by four bank circuit comprising one input/output pin; 
         FIGS. 10A and 10B  illustrate one embodiment of a segmented circuit comprising a four by four switch bank coupled to a primary processor; 
         FIG. 11  illustrates one embodiment of a process for sequentially energizing a segmented circuit; 
         FIG. 12  illustrates one embodiment of a power segment comprising a plurality of daisy chained power converters; 
         FIG. 13  illustrates one embodiment of a segmented circuit configured to maximize power available for critical and/or power intense functions; 
         FIG. 14  illustrates one embodiment of a power system comprising a plurality of daisy chained power converters configured to be sequentially energized; 
         FIG. 15  illustrates one embodiment of a segmented circuit comprising an isolated control section; 
         FIG. 16  illustrates one embodiment of a segmented circuit comprising an accelerometer; 
         FIG. 17  illustrates one embodiment of a process for sequential start-up of a segmented circuit; and 
         FIG. 18  illustrates one embodiment of a method  1950  for controlling a surgical instrument comprising a segmented circuit, such as, for example, the segmented control circuit  1602  illustrated in  FIG. 12 . 
     
    
    
     DETAILED DESCRIPTION 
     Applicant of the present application owns the following patent applications that were filed on Mar. 1, 2013 and which are each herein incorporated by reference in their respective entireties:
         U.S. patent application Ser. No. 13/782,295, entitled ARTICULATABLE SURGICAL INSTRUMENTS WITH CONDUCTIVE PATHWAYS FOR SIGNAL COMMUNICATION, now U.S. Pat. No. 9,700,309;   U.S. patent application Ser. No. 13/782,323, entitled ROTARY POWERED ARTICULATION JOINTS FOR SURGICAL INSTRUMENTS, now U.S. Patent Application Publication No. 2014/0246472;   U.S. patent application Ser. No. 13/782,338, entitled THUMBWHEEL SWITCH ARRANGEMENTS FOR SURGICAL INSTRUMENTS, now U.S. Patent Application Publication No. 2014/0249557;   U.S. patent application Ser. No. 13/782,499, entitled ELECTROMECHANICAL SURGICAL DEVICE WITH SIGNAL RELAY ARRANGEMENT, now U.S. Pat. No. 9,358,003;   U.S. patent application Ser. No. 13/782,460, entitled MULTIPLE PROCESSOR MOTOR CONTROL FOR MODULAR SURGICAL INSTRUMENTS, now U.S. Pat. No. 9,554,794;   U.S. patent application Ser. No. 13/782,358, entitled JOYSTICK SWITCH ASSEMBLIES FOR SURGICAL INSTRUMENTS, now U.S. Pat. No. 9,326,767;   U.S. patent application Ser. No. 13/782,481, entitled SENSOR STRAIGHTENED END EFFECTOR DURING REMOVAL THROUGH TROCAR, now U.S. Pat. No. 9,468,438;   U.S. patent application Ser. No. 13/782,518, entitled CONTROL METHODS FOR SURGICAL INSTRUMENTS WITH REMOVABLE IMPLEMENT PORTIONS, now U.S. Patent Application Publication No. 2014/0246475;   U.S. patent application Ser. No. 13/782,375, entitled ROTARY POWERED SURGICAL INSTRUMENTS WITH MULTIPLE DEGREES OF FREEDOM, now U.S. Pat. No. 9,398,911; and   U.S. patent application Ser. No. 13/782,536, entitled SURGICAL INSTRUMENT SOFT STOP, now U.S. Pat. No. 9,307,986 are hereby incorporated by reference in their entireties.       

     Applicant of the present application also owns the following patent applications that were filed on Mar. 14, 2013 and which are each herein incorporated by reference in their respective entireties:
         U.S. patent application Ser. No. 13/803,097, entitled ARTICULATABLE SURGICAL INSTRUMENT COMPRISING A FIRING DRIVE, now U.S. Pat. No. 9,687,230;   U.S. patent application Ser. No. 13/803,193, entitled CONTROL ARRANGEMENTS FOR A DRIVE MEMBER OF A SURGICAL INSTRUMENT, now U.S. Pat. No. 9,332,987;   U.S. patent application Ser. No. 13/803,053, entitled INTERCHANGEABLE SHAFT ASSEMBLIES FOR USE WITH A SURGICAL INSTRUMENT, now U.S. Patent Application Publication No. 2014/0263564;   U.S. patent application Ser. No. 13/803,086, entitled ARTICULATABLE SURGICAL INSTRUMENT COMPRISING AN ARTICULATION LOCK, now U.S. Patent Application Publication No. 2014/0263541;   U.S. patent application Ser. No. 13/803,210, entitled SENSOR ARRANGEMENTS FOR ABSOLUTE POSITIONING SYSTEM FOR SURGICAL INSTRUMENTS, now U.S. Patent Application Publication No. 2014/0263538;   U.S. patent application Ser. No. 13/803,148, entitled MULTI-FUNCTION MOTOR FOR A SURGICAL INSTRUMENT, now U.S. Patent Application Publication No. 2014/0263554;   U.S. patent application Ser. No. 13/803,066, entitled DRIVE SYSTEM LOCKOUT ARRANGEMENTS FOR MODULAR SURGICAL INSTRUMENTS, now U.S. Pat. No. 9,629,623;   U.S. patent application Ser. No. 13/803,117, entitled ARTICULATION CONTROL SYSTEM FOR ARTICULATABLE SURGICAL INSTRUMENTS, now U.S. Pat. No. 9,351,726;   U.S. patent application Ser. No. 13/803,130, entitled DRIVE TRAIN CONTROL ARRANGEMENTS FOR MODULAR SURGICAL INSTRUMENTS, now U.S. Pat. No. 9,351,727; and   U.S. patent application Ser. No. 13/803,159, entitled METHOD AND SYSTEM FOR OPERATING A SURGICAL INSTRUMENT, now U.S. Patent Application Publication No. 2014/0277017.       

     Applicant of the present application also owns the following patent applications that were filed on Mar. 26, 2014 and are each herein incorporated by reference in their respective entireties: 
     U.S. patent application Ser. No. 14/226,142, entitled SURGICAL INSTRUMENT COMPRISING A SENSOR SYSTEM, now U.S. Patent Application Publication No. 2015/0272575; 
     U.S. patent application Ser. No. 14/226,106, entitled POWER MANAGEMENT CONTROL SYSTEMS FOR SURGICAL INSTRUMENTS, now U.S. Patent Application Publication No. 2015/0272582; 
     U.S. patent application Ser. No. 14/226,099, entitled STERILIZATION VERIFICATION CIRCUIT, now U.S. Patent Application Publication No. 2015/0272581; 
     U.S. patent application Ser. No. 14/226,094, entitled VERIFICATION OF NUMBER OF BATTERY EXCHANGES/PROCEDURE COUNT, now U.S. Patent Application Publication No. 2015/0272580; 
     U.S. patent application Ser. No. 14/226,117, entitled POWER MANAGEMENT THROUGH SLEEP OPTIONS OF SEGMENTED CIRCUIT AND WAKE UP CONTROL, now U.S. Patent Application Publication No. 2015/0272574; 
     U.S. patent application Ser. No. 14/226,075, entitled MODULAR POWERED SURGICAL INSTRUMENT WITH DETACHABLE SHAFT ASSEMBLIES, now U.S. Pat. No. 9,743,929; 
     U.S. patent application Ser. No. 14/226,093, entitled FEEDBACK ALGORITHMS FOR MANUAL BAILOUT SYSTEMS FOR SURGICAL INSTRUMENTS, now U.S. Patent Application Publication No. 2015/0272569; 
     U.S. patent application Ser. No. 14/226,116, entitled SURGICAL INSTRUMENT UTILIZING SENSOR ADAPTATION, now U.S. Patent Application Publication No. 2015/0272571; 
     U.S. patent application Ser. No. 14/226,071, entitled SURGICAL INSTRUMENT CONTROL CIRCUIT HAVING A SAFETY PROCESSOR, now U.S. Pat. No. 9,690,362; 
     U.S. patent application Ser. No. 14/226,097, entitled SURGICAL INSTRUMENT COMPRISING INTERACTIVE SYSTEMS, now U.S. Patent Application Publication No. 2015/0272570; 
     U.S. patent application Ser. No. 14/226,126, entitled INTERFACE SYSTEMS FOR USE WITH SURGICAL INSTRUMENTS, now U.S. Patent Application Publication No. 2015/0272572; 
     U.S. patent application Ser. No. 14/226,133, entitled MODULAR SURGICAL INSTRUMENT SYSTEM, now U.S. Patent Application Publication No. 2015/0272557; 
     U.S. patent application Ser. No. 14/226,076, entitled POWER MANAGEMENT THROUGH SEGMENTED CIRCUIT AND VARIABLE VOLTAGE PROTECTION, now U.S. Pat. No. 9,733,663; 
     U.S. patent application Ser. No. 14/226,111, entitled SURGICAL STAPLING INSTRUMENT SYSTEM, now U.S. Pat. No. 9,750,499; and 
     U.S. patent application Ser. No. 14/226,125, entitled SURGICAL INSTRUMENT COMPRISING A ROTATABLE SHAFT, now U.S. Patent Application Publication No. 2015/0280384. 
     Certain exemplary embodiments will now be described to provide an overall understanding of the principles of the structure, function, manufacture, and use of the devices and methods disclosed herein. One or more examples of these embodiments are illustrated in the accompanying drawings. Those of ordinary skill in the art will understand that the devices and methods specifically described herein and illustrated in the accompanying drawings are non-limiting exemplary embodiments. The features illustrated or described in connection with one exemplary embodiment may be combined with the features of other embodiments. Such modifications and variations are intended to be included within the scope of the present invention. 
     Reference throughout the specification to “various embodiments,” “some embodiments,” “one embodiment,” or “an embodiment”, or the like, means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, appearances of the phrases “in various embodiments,” “in some embodiments,” “in one embodiment”, or “in an embodiment”, or the like, in places throughout the specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. Thus, the particular features, structures, or characteristics illustrated or described in connection with one embodiment may be combined, in whole or in part, with the features structures, or characteristics of one or more other embodiments without limitation. Such modifications and variations are intended to be included within the scope of the present invention. 
     The terms “proximal” and “distal” are used herein with reference to a clinician manipulating the handle portion of the surgical instrument. The term “proximal” referring to the portion closest to the clinician and the term “distal” referring to the portion located away from the clinician. It will be further appreciated that, for convenience and clarity, spatial terms such as “vertical,” “horizontal,” “up,” and “down” may be used herein with respect to the drawings. However, surgical instruments are used in many orientations and positions, and these terms are not intended to be limiting and/or absolute. 
     Various exemplary devices and methods are provided for performing laparoscopic and minimally invasive surgical procedures. However, the person of ordinary skill in the art will readily appreciate that the various methods and devices disclosed herein can be used in numerous surgical procedures and applications including, for example, in connection with open surgical procedures. As the present Detailed Description proceeds, those of ordinary skill in the art will further appreciate that the various instruments disclosed herein can be inserted into a body in any way, such as through a natural orifice, through an incision or puncture hole formed in tissue, etc. The working portions or end effector portions of the instruments can be inserted directly into a patient&#39;s body or can be inserted through an access device that has a working channel through which the end effector and elongated shaft of a surgical instrument can be advanced. 
       FIGS. 1-3B  generally depict a motor-driven surgical fastening and cutting instrument  2000 . As illustrated in  FIGS. 1 and 2 , the surgical instrument  2000  may include a handle assembly  2002 , a shaft assembly  2004 , and a power assembly  2006  (“power source,” “power pack,” or “battery pack”). The shaft assembly  2004  may include an end effector  2008  which, in certain circumstances, can be configured to act as an endocutter for clamping, severing, and/or stapling tissue, although, in other embodiments, different types of end effectors may be used, such as end effectors for other types of surgical devices, graspers, cutters, staplers, clip appliers, access devices, drug/gene therapy devices, ultrasound devices, RF device, and/or laser devices, for example. Several RF devices may be found in U.S. Pat. No. 5,403,312, entitled ELECTROSURGICAL HEMOSTATIC DEVICE, which issued on Apr. 4, 1995, and U.S. patent application Ser. No. 12/031,573, entitled SURGICAL FASTENING AND CUTTING INSTRUMENT HAVING RF ELECTRODES, filed Feb. 14, 2008, the entire disclosures of which are incorporated herein by reference in their entirety. 
     Referring primarily to  FIGS. 2, 3A and 3B , the handle assembly  2002  can be employed with a plurality of interchangeable shaft assemblies such as, for example, the shaft assembly  2004 . Such interchangeable shaft assemblies may comprise surgical end effectors such as, for example, the end effector  2008  that can be configured to perform one or more surgical tasks or procedures. Examples of suitable interchangeable shaft assemblies are disclosed in U.S. Provisional Patent Application Ser. No. 61/782,866, entitled CONTROL SYSTEM OF A SURGICAL INSTRUMENT, and filed Mar. 14, 2013, the entire disclosure of which is hereby incorporated by reference herein in its entirety. 
     Referring primarily to  FIG. 2 , the handle assembly  2002  may comprise a housing  2010  that consists of a handle  2012  that may be configured to be grasped, manipulated and actuated by a clinician. However, it will be understood that the various unique and novel arrangements of the various forms of interchangeable shaft assemblies disclosed herein may also be effectively employed in connection with robotically-controlled surgical systems. Thus, the term “housing” may also encompass a housing or similar portion of a robotic system that houses or otherwise operably supports at least one drive system that is configured to generate and apply at least one control motion which could be used to actuate the interchangeable shaft assemblies disclosed herein and their respective equivalents. For example, the interchangeable shaft assemblies disclosed herein may be employed with various robotic systems, instruments, components and methods disclosed in U.S. patent application Ser. No. 13/118,241, entitled SURGICAL STAPLING INSTRUMENTS WITH ROTATABLE STAPLE DEPLOYMENT ARRANGEMENTS, now U.S. Pat. No. 9,072,535, which is incorporated by reference herein in its entirety. 
     Referring again to  FIG. 2 , the handle assembly  2002  may operably support a plurality of drive systems therein that can be configured to generate and apply various control motions to corresponding portions of the interchangeable shaft assembly that is operably attached thereto. For example, the handle assembly  2002  can operably support a first or closure drive system, which may be employed to apply closing and opening motions to the shaft assembly  2004  while operably attached or coupled to the handle assembly  2002 . In at least one form, the handle assembly  2002  may operably support a firing drive system that can be configured to apply firing motions to corresponding portions of the interchangeable shaft assembly attached thereto. 
     Referring primarily to  FIGS. 3A and 3B , the handle assembly  2002  may include a motor  2014  which can be controlled by a motor driver  2015  and can be employed by the firing system of the surgical instrument  2000 . In various forms, the motor  2014  may be a DC brushed driving motor having a maximum rotation of, approximately, 25,000 RPM, for example. In other arrangements, the motor  2014  may include a brushless motor, a cordless motor, a synchronous motor, a stepper motor, or any other suitable electric motor. In certain circumstances, the motor driver  2015  may comprise an H-Bridge field-effect transistors (FETs)  2019 , as illustrated in  FIGS. 3A and 3B , for example. The motor  2014  can be powered by the power assembly  2006  ( FIGS. 3A and 3B ) which can be releasably mounted to the handle assembly  2002  for supplying control power to the surgical instrument  2000 . The power assembly  2006  may comprise a battery which may include a number of battery cells connected in series that can be used as the power source to power the surgical instrument  2000 . In certain circumstances, the battery cells of the power assembly  2006  may be replaceable and/or rechargeable. In at least one example, the battery cells can be Lithium-Ion batteries which can be separably couplable to the power assembly  2006 . 
     The shaft assembly  2004  may include a shaft assembly controller  2022  which can communicate with the power management controller  2016  through an interface while the shaft assembly  2004  and the power assembly  2006  are coupled to the handle assembly  2002 . For example, the interface may comprise a first interface portion  2025  which may include one or more electric connectors for coupling engagement with corresponding shaft assembly electric connectors and a second interface portion  2027  which may include one or more electric connectors for coupling engagement with corresponding power assembly electric connectors to permit electrical communication between the shaft assembly controller  2022  and the power management controller  2016  while the shaft assembly  2004  and the power assembly  2006  are coupled to the handle assembly  2002 . One or more communication signals can be transmitted through the interface to communicate one or more of the power requirements of the attached interchangeable shaft assembly  2004  to the power management controller  2016 . In response, the power management controller may modulate the power output of the battery of the power assembly  2006 , as described below in greater detail, in accordance with the power requirements of the attached shaft assembly  2004 . In certain circumstances, one or more of the electric connectors may comprise switches which can be activated after mechanical coupling engagement of the handle assembly  2002  to the shaft assembly  2004  and/or to the power assembly  2006  to allow electrical communication between the shaft assembly controller  2022  and the power management controller  2016 . 
     In certain circumstances, the interface can facilitate transmission of the one or more communication signals between the power management controller  2016  and the shaft assembly controller  2022  by routing such communication signals through a main controller  2017  residing in the handle assembly  2002 , for example. In other circumstances, the interface can facilitate a direct line of communication between the power management controller  2016  and the shaft assembly controller  2022  through the handle assembly  2002  while the shaft assembly  2004  and the power assembly  2006  are coupled to the handle assembly  2002 . 
     In one instance, the main microcontroller  2017  may be any single core or multicore processor such as those known under the trade name ARM Cortex by Texas Instruments. In one instance, the surgical instrument  2000  may comprise a power management controller  2016  such as, for example, a safety microcontroller platform comprising two microcontroller-based families such as TMS570 and RM4x known under the trade name Hercules ARM Cortex R4, also by Texas Instruments. Nevertheless, other suitable substitutes for microcontrollers and safety processor may be employed, without limitation. In one instance, the safety processor may be configured specifically for IEC 61508 and ISO 26262 safety critical applications, among others, to provide advanced integrated safety features while delivering scalable performance, connectivity, and memory options. 
     In certain instances, the microcontroller  2017  may be an LM 4F230H5QR, available from Texas Instruments, for example. In at least one example, the Texas Instruments LM4F230H5QR is an ARM Cortex-M4F Processor Core comprising on-chip memory of 256 KB single-cycle flash memory, or other non-volatile memory, up to 40 MHz, a prefetch buffer to improve performance above 40 MHz, a 32 KB single-cycle serial random access memory (SRAM), internal read-only memory (ROM) loaded with StellarisWare® software, 2 KB electrically erasable programmable read-only memory (EEPROM), one or more pulse width modulation (PWM) modules, one or more quadrature encoder inputs (QEI) analog, one or more 12-bit Analog-to-Digital Converters (ADC) with 12 analog input channels, among other features that are readily available for the product datasheet. The present disclosure should not be limited in this context. 
     The power assembly  2006  may include a power management circuit which may comprise the power management controller  2016 , a power modulator  2038 , and a current sense circuit  2036 . The power management circuit can be configured to modulate power output of the battery based on the power requirements of the shaft assembly  2004  while the shaft assembly  2004  and the power assembly  2006  are coupled to the handle assembly  2002 . For example, the power management controller  2016  can be programmed to control the power modulator  2038  of the power output of the power assembly  2006  and the current sense circuit  2036  can be employed to monitor power output of the power assembly  2006  to provide feedback to the power management controller  2016  about the power output of the battery so that the power management controller  2016  may adjust the power output of the power assembly  2006  to maintain a desired output. 
     It is noteworthy that the power management controller  2016  and/or the shaft assembly controller  2022  each may comprise one or more processors and/or memory units which may store a number of software modules. Although certain modules and/or blocks of the surgical instrument  2000  may be described by way of example, it can be appreciated that a greater or lesser number of modules and/or blocks may be used. Further, although various instances may be described in terms of modules and/or blocks to facilitate description, such modules and/or blocks may be implemented by one or more hardware components, e.g., processors, Digital Signal Processors (DSPs), Programmable Logic Devices (PLDs), Application Specific Integrated Circuits (ASICs), circuits, registers and/or software components, e.g., programs, subroutines, logic and/or combinations of hardware and software components. 
     In certain instances, the surgical instrument  2000  may comprise an output device  2042  which may include one or more devices for providing a sensory feedback to a user. Such devices may comprise, for example, visual feedback devices (e.g., an LCD display screen, LED indicators), audio feedback devices (e.g., a speaker, a buzzer) or tactile feedback devices (e.g., haptic actuators). In certain circumstances, the output device  2042  may comprise a display  2043  which may be included in the handle assembly  2002 . The shaft assembly controller  2022  and/or the power management controller  2016  can provide feedback to a user of the surgical instrument  2000  through the output device  2042 . The interface  2024  can be configured to connect the shaft assembly controller  2022  and/or the power management controller  2016  to the output device  2042 . The reader will appreciate that the output device  2042  can instead be integrated with the power assembly  2006 . In such circumstances, communication between the output device  2042  and the shaft assembly controller  2022  may be accomplished through the interface  2024  while the shaft assembly  2004  is coupled to the handle assembly  2002 . 
     Having described a surgical instrument  2000  in general terms, the description now turns to a detailed description of various electrical/electronic component of the surgical instrument  2000 . For expedience, any references hereinbelow to the surgical instrument  2000  should be construed to refer to the surgical instrument  2000  shown in connection with  FIGS. 1-3B . Turning now to  FIGS. 4A and 4B , where one embodiment of a segmented circuit  1000  comprising a plurality of circuit segments  1002   a - 1002   g  is illustrated. The segmented circuit  1000  comprising the plurality of circuit segments  1002   a - 1002   g  is configured to control a powered surgical instrument, such as, for example, the surgical instrument  2000  illustrated in  FIGS. 1-3B , without limitation. The plurality of circuit segments  1002   a - 1002   g  is configured to control one or more operations of the powered surgical instrument  2000 . A safety processor segment  1002   a  (Segment 1) comprises a safety processor  1004 . A primary processor segment  1002   b  (Segment 2) comprises a primary processor  1006 . The safety processor  1004  and/or the primary processor  1006  are configured to interact with one or more additional circuit segments  1002   c - 1002   g  to control operation of the powered surgical instrument  2000 . The primary processor  1006  comprises a plurality of inputs coupled to, for example, one or more circuit segments  1002   c - 1002   g , a battery  1008 , and/or a plurality of switches  1058   a - 1070 . The segmented circuit  1000  may be implemented by any suitable circuit, such as, for example, a printed circuit board assembly (PCBA) within the powered surgical instrument  2000 . It should be understood that the term processor as used herein includes any microprocessor, microcontroller, or other basic computing device that incorporates the functions of a computer&#39;s central processing unit (CPU) on an integrated circuit or at most a few integrated circuits. The processor is a multipurpose, programmable device that accepts digital data as input, processes it according to instructions stored in its memory, and provides results as output. It is an example of sequential digital logic, as it has internal memory. Processors operate on numbers and symbols represented in the binary numeral system. 
     In one embodiment, the main processor  1006  may be any single core or multicore processor such as those known under the trade name ARM Cortex by Texas Instruments. In one embodiment, the safety processor  1004  may be a safety microcontroller platform comprising two microcontroller-based families such as TMS570 and RM4x known under the trade name Hercules ARM Cortex R4, also by Texas Instruments. Nevertheless, other suitable substitutes for microcontrollers and safety processor may be employed, without limitation. In one embodiment, the safety processor  1004  may be configured specifically for IEC 61508 and ISO 26262 safety critical applications, among others, to provide advanced integrated safety features while delivering scalable performance, connectivity, and memory options. 
     In certain instances, the main processor  1006  may be an LM 4F230H5QR, available from Texas Instruments, for example. In at least one example, the Texas Instruments LM4F230H5QR is an ARM Cortex-M4F Processor Core comprising on-chip memory of 256 KB single-cycle flash memory, or other non-volatile memory, up to 40 MHz, a prefetch buffer to improve performance above 40 MHz, a 32 KB single-cycle serial random access memory (SRAM), internal read-only memory (ROM) loaded with StellarisWare® software, 2 KB electrically erasable programmable read-only memory (EEPROM), one or more pulse width modulation (PWM) modules, one or more quadrature encoder inputs (QEI) analog, one or more 12-bit Analog-to-Digital Converters (ADC) with 12 analog input channels, among other features that are readily available for the product datasheet. Other processors may be readily substituted and, accordingly, the present disclosure should not be limited in this context. 
     In one embodiment, the segmented circuit  1000  comprises an acceleration segment  1002   c  (Segment 3). The acceleration segment  1002   c  comprises an acceleration sensor  1022 . The acceleration sensor  1022  may comprise, for example, an accelerometer. The acceleration sensor  1022  is configured to detect movement or acceleration of the powered surgical instrument  2000 . In some embodiments, input from the acceleration sensor  1022  is used, for example, to transition to and from a sleep mode, identify an orientation of the powered surgical instrument, and/or identify when the surgical instrument has been dropped. In some embodiments, the acceleration segment  1002   c  is coupled to the safety processor  1004  and/or the primary processor  1006 . 
     In one embodiment, the segmented circuit  1000  comprises a display segment  1002   d  (Segment 4). The display segment  1002   d  comprises a display connector  1024  coupled to the primary processor  1006 . The display connector  1024  couples the primary processor  1006  to a display  1028  through one or more display driver integrated circuits  1026 . The display driver integrated circuits  1026  may be integrated with the display  1028  and/or may be located separately from the display  1028 . The display  1028  may comprise any suitable display, such as, for example, an organic light-emitting diode (OLED) display, a liquid-crystal display (LCD), and/or any other suitable display. In some embodiments, the display segment  1002   d  is coupled to the safety processor  1004 . 
     In some embodiments, the segmented circuit  1000  comprises a shaft segment  1002   e  (Segment 5). The shaft segment  1002   e  comprises one or more controls for a shaft  2004  coupled to the surgical instrument  2000  and/or one or more controls for an end effector  2006  coupled to the shaft  2004 . The shaft segment  1002   e  comprises a shaft connector  1030  configured to couple the primary processor  1006  to a shaft PCBA  1031 . The shaft PCBA  1031  comprises a first articulation switch  1036 , a second articulation switch  1032 , and a shaft PCBA electrically erasable programmable read-only memory (EEPROM)  1034 . In some embodiments, the shaft PCBA EEPROM  1034  comprises one or more parameters, routines, and/or programs specific to the shaft  2004  and/or the shaft PCBA  1031 . The shaft PCBA  1031  may be coupled to the shaft  2004  and/or integral with the surgical instrument  2000 . In some embodiments, the shaft segment  1002   e  comprises a second shaft EEPROM  1038 . The second shaft EEPROM  1038  comprises a plurality of algorithms, routines, parameters, and/or other data corresponding to one or more shafts  2004  and/or end effectors  2006  which may be interfaced with the powered surgical instrument  2000 . 
     In some embodiments, the segmented circuit  1000  comprises a position encoder segment  1002   f  (Segment 6). The position encoder segment  1002   f  comprises one or more magnetic rotary position encoders  1040   a - 1040   b . The one or more magnetic rotary position encoders  1040   a - 1040   b  are configured to identify the rotational position of a motor  1048 , a shaft  2004 , and/or an end effector  2006  of the surgical instrument  2000 . In some embodiments, the magnetic rotary position encoders  1040   a - 1040   b  may be coupled to the safety processor  1004  and/or the primary processor  1006 . 
     In some embodiments, the segmented circuit  1000  comprises a motor segment  1002   g  (Segment 7). The motor segment  1002   g  comprises a motor  1048  configured to control one or more movements of the powered surgical instrument  2000 . The motor  1048  is coupled to the primary processor  1006  by an H-Bridge driver  1042  and one or more H-bridge field-effect transistors (FETs)  1044 . The H-bridge FETs  1044  are coupled to the safety processor  1004 . A motor current sensor  1046  is coupled in series with the motor  1048  to measure the current draw of the motor  1048 . The motor current sensor  1046  is in signal communication with the primary processor  1006  and/or the safety processor  1004 . In some embodiments, the motor  1048  is coupled to a motor electromagnetic interference (EMI) filter  1050 . 
     The segmented circuit  1000  comprises a power segment  1002   h  (Segment 8). A battery  1008  is coupled to the safety processor  1004 , the primary processor  1006 , and one or more of the additional circuit segments  1002   c - 1002   g . The battery  1008  is coupled to the segmented circuit  1000  by a battery connector  1010  and a current sensor  1012 . The current sensor  1012  is configured to measure the total current draw of the segmented circuit  1000 . In some embodiments, one or more voltage converters  1014   a ,  1014   b ,  1016  are configured to provide predetermined voltage values to one or more circuit segments  1002   a - 1002   g . For example, in some embodiments, the segmented circuit  1000  may comprise 3.3V voltage converters  1014   a - 1014   b  and/or 5V voltage converters  1016 . A boost converter  1018  is configured to provide a boost voltage up to a predetermined amount, such as, for example, up to 13V. The boost converter  1018  is configured to provide additional voltage and/or current during power intensive operations and prevent brownout or low-power conditions. 
     In some embodiments, the safety segment  1002   a  comprises a motor power interrupt  1020 . The motor power interrupt  1020  is coupled between the power segment  1002   h  and the motor segment  1002   g . The safety segment  1002   a  is configured to interrupt power to the motor segment  1002   g  when an error or fault condition is detected by the safety processor  1004  and/or the primary processor  1006  as discussed in more detail herein. Although the circuit segments  1002   a - 1002   g  are illustrated with all components of the circuit segments  1002   a - 1002   h  located in physical proximity, one skilled in the art will recognize that a circuit segment  1002   a - 1002   h  may comprise components physically and/or electrically separate from other components of the same circuit segment  1002   a - 1002   g . In some embodiments, one or more components may be shared between two or more circuit segments  1002   a - 1002   g.    
     In some embodiments, a plurality of switches  1056 - 1070  are coupled to the safety processor  1004  and/or the primary processor  1006 . The plurality of switches  1056 - 1070  may be configured to control one or more operations of the surgical instrument  2000 , control one or more operations of the segmented circuit  1100 , and/or indicate a status of the surgical instrument  2000 . For example, a bail-out door switch  1056  is configured to indicate the status of a bail-out door. A plurality of articulation switches, such as, for example, a left side articulation left switch  1058   a , a left side articulation right switch  1060   a , a left side articulation center switch  1062   a , a right side articulation left switch  1058   b , a right side articulation right switch  1060   b , and a right side articulation center switch  1062   b  are configured to control articulation of a shaft  2004  and/or an end effector  2006 . A left side reverse switch  1064   a  and a right side reverse switch  1064   b  are coupled to the primary processor  1006 . In some embodiments, the left side switches comprising the left side articulation left switch  1058   a , the left side articulation right switch  1060   a , the left side articulation center switch  1062   a , and the left side reverse switch  1064   a  are coupled to the primary processor  1006  by a left flex connector  1072   a . The right side switches comprising the right side articulation left switch  1058   b , the right side articulation right switch  1060   b , the right side articulation center switch  1062   b , and the right side reverse switch  1064   b  are coupled to the primary processor  1006  by a right flex connector  1072   b . In some embodiments, a firing switch  1066 , a clamp release switch  1068 , and a shaft engaged switch  1070  are coupled to the primary processor  1006 . 
     The plurality of switches  1056 - 1070  may comprise, for example, a plurality of handle controls mounted to a handle of the surgical instrument  2000 , a plurality of indicator switches, and/or any combination thereof. In various embodiments, the plurality of switches  1056 - 1070  allow a surgeon to manipulate the surgical instrument, provide feedback to the segmented circuit  1000  regarding the position and/or operation of the surgical instrument, and/or indicate unsafe operation of the surgical instrument  2000 . In some embodiments, additional or fewer switches may be coupled to the segmented circuit  1000 , one or more of the switches  1056 - 1070  may be combined into a single switch, and/or expanded to multiple switches. For example, in one embodiment, one or more of the left side and/or right side articulation switches  1058   a - 1064   b  may be combined into a single multi-position switch. 
       FIGS. 5A and 5B  illustrate a segmented circuit  1100  comprising one embodiment of a safety processor  1104  configured to implement a watchdog function, among other safety operations. The safety processor  1004  and the primary processor  1106  of the segmented circuit  1100  are in signal communication. A plurality of circuit segments  1102   c - 1102   h  are coupled to the primary processor  1106  and are configured to control one or more operations of a surgical instrument, such as, for example, the surgical instrument  2000  illustrated in  FIGS. 1-3B . For example, in the illustrated embodiment, the segmented circuit  1100  comprises an acceleration segment  1102   c , a display segment  1102   d , a shaft segment  1102   e , an encoder segment  1102   f , a motor segment  1102   g , and a power segment  1102   h . Each of the circuit segments  1102   c - 1102   g  may be coupled to the safety processor  1104  and/or the primary processor  1106 . The primary processor is also coupled to a flash memory  1186 . A microprocessor alive heartbeat signal is provided at output  1196 . 
     The acceleration segment  1102   c  comprises an accelerometer  1122  configured to monitor movement of the surgical instrument  2000 . In various embodiments, the accelerometer  1122  may be a single, double, or triple axis accelerometer. The accelerometer  1122  may be employed to measures proper acceleration that is not necessarily the coordinate acceleration (rate of change of velocity). Instead, the accelerometer sees the acceleration associated with the phenomenon of weight experienced by a test mass at rest in the frame of reference of the accelerometer  1122 . For example, the accelerometer  1122  at rest on the surface of the earth will measure an acceleration g=9.8 m/s 2  (gravity) straight upwards, due to its weight. Another type of acceleration that accelerometer  1122  can measure is g-force acceleration. In various other embodiments, the accelerometer  1122  may comprise a single, double, or triple axis accelerometer. Further, the acceleration segment  1102   c  may comprise one or more inertial sensors to detect and measure acceleration, tilt, shock, vibration, rotation, and multiple degrees-of-freedom (DoF). A suitable inertial sensor may comprise an accelerometer (single, double, or triple axis), a magnetometer to measure a magnetic field in space such as the earth&#39;s magnetic field, and/or a gyroscope to measure angular velocity. 
     The display segment  1102   d  comprises a display embedded in the surgical instrument  2000 , such as, for example, an OLED display. In certain embodiments, the surgical instrument  2000  may comprise an output device which may include one or more devices for providing a sensory feedback to a user. Such devices may comprise, for example, visual feedback devices (e.g., an LCD display screen, LED indicators), audio feedback devices (e.g., a speaker, a buzzer) or tactile feedback devices (e.g., haptic actuators). In some aspects, the output device may comprise a display which may be included in the handle assembly  2002 , as illustrated in  FIG. 1 . The shaft assembly controller and/or the power management controller can provide feedback to a user of the surgical instrument  2000  through the output device. An interface can be configured to connect the shaft assembly controller and/or the power management controller to the output device. 
     The shaft segment  1102   e  comprises a shaft circuit board  1131 , such as, for example, a shaft PCB, configured to control one or more operations of a shaft  2004  and/or an end effector  2006  coupled to the shaft  2004  and a Hall effect switch  1170  to indicate shaft engagement. The shaft circuit board  1131  also includes a low-power microprocessor  1190  with ferroelectric random access memory (FRAM) technology, a mechanical articulation switch  1192 , a shaft release Hall Effect switch  1194 , and flash memory  1134 . The encoder segment  1102   f  comprises a plurality of motor encoders  1140   a ,  1140   b  configured to provide rotational position information of a motor  1048 , the shaft  2004 , and/or the end effector  2006 . 
     The motor segment  1102   g  comprises a motor  1048 , such as, for example, a brushed DC motor. The motor  1048  is coupled to the primary processor  1106  through a plurality of H-bridge drivers  1142  and a motor controller  1143 . The motor controller  1143  controls a first motor flag  1174   a  and a second motor flag  1174   b  to indicate the status and position of the motor  1048  to the primary processor  1106 . The primary processor  1106  provides a pulse-width modulation (PWM) high signal  1176   a , a PWM low signal  1176   b , a direction signal  1178 , a synchronize signal  1180 , and a motor reset signal  1182  to the motor controller  1143  through a buffer  1184 . The power segment  1102   h  is configured to provide a segment voltage to each of the circuit segments  1102   a - 1102   g.    
     In one embodiment, the safety processor  1104  is configured to implement a watchdog function with respect to one or more circuit segments  1102   c - 1102   h , such as, for example, the motor segment  1102   g . In this regards, the safety processor  1104  employs the watchdog function to detect and recover from malfunctions of the primary processor  10006 . During normal operation, the safety processor  1104  monitors for hardware faults or program errors of the primary processor  1104  and to initiate corrective action or actions. The corrective actions may include placing the primary processor  10006  in a safe state and restoring normal system operation. In one embodiment, the safety processor  1104  is coupled to at least a first sensor. The first sensor measures a first property of the surgical instrument  2000 . In some embodiments, the safety processor  1104  is configured to compare the measured property of the surgical instrument  2000  to a predetermined value. For example, in one embodiment, a motor sensor  1140   a  is coupled to the safety processor  1104 . The motor sensor  1140   a  provides motor speed and position information to the safety processor  1104 . The safety processor  1104  monitors the motor sensor  1140   a  and compares the value to a maximum speed and/or position value and prevents operation of the motor  1048  above the predetermined values. In some embodiments, the predetermined values are calculated based on real-time speed and/or position of the motor  1048 , calculated from values supplied by a second motor sensor  1140   b  in communication with the primary processor  1106 , and/or provided to the safety processor  1104  from, for example, a memory module coupled to the safety processor  1104 . 
     In some embodiments, a second sensor is coupled to the primary processor  1106 . The second sensor is configured to measure the first physical property. The safety processor  1104  and the primary processor  1106  are configured to provide a signal indicative of the value of the first sensor and the second sensor respectively. When either the safety processor  1104  or the primary processor  1106  indicates a value outside of an acceptable range, the segmented circuit  1100  prevents operation of at least one of the circuit segments  1102   c - 1102   h , such as, for example, the motor segment  1102   g . For example, in the embodiment illustrated in  FIGS. 5A and 5B , the safety processor  1104  is coupled to a first motor position sensor  1140   a  and the primary processor  1106  is coupled to a second motor position sensor  1140   b . The motor position sensors  1140   a ,  1140   b  may comprise any suitable motor position sensor, such as, for example, a magnetic angle rotary input comprising a sine and cosine output. The motor position sensors  1140   a ,  1140   b  provide respective signals to the safety processor  1104  and the primary processor  1106  indicative of the position of the motor  1048 . 
     The safety processor  1104  and the primary processor  1106  generate an activation signal when the values of the first motor sensor  1140   a  and the second motor sensor  1140   b  are within a predetermined range. When either the primary processor  1106  or the safety processor  1104  to detect a value outside of the predetermined range, the activation signal is terminated and operation of at least one circuit segment  1102   c - 1102   h , such as, for example, the motor segment  1102   g , is interrupted and/or prevented. For example, in some embodiments, the activation signal from the primary processor  1106  and the activation signal from the safety processor  1104  are coupled to an AND gate. The AND gate is coupled to a motor power switch  1120 . The AND gate maintains the motor power switch  1120  in a closed, or on, position when the activation signal from both the safety processor  1104  and the primary processor  1106  are high, indicating a value of the motor sensors  1140   a ,  1140   b  within the predetermined range. When either of the motor sensors  1140   a ,  1140   b  detect a value outside of the predetermined range, the activation signal from that motor sensor  1140   a ,  1140   b  is set low, and the output of the AND gate is set low, opening the motor power switch  1120 . In some embodiments, the value of the first sensor  1140   a  and the second sensor  1140   b  is compared, for example, by the safety processor  1104  and/or the primary processor  1106 . When the values of the first sensor and the second sensor are different, the safety processor  1104  and/or the primary processor  1106  may prevent operation of the motor segment  1102   g.    
     In some embodiments, the safety processor  1104  receives a signal indicative of the value of the second sensor  1140   b  and compares the second sensor value to the first sensor value. For example, in one embodiment, the safety processor  1104  is coupled directly to a first motor sensor  1140   a . A second motor sensor  1140   b  is coupled to a primary processor  1106 , which provides the second motor sensor  1140   b  value to the safety processor  1104 , and/or coupled directly to the safety processor  1104 . The safety processor  1104  compares the value of the first motor sensor  1140  to the value of the second motor sensor  1140   b . When the safety processor  1104  detects a mismatch between the first motor sensor  1140   a  and the second motor sensor  1140   b , the safety processor  1104  may interrupt operation of the motor segment  1102   g , for example, by cutting power to the motor segment  1102   g.    
     In some embodiments, the safety processor  1104  and/or the primary processor  1106  is coupled to a first sensor  1140   a  configured to measure a first property of a surgical instrument and a second sensor  1140   b  configured to measure a second property of the surgical instrument. The first property and the second property comprise a predetermined relationship when the surgical instrument is operating normally. The safety processor  1104  monitors the first property and the second property. When a value of the first property and/or the second property inconsistent with the predetermined relationship is detected, a fault occurs. When a fault occurs, the safety processor  1104  takes at least one action, such as, for example, preventing operation of at least one of the circuit segments, executing a predetermined operation, and/or resetting the primary processor  1106 . For example, the safety processor  1104  may open the motor power switch  1120  to cut power to the motor circuit segment  1102   g  when a fault is detected. 
       FIG. 6  illustrates a block diagram of one embodiment of a segmented circuit  1200  comprising a safety processor  1204  configured to monitor and compare a first property and a second property of a surgical instrument, such as, for example, the surgical instrument  2000  illustrated in  FIGS. 1-3B . The safety processor  1204  is coupled to a first sensor  1246  and a second sensor  1266 . The first sensor  1246  is configured to monitor a first physical property of the surgical instrument  2000 . The second sensor  1266  is configured to monitor a second physical property of the surgical instrument  2000 . The first and second properties comprise a predetermined relationship when the surgical instrument  2000  is operating normally. For example, in one embodiment, the first sensor  1246  comprises a motor current sensor configured to monitor the current draw of a motor from a power source. The motor current draw may be indicative of the speed of the motor. The second sensor comprises a linear hall sensor configured to monitor the position of a cutting member within an end effector, for example, an end effector  2006  coupled to the surgical instrument  2000 . The position of the cutting member is used to calculate a cutting member speed within the end effector  2006 . The cutting member speed has a predetermined relationship with the speed of the motor when the surgical instrument  2000  is operating normally. 
     The safety processor  1204  provides a signal to the main processor  1206  indicating that the first sensor  1246  and the second sensor  1266  are producing values consistent with the predetermined relationship. When the safety processor  1204  detects a value of the first sensor  1246  and/or the second sensor  1266  inconsistent with the predetermined relationship, the safety processor  1206  indicates an unsafe condition to the primary processor  1206 . The primary processor  1206  interrupts and/or prevents operation of at least one circuit segment. In some embodiments, the safety processor  1204  is coupled directly to a switch configured to control operation of one or more circuit segments. For example, with reference to  FIGS. 5A and 5B , in one embodiment, the safety processor  1104  is coupled directly to a motor power switch  1120 . The safety processor  1104  opens the motor power switch  1120  to prevent operation of the motor segment  1102   g  when a fault is detected. 
     Referring back to  FIGS. 5A and 5B , in one embodiment, the safety processor  1104  is configured to execute an independent control algorithm. In operation, the safety processor  1104  monitors the segmented circuit  1100  and is configured to control and/or override signals from other circuit components, such as, for example, the primary processor  1106 , independently. The safety processor  1104  may execute a preprogrammed algorithm and/or may be updated or programmed on the fly during operation based on one or more actions and/or positions of the surgical instrument  2000 . For example, in one embodiment, the safety processor  1104  is reprogrammed with new parameters and/or safety algorithms each time a new shaft and/or end effector is coupled to the surgical instrument  2000 . In some embodiments, one or more safety values stored by the safety processor  1104  are duplicated by the primary processor  1106 . Two-way error detection is performed to ensure values and/or parameters stored by either of the processors  1104 ,  1106  are correct. 
     In some embodiments, the safety processor  1104  and the primary processor  1106  implement a redundant safety check. The safety processor  1104  and the primary processor  1106  provide periodic signals indicating normal operation. For example, during operation, the safety processor  1104  may indicate to the primary processor  1106  that the safety processor  1104  is executing code and operating normally. The primary processor  1106  may, likewise, indicate to the safety processor  1104  that the primary processor  1106  is executing code and operating normally. In some embodiments, communication between the safety processor  1104  and the primary processor  1106  occurs at a predetermined interval. The predetermined interval may be constant or may be variable based on the circuit state and/or operation of the surgical instrument  2000 . 
       FIG. 7  is a block diagram illustrating a safety process  1250  configured to be implemented by a safety processor, such as, for example, the safety process  1104  illustrated in  FIGS. 5A and 5B . In one embodiment, values corresponding to a plurality of properties of a surgical instrument  2000  are provided to the safety processor  1104 . The plurality of properties is monitored by a plurality of independent sensors and/or systems. For example, in the illustrated embodiment, a measured cutting member speed  1252 , a propositional motor speed  1254 , and an intended direction of motor signal  1256  are provided to a safety processor  1104 . The cutting member speed  1252  and the propositional motor speed  1254  may be provided by independent sensors, such as, for example, a linear hall sensor and a current sensor respectively. The intended direction of motor signal  1256  may be provided by a primary processor, for example, the primary processor  1106  illustrated in  FIGS. 5A and 5B . The safety processor  1104  compares  1258  the plurality of properties and determines when the properties are consistent with a predetermined relationship. When the plurality of properties comprises values consistent with the predetermined relationship  1260   a , no action is taken  1262 . When the plurality of properties comprises values inconsistent with the predetermined relationship  1260   b , the safety processor  1104  executes one or more actions, such as, for example, blocking a function, executing a function, and/or resetting a processor. For example, in the process  1250  illustrated in  FIG. 7 , the safety processor  1104  interrupts operation of one or more circuit segments, such as, for example, by interrupting power  1264  to a motor segment. 
     Referring back to  FIGS. 5A and 5B , the segmented circuit  1100  comprises a plurality of switches  1156 - 1170  configured to control one or more operations of the surgical instrument  2000 . For example, in the illustrated embodiment, the segmented circuit  1100  comprises a clamp release switch  1168 , a firing trigger  1166 , and a plurality of switches  1158   a - 1164   b  configured to control articulation of a shaft  2004  and/or end effector  2006  coupled to the surgical instrument  2000 . The clamp release switch  1168 , the fire trigger  1166 , and the plurality of articulation switches  1158   a - 1164   b  may comprise analog and/or digital switches. In particular, switch  1156  indicates the mechanical switch lifter down position, switches  1158   a ,  1158   b  indicate articulate left (1) and (2), switch  1160   a ,  1160   b  indicate articulate right (1) and (2), switches  1162   a ,  1162   b  indicate articulate center (1) and (2), and switches  1164   a ,  1164   b  indicate reverse/left and reverse/right. 
     For example,  FIG. 8  illustrates one embodiment of a switch bank  1300  comprising a plurality of switches SW 1 -SW 16  configured to control one or more operations of a surgical instrument. The switch bank  1300  may be coupled to a primary processor, such as, for example, the primary processor  1106 . In some embodiments, one or more diodes D 1 -D 8  are coupled to the plurality of switches SW 1 -SW 16 . Any suitable mechanical, electromechanical, or solid state switches may be employed to implement the plurality of switches  1156 - 1170 , in any combination. For example, the switches  1156 - 1170  may limit switches operated by the motion of components associated with the surgical instrument  2000  or the presence of an object. Such switches may be employed to control various functions associated with the surgical instrument  2000 . A limit switch is an electromechanical device that consists of an actuator mechanically linked to a set of contacts. When an object comes into contact with the actuator, the device operates the contacts to make or break an electrical connection. Limit switches are used in a variety of applications and environments because of their ruggedness, ease of installation, and reliability of operation. They can determine the presence or absence, passing, positioning, and end of travel of an object. In other implementations, the switches  1156 - 1170  may be solid state switches that operate under the influence of a magnetic field such as Hall-effect devices, magneto-resistive (MR) devices, giant magneto-resistive (GMR) devices, magnetometers, among others. In other implementations, the switches  1156 - 1170  may be solid state switches that operate under the influence of light, such as optical sensors, infrared sensors, ultraviolet sensors, among others. Still, the switches  1156 - 1170  may be solid state devices such as transistors (e.g., FET, Junction-FET, metal-oxide semiconductor-FET (MOSFET), bipolar, and the like). Other switches may include wireless switches, ultrasonic switches, accelerometers, inertial sensors, among others. 
       FIG. 9  illustrates one embodiment of a switch bank  1350  comprising a plurality of switches. In various embodiments, one or more switches are configured to control one or more operations of a surgical instrument, such as, for example, the surgical instrument  2000  illustrated in  FIGS. 1-3B . A plurality of articulation switches SW 1 -SW 16  is configured to control articulation of a shaft  2004  and/or an end effector  2006  coupled to the surgical instrument  2000 . A firing trigger  1366  is configured to fire the surgical instrument  2000 , for example, to deploy a plurality of staples, translate a cutting member within the end effector  2006 , and/or deliver electrosurgical energy to the end effector  2006 . In some embodiments, the switch bank  1350  comprises one or more safety switches configured to prevent operation of the surgical instrument  2000 . For example, a bailout switch  1356  is coupled to a bailout door and prevents operation of the surgical instrument  2000  when the bailout door is in an open position. 
       FIGS. 10A and 10B  illustrate one embodiment of a segmented circuit  1400  comprising a switch bank  1450  coupled to the primary processor  1406 . The switch bank  1450  is similar to the switch bank  1350  illustrated in  FIG. 9 . The switch bank  1450  comprises a plurality of switches SW 1 -SW 16  configured to control one or more operations of a surgical instrument, such as, for example, the surgical instrument  2000  illustrated in  FIGS. 1-3B . The switch bank  1450  is coupled to an analog input of the primary processor  1406 . Each of the switches within the switch bank  1450  is further coupled to an input/output expander  1463  coupled to a digital input of the primary processor  1406 . The primary processor  1406  receives input from the switch bank  1450  and controls one or more additional segments of the segmented circuit  1400 , such as, for example, a motor segment  1402   g  in response to manipulation of one or more switches of the switch bank  1450 . 
     In some embodiments, a potentiometer  1469  is coupled to the primary processor  1406  to provide a signal indicative of a clamp position of an end effector  2006  coupled to the surgical instrument  2000 . The potentiometer  1469  may replace and/or supplement a safety processor (not shown) by providing a signal indicative of a clamp open/closed position used by the primary processor  1106  to control operation of one or more circuit segments, such as, for example, the motor segment  1102   g . For example, when the potentiometer  1469  indicates that the end effector is in a fully clamped position and/or a fully open position, the primary processor  1406  may open the motor power switch  1420  and prevent further operation of the motor segment  1402   g  in a specific direction. In some embodiments, the primary processor  1406  controls the current delivered to the motor segment  1402   g  in response to a signal received from the potentiometer  1469 . For example, the primary processor  1406  may limit the energy that can be delivered to the motor segment  1402   g  when the potentiometer  1469  indicates that the end effector is closed beyond a predetermined position. 
     Referring back to  FIGS. 5A and 5B , the segmented circuit  1100  comprises an acceleration segment  1102   c . The acceleration segment comprises an accelerometer  1122 . The accelerometer  1122  may be coupled to the safety processor  1104  and/or the primary processor  1106 . The accelerometer  1122  is configured to monitor movement of the surgical instrument  2000 . The accelerometer  1122  is configured to generate one or more signals indicative of movement in one or more directions. For example, in some embodiments, the accelerometer  1122  is configured to monitor movement of the surgical instrument  2000  in three directions. In other embodiments, the acceleration segment  1102   c  comprises a plurality of accelerometers  1122 , each configured to monitor movement in a signal direction. 
     In some embodiments, the accelerometer  1122  is configured to initiate a transition to and/or from a sleep mode, e.g., between sleep-mode and wake-up mode and vice versa. Sleep mode may comprise a low-power mode in which one or more of the circuit segments  1102   a - 1102   g  are deactivated or placed in a low-power state. For example, in one embodiment, the accelerometer  1122  remains active in sleep mode and the safety processor  1104  is placed into a low-power mode in which the safety processor  1104  monitors the accelerometer  1122 , but otherwise does not perform any functions. The remaining circuit segments  1102   b - 1102   g  are powered off. In various embodiments, the primary processor  1104  and/or the safety processor  1106  are configured to monitor the accelerometer  1122  and transition the segmented circuit  1100  to sleep mode, for example, when no movement is detected within a predetermined time period. Although described in connection with the safety processor  1104  monitoring the accelerometer  1122 , the sleep-mode/wake-up mode may be implemented by the safety processor  1104  monitoring any of the sensors, switches, or other indicators associated with the surgical instrument  2000  as described herein. For example, the safety processor  1104  may monitor an inertial sensor, or a one or more switches. 
     In some embodiments, the segmented circuit  1100  transitions to sleep mode after a predetermined period of inactivity. A timer is in signal communication with the safety processor  1104  and/or the primary processor  1106 . The timer may be integral with the safety processor  1104 , the primary processor  1106 , and/or may be a separate circuit component. The timer is configured to monitor a time period since a last movement of the surgical instrument  2000  was detected by the accelerometer  1122 . When the counter exceeds a predetermined threshold, the safety processor  1104  and/or the primary processor  1106  transitions the segmented circuit  1100  into sleep mode. In some embodiments, the timer is reset each time the accelerometer  1122  detects movement. 
     In some embodiments, all circuit segments except the accelerometer  1122 , or other designated sensors and/or switches, and the safety processor  1104  are deactivated when in sleep mode. The safety processor  1104  monitors the accelerometer  1122 , or other designated sensors and/or switches. When the accelerometer  1122  indicates movement of the surgical instrument  2000 , the safety processor  1104  initiates a transition from sleep mode to operational mode. In operational mode, all of the circuit segments  1102   a - 1102   h  are fully energized and the surgical instrument  2000  is ready for use. In some embodiments, the safety processor  1104  transitions the segmented circuit  1100  to the operational mode by providing a signal to the primary processor  1106  to transition the primary processor  1106  from sleep mode to a full power mode. The primary processor  1106 , then transitions each of the remaining circuit segments  1102   d - 1102   h  to operational mode. 
     The transition to and/or from sleep mode may comprise a plurality of stages. For example, in one embodiment, the segmented circuit  1100  transitions from the operational mode to the sleep mode in four stages. The first stage is initiated after the accelerometer  1122  has not detected movement of the surgical instrument for a first predetermined time period. After the first predetermined time period the segmented circuit  1100  dims a backlight of the display segment  1102   d . When no movement is detected within a second predetermined period, the safety processor  1104  transitions to a second stage, in which the backlight of the display segment  1102   d  is turned off. When no movement is detected within a third predetermined time period, the safety processor  1104  transitions to a third stage, in which the polling rate of the accelerometer  1122  is reduced. When no movement is detected within a fourth predetermined time period, the display segment  1102   d  is deactivated and the segmented circuit  1100  enters sleep mode. In sleep mode, all of the circuit segments except the accelerometer  1122  and the safety processor  1104  are deactivated. The safety processor  1104  enters a low-power mode in which the safety processor  1104  only polls the accelerometer  1122 . The safety processor  1104  monitors the accelerometer  1122  until the accelerometer  1122  detects movement, at which point the safety processor  1104  transitions the segmented circuit  1100  from sleep mode to the operational mode. 
     In some embodiments, the safety processor  1104  transitions the segmented circuit  1100  to the operational mode only when the accelerometer  1122  detects movement of the surgical instrument  2000  above a predetermined threshold. By responding only to movement above a predetermined threshold, the safety processor  1104  prevents inadvertent transition of the segmented circuit  1100  to operational mode when the surgical instrument  2000  is bumped or moved while stored. In some embodiments, the accelerometer  1122  is configured to monitor movement in a plurality of directions. For example, the accelerometer  1122  may be configured to detect movement in a first direction and a second direction. The safety processor  1104  monitors the accelerometer  1122  and transitions the segmented circuit  1100  from sleep mode to operational mode when movement above a predetermined threshold is detected in both the first direction and the second direction. By requiring movement above a predetermined threshold in at least two directions, the safety processor  1104  is configured to prevent inadvertent transition of the segmented circuit  1100  from sleep mode due to incidental movement during storage. 
     In some embodiments, the accelerometer  1122  is configured to detect movement in a first direction, a second direction, and a third direction. The safety processor  1104  monitors the accelerometer  1122  and is configured to transition the segmented circuit  1100  from sleep mode only when the accelerometer  1122  detects oscillating movement in each of the first direction, second direction, and third direction. In some embodiments, oscillating movement in each of a first direction, a second direction, and a third direction correspond to movement of the surgical instrument  2000  by an operator and therefore transition to the operational mode is desirable when the accelerometer  1122  detects oscillating movement in three directions. 
     In some embodiments, as the time since the last movement detected increases, the predetermined threshold of movement required to transition the segmented circuit  1100  from sleep mode also increases. For example, in some embodiments, the timer continues to operate during sleep mode. As the timer count increases, the safety processor  1104  increases the predetermined threshold of movement required to transition the segmented circuit  1100  to operational mode. The safety processor  1104  may increase the predetermined threshold to an upper limit. For example, in some embodiments, the safety processor  1104  transitions the segmented circuit  1100  to sleep mode and resets the timer. The predetermined threshold of movement is initially set to a low value, requiring only a minor movement of the surgical instrument  2000  to transition the segmented circuit  1100  from sleep mode. As the time since the transition to sleep mode, as measured by the timer, increases, the safety processor  1104  increases the predetermined threshold of movement. At a time T, the safety processor  1104  has increased the predetermined threshold to an upper limit. For all times T+, the predetermined threshold maintains a constant value of the upper limit. 
     In some embodiments, one or more additional and/or alternative sensors are used to transition the segmented circuit  1100  between sleep mode and operational mode. For example, in one embodiment, a touch sensor is located on the surgical instrument  2000 . The touch sensor is coupled to the safety processor  1104  and/or the primary processor  1106 . The touch sensor is configured to detect user contact with the surgical instrument  2000 . For example, the touch sensor may be located on the handle of the surgical instrument  2000  to detect when an operator picks up the surgical instrument  2000 . The safety processor  1104  transitions the segmented circuit  1100  to sleep mode after a predetermined period has passed without the accelerometer  1122  detecting movement. The safety processor  1104  monitors the touch sensor and transitions the segmented circuit  1100  to operational mode when the touch sensor detects user contact with the surgical instrument  2000 . The touch sensor may comprise, for example, a capacitive touch sensor, a temperature sensor, and/or any other suitable touch sensor. In some embodiments, the touch sensor and the accelerometer  1122  may be used to transition the device between sleep mode and operation mode. For example, the safety processor  1104  may only transition the device to sleep mode when the accelerometer  1122  has not detected movement within a predetermined period and the touch sensor does not indicate a user is in contact with the surgical instrument  2000 . Those skilled in the art will recognize that one or more additional sensors may be used to transition the segmented circuit  1100  between sleep mode and operational mode. In some embodiments, the touch sensor is only monitored by the safety processor  1104  when the segmented circuit  1100  is in sleep mode. 
     In some embodiments, the safety processor  1104  is configured to transition the segmented circuit  1100  from sleep mode to the operational mode when one or more handle controls are actuated. After transitioning to sleep mode, such as, for example, after the accelerometer  1122  has not detected movement for a predetermined period, the safety processor  1104  monitors one or more handle controls, such as, for example, the plurality of articulation switches  1158   a - 1164   b . In other embodiments, the one or more handle controls comprise, for example, a clamp control  1166 , a release button  1168 , and/or any other suitable handle control. An operator of the surgical instrument  2000  may actuate one or more of the handle controls to transition the segmented circuit  1100  to operational mode. When the safety processor  1104  detects the actuation of a handle control, the safety processor  1104  initiates the transition of the segmented circuit  1100  to operational mode. Because the primary processor  1106  is in not active when the handle control is actuated, the operator can actuate the handle control without causing a corresponding action of the surgical instrument  2000 . 
       FIG. 16  illustrates one embodiment of a segmented circuit  1900  comprising an accelerometer  1922  configured to monitor movement of a surgical instrument, such as, for example, the surgical instrument  2000  illustrated in  FIGS. 1-3B . A power segment  1902  provides power from a battery  1908  to one or more circuit segments, such as, for example, the accelerometer  1922 . The accelerometer  1922  is coupled to a processor  1906 . The accelerometer  1922  is configured to monitor movement the surgical instrument  2000 . The accelerometer  1922  is configured to generate one or more signals indicative of movement in one or more directions. For example, in some embodiments, the accelerometer  1922  is configured to monitor movement of the surgical instrument  2000  in three directions. 
     In certain instances, the processor  1906  may be an LM 4F230H5QR, available from Texas Instruments, for example. The processor  1906  is configured to monitor the accelerometer  1922  and transition the segmented circuit  1900  to sleep mode, for example, when no movement is detected within a predetermined time period. In some embodiments, the segmented circuit  1900  transitions to sleep mode after a predetermined period of inactivity. For example, a safety processor  1904  may transitions the segmented circuit  1900  to sleep mode after a predetermined period has passed without the accelerometer  1922  detecting movement. In certain instances, the accelerometer  1922  may be an LIS331DLM, available from STMicroelectronics, for example. A timer is in signal communication with the processor  1906 . The timer may be integral with the processor  1906  and/or may be a separate circuit component. The timer is configured to count time since a last movement of the surgical instrument  2000  was detected by the accelerometer  1922 . When the counter exceeds a predetermined threshold, the processor  1906  transitions the segmented circuit  1900  into sleep mode. In some embodiments, the timer is reset each time the accelerometer  1922  detects movement. 
     In some embodiments, the accelerometer  1922  is configured to detect an impact event. For example, when a surgical instrument  2000  is dropped, the accelerometer  1922  will detect acceleration due to gravity in a first direction and then a change in acceleration in a second direction (caused by impact with a floor and/or other surface). As another example, when the surgical instrument  2000  impacts a wall, the accelerometer  1922  will detect a spike in acceleration in one or more directions. When the accelerometer  1922  detects an impact event, the processor  1906  may prevent operation of the surgical instrument  2000 , as impact events can loosen mechanical and/or electrical components. In some embodiments, only impacts above a predetermined threshold prevent operation. In other embodiments, all impacts are monitored and cumulative impacts above a predetermined threshold may prevent operation of the surgical instrument  2000 . 
     With reference back to  FIGS. 5A and 5B , in one embodiment, the segmented circuit  1100  comprises a power segment  1102   h . The power segment  1102   h  is configured to provide a segment voltage to each of the circuit segments  1102   a - 1102   g . The power segment  1102   h  comprises a battery  1108 . The battery  1108  is configured to provide a predetermined voltage, such as, for example, 12 volts through battery connector  1110 . One or more power converters  1114   a ,  1114   b ,  1116  are coupled to the battery  1108  to provide a specific voltage. For example, in the illustrated embodiments, the power segment  1102   h  comprises an axillary switching converter  1114   a , a switching converter  1114   b , and a low-drop out (LDO) converter  1116 . The switch converters  1114   a ,  1114   b  are configured to provide 3.3 volts to one or more circuit components. The LDO converter  1116  is configured to provide 5.0 volts to one or more circuit components. In some embodiments, the power segment  1102   h  comprises a boost converter  1118 . A transistor switch (e.g., N-Channel MOSFET)  1115  is coupled to the power converters  1114   b ,  1116 . The boost converter  1118  is configured to provide an increased voltage above the voltage provided by the battery  1108 , such as, for example, 13 volts. The boost converter  1118  may comprise, for example, a capacitor, an inductor, a battery, a rechargeable battery, and/or any other suitable boost converter for providing an increased voltage. The boost converter  1118  provides a boosted voltage to prevent brownouts and/or low-power conditions of one or more circuit segments  1102   a - 1102   g  during power-intensive operations of the surgical instrument  2000 . The embodiments, however, are not limited to the voltage range(s) described in the context of this specification. 
     In some embodiments, the segmented circuit  1100  is configured for sequential start-up. An error check is performed by each circuit segment  1102   a - 1102   g  prior to energizing the next sequential circuit segment  1102   a - 1102   g .  FIG. 11  illustrates one embodiment of a process for sequentially energizing a segmented circuit  1270 , such as, for example, the segmented circuit  1100 . When a battery  1108  is coupled to the segmented circuit  1100 , the safety processor  1104  is energized  1272 . The safety processor  1104  performs a self-error check  1274 . When an error is detected  1276   a , the safety processor stops energizing the segmented circuit  1100  and generates an error code  1278   a . When no errors are detected  1276   b , the safety processor  1104  initiates  1278   b  power-up of the primary processor  1106 . The primary processor  1106  performs a self-error check. When no errors are detected, the primary processor  1106  begins sequential power-up of each of the remaining circuit segments  1278   b . Each circuit segment is energized and error checked by the primary processor  1106 . When no errors are detected, the next circuit segment is energized  1278   b . When an error is detected, the safety processor  1104  and/or the primary process stops energizing the current segment and generates an error  1278   a . The sequential start-up continues until all of the circuit segments  1102   a - 1102   g  have been energized. In some embodiments, the segmented circuit  1100  transitions from sleep mode following a similar sequential power-up process  1250 . 
       FIG. 12  illustrates one embodiment of a power segment  1502  comprising a plurality of daisy chained power converters  1514 ,  1516 ,  1518 . The power segment  1502  comprises a battery  1508 . The battery  1508  is configured to provide a source voltage, such as, for example, 12V. A current sensor  1512  is coupled to the battery  1508  to monitor the current draw of a segmented circuit and/or one or more circuit segments. The current sensor  1512  is coupled to an FET switch  1513 . The battery  1508  is coupled to one or more voltage converters  1509 ,  1514 ,  1516 . An always on converter  1509  provides a constant voltage to one or more circuit components, such as, for example, a motion sensor  1522 . The always on converter  1509  comprises, for example, a 3.3V converter. The always on converter  1509  may provide a constant voltage to additional circuit components, such as, for example, a safety processor (not shown). The battery  1508  is coupled to a boost converter  1518 . The boost converter  1518  is configured to provide a boosted voltage above the voltage provided by the battery  1508 . For example, in the illustrated embodiment, the battery  1508  provides a voltage of 12V. The boost converter  1518  is configured to boost the voltage to 13V. The boost converter  1518  is configured to maintain a minimum voltage during operation of a surgical instrument, for example, the surgical instrument  2000  illustrated in  FIGS. 1-3B . Operation of a motor can result in the power provided to the primary processor  1506  dropping below a minimum threshold and creating a brownout or reset condition in the primary processor  1506 . The boost converter  1518  ensures that sufficient power is available to the primary processor  1506  and/or other circuit components, such as the motor controller  1543 , during operation of the surgical instrument  2000 . In some embodiments, the boost converter  1518  is coupled directly one or more circuit components, such as, for example, an OLED display  1588 . 
     The boost converter  1518  is coupled to a one or more step-down converters to provide voltages below the boosted voltage level. A first voltage converter  1516  is coupled to the boost converter  1518  and provides a first stepped-down voltage to one or more circuit components. In the illustrated embodiment, the first voltage converter  1516  provides a voltage of 5V. The first voltage converter  1516  is coupled to a rotary position encoder  1540 . A FET switch  1517  is coupled between the first voltage converter  1516  and the rotary position encoder  1540 . The FET switch  1517  is controlled by the processor  1506 . The processor  1506  opens the FET switch  1517  to deactivate the position encoder  1540 , for example, during power intensive operations. The first voltage converter  1516  is coupled to a second voltage converter  1514  configured to provide a second stepped-down voltage. The second stepped-down voltage comprises, for example, 3.3V. The second voltage converter  1514  is coupled to a processor  1506 . In some embodiments, the boost converter  1518 , the first voltage converter  1516 , and the second voltage converter  1514  are coupled in a daisy chain configuration. The daisy chain configuration allows the use of smaller, more efficient converters for generating voltage levels below the boosted voltage level. The embodiments, however, are not limited to the particular voltage range(s) described in the context of this specification. 
       FIG. 13  illustrates one embodiment of a segmented circuit  1600  configured to maximize power available for critical and/or power intense functions. The segmented circuit  1600  comprises a battery  1608 . The battery  1608  is configured to provide a source voltage such as, for example, 12V. The source voltage is provided to a plurality of voltage converters  1619 ,  1618 . An always-on voltage converter  1619  provides a constant voltage to one or more circuit components, for example, a motion sensor  1622  and a safety processor  1604 . The always-on voltage converter  1619  is directly coupled to the battery  1608 . The always-on converter  1619  provides a voltage of, for example, 3.3V. The embodiments, however, are not limited to the particular voltage range(s) described in the context of this specification. 
     The segmented circuit  1600  comprises a boost converter  1618 . The boost converter  1618  provides a boosted voltage above the source voltage provided by the battery  1608 , such as, for example, 13V. The boost converter  1618  provides a boosted voltage directly to one or more circuit components, such as, for example, an OLED display  1688  and a motor controller  1643 . By coupling the OLED display  1688  directly to the boost converter  1618 , the segmented circuit  1600  eliminates the need for a power converter dedicated to the OLED display  1688 . The boost converter  1618  provides a boosted voltage to the motor controller  1643  and the motor  1648  during one or more power intensive operations of the motor  1648 , such as, for example, a cutting operation. The boost converter  1618  is coupled to a step-down converter  1616 . The step-down converter  1616  is configured to provide a voltage below the boosted voltage to one or more circuit components, such as, for example, 5V. The step-down converter  1616  is coupled to, for example, an FET switch  1651  and a position encoder  1640 . The FET switch  1651  is coupled to the primary processor  1606 . The primary processor  1606  opens the FET switch  1651  when transitioning the segmented circuit  1600  to sleep mode and/or during power intensive functions requiring additional voltage delivered to the motor  1648 . Opening the FET switch  1651  deactivates the position encoder  1640  and eliminates the power draw of the position encoder  1640 . The embodiments, however, are not limited to the particular voltage range(s) described in the context of this specification. 
     The step-down converter  1616  is coupled to a linear converter  1614 . The linear converter  1614  is configured to provide a voltage of, for example, 3.3V. The linear converter  1614  is coupled to the primary processor  1606 . The linear converter  1614  provides an operating voltage to the primary processor  1606 . The linear converter  1614  may be coupled to one or more additional circuit components. The embodiments, however, are not limited to the particular voltage range(s) described in the context of this specification. 
     The segmented circuit  1600  comprises a bailout switch  1656 . The bailout switch  1656  is coupled to a bailout door on the surgical instrument  2000 . The bailout switch  1656  and the safety processor  1604  are coupled to an AND gate  1609 . The AND gate  1609  provides an input to a FET switch  1613 . When the bailout switch  1656  detects a bailout condition, the bailout switch  1656  provides a bailout shutdown signal to the AND gate  1609 . When the safety processor  1604  detects an unsafe condition, such as, for example, due to a sensor mismatch, the safety processor  1604  provides a shutdown signal to the AND gate  1609 . In some embodiments, both the bailout shutdown signal and the shutdown signal are high during normal operation and are low when a bailout condition or an unsafe condition is detected. When the output of the AND gate  1609  is low, the FET switch  1613  is opened and operation of the motor  1648  is prevented. In some embodiments, the safety processor  1604  utilizes the shutdown signal to transition the motor  1648  to an off state in sleep mode. A third input to the FET switch  1613  is provided by a current sensor  1612  coupled to the battery  1608 . The current sensor  1612  monitors the current drawn by the circuit  1600  and opens the FET switch  1613  to shut-off power to the motor  1648  when an electrical current above a predetermined threshold is detected. The FET switch  1613  and the motor controller  1643  are coupled to a bank of FET switches  1645  configured to control operation of the motor  1648 . 
     A motor current sensor  1646  is coupled in series with the motor  1648  to provide a motor current sensor reading to a current monitor  1647 . The current monitor  1647  is coupled to the primary processor  1606 . The current monitor  1647  provides a signal indicative of the current draw of the motor  1648 . The primary processor  1606  may utilize the signal from the motor current  1647  to control operation of the motor, for example, to ensure the current draw of the motor  1648  is within an acceptable range, to compare the current draw of the motor  1648  to one or more other parameters of the circuit  1600  such as, for example, the position encoder  1640 , and/or to determine one or more parameters of a treatment site. In some embodiments, the current monitor  1647  may be coupled to the safety processor  1604 . 
     In some embodiments, actuation of one or more handle controls, such as, for example, a firing trigger, causes the primary processor  1606  to decrease power to one or more components while the handle control is actuated. For example, in one embodiment, a firing trigger controls a firing stroke of a cutting member. The cutting member is driven by the motor  1648 . Actuation of the firing trigger results in forward operation of the motor  1648  and advancement of the cutting member. During firing, the primary processor  1606  closes the FET switch  1651  to remove power from the position encoder  1640 . The deactivation of one or more circuit components allows higher power to be delivered to the motor  1648 . When the firing trigger is released, full power is restored to the deactivated components, for example, by closing the FET switch  1651  and reactivating the position encoder  1640 . 
     In some embodiments, the safety processor  1604  controls operation of the segmented circuit  1600 . For example, the safety processor  1604  may initiate a sequential power-up of the segmented circuit  1600 , transition of the segmented circuit  1600  to and from sleep mode, and/or may override one or more control signals from the primary processor  1606 . For example, in the illustrated embodiment, the safety processor  1604  is coupled to the step-down converter  1616 . The safety processor  1604  controls operation of the segmented circuit  1600  by activating or deactivating the step-down converter  1616  to provide power to the remainder of the segmented circuit  1600 . 
       FIG. 14  illustrates one embodiment of a power system  1700  comprising a plurality of daisy chained power converters  1714 ,  1716 ,  1718  configured to be sequentially energized. The plurality of daisy chained power converters  1714 ,  1716 ,  1718  may be sequentially activated by, for example, a safety processor during initial power-up and/or transition from sleep mode. The safety processor may be powered by an independent power converter (not shown). For example, in one embodiment, when a battery voltage V BATT  is coupled to the power system  1700  and/or an accelerometer detects movement in sleep mode, the safety processor initiates a sequential start-up of the daisy chained power converters  1714 ,  1716 ,  1718 . The safety processor activates the 13V boost section  1718 . The boost section  1718  is energized and performs a self-check. In some embodiments, the boost section  1718  comprises an integrated circuit  1720  configured to boost the source voltage and to perform a self check. A diode D prevents power-up of a 5V supply section  1716  until the boost section  1718  has completed a self-check and provided a signal to the diode D indicating that the boost section  1718  did not identify any errors. In some embodiments, this signal is provided by the safety processor. The embodiments, however, are not limited to the particular voltage range(s) described in the context of this specification. 
     The 5V supply section  1716  is sequentially powered-up after the boost section  1718 . The 5V supply section  1716  performs a self-check during power-up to identify any errors in the 5V supply section  1716 . The 5V supply section  1716  comprises an integrated circuit  1715  configured to provide a step-down voltage from the boost voltage and to perform an error check. When no errors are detected, the 5V supply section  1716  completes sequential power-up and provides an activation signal to the 3.3V supply section  1714 . In some embodiments, the safety processor provides an activation signal to the 3.3V supply section  1714 . The 3.3V supply section comprises an integrated circuit  1713  configured to provide a step-down voltage from the 5V supply section  1716  and perform a self-error check during power-up. When no errors are detected during the self-check, the 3.3V supply section  1714  provides power to the primary processor. The primary processor is configured to sequentially energize each of the remaining circuit segments. By sequentially energizing the power system  1700  and/or the remainder of a segmented circuit, the power system  1700  reduces error risks, allows for stabilization of voltage levels before loads are applied, and prevents large current draws from all hardware being turned on simultaneously in an uncontrolled manner. The embodiments, however, are not limited to the particular voltage range(s) described in the context of this specification. 
     In one embodiment, the power system  1700  comprises an over voltage identification and mitigation circuit. The over voltage identification and mitigation circuit is configured to detect a monopolar return current in the surgical instrument and interrupt power from the power segment when the monopolar return current is detected. The over voltage identification and mitigation circuit is configured to identify ground floatation of the power system. The over voltage identification and mitigation circuit comprises a metal oxide varistor. The over voltage identification and mitigation circuit comprises at least one transient voltage suppression diode. 
       FIG. 15  illustrates one embodiment of a segmented circuit  1800  comprising an isolated control section  1802 . The isolated control section  1802  isolates control hardware of the segmented circuit  1800  from a power section (not shown) of the segmented circuit  1800 . The control section  1802  comprises, for example, a primary processor  1806 , a safety processor (not shown), and/or additional control hardware, for example, a FET Switch  1817 . The power section comprises, for example, a motor, a motor driver, and/or a plurality of motor MOSFETS. The isolated control section  1802  comprises a charging circuit  1803  and a rechargeable battery  1808  coupled to a 5V power converter  1816 . The charging circuit  1803  and the rechargeable battery  1808  isolate the primary processor  1806  from the power section. In some embodiments, the rechargeable battery  1808  is coupled to a safety processor and any additional support hardware. Isolating the control section  1802  from the power section allows the control section  1802 , for example, the primary processor  1806 , to remain active even when main power is removed, provides a filter, through the rechargeable battery  1808 , to keep noise out of the control section  1802 , isolates the control section  1802  from heavy swings in the battery voltage to ensure proper operation even during heavy motor loads, and/or allows for real-time operating system (RTOS) to be used by the segmented circuit  1800 . In some embodiments, the rechargeable battery  1808  provides a stepped-down voltage to the primary processor, such as, for example, 3.3V. The embodiments, however, are not limited to the particular voltage range(s) described in the context of this specification. 
       FIG. 17  illustrates one embodiment of a process for sequential start-up of a segmented circuit, such as, for example, the segmented circuit  1100  illustrated in  FIGS. 5A and 5B . The sequential start-up process  1820  begins when one or more sensors initiate a transition from sleep mode to operational mode. When the one or more sensors stop detecting state changes  1822 , a timer is started  1824 . The timer counts the time since the last movement/interaction with the surgical instrument  2000  was detected by the one or more sensors. The timer count is compared  1826  to a table of sleep mode stages by, for example, the safety processor  1104 . When the timer count exceeds one or more counts for transition to a sleep mode stage  1828   a , the safety processor  1104  stops energizing  1830  the segmented circuit  1100  and transitions the segmented circuit  1100  to the corresponding sleep mode stage. When the timer count is below the threshold for any of the sleep mode stages  1828   b , the segmented circuit  1100  continues to sequentially energize the next circuit segment  1832 . 
     With reference back to  FIGS. 5A and 5B , in some embodiments, the segmented circuit  1100  comprises one or more environmental sensors to detect improper storage and/or treatment of a surgical instrument. For example, in one embodiment, the segmented circuit  1100  comprises a temperature sensor. The temperature sensor is configured to detect the maximum and/or minimum temperature that the segmented circuit  1100  is exposed to. The surgical instrument  2000  and the segmented circuit  1100  comprise a design limit exposure for maximum and/or minimum temperatures. When the surgical instrument  2000  is exposed to temperatures exceeding the limits, for example, a temperature exceeding the maximum limit during a sterilization technique, the temperature sensor detects the overexposure and prevents operation of the device. The temperature sensor may comprise, for example, a bi-metal strip configured to disable the surgical instrument  2000  when exposed to a temperature above a predetermined threshold, a solid-state temperature sensor configured to store temperature data and provide the temperature data to the safety processor  1104 , and/or any other suitable temperature sensor. 
     In some embodiments, the accelerometer  1122  is configured as an environmental safety sensor. The accelerometer  1122  records the acceleration experienced by the surgical instrument  2000 . Acceleration above a predetermined threshold may indicate, for example, that the surgical instrument has been dropped. The surgical instrument comprises a maximum acceleration tolerance. When the accelerometer  1122  detects acceleration above the maximum acceleration tolerance, safety processor  1104  prevents operation of the surgical instrument  2000 . 
     In some embodiments, the segmented circuit  1100  comprises a moisture sensor. The moisture sensor is configured to indicate when the segmented circuit  1100  has been exposed to moisture. The moisture sensor may comprise, for example, an immersion sensor configured to indicate when the surgical instrument  2000  has been fully immersed in a cleaning fluid, a moisture sensor configured to indicate when moisture is in contact with the segmented circuit  1100  when the segmented circuit  1100  is energized, and/or any other suitable moisture sensor. 
     In some embodiments, the segmented circuit  1100  comprises a chemical exposure sensor. The chemical exposure sensor is configured to indicate when the surgical instrument  2000  has come into contact with harmful and/or dangerous chemicals. For example, during a sterilization procedure, an inappropriate chemical may be used that leads to degradation of the surgical instrument  2000 . The chemical exposure sensor may indicate inappropriate chemical exposure to the safety processor  1104 , which may prevent operation of the surgical instrument  2000 . 
     The segmented circuit  1100  is configured to monitor a number of usage cycles. For example, in one embodiment, the battery  1108  comprises a circuit configured to monitor a usage cycle count. In some embodiments, the safety processor  1104  is configured to monitor the usage cycle count. Usage cycles may comprise surgical events initiated by a surgical instrument, such as, for example, the number of shafts  2004  used with the surgical instrument  2000 , the number of cartridges inserted into and/or deployed by the surgical instrument  2000 , and/or the number of firings of the surgical instrument  2000 . In some embodiments, a usage cycle may comprise an environmental event, such as, for example, an impact event, exposure to improper storage conditions and/or improper chemicals, a sterilization process, a cleaning process, and/or a reconditioning process. In some embodiments, a usage cycle may comprise a power assembly (e.g., battery pack) exchange and/or a charging cycle. 
     The segmented circuit  1100  may maintain a total usage cycle count for all defined usage cycles and/or may maintain individual usage cycle counts for one or more defined usage cycles. For example, in one embodiment, the segmented circuit  1100  may maintain a single usage cycle count for all surgical events initiated by the surgical instrument  2000  and individual usage cycle counts for each environmental event experienced by the surgical instrument  2000 . The usage cycle count is used to enforce one or more behaviors by the segmented circuit  1100 . For example, usage cycle count may be used to disable a segmented circuit  1100 , for example, by disabling a battery  1108 , when the number of usage cycles exceeds a predetermined threshold or exposure to an inappropriate environmental event is detected. In some embodiments, the usage cycle count is used to indicate when suggested and/or mandatory service of the surgical instrument  2000  is necessary. 
       FIG. 18  illustrates one embodiment of a method  1950  for controlling a surgical instrument comprising a segmented circuit, such as, for example, the segmented control circuit  1602  illustrated in  FIG. 12 . At  1952 , a power assembly  1608  is coupled to the surgical instrument. The power assembly  1608  may comprise any suitable battery, such as, for example, the power assembly  2006  illustrates in  FIGS. 1-3B . The power assembly  1608  is configured to provide a source voltage to the segmented control circuit  1602 . The source voltage may comprise any suitable voltage, such as, for example, 12V. At  1954 , the power assembly  1608  energizes a voltage boost convertor  1618 . The voltage boost convertor  1618  is configured to provide a set voltage. The set voltage comprises a voltage greater than the source voltage provided by the power assembly  1608 . For example, in some embodiments, the set voltage comprises a voltage of 13V. In a third step  1956 , the voltage boost convertor  1618  energizes one or more voltage regulators to provide one or more operating voltages to one or more circuit components. The operating voltages comprise a voltage less than the set voltage provided by the voltage boost convertor. 
     In some embodiments, the boost convertor  1618  is coupled to a first voltage regulator  1616  configured to provide a first operating voltage. The first operating voltage provided by the first voltage regulator  1616  is less than the set voltage provided by the voltage boost convertor. For example, in some embodiments, the first operating voltage comprises a voltage of 5V. In some embodiments, the boost convertor is coupled to a second voltage regulator  1614 . The second voltage regulator  1614  is configured to provide a second operating voltage. The second operating voltage comprises a voltage less than the set voltage and the first operating voltage. For example, in some embodiments, the second operating voltage comprises a voltage of 3.3V. In some embodiments, the battery  1608 , voltage boost convertor  1618 , first voltage regulator  1616 , and second voltage regulator  1614  are configured in a daisy chain configuration. The battery  1608  provides the source voltage to the voltage boost convertor  1618 . The voltage boost convertor  1618  boosts the source voltage to the set voltage. The voltage boost convertor  1618  provides the set voltage to the first voltage regulator  1616 . The first voltage regulator  1616  generates the first operating voltage and provides the first operating voltage to the second voltage regulator  1614 . The second voltage regulator  1614  generates the second operating voltage. 
     In some embodiments, one or more circuit components are energized directly by the voltage boost convertor  1618 . For example, in some embodiments, an OLED display  1688  is coupled directly to the voltage boost convertor  1618 . The voltage boost convertor  1618  provides the set voltage to the OLED display  1688 , eliminating the need for the OLED to have a power generator integral therewith. In some embodiments, a processor, such as, for example, the safety processor  1604  illustrated in  FIGS. 5A and 5B , verifies the voltage provided by the voltage boost convertor  1618  and/or the one or more voltage regulators  1616 ,  1614 . The safety processor  1604  is configured to verify a voltage provided by each of the voltage boost convertor  1618  and the voltage regulators  1616 ,  1614 . In some embodiments, the safety processor  1604  verifies the set voltage. When the set voltage is equal to or greater than a first predetermined value, the safety processor  1604  energizes the first voltage regulator  1616 . The safety processor  1604  verifies the first operational voltage provided by the first voltage regulator  1616 . When the first operational voltage is equal to or greater than a second predetermined value, the safety processor  1604  energizes the second voltage regulator  1614 . The safety processor  1604  then verifies the second operational voltage. When the second operational voltage is equal to or greater than a third predetermined value, the safety processor  1604  energizes each of the remaining circuit components of the segmented circuit  1600 . 
     Various aspects of the subject matter described herein relate to methods of controlling power management of a surgical instrument through a segmented circuit and variable voltage protection. In one embodiment, a method of controlling power management in a surgical instrument comprising a primary processor, a safety processor, and a segmented circuit comprising a plurality of circuit segments in signal communication with the primary processor, the plurality of circuit segments comprising a power segment, the method comprising providing, by the power segment, variable voltage control of each segment. In one embodiment, the method comprises providing, by the power segment comprising a boost converter, power stabilization for at least one of the segment voltages. The method also comprises providing, by the boost converter, power stabilization to the primary processor and the safety processor. The method also comprises providing, by the boost converter, a constant voltage to the primary processor and the safety processor above a predetermined threshold independent of a power draw of the plurality of circuit segments. The method also comprises detecting, by an over voltage identification and mitigation circuit, a monopolar return current in the surgical instrument and interrupting power from the power segment when the monopolar return current is detected. The method also comprises identifying, by the over voltage identification and mitigation circuit, ground floatation of the power system. 
     In another embodiment, the method also comprises energizing, by the power segment, each of the plurality of circuit segments sequentially and error checking each circuit segment prior to energizing a sequential circuit segment. The method also comprises energizing the safety processor by a power source coupled to the power segment, performing an error check, by the safety processor, when the safety processor is energized, and performing, and energizing, the safety processor, the primary processor when no errors are detected during the error check. The method also comprises performing an error check, by the primary processor when the primary processor is energized, and wherein when no errors are detected during the error check, sequentially energizing, by the primary processor, each of the plurality of circuit segments. The method also comprises error checking, by the primary processor, each of the plurality of circuit segments. 
     In another embodiment, the method comprises, energizing, by the boost convertor the safety processor when a power source is connected to the power segment, performing, by the safety processor an error check, and energizing the primary processor, by the safety processor, when no errors are detected during the error check. The method also comprises performing an error check, by the primary process, and sequentially energizing, by the primary processor, each of the plurality of circuit segments when no errors are detected during the error check. The method also comprises error checking, by the primary processor, each of the plurality of circuit segments. 
     In another embodiment, the method also comprises, providing, by a power segment, a segment voltage to the primary processor, providing variable voltage protection of each segment, providing, by a boost converter, power stabilization for at least one of the segment voltages, an over voltage identification, and a mitigation circuit, energizing, by the power segment, each of the plurality of circuit segments sequentially, and error checking each circuit segment prior to energizing a sequential circuit segment. 
     Various aspects of the subject matter described herein relate to methods of controlling an surgical instrument control circuit having a safety processor. In one embodiment, a method of controlling a surgical instrument comprising a control circuit comprising a primary processor, a safety processor in signal communication with the primary processor, and a segmented circuit comprising a plurality of circuit segments in signal communication with the primary processor, the method comprising monitoring, by the safety processor, one or more parameters of the plurality of circuit segments. The method also comprises verifying, by the safety processor, the one or more parameters of the plurality of circuit segments and verifying the one or more parameters independently of one or more control signals generated by the primary processor. The method further comprises verifying, by the safety processor, a velocity of a cutting element. The method also comprises monitoring, by a first sensor, a first property of the surgical instrument, monitoring, by a second sensor a second property of the surgical instrument, wherein the first property and the second property comprise a predetermined relationship, and wherein the first sensor and the second sensor are in signal communication with the safety processor. The method also comprises preventing, by the safety processor, operation of at least one of the plurality of circuit segments when the fault is detected, wherein a fault comprises the first property and the second property having values inconsistent with the predetermined relationship. The method also comprises, monitoring, by a Hall-effect sensor, a cutting member position and monitoring, by a motor current sensor, a motor current. 
     In another embodiment, the method comprises disabling, by the safety processor, at least one of the plurality of circuit segments when a mismatch is detected between the verification of the one or more parameters and the one or more control signals generated by the primary processor. The method also comprises preventing by the safety processor, operation of a motor segment and interrupting power flow to the motor segment from the power segment. The method also comprises preventing, by the safety processor, forward operation of a motor segment and when the fault is detected allowing, by the safety processor, reverse operation of the motor segment. 
     In another embodiment the segmented circuit comprises a motor segment and a power segment, the method comprising controlling, by the motor segment, one or more mechanical operations of the surgical instrument and monitoring, by the safety processor, one or more parameters of the plurality of circuit segments. The method also comprises verifying, by the safety processor, the one or more parameters of the plurality of circuit segments and the independently verifying, by the safety processor, the one or more parameters independently of one or more control signals generated by the primary processor. 
     In another embodiment, the method also comprises independently verifying, by the safety processor, the velocity of a cutting element. The method also comprises monitoring, by a first sensor, a first property of the surgical instrument, monitoring, by a second sensor, a second property of the surgical instrument, wherein the first property and the second property comprise a predetermined relationship, and wherein the first sensor and the second sensor are in signal communication with the safety processor, wherein a fault comprises the first property and the second property having values inconsistent with the predetermined relationship, and preventing, by the safety processor, the operation of at least one of the plurality of circuit segments when the fault is detected by the safety processor. The method also comprises monitoring, by a Hall-effect sensor, a cutting member position and monitoring, by a motor current sensor, a motor current. 
     In another embodiment, the method comprises disabling, by the safety processor, at least one of the plurality of circuit segments when a mismatch is detected between the verification of the one or more parameters and the one or more control signals generated by the primary processor. The method also comprises preventing, by the safety processor, operation of the motor segment and interrupting power flow to the motor segment from the power segment. The method also comprises preventing, by the safety processor, forward operation of the motor segment and allowing, by the safety processor, reverse operation of the motor segment when the fault is detected. 
     In another embodiment, the method comprises monitoring, by the safety processor, one or more parameters of the plurality of circuit segments, verifying, by the safety processor, the one or more parameters of the plurality of circuit segments, verifying, by the safety processor, the one or more parameters independently of one or more control signals generated by the primary processor, and disabling, by the safety processor, at least one of the plurality of circuit segments when a mismatch is detected between the verification of the one or more parameters and the one or more control signals generated by the primary processor. The method also comprises monitoring, by a first sensor, a first property of the surgical instrument, monitoring, by a second sensor, a second property of the surgical instrument, wherein the first property and the second property comprise a predetermined relationship, and wherein the first sensor and the second sensor are in signal communication with the safety processor, wherein a fault comprises the first property and the second property having values inconsistent with the predetermined relationship, and wherein when the fault is detected, preventing, by the safety processor, operation of at least one of the plurality of circuit segments. The method also comprises preventing, by the safety processor, operation of a motor segment by interrupting power flow to the motor segment from the power segment when a fault is detected prevent. 
     Various aspects of the subject matter described herein relate to methods of controlling power management of a surgical instrument through sleep options of segmented circuit and wake up control, the surgical instrument comprising a control circuit comprising a primary processor, a safety processor in signal communication with the primary processor, and a segmented circuit comprising a plurality of circuit segments in signal communication with the primary processor, the plurality of circuit segments comprising a power segment, the method comprising transitioning, by the safety processor, the primary processor and at least one of the plurality of circuit segments from an active mode to a sleep mode and from the sleep mode to the active mode. The method also comprises tracking, by a timer, a time from a last user initiated event and wherein when the time from the last user initiated event exceeds a predetermined threshold, transitioning, by the safety processor, the primary processor and at least one of the plurality of circuit segments to the sleep mode. The method also comprises detecting, by an acceleration segment comprising an accelerometer, one or more movements of the surgical instrument. The method also comprises tracking, by the timer, a time from the last movement detected by the acceleration segment. The method also comprises maintaining, by the safety processor, the acceleration segment in the active mode when transitioning the plurality of circuit segments to the sleep mode. 
     In another embodiment, the method also comprises transitioning to the sleep mode in a plurality of stages. The method also comprises transitioning the segmented circuit to a first stage after a first predetermined period and dimming a backlight of the display segment, transitioning the segmented circuit to a second stage after a second predetermined period and turning the backlight off, transitioning the segmented circuit to a third stage after a third predetermined period and reducing a polling rate of the accelerometer, and transitioning the segmented circuit to a fourth stage after a fourth predetermined period and turning a display off and transitioning the surgical instrument to the sleep mode. 
     In another embodiment comprising detecting, by a touch sensor, user contact with a surgical instrument and transitioning, by the safety processor, the primary processor and a plurality of circuit segments from a sleep mode to an active mode when the touch sensor detects a user in contact with surgical instrument. The method also comprises monitoring, by the safety processor, at least one handle control and transitioning, by the safety processor, the primary processor and the plurality of circuit segments from the sleep mode to the active mode when the at least one handle control is actuated. 
     In another embodiment, the method comprises transitioning, by the safety processor, the surgical device to the active mode when the accelerometer detects movement of the surgical instrument above a predetermined threshold. The method also comprises monitoring, by the safety processor, the accelerometer for movement in at least a first direction and a second direction and transitioning, by the safety processor, the surgical instrument from the sleep mode to the operational mode when movement above a predetermined threshold is detected in at least the first direction and the second direction. The method also comprises monitoring, by the safety processor, the accelerometer for oscillating movement above the predetermined threshold in the first direction, the second direction, and a third direction, and transitioning, by the safety processor, the surgical instrument from the sleep mode to the operational mode when oscillating movement is detected above the predetermined threshold in the first direction, second direction, and third direction. The method also comprises increasing the predetermined as the time from the previous movement increases. 
     In another embodiment, the method comprises transitioning, by the safety processor, the primary processor and at least one of the plurality of circuit segments from an active mode to a sleep mode and from the sleep mode to the active mode when a time from the last user initiated event exceeds a predetermined threshold, tracking, by a timer, a time from the last movement detected by the acceleration segment, and transitioning, by the safety processor, the surgical device to the active mode when the acceleration segment detects movement of the surgical instrument above a predetermined threshold. 
     In another embodiment, a method of controlling a surgical instrument comprises tracking a time from a last user initiated event and disabling, by the safety processor, a backlight of a display when the time from the last user initiated event exceeds a predetermined threshold. The method also comprises flashing, by the safety processor, the backlight of the display to indicate to a user to look at the display. 
     Various aspects of the subject matter described herein relate to methods of verifying the sterilization of a surgical instrument through a sterilization verification circuit, the surgical instrument comprising a control circuit comprising a primary processor, a safety processor in signal communication with the primary processor and a segmented circuit comprising a plurality of circuit segments in signal communication with the primary processor, the plurality of circuit segments comprising a storage verification segment, the method comprising indicating when a surgical instrument has been properly stored and sterilized. The method also comprises detecting, by at least one sensor, one or more improper storage or sterilization parameters. The method also comprises sensing, by a drop protection sensor, when the instrument has been dropped and preventing, by the safety processor, operation of at least one of the plurality of circuit segments when the drop protection sensor detects that the surgical instrument has been dropped. The method also comprises preventing, by the safety processor, operation of at least one of the plurality of circuit segments when a temperature above a predetermined threshold is detected by a temperature sensor. The method also comprises preventing, by the safety processor, operation of at least one of the plurality of circuit segments when the temperature sensor detects a temperature above a predetermined threshold. 
     In another embodiment, the method comprises controlling, by the safety processor, operation of at least one of the plurality of circuit segments when a moisture detection sensor detects moisture. The method also comprises detecting, by a moisture detection sensor, an autoclave cycle and preventing, by the safety processor, operation of the surgical instrument unless the autoclave cycle has been detected. The method also comprises preventing, by the safety processor, operation of the at least one of the plurality of circuit segments when moisture is detected during a staged circuit start-up. 
     In another embodiment, the method comprises indicating, by the plurality of circuit segments comprising a sterilization verification segment, when a surgical instrument has been properly sterilized. The method also comprises detecting, by at least one sensor of the sterilization verification segment, sterilization of the surgical instrument. The method also comprises indicating, by a storage verification segment, when a surgical instrument has been properly stored. The method also comprises detecting, by at least one sensor of the storage verification segment, improper storage of the surgical instrument. 
     The entire disclosures of: 
     U.S. Pat. No. 5,403,312, entitled ELECTROSURGICAL HEMOSTATIC DEVICE, which issued on Apr. 4, 1995; 
     U.S. Pat. No. 7,000,818, entitled SURGICAL STAPLING INSTRUMENT HAVING SEPARATE DISTINCT CLOSING AND FIRING SYSTEMS, which issued on Feb. 21, 2006; 
     U.S. Pat. No. 7,422,139, entitled MOTOR-DRIVEN SURGICAL CUTTING AND FASTENING INSTRUMENT WITH TACTILE POSITION FEEDBACK, which issued on Sep. 9, 2008; 
     U.S. Pat. No. 7,464,849, entitled ELECTRO-MECHANICAL SURGICAL INSTRUMENT WITH CLOSURE SYSTEM AND ANVIL ALIGNMENT COMPONENTS, which issued on Dec. 16, 2008; 
     U.S. Pat. No. 7,670,334, entitled SURGICAL INSTRUMENT HAVING AN ARTICULATING END EFFECTOR, which issued on Mar. 2, 2010; 
     U.S. Pat. No. 7,753,245, entitled SURGICAL STAPLING INSTRUMENTS, which issued on Jul. 13, 2010; 
     U.S. Pat. No. 8,393,514, entitled SELECTIVELY ORIENTABLE IMPLANTABLE FASTENER CARTRIDGE, which issued on Mar. 12, 2013; 
     U.S. patent application Ser. No. 11/343,803, entitled SURGICAL INSTRUMENT HAVING RECORDING CAPABILITIES, now U.S. Pat. No. 7,845,537; 
     U.S. patent application Ser. No. 12/031,573, entitled SURGICAL CUTTING AND FASTENING INSTRUMENT HAVING RF ELECTRODES, filed Feb. 14, 2008; 
     U.S. patent application Ser. No. 12/031,873, entitled END EFFECTORS FOR A SURGICAL CUTTING AND STAPLING INSTRUMENT, filed Feb. 15, 2008, now U.S. Pat. No. 7,980,443; 
     U.S. patent application Ser. No. 12/235,782, entitled MOTOR-DRIVEN SURGICAL CUTTING INSTRUMENT, now U.S. Pat. No. 8,210,411; 
     U.S. patent application Ser. No. 12/249,117, entitled POWERED SURGICAL CUTTING AND STAPLING APPARATUS WITH MANUALLY RETRACTABLE FIRING SYSTEM, now U.S. Pat. No. 8,608,045; 
     U.S. patent application Ser. No. 12/647,100, entitled MOTOR-DRIVEN SURGICAL CUTTING INSTRUMENT WITH ELECTRIC ACTUATOR DIRECTIONAL CONTROL ASSEMBLY, filed Dec. 24, 2009, now U.S. Pat. No. 8,220,688; 
     U.S. patent application Ser. No. 12/893,461, entitled STAPLE CARTRIDGE, filed Sep. 29, 2010, now U.S. Pat. No. 8,733,613; 
     U.S. patent application Ser. No. 13/036,647, entitled SURGICAL STAPLING INSTRUMENT, filed Feb. 28, 2011, now U.S. Pat. No. 8,561,870; 
     U.S. patent application Ser. No. 13/118,241, entitled SURGICAL STAPLING INSTRUMENTS WITH ROTATABLE STAPLE DEPLOYMENT ARRANGEMENTS, now U.S. Pat. No. 9,072,535; 
     U.S. patent application Ser. No. 13/524,049, entitled ARTICULATABLE SURGICAL INSTRUMENT COMPRISING A FIRING DRIVE, filed on Jun. 15, 2012, now U.S. Pat. No. 9,101,358; 
     U.S. patent application Ser. No. 13/800,025, entitled STAPLE CARTRIDGE TISSUE THICKNESS SENSOR SYSTEM, filed on Mar. 13, 2013, now U.S. Pat. No. 9,345,481; 
     U.S. patent application Ser. No. 13/800,067, entitled STAPLE CARTRIDGE TISSUE THICKNESS SENSOR SYSTEM, filed on Mar. 13, 2013, now U.S. Patent Application Publication No. 2014/0263552; 
     U.S. Patent Application Publication No. 2007/0175955, entitled SURGICAL CUTTING AND FASTENING INSTRUMENT WITH CLOSURE TRIGGER LOCKING MECHANISM, filed Jan. 31, 2006; and 
     U.S. Patent Application Publication No. 2010/0264194, entitled SURGICAL STAPLING INSTRUMENT WITH AN ARTICULATABLE END EFFECTOR, filed Apr. 22, 2010, now U.S. Pat. No. 8,308,040, are hereby incorporated by reference herein. 
     In accordance with various embodiments, the surgical instruments described herein may comprise one or more processors (e.g., microprocessor, microcontroller) coupled to various sensors. In addition, to the processor(s), a storage (having operating logic) and communication interface, are coupled to each other. 
     As described earlier, the sensors may be configured to detect and collect data associated with the surgical device. The processor processes the sensor data received from the sensor(s). 
     The processor may be configured to execute the operating logic. The processor may be any one of a number of single or multi-core processors known in the art. The storage may comprise volatile and non-volatile storage media configured to store persistent and temporal (working) copy of the operating logic. 
     In various embodiments, the operating logic may be configured to process the collected biometric associated with motion data of the user, as described above. In various embodiments, the operating logic may be configured to perform the initial processing, and transmit the data to the computer hosting the application to determine and generate instructions. For these embodiments, the operating logic may be further configured to receive information from and provide feedback to a hosting computer. In alternate embodiments, the operating logic may be configured to assume a larger role in receiving information and determining the feedback. In either case, whether determined on its own or responsive to instructions from a hosting computer, the operating logic may be further configured to control and provide feedback to the user. 
     In various embodiments, the operating logic may be implemented in instructions supported by the instruction set architecture (ISA) of the processor, or in higher level languages and compiled into the supported ISA. The operating logic may comprise one or more logic units or modules. The operating logic may be implemented in an object oriented manner. The operating logic may be configured to be executed in a multi-tasking and/or multi-thread manner. In other embodiments, the operating logic may be implemented in hardware such as a gate array. 
     In various embodiments, the communication interface may be configured to facilitate communication between a peripheral device and the computing system. The communication may include transmission of the collected biometric data associated with position, posture, and/or movement data of the user&#39;s body part(s) to a hosting computer, and transmission of data associated with the tactile feedback from the host computer to the peripheral device. In various embodiments, the communication interface may be a wired or a wireless communication interface. An example of a wired communication interface may include, but is not limited to, a Universal Serial Bus (USB) interface. An example of a wireless communication interface may include, but is not limited to, a Bluetooth interface. 
     For various embodiments, the processor may be packaged together with the operating logic. In various embodiments, the processor may be packaged together with the operating logic to form a System in Package (SiP). In various embodiments, the processor may be integrated on the same die with the operating logic. In various embodiments, the processor may be packaged together with the operating logic to form a System on Chip (SoC). 
     Various embodiments may be described herein in the general context of computer executable instructions, such as software, program modules, and/or engines being executed by a processor. Generally, software, program modules, and/or engines include any software element arranged to perform particular operations or implement particular abstract data types. Software, program modules, and/or engines can include routines, programs, objects, components, data structures and the like that perform particular tasks or implement particular abstract data types. An implementation of the software, program modules, and/or engines components and techniques may be stored on and/or transmitted across some form of computer-readable media. In this regard, computer-readable media can be any available medium or media useable to store information and accessible by a computing device. Some embodiments also may be practiced in distributed computing environments where operations are performed by one or more remote processing devices that are linked through a communications network. In a distributed computing environment, software, program modules, and/or engines may be located in both local and remote computer storage media including memory storage devices. A memory such as a random access memory (RAM) or other dynamic storage device may be employed for storing information and instructions to be executed by the processor. The memory also may be used for storing temporary variables or other intermediate information during execution of instructions to be executed by the processor. 
     Although some embodiments may be illustrated and described as comprising functional components, software, engines, and/or modules performing various operations, it can be appreciated that such components or modules may be implemented by one or more hardware components, software components, and/or combination thereof. The functional components, software, engines, and/or modules may be implemented, for example, by logic (e.g., instructions, data, and/or code) to be executed by a logic device (e.g., processor). Such logic may be stored internally or externally to a logic device on one or more types of computer-readable storage media. In other embodiments, the functional components such as software, engines, and/or modules may be implemented by hardware elements that may include processors, microprocessors, circuits, circuit elements (e.g., transistors, resistors, capacitors, inductors, and so forth), integrated circuits, application specific integrated circuits (ASIC), programmable logic devices (PLD), digital signal processors (DSP), field programmable gate array (FPGA), logic gates, registers, semiconductor device, chips, microchips, chip sets, and so forth. 
     Examples of software, engines, and/or modules may include software components, programs, applications, computer programs, application programs, system programs, machine programs, operating system software, middleware, firmware, software modules, routines, subroutines, functions, methods, procedures, software interfaces, application program interfaces (API), instruction sets, computing code, computer code, code segments, computer code segments, words, values, symbols, or any combination thereof. Determining whether an embodiment is implemented using hardware elements and/or software elements may vary in accordance with any number of factors, such as desired computational rate, power levels, heat tolerances, processing cycle budget, input data rates, output data rates, memory resources, data bus speeds and other design or performance constraints. 
     One or more of the modules described herein may comprise one or more embedded applications implemented as firmware, software, hardware, or any combination thereof. One or more of the modules described herein may comprise various executable modules such as software, programs, data, drivers, application program interfaces (APIs), and so forth. The firmware may be stored in a memory of the controller  2016  and/or the controller  2022  which may comprise a nonvolatile memory (NVM), such as in bit-masked read-only memory (ROM) or flash memory. In various implementations, storing the firmware in ROM may preserve flash memory. The nonvolatile memory (NVM) may comprise other types of memory including, for example, programmable ROM (PROM), erasable programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or battery backed random-access memory (RAM) such as dynamic RAM (DRAM), Double-Data-Rate DRAM (DDRAM), and/or synchronous DRAM (SDRAM). 
     In some cases, various embodiments may be implemented as an article of manufacture. The article of manufacture may include a computer readable storage medium arranged to store logic, instructions and/or data for performing various operations of one or more embodiments. In various embodiments, for example, the article of manufacture may comprise a magnetic disk, optical disk, flash memory or firmware containing computer program instructions suitable for execution by a general purpose processor or application specific processor. The embodiments, however, are not limited in this context. 
     The functions of the various functional elements, logical blocks, modules, and circuits elements described in connection with the embodiments disclosed herein may be implemented in the general context of computer executable instructions, such as software, control modules, logic, and/or logic modules executed by the processing unit. Generally, software, control modules, logic, and/or logic modules comprise any software element arranged to perform particular operations. Software, control modules, logic, and/or logic modules can comprise routines, programs, objects, components, data structures and the like that perform particular tasks or implement particular abstract data types. An implementation of the software, control modules, logic, and/or logic modules and techniques may be stored on and/or transmitted across some form of computer-readable media. In this regard, computer-readable media can be any available medium or media useable to store information and accessible by a computing device. Some embodiments also may be practiced in distributed computing environments where operations are performed by one or more remote processing devices that are linked through a communications network. In a distributed computing environment, software, control modules, logic, and/or logic modules may be located in both local and remote computer storage media including memory storage devices. 
     Additionally, it is to be appreciated that the embodiments described herein illustrate example implementations, and that the functional elements, logical blocks, modules, and circuits elements may be implemented in various other ways which are consistent with the described embodiments. Furthermore, the operations performed by such functional elements, logical blocks, modules, and circuits elements may be combined and/or separated for a given implementation and may be performed by a greater number or fewer number of components or modules. As will be apparent to those of skill in the art upon reading the present disclosure, each of the individual embodiments described and illustrated herein has discrete components and features which may be readily separated from or combined with the features of any of the other several aspects without departing from the scope of the present disclosure. Any recited method can be carried out in the order of events recited or in any other order which is logically possible. 
     It is worthy to note that any reference to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is comprised in at least one embodiment. The appearances of the phrase “in one embodiment” or “in one aspect” in the specification are not necessarily all referring to the same embodiment. 
     Unless specifically stated otherwise, it may be appreciated that terms such as “processing,” “computing,” “calculating,” “determining,” or the like, refer to the action and/or processes of a computer or computing system, or similar electronic computing device, such as a general purpose processor, a DSP, ASIC, FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein that manipulates and/or transforms data represented as physical quantities (e.g., electronic) within registers and/or memories into other data similarly represented as physical quantities within the memories, registers or other such information storage, transmission or display devices. 
     It is worthy to note that some embodiments may be described using the expression “coupled” and “connected” along with their derivatives. These terms are not intended as synonyms for each other. For example, some embodiments may be described using the terms “connected” and/or “coupled” to indicate that two or more elements are in direct physical or electrical contact with each other. The term “coupled,” however, also may mean that two or more elements are not in direct contact with each other, but yet still co-operate or interact with each other. With respect to software elements, for example, the term “coupled” may refer to interfaces, message interfaces, application program interface (API), exchanging messages, and so forth. 
     It should be appreciated that any patent, publication, or other disclosure material, in whole or in part, that is said to be incorporated by reference herein is incorporated herein only to the extent that the incorporated material does not conflict with existing definitions, statements, or other disclosure material set forth in this disclosure. As such, and to the extent necessary, the disclosure as explicitly set forth herein supersedes any conflicting material incorporated herein by reference. Any material, or portion thereof, that is said to be incorporated by reference herein, but which conflicts with existing definitions, statements, or other disclosure material set forth herein will only be incorporated to the extent that no conflict arises between that incorporated material and the existing disclosure material. 
     The disclosed embodiments have application in conventional endoscopic and open surgical instrumentation as well as application in robotic-assisted surgery. 
     Embodiments of the devices disclosed herein can be designed to be disposed of after a single use, or they can be designed to be used multiple times. Embodiments may, in either or both cases, be reconditioned for reuse after at least one use. Reconditioning may include any combination of the steps of disassembly of the device, followed by cleaning or replacement of particular pieces, and subsequent reassembly. In particular, embodiments of the device may be disassembled, and any number of the particular pieces or parts of the device may be selectively replaced or removed in any combination. Upon cleaning and/or replacement of particular parts, embodiments of the device may be reassembled for subsequent use either at a reconditioning facility, or by a surgical team immediately prior to a surgical procedure. Those skilled in the art will appreciate that reconditioning of a device may utilize a variety of techniques for disassembly, cleaning/replacement, and reassembly. Use of such techniques, and the resulting reconditioned device, are all within the scope of the present application. 
     By way of example only, embodiments described herein may be processed before surgery. First, a new or used instrument may be obtained and when necessary cleaned. The instrument may then be sterilized. In one sterilization technique, the instrument is placed in a closed and sealed container, such as a plastic or TYVEK bag. The container and instrument may then be placed in a field of radiation that can penetrate the container, such as gamma radiation, x-rays, or high-energy electrons. The radiation may kill bacteria on the instrument and in the container. The sterilized instrument may then be stored in the sterile container. The sealed container may keep the instrument sterile until it is opened in a medical facility. A device may also be sterilized using any other technique known in the art, including but not limited to beta or gamma radiation, ethylene oxide, or steam. 
     One skilled in the art will recognize that the herein described components (e.g., operations), devices, objects, and the discussion accompanying them are used as examples for the sake of conceptual clarity and that various configuration modifications are contemplated. Consequently, as used herein, the specific exemplars set forth and the accompanying discussion are intended to be representative of their more general classes. In general, use of any specific exemplar is intended to be representative of its class, and the non-inclusion of specific components (e.g., operations), devices, and objects should not be taken limiting. 
     With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations are not expressly set forth herein for sake of clarity. 
     The herein described subject matter sometimes illustrates different components contained within, or connected with, different other components. It is to be understood that such depicted architectures are merely examples and that in fact many other architectures may be implemented which achieve the same functionality. In a conceptual sense, any arrangement of components to achieve the same functionality is effectively “associated” such that the desired functionality is achieved. Hence, any two components herein combined to achieve a particular functionality can be seen as “associated with” each other such that the desired functionality is achieved, irrespective of architectures or intermedial components. Likewise, any two components so associated can also be viewed as being “operably connected,” or “operably coupled,” to each other to achieve the desired functionality, and any two components capable of being so associated can also be viewed as being “operably couplable,” to each other to achieve the desired functionality. Specific examples of operably couplable include but are not limited to physically mateable and/or physically interacting components, and/or wirelessly interactable, and/or wirelessly interacting components, and/or logically interacting, and/or logically interactable components. 
     Some aspects may be described using the expression “coupled” and “connected” along with their derivatives. It should be understood that these terms are not intended as synonyms for each other. For example, some aspects may be described using the term “connected” to indicate that two or more elements are in direct physical or electrical contact with each other. In another example, some aspects may be described using the term “coupled” to indicate that two or more elements are in direct physical or electrical contact. The term “coupled,” however, also may mean that two or more elements are not in direct contact with each other, but yet still co-operate or interact with each other. 
     In some instances, one or more components may be referred to herein as “configured to,” “configurable to,” “operable/operative to,” “adapted/adaptable,” “able to,” “conformable/conformed to,” etc. Those skilled in the art will recognize that “configured to” can generally encompass active-state components and/or inactive-state components and/or standby-state components, unless context requires otherwise. 
     While particular aspects of the present subject matter described herein have been shown and described, it will be apparent to those skilled in the art that, based upon the teachings herein, changes and modifications may be made without departing from the subject matter described herein and its broader aspects and, therefore, the appended claims are to encompass within their scope all such changes and modifications as are within the true scope of the subject matter described herein. It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.). It will be further understood by those within the art that when a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim recitation to claims containing only one such recitation, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an” (e.g., “a” and/or “an” should typically be interpreted to mean “at least one” or “one or more”); the same holds true for the use of definite articles used to introduce claim recitations. 
     In addition, even when a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of “two recitations,” without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to “at least one of A, B, and C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, and C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances where a convention analogous to “at least one of A, B, or C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, or C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that typically a disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms unless context dictates otherwise. For example, the phrase “A or B” will be typically understood to include the possibilities of “A” or “B” or “A and B.” 
     With respect to the appended claims, those skilled in the art will appreciate that recited operations therein may generally be performed in any order. Also, although various operational flows are presented in a sequence(s), it should be understood that the various operations may be performed in other orders than those which are illustrated, or may be performed concurrently. Examples of such alternate orderings may include overlapping, interleaved, interrupted, reordered, incremental, preparatory, supplemental, simultaneous, reverse, or other variant orderings, unless context dictates otherwise. Furthermore, terms like “responsive to,” “related to,” or other past-tense adjectives are generally not intended to exclude such variants, unless context dictates otherwise. 
     In summary, numerous benefits have been described which result from employing the concepts described herein. The foregoing description of the one or more embodiments has been presented for purposes of illustration and description. It is not intended to be exhaustive or limiting to the precise form disclosed. Modifications or variations are possible in light of the above teachings. The one or more embodiments were chosen and described in order to illustrate principles and practical application to thereby enable one of ordinary skill in the art to utilize the various embodiments and with various modifications as are suited to the particular use contemplated. It is intended that the claims submitted herewith define the overall scope.