US20090118751A1 - Apparatus and method for alerting generator functions in an ultrasonic surgical system - Google Patents

Abstract

The present invention provides a system for surgery which includes an ultrasonic hand piece having a end-effector, a console having a digital signal processor (DSP) for controlling the hand piece, and a memory disposed in the end-effector. The generator console sends a drive current to drive the hand piece which imparts ultrasonic longitudinal movement to the blade. As the generator console reads the memory, the hand piece is authenticated for use with the generator console if a copyrighted data string is present in the memory. In a particular embodiment, the data string is an encrypted code, where the hand piece is authenticated for use with the console by decoding a corresponding encryption algorithm resident in the generator console and providing a responding data pattern.

Description

RELATED APPLICATIONS
• The present invention is a continuation of and claims priority to U.S. patent application Ser. No. 09/975,127, filed Oct. 10, 2001, which claims priority to U.S. Provisional Patent Application Ser. No. 60/241,886 filed on Oct. 20, 2000 and entitled “BLADE IDENTIFICATION IN AN ULTRASONIC SURGICAL HANDPIECE”.
BACKGROUND OF THE INVENTION
• 1. Field of the Invention
• The present invention generally relates to an apparatus and method for alerting generator functions in an ultrasonic surgical system and more particularly, to an ultrasonic surgical system for providing information to a generator from an ultrasonic surgical instrument.
• 2. Description of the Related Art
• It is known that electric scalpels and lasers can be used as a surgical instrument to perform the dual function of simultaneously effecting the incision and hemostatis of soft tissue by cauterizing tissues and blood vessels. However, such instruments employ very high temperatures to achieve coagulation, causing vaporization and fumes as well as splattering. Additionally, the use of such instruments often results in relatively wide zones of thermal tissue damage.
• Cutting and cauterizing of tissue by means of surgical blades vibrated at high speeds by ultrasonic drive mechanisms is also well known. One of the problems associated with such ultrasonic cutting instruments is uncontrolled or undamped vibrations and the heat as well as material fatigue resulting therefrom. In an operating room environment attempts have been made to control this heating problem by the inclusion of cooling systems with heat exchangers to cool the blade. In one known system, for example, the ultrasonic cutting and tissue fragmentation system requires a cooling system augmented with a water circulating jacket and means for irrigation and aspiration of the cutting site. Another known system requires the delivery of cryogenic fluids to the cutting blade.
• It is known to limit the current delivered to the transducer as a means for limiting the heat generated therein. However, this could result in insufficient power to the blade at a time when it is needed for the most effective treatment of the patient. U.S. Pat. No. 5,026,387 to Thomas, which is assigned to the assignee of the present application and is incorporated herein by reference, discloses a system for controlling the heat in an ultrasonic surgical cutting and hemostasis system without the use of a coolant, by controlling the drive energy supplied to the blade. In the system according to this patent an ultrasonic generator is provided which produces an electrical signal of a particular voltage, current and frequency, e.g. 55,500 cycles per second. The generator is connected by a cable to a hand piece which contains piezoceramic elements forming an ultrasonic transducer. In response to a switch on the hand piece or a foot switch connected to the generator by another cable, the generator signal is applied to the transducer, which causes a longitudinal vibration of its elements. A structure connects the transducer to a surgical blade, which is thus vibrated at ultrasonic frequencies when the generator signal is applied to the transducer. The structure is designed to resonate at the selected frequency, thus amplifying the motion initiated by the transducer.
• The signal provided to the transducer is controlled so as to provide power on demand to the transducer in response to the continuous or periodic sensing of the loading condition (tissue contact or withdrawal) of the blade. As a result, the device goes from a low power, idle state to a selectable high power, cutting state automatically depending on whether the scalpel is or is not in contact with tissue. A third, high power coagulation mode is manually selectable with automatic return to an idle power level when the blade is not in contact with tissue. Since the ultrasonic power is not continuously supplied to the blade, it generates less ambient heat, but imparts sufficient energy to the tissue for incisions and cauterization when necessary.
• The control system in the Thomas patent is of the analog type. A phase lock loop that includes a voltage controlled oscillator, a frequency divider, a power switch, a match net and a phase detector, stabilizes the frequency applied to the hand piece. A microprocessor controls the amount of power by sampling the frequency current and voltage applied to the hand piece, because these parameters change with load on the blade.
• The power versus load curve in a generator in a typical ultrasonic surgical system, such as that described in the Thomas patent has two segments. The first segment has a positive slope of increasing power, as the load increases, which indicates constant current delivery. The second segment has a negative slope of decreasing power as the load increases, which indicates a constant or saturated output voltage. The regulated current for the first segment is fixed by the design of the electronic components and the second segment voltage is limited by the maximum output voltage of the design. This arrangement is inflexible since the power versus load characteristics of the output of such a system can not be optimized to various types of hand piece transducers and ultrasonic blades. The performance of traditional analog ultrasonic power systems for surgical instruments is affected by the component tolerances and their variability in the generator electronics due to changes in operating temperature. In particular, temperature changes can cause wide variations in key system parameters such as frequency lock range, drive signal level, and other system performance measures.
• In order to operate an ultrasonic surgical system in an efficient manner, during startup the frequency of the signal supplied to the hand piece transducer is swept over a range to locate the resonance frequency. Once it is found, the generator phase lock loop locks on to the resonance frequency, keeps monitoring of the transducer current to voltage phase angle and maintains the transducer resonating by driving it at the resonance frequency. A key function of such systems is to maintain the transducer resonating across load and temperature changes that vary the resonance frequency. However, these traditional ultrasonic drive systems have little to no flexibility with regards to adaptive frequency control. Such flexibility is key to the system's ability to discriminate undesired resonances. In particular, these systems can only search for resonance in one direction, i.e., with increasing or decreasing frequencies and their search pattern is fixed. The system cannot hop over other resonance modes or make any heuristic decisions such as what resonance/s to skip or lock onto and ensure delivery of power only when appropriate frequency lock is achieved.
• The prior art ultrasonic generator systems also have little flexibility with regard to amplitude control, which would allow the system to employ adaptive control algorithms and decision making. For example, these fixed systems lack the ability to make heuristic decisions with regards to the output drive, e.g., current or frequency, based on the load on the blade and/or the current to voltage phase angle. It also limits the system=s ability to set optimal transducer drive signal levels for consistent efficient performance, which would increase the useful life of the transducer and ensure safe operating conditions for the blade. Further, the lack of control over amplitude and frequency control reduces the system's ability to perform diagnostic tests on the transducer/blade system and to support troubleshooting in general.
• However, the prior art systems do not provide for authentication of the use of the hand piece with the generator console. Furthermore, conducting diagnostic and performance tests in the prior art systems is cumbersome. Reprogramming or upgrading of the console in the prior art systems is also burdensome, since each console needs to be independently tested and upgraded. In addition, the prior art system do not allow operation of the console with varied driving current and output displacement, depending on the type and output ability of hand piece in operation with the console. Therefore, there is a need in the art for an improved system for implementing surgical procedures which overcomes these and other disadvantages in the prior art.
SUMMARY OF THE INVENTION
• The present invention provides a system for implementing surgical procedures which includes an ultrasonic surgical hand piece having an end-effector, a generator console having a digital signal processor (DSP) for controlling the hand piece, and a memory device such as an EEPROM (Electrically Erasable Programmable Read Only Memory) disposed in the sheath of the end-effector or in the handle, grip, or mount portion of shears or scissors or forceps. A data string, which identifies the hand piece and generator performance characteristics, is stored in the memory device. During initialization of the system and/or periodically during standby or ready or while in use, the generator console sends an interrogation signal to the hand piece to obtain a readout of the memory. As the generator console reads the memory, the hand piece blade or shears is authenticated for use with the generator console if the proper data string is present. The hand piece blade or shears is not authenticated for use with the console if the data string is not present or is not correct. In a particular embodiment of the invention, the data string is an encrypted code, where the hand piece or blade or shears is authenticated for use with the generator console by decoding a corresponding encryption algorithm resident in the console and providing a responding data pattern.
• Moreover, to prevent errors in operating the hand piece or blade or shears, the memory can store certain diagnostic information which the generator console can utilize in determining whether the operation of the hand piece should be handicapped or disabled or alert an end user without handicap- or disable-mode operations. For instance, the memory can store information such as limits on the time that the hand piece is active, the number of activations within a time period, the number of defective blades used, operating temperature, maximum allowable rate of change in temperature, and other limits. Those limits stored in the memory can be re-initialized accordingly based on various operational conditions of the hand piece.
• The memory can also be used to reprogram or upgrade the generator console, if needed. For example, new hand pieces are issued periodically as new system functionality is achieved. When such a new hand piece is connected, the system perform diagnostic tests to determine whether a reprogram or upgrade of the generator console is needed. If it is determined that a reprogram or upgrade is needed, the generator console reads the memory located in the sheath of the end-effector of the hand piece where a reprogram or upgrade code is stored. Using the reprogram or upgrade code read from the memory, the generator console is reprogrammed or upgraded accordingly. Therefore, the generator consoles in the field can be upgraded automatically without having to return them to the manufacturer or to send a service technician to the generator console. Alternately, rather than reprogramming the generator memory, the blade/shear memory data is utilized by the generator console as the basis for operation parameters for the particular blade/shear in use. Default parameters are reverted to in operating the hand piece when particular parameters are not present in subsequent blades/shears attached to handpiece.
• The memory can also store energy level information and corresponding output displacement for driving the particular hand piece. By reading the energy level information, the generator console can drive the hand piece according to the output displacement which is best for that hand piece and/or blade/shears.
• In addition, the memory can store frequency sweep information including the nominal resonant frequency, and start and stop sweep points for effecting a frequency sweep. Upon reading of the frequency sweep information stored in the memory, the generator console effects a frequency sweep in the indicated frequency range for detecting a resonant frequency for operating the hand piece. In addition, the memory can store frequencies or frequency ranges that should not be swept, such as frequencies that are or tend to be transverse-resonant which should be avoided. These stored frequencies can be in the wider specified sweep range allowed, which is stored in the blade/shear memory.
• In accordance with the invention, a method is provided for implementing procedures in a system including an ultrasonic surgical hand piece having a end-effector, a console having a digital signal processor (DSP) for controlling the hand piece, and a memory disposed in the sheath of the end-effector in or attached to the hand piece. The method according to the invention includes reading information stored in the memory, determining whether a particular data string is present in the memory, authenticating use of the hand piece or blade or shear with the console if the data string is present, sending a drive current to drive the hand piece, and imparting ultrasonic movement to the end-effector of the hand piece according to information in the memory. In a particular embodiment, the method according to the invention also includes decoding an encryption algorithm in the generator console, and providing a responding data pattern, where the data string is an encrypted code.
• In a further embodiment, the method according to the invention includes instructing the hand piece to operate in a handicap mode if the temperature of the hand piece exceeds a handicap limit, and disabling the hand piece if the temperature of the hand piece exceeds a disable limit. The method according to the invention can also include instructing the hand piece to operate in a handicap mode if the number of defective blades found in a time period of operating the hand piece exceeds a handicap limit, and disabling the hand piece if the number of defective blades found in the time period exceeds a disable limit. The method according to the invention can further include instructing the hand piece to operate in a handicap mode if the time the hand piece has been active exceeds a handicap limit, and disabling the hand piece if the number of defective blades found in the time the hand piece has been active exceeds a disable limit. The method according to the invention can include further steps of instructing the hand piece to operate in a handicap mode if the number of activations for the hand piece within a time period exceeds a handicap limit, and disabling the hand piece if the number of activations for the hand piece within the time period exceeds a disable limit. The handicap and disable limits stored in the memory can be re-initialized based on varied operational conditions of the hand piece.
• In an additional embodiment, the method according to the invention also includes determining whether a reprogramming or upgrade of the generator console is needed, reading a reprogram or upgrade code stored in the memory and reprogramming the generator console using the reprogram or upgrade code, if it is determined that a reprogram or upgrade of the generator console is needed.
• Moreover, the method according to another embodiment of the invention further includes reading energy level information stored in the memory, and driving the hand piece according to a corresponding output displacement, where the energy level information stored in the memory is correlated with corresponding output displacement for driving the particular hand piece or blade or shears. In yet another embodiment, the method according to the invention also includes reading a nominal resonant frequency, a start sweep point and a stop sweep point delimiting a frequency range from the memory, effecting a frequency sweep in the frequency range, and detecting a resonant frequency for operating the hand piece. Alternatively, the frequency range information stored in the memory can be a nominal resonant frequency, a bias amount and a margin amount, where the frequency range for the frequency sweep is calculated based on the nominal resonant frequency, the bias amount and the margin amount. In addition, frequencies or frequency bands to be avoided in the sweeping or driving, or the transverse resonant frequencies, can be stored for use by the generator to operate the handpiece or portion diagnostics.
BRIEF DESCRIPTION OF THE DRAWINGS
• The foregoing and other advantages and features of the invention will become more apparent from the detailed description of the preferred embodiments of the invention given below with reference to the accompanying drawings (not necessarily drawn to scale) in which:
• FIG. 1 is an illustration of a console for an ultrasonic surgical cutting and hemostasis system, as well as a hand piece and foot switch in which the method of the present invention is implemented;
• FIG. 2 is a schematic view of a cross section through the ultrasonic scalpel hand piece of the system ofFIG. 1;
• FIG. 3A andFIG. 3B are block diagrams illustrating the ultrasonic according to an embodiment of the invention;
• FIG. 4 is a diagram that illustrates a non-volatile memory in the sheath of the end-effector in the ultrasonic surgical hand piece according to the invention;
• FIG. 4B is a diagram that illustrates a non-volatile memory in the handle/grip/mount portion (non-sheath portion) of ultrasonic shears according to the invention;
• FIG. 5 is a flow diagram illustrating the operation of the non-volatile memory according to the invention as proprietary lockout for preventing inappropriate use of the ultrasonic surgical hand piece;
• FIG. 5A is a flow diagram illustrating the operation of the non-volatile memory according to the invention;
• FIG. 6 andFIG. 7 are flow diagrams illustrating the operation of the non-volatile memory according to the invention for error prevention when using the ultrasonic surgical hand piece;
• FIG. 6A andFIG. 7A are flow diagrams illustrating the operation of the non-volatile memory according to the invention;
• FIG. 8 is a flow diagram illustrating the operation of the non-volatile memory according to the invention for reprogramming or upgrading the console using the hand piece;
• FIG. 9 is a flow diagram illustrating the operation of the ultrasonic surgical hand piece at a resonant frequency using information stored in the memory according to the invention;
• FIG. 10 is a diagram illustrating an alternative embodiment of the operation of the hand piece at a resonant frequency using information stored in the non-volatile memory according to the invention;
• FIG. 10A is a diagram illustrating an alternative embodiment whereby frequencies to avoid operating the handpiece are included in the blade/shears memory.
• FIG. 11 is an isometric view of a portion of the ultrasonic surgical hand piece with a non-volatile memory in the end-effector in accordance with the invention;
• FIG. 12 is a side view of a portion of the ultrasonic surgical hand piece with a non-volatile memory in the end-effector in accordance with the invention;
• FIG. 13 is a side section view of a portion of the ultrasonic surgical hand piece with a non-volatile memory in the end-effector in accordance with the invention;
• FIG. 14 is a diagram illustrating an alternative embodiment utilizing a handpiece adaptor to bridge the non-volatile memory signal to the handpiece according to the invention; and
• FIG. 15 is an illustration of an electromagnetic coupling means for conveying memory data to and/or from the non-volatile memory according to the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
• FIG. 1 is an illustration of a system for implementing surgical procedures according to the invention. By means of a first set of wires in cable20, electrical energy, i.e., drive current, is sent from thegenerator console10 to ahandpiece30 where it imparts ultrasonic longitudinal movement to a surgical device, such as a sharp end-effector32. This blade can be used for simultaneous dissection and cauterization of tissue. The supply of ultrasonic current to thehand piece30 may be under the control of aswitch34 located on the hand piece, which is connected to the generator in thegenerator console10 via wires in cable20. The generator may also be controlled by afoot switch40, which is connected to thegenerator console10 by anothercable50. Thus, in use a surgeon may apply an ultrasonic electrical signal to the hand piece, causing the blade to vibrate longitudinally at an ultrasonic frequency, by operating theswitch34 on the hand piece with his finger, or by operating thefoot switch40 with his foot.
• Thegenerator console10 includes a liquidcrystal display device12, which can be used for indicating the selected cutting power level in various means such, as percentage of maximum cutting power or numerical power levels associated with cutting power. The liquidcrystal display device12 can also be utilized to display other parameters of the system.Power switch11 is used to turn on the unit. While it is warming up, the Astandby® light13 is illuminated. When it is ready for operation, theAready® indicator14 is illuminated and the standby light goes out. If the unit is to supply maximum power, theMAX button15 is depressed. If a lesser power is desired, theMIN button17 is activated. This automatically deactivates the MAX button. The level of power when MIN is active is set bybutton16.
• When power is applied to the ultrasonic hand piece by operation of either switch34 or40, the assembly will cause the surgical scalpel or blade to vibrate longitudinally at approximately 55.5 kHz, and the amount of longitudinal movement will vary proportionately with the amount of driving power (current) applied, as adjustably selected by the user. When relatively high cutting power is applied, the blade is designed to move longitudinally in the range of about 40 to 100 microns at the ultrasonic vibrational rate. Such ultrasonic vibration of the blade will generate heat as the blade contacts tissue, i.e., the acceleration of the blade through the tissue converts the mechanical energy of the moving blade to thermal energy in a very narrow and localized area. This localized heat creates a narrow zone of coagulation, which will reduce or eliminate bleeding in small vessels, such as those less than one millimeter in diameter. The cutting efficiency of the blade, as well as the degree of hemostasis, will vary with the level of driving power applied, the cutting rate or force applied by the surgeon to the blade, the nature of the tissue type and the vascularity of the tissue.
• As illustrated in more detail inFIG. 2, theultrasonic hand piece30 houses apiezoelectric transducer36 for converting electrical energy to mechanical energy that results in longitudinal vibrational motion of the ends of the transducer. Thetransducer36 is in the form of a stack of ceramic piezoelectric elements with a motion null point located at some point along the stack. The transducer stack is mounted between twocylinders31 and33. In addition acylinder35 is attached tocylinder33, which in turn is mounted to the housing at another motionnull point37. Ahorn38 is also attached to the null point on one side and to acoupler39 on the other side.Blade32 is fixed to thecoupler39. As a result, theblade32 will vibrate in the longitudinal direction at an ultrasonic frequency rate with thetransducer36. The ends of the transducer achieve maximum motion with a portion of the stack constituting a motionless node, when the transducer is driven at maximum current at the transducer's resonant frequency. However, the current providing the maximum motion will vary with each hand piece and is a valve stored in the non-volatile memory of the hand piece so the system can use it.
• The parts of the hand piece are designed such that the combination will oscillate at the same resonant frequency. In particular, the elements are tuned such that the resulting length of each such element is one-half wavelength or a multiple thereof. Longitudinal back and forth motion is amplified as the diameter closer to theblade32 of theacoustical mounting horn38 decreases. Thus, thehorn38 as well as the blade/coupler are shaped and dimensioned so as to amplify blade motion and provide harmonic vibration in resonance with the rest of the acoustic system, which produces the maximum back and forth motion of the end of theacoustical mounting horn38 close to theblade32. A motion from 20 to 25 microns at the transducer stack is amplified by thehorn38 into blade movement of about 40 to 100 microns.
• The system which creates the ultrasonic electrical signal for driving the transducer in the hand piece is illustrated inFIG. 3A andFIG. 3B. This drive system is flexible and can create a drive signal at a desired frequency and power level setting. ADSP60 or microprocessor in the system is used for monitoring the appropriate power parameters and vibratory frequency as well as causing the appropriate power level to be provided in either the cutting or coagulation operating modes. TheDSP60 or microprocessor also stores computer programs which are used to perform diagnostic tests on components of the system, such as the transducer/blade.
• For example, under the control of a program stored in the DSP ormicroprocessor60, such as a phase correction algorithm, the frequency during startup can be set to a particular value, e.g., 50 kHz. It can than be caused to sweep up at a particular rate until a change in impedance, indicating the approach to resonance, is detected. Then the sweep rate can be reduced so that the system does not overshoot the resonance frequency, e.g., 55 kHz. The sweep rate can be achieved by having the frequency change in increments, e.g., 50 cycles. If a slower rate is desired, the program can decrease the increment, e.g., to 25 cycles which both can be based adaptively on the measured transducer impedance magnitude and phase. Of course, a faster rate can be achieved by increasing the size of the increment. Further, the rate of sweep can be changed by changing the rate at which the frequency increment is updated.
• If it is known that there is a undesired resonant mode, e.g., at say 51 kHz, the program can cause the frequency to sweep down, e.g., from 60 kHz, to find resonance. Also, the system can sweep up from 50 kHz and hop over 51 kHz where the undesired resonance is located. In any event, the system has a great degree of flexibility
• In operation, the user sets a particular power level to be used with the surgical instrument. This is done with powerlevel selection switch16 on the front panel of the console. The switch generatessignals150 that are applied to theDSP60. TheDSP60 then displays the selected power level by sending a signal on line152 (FIG. 3B) to the consolefront panel display12.
• To actually cause the surgical blade to vibrate, the user activates thefoot switch40 or thehand piece switch34. This activation puts a signal online154 inFIG. 3A. This signal is effective to cause power to be delivered from push-pull amplifier78 to thetransducer36. When the DSP ormicroprocessor60 has achieved lock on the hand piece transducer resonance frequency and power has been successfully applied to the hand piece transducer, an audio drive signal is put online156. This causes an audio indication in the system to sound, which communicates to the user that power is being delivered to the hand piece and that the scalpel is active and operational.
• In order to obtain the impedance measurements and phase measurements, theDSP60 and the other circuit elements ofFIGS. 3A and 3B are used. In particular, push-pull amplifier78 delivers the ultrasonic signal to apower transformer86, which in turn delivers the signal over aline85 in cable20 to thepiezoelectric transducers36 in the hand piece. The current inline85 and the voltage on that line are detected bycurrent sense circuit88 and voltage sense circuit92. The current and voltage sense signals are sent toaverage voltage circuit122 and averagecurrent circuit120, respectively, which take the average values of these signals. The average voltage is converted by analog-to-digital converter (ADC)126 into a digital code that is input toDSP60. Likewise, the current average signal is converted by analog-to-digital converter (ADC)124 into a digital code that is input toDSP60. In the DSP the ratio of voltage to current is calculated on an ongoing basis to give the present impedance values as the frequency is changed. A significant change in impedance occurs as resonance is approached.
• The signals fromcurrent sense88 and voltage sense92 are also applied to respectivezero crossing detectors100,102. These produce a pulse whenever the respective signals cross zero. The pulse fromdetector100 is applied to phasedetection logic104, which can include a counter that is started by that signal. The pulse fromdetector102 is likewise applied tologic circuit104 and can be used to stop the counter. As a result, the count which is reached by the counter is a digital code online104, which represents the difference in phase between the current and voltage. The size of this phase difference is also an indication of resonance. These signals can be used as part of a phase lock loop that cause the generator frequency to lock onto resonance, e.g., by comparing the phase delta to a phase set point in the DSP in order to generate a frequency signal to a direct digital synthesis (DDS)circuit128 that drives the push-pull amplifier78.
• Further, the impedance and phase values can be used as indicated above in a diagnosis phase of operation to detect if the blade is loose. In such a case the DSP does not seek to establish phase lock at resonance, but rather drives the hand piece at particular frequencies and measures the impedance and phase to determine if the blade is tight.
• The transducer drive circuitry ofpower transformer86 shown inFIG. 3B may be represented by an equivalent electrical circuit having components Co, Ls, Cs, and Rs form a transducer equivalent circuit Tequiv, where Co is a shunt capacitance and represents the electrical capacitance of the piezoelectric elements of thepiezoelectric transducer36 shown inFIG. 2.
• Ls, Cs and Rs form an electrical equivalent of the overall mechanical system and collectively represent the mechanical branch. Ls is the effective mass of the system, Cs is the effective compliance and Rs represents mechanical losses associated with friction, internal material dissipation and/or the power delivered to the tissue.
• An Inductor Lt is also provided and is matched to the shunt capacitance Co at the resonance of the ultrasonic system, such as approximately 55.5 kHz. Hence, Lt and Co electrically cancel each other at the resonant frequency. As a result, all of the drive current will flow through the mechanical branch. This helps to ensure that the ultrasonic excursion of the transducer is primarily proportional to the drive current.
• Two resistors Rp/2 sum in series to a resistance of Rp. This resistance helps to establish an upper limit of the overall impedance of the output circuit, and also establishes an upper limit for the drive voltage. In preferred embodiments, Rp is a relatively large resistance. At resonance, the parallel combination of Rp and Rs is effectively Rs, because Rs is much smaller then Rp, even when coagulating and cutting tissue.
• A series combination of capacitors Cv1 and Cv2 is used to form a voltage divider. Together these capacitors reduce the high voltage that typically drives the transducer to a level which is appropriate for signal processing by integrated circuits (not shown). A transformer Vt couples the reduced voltage to the feedback circuitry (voltage sense92 ofFIG. 3B) and also provides isolation between the drive circuitry and the other circuitry of the generator.
• A small voltage drop is provided across the series combination of resistors R3 and R4. In the preferred embodiment, the series combination is a relatively low resistance in the order of ohms. The voltage drop across R3 and R4 is proportional to the drive current. This voltage is provided to the feedback circuitry (current sense88 ofFIG. 3B) through a transformer IT, which also isolates the drive circuitry from the rest of the circuitry of the generator. This signal represents current in the control algorithms implemented in the generator.
• A pair of resistors R1, R2 is used to establish a minimum impedance level to the control circuitry for use in the control algorithms. The resistance is divided between two output arms Vout1, Vout2 of the power transformer to help mitigate electromagnetic radiation and leakage current.
• FIG. 4 is a diagram that illustrates anon-volatile memory400 in the sheath of the end-effector according to the invention. Thememory400 is advantageously provided in the sheath of the end-effector for reducing unneeded complexity in electrical isolation configurations which contribute to increases in costs, complications in cross-talk noise issues, and adversely affects the ergonomic performance of thehand piece30. By placing thememory400 in the sheath of the end-effector, adequate electrical isolation of the circuitry in thememory400 from thehand piece30, the human operator thereof, and the patient is readily achieved. Also, the number of wires in cable20 can be reduced.
• FIG. 4B is a diagram that illustrates anon-volatile memory303 in the grip portion ofshears300 according to the invention. Alternate or additional locations for memory are also shown asmemory301 located in the mount portion and/ormemory302 in the grip portion ofshears300. Theshears300 is attached tohandpiece310. Thecontacts304 and305 are resident within, outside, or embedded into the shears mount or grip vicinity and are wired to the memory. These contacts make connection with corresponding contacts within or on the handpiece to permit generator communications through the handpiece to the memory in the shears.
• FIG. 5 is a flow diagram that illustrates the operation of thememory400 as a proprietary lockout for preventing inappropriate use of thehand piece30. Thememory400 can be utilized to prevent unauthorized, unintentional or inadvertent use of the end effector or blade or shears with thegenerator console10. Inappropriate usage includes hazardous use, poor operational usage, or non-compatible use or unapproved use with thegenerator console10.
• FIG. 5A is another flow diagram that illustrates the operation of thememory400 or301,302, or303. In this particular embodiment of the method according to the invention, the memory in the blade or shears is periodically queried independent of handpiece activation, for example, at intervals of 10 seconds. This particular embodiment allows generally immediate detection of blade change and generally immediate detection of blade type attached. Such information can contribute to diagnostic functionalities that monitor handpiece temperature, temperature rate of change, and other parameters to adjust triggers and thresholds and allow the display of blade type and related parameters in the generator console in advance of the next activation.
• Instep501, thehandpiece30 is activated, e.g., by pressing thebutton18 on thegenerator console10 for hand activation of the handpiece. Instep503, thegenerator console10 then reads thememory400. Instep505, it is determined whether a proprietary data string is present in thememory400. The data string, input into the non-volatile memory for all authorized hand pieces, is in digital or analog form. The data string can also be a musical, speech, or sound effect in either digital or analog format. Having a proper proprietary string in thememory400 means that the use of the hand piece with thegenerator console10 is authorized or authenticated. If the data string is present in thememory400, thehand piece30 is enabled or activated by the generator console10 (step507). If the data string is not present in thememory400 or an improper data string is present, thehand piece30 is not enabled (step509), and an error message appears on thedisplay device12 at thegenerator console10 indicating unauthorized use.
• In a specific embodiment according to the invention, when thegenerator console10 reads the data string in thememory400, a cyclical redundancy check (CRC) is used to detect read errors and/or to authenticate the hand piece. A CRC is a mathematical method that permits errors in long runs of data to be detected with a very high degree of accuracy. Before data is transmitted over a phone, for example, the sender can compute a 32-bit CRC value from the data's contents. If the receiver computes a different CRC value, then the data was corrupted during transmission. Matching CRC values confirms with near certainty that the data was transmitted intact.
• According to the CRC authentication technique, the entire block of data is treated as a long binary number which is divided by a conveniently small number and the remainder is used as the check value that is tacked onto the end of the data block. Choosing a prime number as the divisor provides excellent error detection. The number representing the complete block (main data plus CRC value) is always a multiple of the original divisor, so using the same divisor always results in a new remainder of zero. This means that the same division process can be used to check incoming data as is used to generate the CRC value for outgoing data. At the transmitter, the remainder is (usually) non-zero and is sent immediately after the real data. At the receiver, the entire data block is checked and if the remainder is zero, then the data transmission is confirmed.
• An 8-bit CRC generator can be implemented in hardware, software or firmware in thememory400. Firmware is the controller software for a hardware device, which can be written or programmed in a non-volatile memory (e.g., memory400) such as an EEPROM or flash ROM (read only memory). The firmware can be updated with a flash program for detection and correction of bugs in the controller software or to improve performance of the hardware device. An exemplary EEPROM used in implementing the invention is the 256-bit DS2430A 1 wire device organized as one page of 32 bytes for random access with a 64-bit one-time programmable application register, which is a part of the iButtonJ family of hardware devices commercially available from Dallas SemiconductorJ.
• The following exemplary software code in AC® which is a commonly used programming language in the art, illustrates how the 8-bit CRC is calculated when reading the data string in thememory400 for authenticating use of the hand piece with thegenerator console10. Prior to the calculation of the CRC of a block of data, the 8-bit CRC is first initialized to zero. When thegenerator console10 reads the 8 bytes of the data string in thememory400, an 8-bit CRC is calculated for each of the 8 bytes of the data string. If the resultant 8-bit CRC is equal to zero, then the use of the hand piece with thegenerator console10 is authenticated, and the hand piece is enabled. If the resultant 8-bit CRC is not equal to zero, then the use of the hand piece with thegenerator console10 is not authenticated, the hand piece not enabled, and an error message appears on thedisplay device12 at thegenerator console10 indicating unauthorized use.

• /*
  FUNCTION

  mlan_CRC8

  PASSED PARAMETERS

  	>data= - data byte to calculate the 8 bit crc from
  	>crc8= - the current CRC.

  RETURN

  	the updated 8 bit CRC.
  	/*
  	static uchar crc_table[ ] =
  	{

  	0, 94, 188,226, 97, 63,221, 131, 194,156,126, 32,163,253, 31, 65
  	157,195, 33,127,252,162, 64, 30, 95, 1,227, 189, 62, 96,130,220,
  	190,224, 2, 92,223,129, 99, 61,124, 34, 192,158, 29, 67,161,255,
  	70, 24,250,164, 39,121,155,197,132,218 56,102,229,187, 89, 7,
  	219,133,103,57,186,228, 6, 88, 25, 71, 165,251,120, 38,196,154,
  	101, 59,217,135, 4, 90,184,230,167,249, 27, 69,198,152,122,36,
  	248,166, 68, 26,153,199, 37,123, 58,100,134,216, 91, 5,231,185
  	140,210, 48,110,237,179, 81, 15, 78, 16,242,172, 47,113,147,205,
  	17, 79,173,243,112, 46,204,146,211, 141,111, 49,178,236, 14, 80,
  	175,241, 19, 77,206,144,114, 44,109, 51,209,143, 12, 82,176,238,
  	50,108,142,208, 83, 13,239,177,240,174, 76, 18,145,207, 45,115,
  	202,148,118, 40,171,245, 23, 73, 8, 86,180,234,105, 55,213,139,
  	87, 9,235,181, 54,104,138,212,149,203, 41,119,244,170, 72, 22,
  	233,183, 85, 11,136,214, 52,106, 43,117,151,201, 74, 20,246,168,
  	116, 42,200,150, 21, 75,169,247,182,232, 10, 84,215,137,107,53

  };

  uchar mlan_CRC8(uchar data, uchar crc8)

  {

  return crc_table[crc8 {circumflex over ( )} data];

  }

• Another exemplary software code is listed below for calculating a 16-bit CRC for thememory400. Similarly, prior to the calculation of the CRC of a block of data, the 16-bit CRC is first initialized to zero. When thegenerator console10 reads the 16 bytes of the data string in thememory400, an 16-bit CRC is calculated for each of bytes1 through30 of the data string, and the results are stored inbytes31 and32. After comparing the results, if the resultant CRC is equal to zero, then the use of the hand piece with thegenerator console10 is authenticated, and the hand piece is enabled. If the resultant CRC is not equal to zero, then the use of the hand piece with thegenerator console10 is not authenticated, the hand piece not enabled, and an error message appears on thedisplay device12 at thegenerator console10 indicating unauthorized use.

• /*
  FUNCTION

  mlan_CRC16

  PASSED PARAMETERS

  	>data= - current word to add into the CRC
  	>crc16= - the current value of the 16 bit CRC

  RETURN

  new value of the 16 bit CRC

  /*

  static int oddparity[16] = {0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0};

  uint mlan-CRC16(uint data, uint crc16)

  {

  	data = (data {circumflex over ( )} (crc16 & 0xff)) & 0xff;
  	crc16>>=8;

  if (oddparity[data &0xf] {circumflex over ( )} oddparity[data >> 4])

  crc16 {circumflex over ( )} =0xc001;

  data <<=6;

  crc16 {circumflex over ( )} = data;

  data <<= 1;

  crc16 {circumflex over ( )} = data;

  return crc16;

  }

• Furthermore, the data string in thememory400 can be an encrypted code which, when decoded by a corresponding encryption algorithm resident at thegenerator console10, provides a responding data pattern that serves to authenticate proper usage of the hand piece with the console. Encryption is achieved with algorithms that use a computer “key” to encrypt and decrypt messages by turning text or other data into an unrecognizable digital form and then by restoring it to its original form. The longer the “key,” the more computing is required to crack the code. To decipher an encrypted message by brute force, one would need to try every possible key. Computer keys are made of “bits” of information of various length. For instance, an 8-bit key has 256 (2 to the eighth power) possible values. A 56-bit key creates 72 quadrillion possible combinations. If the key is 128 bits long, or the equivalent of a 16-character message on a personal computer, a brute-force attack would be 4.7 sextillion (4,700,000,000,000,000,000,000) times more difficult than cracking a 56-bit key. With encryption, unauthorized use of the hand piece with thegenerator console10 is generally prevented, with a rare possibility of the encrypted code being deciphered for unauthenticated use.
• A unique identification (ID) number is registered and stored in the memory (e.g.,memory400 or301) for every hand piece and blade and shears manufactured which is compatible for use with thegenerator console10, where identity is assured since no two hand pieces or blades or shears are alike. In a specific embodiment according to the invention, thememory400 is the DS2430A 1 wire EEPROM device, commercially available from DALLAS SEMICONDUCTORJ, which stores a factory-lasered and tested 64-bit ID number for each hand piece manufactured. The ID number can be a model or model family number, in addition to being a unique serial number ID for each individual hand piece. This allows thegenerator console10 to acknowledge its compatibility and useability therewith, without requiring a list of serial numbers for that model or model family. Foundry lock data in a hardware format and protocol is stored in thememory400 to ensure compatibility with other products of generally the same communications protocol, e.g., the products of the MICROLANJ protocol commercially available from DALLAS SEMICONDUCTORJ. This advantageously provides scalability for providing a system with additional surgical devices on a local area network (LAN) operated on generally the same communications protocol.
• FIG. 6 andFIG. 7 are flow diagrams that illustrate the operation of thememory400 or301 according to the invention for error prevention when using thehandpiece30 with thegenerator console10. To prevent errors in operating thehandpiece30, thememory400 or301 can store certain diagnostic information which thegenerator console10 can utilize in determining whether the operation of thehandpiece30 should be handicapped or disabled. For instance, thememory400 or301 can store information such as limits on the time that the hand piece is active, the number of activations within a time period, the number of defective blades used, operating temperature, allowable temperature rate of change, and any other performance characteristics such as, e.g., those listed in Table 1. Those skilled in the art can appreciate that other error prevention, diagnostic and performance characteristics can be stored inmemory400 or301. Exemplary performance characteristics that can be stored inmemory400 or301 (as shown in Table 1) include surgical device type information and revision data (row 1 in Table 1), current set point (row 2), transducer capacitance (row 3), cable capacitance (row 4), phase margin for the handpiece equipped with a test tip or end-effector (row 5), resonant frequency (row 6), remaining operating procedures (row 7), lower bound or threshold on operating frequency (row 8, upper bound or threshold on operating frequency (row 9), maximum output power (row 10), power control information and authorization (row 11, handpiece impedance (row 12), total on-time information at specific power levels (rows 13 and 14), handpiece enable/disable diagnostics information (row 15), handpiece error codes (row 16), temperature range and change data (rows 17, 18 and 19), current excess load limit (row 20), high impedance fault limit (row 21), and cyclical redundancy check (CRC) data (row 22). Other characteristics such as blade dampening behavior can also be stored in the memory.
• Moreover, thememory400 can store user-specific data such as user name, internal tracking number, calibration schedule, and custom output performance specifications. The user-specific data can be manipulated or programmed through thegenerator console10 or initialized at the time the end effector is made at the factory. In addition, the memory can be used in conjunction of specialized instruments such as cartery or self-heating devices, homogenizers and liquifiers.

• TABLE 1
  1	Bits 1-3: Device Type
  	Bits 4-8: Revision
  2	Current set point
  	Isetpoint
  3	Transducer Capacitance
  	Co
  4	Cable Capacitance
  	Cc
  5	Phase margin with test tip
  	Pm0
  6	Resonance frequency
  	fro
  7	Allowed Procedures Remaining
  8	Lower bound on seek/lock frequency
  	(offset from fro)
  	flower bound
  9	Upper bound on seek/lock frequency
  	(offset from fro)
  	fupper bound
  10	Maximum output power @ level 5Wmax,
  11	Bit 1 Backside power curve control
  	variable:
  	Capped Power = 1; Descending power = 0
  	Bit 2; Single cap at all levels = 1,
  	Different cap for each power level = 0
  	Bit 3: Hand piece Authorized Activation
  	Flag.
  	Bits 4-8: Unused
  12	Hand piece Impedance, Re |Z|
  13	Total On-Time @ level 5
  14	Total on-Time @ level <5
  15	Hand piece Diagnostics Enable/Disable
  	Flags byte no. 1
  	Hand piece Diagnostics Enable/Disable
  	Flags byte no. 2
  16	Hand piece error code 1 (newest)
  	Hand piece error code 2
  	Hand piece error code 3
  	Hand piece error code 4
  	Hand piece error code 5 (oldest)
  17	ΔCoOverTemp Entry
  18	ΔCoOver Temp Exit
  19	CoMax Rate of Change
  20	Current Excessive Load Limit
  21	High Impedance with test tip fault limit
  22	Data CRC

• FIG. 6A andFIG. 7A are flow diagrams that illustrate the alerting of an end user to issues or difficulties triggered by parameters stored in the blade/shears memory. Rather than handicapping or reducing functional capabilities, which can interrupt or degrade the surgeon=s ability to perform the procedure, this particular embodiment of the method according to the invention allows the end user to manually halt use at a convenient point in context with the nature of the alarm and the surgical work immediately at hand.
• According to a specific embodiment of the invention, once thehandpiece30 is activated for use, thegenerator console10 reads thememory400 or301 (step601) for the diagnostic information. Instep603, thegenerator console10 determines whether the temperature of thehandpiece30 is over the handicap limit stored in thememory400. If so, thegenerator console10 then instructs thehandpiece30 to operate in the handicap mode (step605), e.g., operating below a certain speed or vibrational frequency or in a limited mode such as coagulation or cutting in order to avoid overheating. If not, the flow control goes to step607, where thegenerator console10 determines whether the temperature of thehandpiece30 is over the disable limit stored in thememory400. If so, thegenerator console10 disables the handpiece30 (step609). If not, the flow control goes to step611, where thegenerator console10 determines whether the number of defective blades found within a time period of operating thehandpiece30 has exceeded the handicap limit stored in thememory400. If so, thegenerator console10 then instructs thehand piece30 to operate in the handicap mode (step613), e.g., operating below a certain speed or vibrational frequency or in a limited mode such as coagulation or cutting in order to decrease the incidence of causing theblade32 to become defective. The handicap mode instep613 is not necessarily the same as the handicap mode instep605, depending on the optimal mode for operating thehandpiece30 under the circumstances with respect tosteps603 and611.
• If the number of defective blades found has not exceeded the handicap limit, the flow control is directed to step615, where thegenerator console10 determines whether the number of defective blades found within a time period has exceeded the disable limit stored in thememory400. If so, thegenerator console10 disables the handpiece30 (step609). If not, the control flow is directed, via step A, to step617, where thegenerator console10 determines whether the time thehandpiece30 has been active has exceeded the handicap limit stored inmemory400. If so, thegenerator console10 instructs thehandpiece30 to operate in a handicap mode, e.g., operating below a certain speed or vibrational frequency or in a limited mode such as coagulation or cutting. The handicap mode instep619 is not necessarily the same as the handicap mode insteps605 or613, depending on the optimal mode for operating thehandpiece30 under the circumstances with respect tosteps603,611 and617.
• If the time thehandpiece30 has been active has not exceeded the handicap limit, the flow control is directed to step621, where thegenerator console10 determines whether the time the hand piece has been active has exceeded the disable limit stored in thememory400. If so, the control flow is directed, via step B, to step609 where thegenerator console10 disables thehandpiece30. If not, the control flow goes to step623, where thegenerator console10 determines whether the number of activations for thehandpiece30 within a time period has exceeded the handicap limit stored inmemory400. If so, thegenerator console10 instructs thehandpiece30 to operate in a handicap mode (step625), e.g., operating below a certain speed or vibrational frequency or in a limited mode such as coagulation or cutting. The handicap mode instep625 is not necessarily the same as the handicap mode insteps605,613 or619, depending on the optimal mode for operating thehandpiece30 under the circumstances with respect tosteps603,611,617 and623.
• If the number of activations for thehandpiece30 within a time period has not exceeded the handicap limit, the flow control is directed to step627, where thegenerator console10 determines whether the number of activations for thehandpiece30 within a time period has exceeded the disable limit stored in thememory400. If so, the control flow is directed, via step B, to step609 where thegenerator console10 disables thehandpiece30. If not, the control flow is directed, via step C, to step601 from which the process step according to this particular embodiment of the invention are repeated until thehandpiece30 is caused to be disabled.
• The disable limits and the handicap limits described herein with respect toFIG. 6 andFIG. 7 may be of substantively different criteria for thegenerator console10 to determine the operational mode of thehandpiece30. Thememory400 may be re-initialized for different disable or handicap limits for varied operational conditions of thehandpiece30. Thegenerator console10 may likewise be re-initialized to operate on varied criteria for controlling the operational mode of thehandpiece30 based on the information stored in thememory400.
• FIG. 8 is a flow diagram that illustrates the operation of thememory400 according to the invention for reprogramming or upgrading thegenerator console10 using thehandpiece30. Instep801, thegenerator console10 performs diagnostic tests on the functions of the console. It is determined instep803 whether any functions are deemed inadequate, e.g., functions that need to be altered, disabled or added. For example, the error prevention functions described herein with respect toFIG. 6 andFIG. 7 may need to be added, or the handicap limits and operational modes may need to be re-initialized. If it is determined that certain functions are inadequate, the flow control is directed to step807. Instep807, thegenerator console10 reads thememory400 of thehandpiece30 where the reprogram code has been stored instep800. Using the reprogram code read from thememory400, the functions of thegenerator console10 is reprogrammed.
• If it is determined instep803 that the functions of thegenerator console10 are adequate or the memory has a newer version of the program, then thegenerator console10 has the flow control directed to step805. It is determined instep805 whether an upgrade is needed for thegenerator console10. If so, the flow control is directed to step807. Instep807, thegenerator console10 reads thememory400 of thehandpiece30 where the reprogram or upgrade code has been stored instep800. Using the reprogram or upgrade code read from thememory400, the functions of thegenerator console10 is reprogrammed and upgraded. For example, if thegenerator console10 is experiencing operational difficulties with a specific generation or version of the hand piece, an upgrade from thememory400 instructs thegenerator console10 to allow its use with only newer versions or generations of the hand piece. Thememory400 can also store information including the manufacture date, design revision, manufacturing code, lot code or other manufacture-related information for a specific grouping of hand pieces according to generation or version having operational difficulties or defectiveness, from which thegenerator console10 can be reprogrammed or upgraded to refuse activation for use with such hand pieces.
• In addition to storing reprogram or upgrade code, thememory400 can also store performance criteria for operating thehandpiece30 with thegenerator console10. For example, thememory400 can store energy level information such as a maximum energy level for driving theparticular handpiece30, because, e.g., a relatively small hand piece may not be able to be driven, in terms of energy levels, as intensely as a relatively large hand piece for large-scale surgical procedures. Information correlating the energy levels for driving thehandpiece30 and the corresponding output displacement can also be stored in thememory400. Thegenerator console10 reads the energy level information stored in thememory400 and drives thehandpiece30 according to the corresponding output displacement. In addition to energy level information, driving signal characteristics, such as types of amplitude modulation, can be stored in thememory400. Using the information stored in thememory400, thegenerator console10 and thehandpiece30 can perform the error prevention described herein with respect toFIG. 6 andFIG. 7, and the reprogramming or upgrade of thegenerator console10 described herein with respect toFIG. 8.
• As described herein with respect toFIG. 2 andFIG. 3 and in the related U.S. application Ser. No. 09/693,621 and incorporated herein by reference, the parts of thehandpiece30 in operational mode are designed, as a whole, to oscillate at generally the same resonant frequency, where the elements of thehandpiece30 are tuned so that the resulting length of each such element is one-half wavelength. Microprocessor orDSP60, using a phase correction algorithm, controls the frequency at which the parts of thehandpiece30 oscillate. Upon activation of thehandpiece30, the oscillating frequency is set at a startup value or nominal resonant frequency such as 50 kHz which is stored in thememory400 of thehandpiece30. A sweep of a frequency range between a start sweep point and a stop sweep point, whose values are also stored in thememory400, is effected under the control of theDSP60 until the detection of a change in impedance which indicates the approach to the resonant frequency. The change in impedance refers to the impedance of, e.g., a parallel equivalent circuit for mathematically modeling the algorithm for controlling the operation of thehandpiece30 as described in the related U.S. application Ser. No. 09/693,621. Having obtained the resonant frequency, the parts of thehandpiece30 are caused to oscillate at that frequency.
• FIG. 9 is a flow diagram that illustrates the operation of thehandpiece30 according to the invention at a resonant frequency using information stored in thememory400. Once thehandpiece30 is activated (step901), thegenerator console10 reads thememory400 of the handpiece30 (step903) and retrieves the information needed for operating thehandpiece30 at the resonant frequency, including the nominal resonant frequency, a frequency range delimited by a start sweep point and a stop sweep point (step905). A frequency sweep in that frequency range is effected under the control of the DSP60 (step907). Detection of the resonant frequency is effected instep909. If the resonant frequency has not yet been detected, the control flow reverts back to step907 where the frequency sweep is continued. Upon detection of the resonant frequency, the control flow is directed to step911 where the parts of thehandpiece30 are caused to oscillate at that resonant frequency.
• FIG. 10 is a diagram that illustrates an alternative embodiment of the operation of thehandpiece30 according to the invention at a resonant frequency using information stored in thememory400. Instead of storing the start and stop sweep points of a frequency range for the frequency sweep, thememory400 or301 stores the nominal resonant frequency and a bias amount. Thegenerator console10 calculates the start and stop sweep points by subtracting and adding the bias amount from the nominal resonant frequency, respectively. A margin, which is a relatively small amount beyond bias, is tacked on to the bias amount to respectively reach the start and stop sweep points of the frequency range in which the frequency sweep for seeking a resonant frequency is conducted. Once the resonant frequency is found, the parts of thehandpiece30 are caused to oscillate at that resonant frequency.
• UsingFIG. 9, the operation of thehandpiece30 according to the invention at a resonant frequency using information stored in thememory400 or301 is illustrated in accordance with this particular embodiment. Once thehandpiece30 is activated (step901), thegenerator console10 reads thememory400 of the handpiece30 (step903) and retrieves the information needed for operating thehandpiece30 at the resonant frequency, including the nominal resonant frequency, the bias amount and the margin amount (step905), from which a frequency range is accordingly calculated as described herein with respect toFIG. 10. Thegenerator console10 calculates the start and stop sweep points by subtracting and adding the bias amount from the nominal resonant frequency, respectively. The margin amount, which is a relatively small amount beyond bias, is tacked on to the bias amount to respectively reach the start and stop sweep points of the frequency range in which the frequency sweep for seeking a resonant frequency is conducted. The frequency sweep in that frequency range is effected under the control of the DSP60 (step907). Detection of the resonant frequency is effected instep909. If the resonant frequency has not yet been detected, the control flow reverts back to step907 where the frequency sweep is continued. Upon detection of the resonant frequency, the control flow is directed to step911 where the parts of thehandpiece30 are caused to oscillate at that resonant frequency.
• Thememory400 for an ultrasonicsurgical handpiece30 according to the invention is located in the sheath of the end-effector. Alternately, the memory device,301,302, or303, can be located in the grip, mount, or handle portion of a shears or shears-like device or other device. Thememory device400 can also be located in one or more locations, including the electrical connector, within the housing of thehandpiece30, or at an in-line location in the cable20. In addition to being an EEPROM, thememory400 be one or a combination of a Read Only Memory (ROM), Erasable Programmable Read Only Memory (EPROM), Random Access Memory (RAM) or any other volatile memory which is powered by a cell, battery, or capacitor such as a super capacitor. Thememory400 can also be a Programmable Array Logic (PAL), Programmable Logic Array (PLA), analog serial storage device, sound storage integrated circuit or similar device, or a memory device in conjunction with a numeric manipulation device such as a microprocessor for the purpose of encryption. Furthermore, thememory400 can be disposed in a non-hand piece device which can be plugged into thehandpiece30 in substitution of the end-effector.
• In yet another embodiment, the blade or shears or end-effector communicates electrically with the switch adaptor or adaptor rather than directly with the Handpiece. The switch adaptor conveys the signal directly or through intermediate processing to the handpiece, acting as a bridge. An example is shown inFIG. 14 whereswitch adaptor2005 has contact means to thehandpiece2000 and to theblade memory contacts2004. This construction is particularly helpful when the adaptor is a switch adaptor and there is insufficient room for passage of wiring from the blade memory directly to the handpiece itself.
• In another embodiment, the memory communicates with the handpiece or with the adaptor via electromagnetic coupling instead of a direct electrical connection. In this method, the memory and support electronics is connected to a coil, all of which is mounted in or on the blade or shears or end-effector. An example is shown inFIG. 15, where acoil1001 is located in the handpiece or the switch adaptor or the adaptor that is positioned in relatively close proximity to thememory coil1002 located on or in the blade or shears. A circuit in the generator console drives and reads thecoil1001. Thereby, the memory is read and/or written to by the generator console without the use of direct wire connections. This method is advantageous over direct electrical contacts since it reduces complexity of end-effector fabrication. It also allows for reading and/or writing to memory of blades or shears or other end-effectors that are packaged in sterile packages which cannot be conveniently opened—yet the data in that memory needs to be known, such as number of uses previously encountered or to permit software upgrades in without opening the sterile package.
• FIGS. 11,12 and13, respectively using an isometric view, side view and side section view, illustrate a particular embodiment of the ultrasonic surgical hand piece with a non-volatile memory (such as an EEPROM) in the end-effector in accordance with the invention.
• TheEEPROM400 is embedded within theplastic handpiece30 or housing of theultrasonic blade32. TheEEPROM400 has two terminations with the power/data contact1120 and theground contact1110. TheEEPROM400 is embedded within thehandpiece30 using an insert or second-shot molding process. TheEEPROM400 is mounted or positioned so that theground contact1110, which is in contact with theblade32, can close the circuit with the transducer36 (FIG. 4). The other termination via the power/data contact1120 is molded into a position that allows wire communication of power or data from thehandpiece30 to theEEPROM400.
• Referring toFIG. 13 in particular, included with theground contact1110 is ametal shim1140 that is wired to theEEPROM400. Theground contact1110, by manipulating themetal shim1140, can close the circuit with the external contact of theblade32, which is isolated from thetransducer36. Also included with the power/data contact1120 is anEEPROM wire1130 connecting theEEPROM400 to thecontact1120. The contact between theEEPROM40 and thehandpiece30 can be a momentary one that is long enough for determining and authenticating the identification of theblade32.
• Although the invention has been particularly shown and described in detail with reference to the preferred embodiments thereof, the embodiments are not intended to be exhaustive or to limit the invention to the precise forms disclosed herein. It will be understood by those skilled in the art that many modifications in form and detail may be made without departing from the spirit and scope of the invention. Similarly, any process steps described herein may be interchangeable with other steps to achieve substantially the same result. All such modifications are intended to be encompassed within the scope of the invention, which is defined by the following claims and their equivalents.

Claims (46)

1. A system for implementing surgical procedures comprising:

an ultrasonic surgical hand piece having an end-effector with a sheath wherein the end-effector is selected from the group consisting of a blade, shears, scissors and forceps;

a generator console for controlling the hand piece, wherein the console sends a drive current to drive the hand piece which imparts ultrasonic longitudinal movement to the blade; and

a memory disposed in the sheath of the end-effector, wherein the console reads information stored in the memory to determine whether a copyrighted data string is present;

wherein the hand piece is authenticated for use with the console if the data string is present.

2. A system for implementing surgical procedures comprising: an ultrasonic surgical handpiece having an end-effector,

a generator console for controlling the hand piece wherein the console sends a drive current to drive the hand piece which imparts ultrasonic longitudinal movement to the end-effector; and

a memory disposed in a portion of the end-effector selected from the group consisting of a grip, handle and mounting, wherein the console reads information stored in the memory to determine whether a data string is present;

wherein the handpiece is authenticated for use with the console if the data string is present.

3. A system for implementing surgical procedures comprising:

an ultrasonic surgical handpiece having an end-effector;

a generator console for controlling the handpiece, wherein the console sends a drive current to drive the handpiece which imparts ultrasonic longitudinal movement to the end-effector; and

a memory disposed with a blade mounting hub of the end-effector, wherein the console reads information stored in the memory to determine whether a data string is present, wherein the handpiece is authenticated for use with the console if the data string is present.

4. The system ofclaim 2 wherein the data string is copyrighted.

5. The system ofclaim 3 wherein the data string is copyrighted.

6. The system ofclaim 2 wherein the memory stores an alarm limit and a disable limit, wherein the console instructs the hand piece to operate in an alarm mode if temperature of the hand piece exceeds the alarm limit, and the console disables the hand piece if the temperature of the hand piece exceeds the disable limit.

7. The system ofclaim 3 wherein the memory stores an alarm limit and a disable limit, wherein the console instructs the hand piece to operate in an alarm mode if temperature of the hand piece exceeds the alarm limit, and the console disables the hand piece if the temperature of the hand piece exceeds the disable limit.

8. The system ofclaim 1 wherein the memory stores an alarm limit and a disable limit, wherein the console instructs the hand piece to operate in an alarm mode if temperature of the hand piece exceeds the alarm limit, and the console disables the hand piece if the temperature of the hand piece exceeds the disable limit.

9. The system for implementing surgical procedures comprising:

an ultrasonic surgical handpiece having a detachable end-effector;

a generator console for controlling the handpiece, wherein the console sends a drive current to drive the handpiece which imparts ultrasonic longitudinal movement to the end-effector; and

a memory disposed with the end-effector, wherein the console writes historical usage and diagnostic information and configuration information into the memory;

wherein the diagnostic information are selected from the group consisting of number of activations, duration of activations, number of uses with substantial time between use, diagnostic error codes, enable use, disable use, serial number of the generator console, and serial number of the handpiece.

10. A system for implementing surgical procedures comprising:

an ultrasonic surgical handpiece having a detachable end-effector selected from the group consisting of a blade and shears;

a generator console having a digital signal processor (DSP) for controlling the handpiece, wherein the console sends a drive current to drive the handpiece which imparts ultrasonic longitudinal movement to the end-effector; and a memory disposed in the end-effector, wherein the console reads the memory and determines if the end-effector has been disabled for disabling the console from driving the end-effector.

11. The system ofclaim 10 wherein the handpiece further comprises an alarm which sounds to notify a potentially compromised state.

12. A system for implementing surgical procedures comprising:

an ultrasonic surgical handpiece having an end-effector selected from the group consisting of a blade and shears;

a generator console having a digital signal processor for controlling the handpiece, wherein the console sends a drive current to drive the handpiece which imparts ultrasonic longitudinal movement to the end-effector; and

a memory disposed with the end-effector, wherein the console reads information stored in the memory and displays the information and an interpretation of the information on the console display.

13. The system ofclaim 12 further comprising a switch adaptor wherein the memory communicates electrically with the switch adaptor through direct contacts;

wherein the switch adaptor conveys the information to the handpiece

14. The system ofclaim 12 further compromising an adaptor wherein the memory communicates electrically with the adaptor through electromagnetic signal coupling;

wherein the adaptor conveys the information via the electromagnetic signal coupling to the handpiece.

15. The system ofclaim 12 further comprising a switch adaptor wherein the memory communicates electrically with the handpiece through electromagnetic signal coupling;

wherein the switch adaptor conveys the information via the electromagnetic signal coupling to the handpiece.

16. The system ofclaim 12 further comprising a switch adaptor wherein the adaptor electrically communicates with the handpiece through direct contacts.

17. The system ofclaim 12 wherein the memory is used in conjunction of specialized instruments selected from the group consisting of cartery devices, homogenizers and liquifiers.

18. The system ofclaim 12 wherein the memory is used to determine compatibility with specific types of the handpiece and to block use of the handpiece if incompatibility with the handpiece is determined.

19. The system ofclaim 1 wherein the hand piece is authenticated for use with the console using cyclical redundancy check (CRC) implemented in a firmware programmed in the memory.

20. The system ofclaim 1 wherein the data string is an encrypted code, and the hand piece is authenticated for use with the console by decoding a corresponding encryption algorithm in the console and providing a responding data pattern.

21. The system ofclaim 1 wherein the memory stores a handicap limit and a disable limit, wherein the console instructs the hand piece to operate in a handicap mode if temperature of the hand piece exceeds the handicap limit, and the console disables the hand piece if the temperature of the hand piece exceeds the disable limit.

22. The system ofclaim 1 wherein the memory stores a handicap limit and a disable limit, wherein the console instructs the hand piece to operate in a handicap mode if a number of defective blades found in a time period of operating the hand piece exceeds the handicap limit, and the console disables the hand piece if the number of defective blades found in the time period exceeds the disable limit.

23. The system ofclaim 1 wherein the memory stores a handicap limit and a disable limit, wherein the console instructs the hand piece to operate in a handicap mode if time the hand piece has been active exceeds the handicap limit, and the console disables the hand piece if the time the hand piece has been active exceeds the disable limit.

24. The system ofclaim 1 wherein the memory stores a handicap limit and a disable limit, wherein the console instructs the hand piece to operate in a handicap mode if number of activations for the hand piece within a time period exceeds the handicap limit, and the console disables the hand piece if the number of activations for the hand piece within the time period exceeds the disable limit.

25. The system ofclaim 21 wherein the handicap limit and the disable limit are re-initialized based on varied operational conditions of the hand piece.

26. The system ofclaim 1 wherein the console is reprogrammed by reading a reprogram code stored in the memory if it is determined that a reprogram of the console is needed, and the console is upgraded by reading an upgrade code stored in the memory if it is determined that an upgrade of the console is needed.

27. The system ofclaim 26 wherein the console reads the reprogram code and the upgrade code from a non-volatile memory of a non-hand piece device which is plugged into the hand piece in substitution of the end-effector.

28. The system ofclaim 1 wherein the information stored in the memory correlates energy level information and corresponding output displacement, wherein the console reads the energy level information and drives the hand piece according to the corresponding output displacement.

29. The system ofclaim 1 wherein the information stored in the memory includes a nominal resonant frequency, a start sweep point and a stop sweep point delimiting a frequency range, wherein a frequency sweep in effect under control of the console in the frequency range for detecting a resonant frequency for operating the hand piece.

30. The system ofclaim 1 wherein the information stored in the memory includes a nominal resonant frequency, a bias amount and a margin amount from which a frequency range is calculated, wherein a frequency sweep in effect under control of the console in the frequency range for detecting a resonant frequency for operating the hand piece.

31. The system ofclaim 1 wherein the memory consists of an Electrically Erasable Programmable Read Only Memory (EEPROM), Read Only Memory (ROM), Erasable Programmable Read Only Memory (EPROM), Random Access Memory (RAM), Programmable Array Logic (PAL), Programmable Logic Array (PLA), analog serial storage device, sound storage integrated circuit, a memory device in conjunction with a numeric manipulation device including a microprocessor for the purpose of encryption, volatile memory which is powered by a device consisting of a cell, battery and capacitor.

32. A method for implementing surgical procedures in a system including an ultrasonic surgical hand piece having a end-effector with a sheath, a console for controlling the hand piece, and a memory disposed in the sheath of the end-effector, the method comprising the steps of:

reading information stored in the memory;

determining whether a copyrighted data string is present in the memory;

authenticating use of the hand piece with the console if the data string is present;

sending a drive current to drive the hand piece; and

imparting ultrasonic movement to the blade.

33. The method ofclaim 32 further comprising the steps of:

decoding an encryption algorithm in the console; and

providing a responding data pattern;

wherein the data string is an encrypted code.

34. The method ofclaim 32 further comprising the steps of:

instructing the hand piece to operate in a handicap mode if temperature of the hand piece exceeds a handicap limit; and

disabling the hand piece if the temperature of the hand piece exceeds a disable limit.

35. The method ofclaim 32 further comprising the steps of:

instructing the hand piece to operate in a handicap mode if number of defective blades found in a time period of operating the hand piece exceeds a handicap limit; and

disabling the hand piece if the number of defective blades found in the time period exceeds a disable limit.

36. The method ofclaim 32 further comprising the steps of:

instructing the hand piece to operate in a handicap mode if time the hand piece has been active exceeds a handicap limit; and

disabling the hand piece if the number of defective blades found in the time the hand piece has been active exceeds a disable limit.

37. The method ofclaim 32 further comprising the steps of:

instructing the hand piece to operate in a handicap mode if number of activations for the hand piece within a time period exceeds a handicap limit; and

disabling the hand piece if the number of activations for the hand piece within the time period exceeds a disable limit.

38. The method ofclaim 34 further comprising the step of re-initializing the handicap limit and the disable limit based on varied operational conditions of the hand piece.

39. The method ofclaim 32 further comprising the steps of:

determining whether a reprogram of the console is needed;

reading a reprogram code stored in the memory and reprogramming the console using the reprogram code, if it is determined that a reprogram of the console is needed;

determining whether an upgrade of the console is needed; and

reading an upgrade code stored in the memory and upgrading the console using the upgrade code, if it is determined that an upgrade of the console is needed.

40. The method ofclaim 32 further comprising the steps of:

reading energy level information stored in the memory; and

driving the hand piece according to a corresponding output displacement;

wherein the energy level information stored in the memory is correlated with corresponding output displacement for driving the hand piece.

41. The method ofclaim 32 further comprising the steps of:

reading a nominal resonant frequency, a start sweep point and a stop sweep point delimiting a frequency range from the memory;

effecting a frequency sweep in the frequency range; and

detecting a resonant frequency for operating the hand piece.

42. The method ofclaim 32 further comprising the steps of:

reading a nominal resonant frequency, a bias amount and a margin amount from the memory;

calculating a frequency range based on the nominal resonant frequency, the bias amount and the margin amount;

effecting a frequency sweep in the frequency range; and

detecting a resonant frequency for operating the hand piece.

43. The method ofclaim 32 further comprising the steps of:

keeping track of a number of uses for the end-effector; and

keeping track of a number of remaining uses allowed for the end-effector.

44. A system for implementing surgical procedures comprising:

an ultrasonic surgical handpiece having an end-effector;

a generator console for controlling the handpiece, wherein the console sends a drive current to drive the handpiece which imparts ultrasonic longitudinal movement to the end-effector; and

a memory disposed with a blade mounting hub of the end-effector, wherein the console reads information stored in the memory to determine whether a data string is present, wherein the end-effector is authenticated for use with the handpiece if the data string is present.

45. The system ofclaim 44 wherein the data string is copyrighted.

46. The system ofclaim 44 wherein the memory stores an alarm limit and a disable limit, wherein the console instructs the hand piece to operate in an alarm mode if temperature of the hand piece exceeds the alarm limit, and the console disables the hand piece if the temperature of the hand piece exceeds the disable limit.

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