US 20110125176 A1
A surgical cutting and fastening instrument. The instrument comprises an end effector, a shaft connected to the end effector, and a handle connected to the shaft. The handle comprises an electric, DC motor connected to a drive train in the shaft for powering the drive train. The handle also comprises a power pack that comprises at least one charge-accumulating device connected to the DC motor for powering the DC motor.
1. A surgical cutting and fastening instrument comprising:
an end effector;
a shaft connected to the end effector, the shaft comprising a drive train for powering the end effector;
an electric, DC motor connected to the drive train for powering the drive train; and
a power pack that comprises at least one charge-accumulating device connected to the DC motor for powering the DC motor.
2. The surgical cutting and fastening instrument of
3. The surgical cutting and fastening instrument of
4. The surgical cutting and fastening instrument of
5. The surgical cutting and fastening instrument of
6. The surgical cutting and fastening instrument of
7. The surgical cutting and fastening instrument of
8. The surgical cutting and fastening instrument of
a memory for storing data; and
a processor connected to the memory.
9. The surgical cutting and fastening instrument of
10. The surgical cutting and fastening instrument of
11. A surgical instrument comprising:
an end effector;
a shaft connected to the end effector, the shaft comprising a drive train for powering the end effector;
an electric, DC motor connected to the drive train for powering the drive train;
a detachable power pack that comprises at least one chargeable DC power source connected to the DC motor for powering the DC motor; and
a charger base, remote from the instrument, for connecting to the removable power pack when detached, wherein the charger base comprises a power source for charging the at least one chargeable DC power source of the power pack.
12. The instrument of
13. The instrument of
14. The instrument of
15. The instrument of
16. The instrument of
17. The instrument of
a memory for storing data; and
a processor connected to the memory.
18. The instrument of
The present non-provisional patent application is a continuation patent application of and claims the benefit from U.S. patent application Ser. No. 12/031,567, filed Feb. 14, 2008, entitled “Motorized Surgical Cutting and Fastening Instrument Having Handle Based Power Source”, U.S. Patent Publication No. US 2009/0209990 A1, the entire disclosure of which is herein incorporated by reference and which is related to and incorporates by reference the following concurrently filed applications:
Surgical staplers have been used in the prior art to simultaneously make a longitudinal incision in tissue and apply lines of staples on opposing sides of the incision. Such instruments commonly include a pair of cooperating jaw members that, if the instrument is intended for endoscopic or laparoscopic applications, are capable of passing through a cannula passageway. One of the jaw members receives a staple cartridge having at least two laterally spaced rows of staples. The other jaw member defines an anvil having staple-forming pockets aligned with the rows of staples in the cartridge. Such instruments typically include a plurality of reciprocating wedges that, when driven distally, pass through openings in the staple cartridge and engage drivers supporting the staples to effect the firing of the staples toward the anvil.
An example of a surgical stapler suitable for endoscopic applications is described in published U.S. patent application Pub. No. 2004/0232196 A1, entitled, “Surgical stapling instrument having separate distinct closing and firing systems,” the disclosure of which is herein incorporated by reference. In use, a clinician is able to close the jaw members of the stapler upon tissue to position the tissue prior to firing. Once the clinician has determined that the jaw members are properly gripping tissue, the clinician can fire the surgical stapler, thereby severing and stapling the tissue. The simultaneous severing and stapling steps avoid complications that may arise when performing such actions sequentially with different surgical tools that respectively only sever or staple.
In addition, it is also known in the prior art to include electrodes in the end effector that can be used to emit/receive RF energy to form a hemostatic line along the cut line. U.S. Pat. No. 5,403,312, entitled “Electrosurgical hemostatic device” (hereinafter the “'312 Patent”), which is incorporated herein by reference, discloses an electrosurgical instrument with an end effector that compresses tissue between one pole (or electrode) of a bipolar energy source on one interfacing surface, and a second pole (or electrode) on a second interfacing surface. The RF energy applied through the compressed tissue in the end effector, which cauterizes the tissue. The end effector described in the '312 Patent also includes staples for stapling the tissue compressed in the end effector.
Motor-powered surgical cutting and fastening instruments, where the motor powers the cutting instrument, are also known in the prior art, such as described in published U.S. application Pub. No. 2007/0175962 A1, entitled “Motor-driven surgical cutting and fastening instrument with tactile position feedback,” which is incorporated herein by reference.
In one general aspect, embodiments of the present invention are directed to surgical cutting and fastening instruments. The instruments may be endoscopic instruments, such as linear endocutters or circular cutters, or laparoscopic instruments. The instruments may be comprised of staples and/or RF electrodes for fastening tissue clamped in the end effector.
Several embodiments disclosed herein are pertinent to cordless motor-powered instruments. The instruments may be powered by a power pack comprising a DC power source, such as one or more series-connected battery cells. A cell selection switch may control how many of the battery cells are being used to power the motor at a given time to control the power available to the motor. This allows the operator of the instrument to have greater control over both the speed and the power of the motor. In another embodiment, the instrument may comprise a power regulator, including, for example, a DC-to-DC converter, that regulates the voltage supplied to the motor. Further, the voltage set point for the power regulator could be set so that the voltage delivered from the power source is less than the voltage at which the power source delivers maximum power. That way, the power source (e.g., a number of series-connected battery cells) could operate on the “left” or increasing side of the power curve, so that increases in power would be available.
In addition, according to various embodiments, the power source may comprise secondary accumulator devices, such as rechargeable batteries or supercapacitors. Such secondary accumulator devices may be charged repeatably by replaceable batteries. A charge management circuit may control the charging of the secondary accumulator devices and provide various status signals, such as an alert, when the charging of the secondary accumulator devices is complete.
In other embodiment, a power pack comprising the secondary accumulator devices may be removable from the instrument and connectable to a remote charger base. The charger base may charge the secondary accumulator devices, such as from the AC electrical mains or a battery. The charger base may also comprise a processor and memory unit. Data stored in a memory of the removable power pack may be downloaded to the charger base, from which it may be uploaded for later use and analysis, such as by the user (e.g., physician), the manufacturer or distributor of the instrument, etc. The data may comprise operating parameters, such as charge cycle information, as well as ID values for various replaceable components of the instrument, such as the staple cartridge.
In addition, the instrument may comprise a torque-limiting device to limit the torque supplied by the motor, to limit thereby actuation forces that may damage components of the instrument. According to various embodiments, the torque-limiting devices may be an electromagnetic or permanent magnet, or mechanical clutch devices connected (either directly or indirectly) to the output pole of the motor.
In another general aspect, the present invention is directed to RF instruments (i.e., surgical cutting and fastening instruments with electrodes at the end effector for applying RF energy to the tissue held by the end effector) with new types of electrode configurations. In general, the new electrode configurations include combinations of smaller active electrodes and larger return electrodes. The smaller active electrodes are used to concentrate the therapeutic energy at the tissue, while the larger return electrodes preferentially are used to complete the circuit with minimal impact on that tissue interface. The return electrodes typically have greater mass and thereby are able to stay cooler during electrosurgical application.
In addition, the end effector, according to various embodiments, may comprise a number of co-linear, segmented active electrodes. The segmented electrodes could be energized synchronously or, more preferably, in sequence. Activating the segmented electrodes in sequence provides the advantages of (1) decreased instantaneous power requirements due to a smaller targeted area of tissue coagulation and (2) allowing other segments to fire if one is shorted out.
In addition, a number of mechanisms for activating the RF electrodes and for articulating the end effector are disclosed herein.
Various embodiments of the present invention are described herein by way of example in conjunction with the following figures, wherein:
The surgical instrument 10 depicted in
The handle 6 of the instrument 10 may include a closure trigger 18 and a firing trigger 20 for actuating the end effector 12. It will be appreciated that instruments having end effectors directed to different surgical tasks may have different numbers or types of triggers or other suitable controls for operating the end effector 12. The end effector 12 is shown separated from the handle 6 by a preferably elongate shaft 8. In one embodiment, a clinician or operator of the instrument 10 may articulate the end effector 12 relative to the shaft 8 by utilizing the articulation control 16, as described in more detail in published U.S. patent application Pub. No. 2007/0158385 A1, entitled “Surgical Instrument Having An Articulating End Effector,” by Geoffrey C. Hueil et al., which is incorporated herein by reference.
The end effector 12 includes in this example, among other things, a staple channel 22 and a pivotally translatable clamping member, such as an anvil 24, which are maintained at a spacing that assures effective stapling and severing of tissue clamped in the end effector 12. The handle 6 includes a pistol grip 26 towards which a closure trigger 18 is pivotally drawn by the clinician to cause clamping or closing of the anvil 24 toward the staple channel 22 of the end effector 12 to thereby clamp tissue positioned between the anvil 24 and channel 22. The firing trigger 20 is farther outboard of the closure trigger 18. Once the closure trigger 18 is locked in the closure position as further described below, the firing trigger 20 may rotate slightly toward the pistol grip 26 so that it can be reached by the operator using one hand. Then the operator may pivotally draw the firing trigger 20 toward the pistol grip 12 to cause the stapling and severing of clamped tissue in the end effector 12. In other embodiments, different types of clamping members besides the anvil 24 could be used, such as, for example, an opposing jaw, etc.
It will be appreciated that the terms “proximal” and “distal” are used herein with reference to a clinician gripping the handle 6 of an instrument 10. Thus, the end effector 12 is distal with respect to the more proximal handle 6. It will be further appreciated that, for convenience and clarity, spatial terms such as “vertical” and “horizontal” are 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 absolute.
The closure trigger 18 may be actuated first. Once the clinician is satisfied with the positioning of the end effector 12, the clinician may draw back the closure trigger 18 to its fully closed, locked position proximate to the pistol grip 26. The firing trigger 20 may then be actuated. The firing trigger 20 returns to the open position (shown in
It should be noted that although the embodiments of the instrument 10 described herein employ an end effector 12 that staples the severed tissue, in other embodiments different techniques for fastening or sealing the severed tissue may be used. For example, end effectors that use RF energy or adhesives to fasten the severed tissue may also be used. U.S. Pat. No. 5,709,680 entitled “Electrosurgical Hemostatic Device” to Yates et al., and U.S. Pat. No. 5,688,270 entitled “Electrosurgical Hemostatic Device with Recessed and/or Offset Electrodes” to Yates et al., which are incorporated herein by reference, disclose an endoscopic cutting instrument that uses RF energy to seal the severed tissue. Published U.S. patent application Pub. No. 2007/0102453 A1 to Jerome R. Morgan, et al. and published U.S. patent application Pub. No. 2007/0102452 A1 to Frederick E. Shelton, IV, et al., which are also incorporated herein by reference, disclose endoscopic cutting instruments that use adhesives to fasten the severed tissue. Accordingly, although the description herein refers to cutting/stapling operations and the like below, it should be recognized that this is an exemplary embodiment and is not meant to be limiting. Other tissue-fastening techniques may also be used.
A bearing 38, positioned at a distal end of the staple channel 22, receives the helical drive screw 36, allowing the helical drive screw 36 to freely rotate with respect to the channel 22. The helical screw shaft 36 may interface a threaded opening (not shown) of the knife 32 such that rotation of the shaft 36 causes the knife 32 to translate distally or proximately (depending on the direction of the rotation) through the staple channel 22. Accordingly, when the main drive shaft 48 is caused to rotate by actuation of the firing trigger 20 (as explained in more detail below), the bevel gear assembly 52 a-c causes the secondary drive shaft 50 to rotate, which in turn, because of the engagement of the drive gears 54, 56, causes the helical screw shaft 36 to rotate, which causes the knife driving member 32 to travel longitudinally along the channel 22 to cut any tissue clamped within the end effector. The sled 33 may be made of, for example, plastic, and may have a sloped distal surface. As the sled 33 traverses the channel 22, the sloped forward surface may push up or drive the staples in the staple cartridge through the clamped tissue and against the anvil 24. The anvil 24 turns the staples, thereby stapling the severed tissue. When the knife 32 is retracted, the knife 32 and sled 33 may become disengaged, thereby leaving the sled 33 at the distal end of the channel 22.
The motor 65 may be a DC brushed driving motor having a maximum rotation of approximately 25,000 RPM with no load. The motor 64 may drive a 90° bevel gear assembly 66 comprising a first bevel gear 68 and a second bevel gear 70. The bevel gear assembly 66 may drive a planetary gear assembly 72. The planetary gear assembly 72 may include a pinion gear 74 connected to a drive shaft 76. The pinion gear 74 may drive a mating ring gear 78 that drives a helical gear drum 80 via a drive shaft 82. A ring 84 may be threaded on the helical gear drum 80. Thus, when the motor 65 rotates, the ring 84 is caused to travel along the helical gear drum 80 by means of the interposed bevel gear assembly 66, planetary gear assembly 72, and ring gear 78.
The handle 6 may also include a run motor sensor 110 in communication with the firing trigger 20 to detect when the firing trigger 20 has been drawn in (or “closed”) toward the pistol grip portion 26 of the handle 6 by the operator to thereby actuate the cutting/stapling operation by the end effector 12. The sensor 110 may be a proportional sensor such as, for example, a rheostat, or variable resistor. When the firing trigger 20 is drawn in, the sensor 110 detects the movement, and sends an electrical signal indicative of the voltage (or power) to be supplied to the motor 65. When the sensor 110 is a variable resistor or the like, the rotation of the motor 65 may be generally proportional to the amount of movement of the firing trigger 20. That is, if the operator only draws or closes the firing trigger 20 in a little bit, the rotation of the motor 65 is relatively low. When the firing trigger 20 is fully drawn in (or in the fully closed position), the rotation of the motor 65 is at its maximum. In other words, the harder the user pulls on the firing trigger 20, the more voltage is applied to the motor 65, causing greater rates of rotation.
The handle 6 may include a middle handle piece 104 adjacent to the upper portion of the firing trigger 20. The handle 6 also may comprise a bias spring 112 connected between posts on the middle handle piece 104 and the firing trigger 20. The bias spring 112 may bias the firing trigger 20 to its fully open position. In that way, when the operator releases the firing trigger 20, the bias spring 112 will pull the firing trigger 20 to its open position, thereby removing actuation of the sensor 110, thereby stopping rotation of the motor 65. Moreover, by virtue of the bias spring 112, any time a user closes the firing trigger 20, the user will experience resistance to the closing operation, thereby providing the user with feedback as to the amount of rotation exerted by the motor 65. Further, the operator could stop retracting the firing trigger 20 to thereby remove force from the sensor 100, to thereby stop the motor 65. As such, the user may stop the deployment of the end effector 12, thereby providing a measure of control of the cutting/fastening operation to the operator.
The distal end of the helical gear drum 80 includes a distal drive shaft 120 that drives a ring gear 122, which mates with a pinion gear 124. The pinion gear 124 is connected to the main drive shaft 48 of the main drive shaft assembly. In that way, rotation of the motor 65 causes the main drive shaft assembly to rotate, which causes actuation of the end effector 12, as described above.
The ring 84 threaded on the helical gear drum 80 may include a post 86 that is disposed within a slot 88 of a slotted arm 90. The slotted arm 90 has an opening 92 its opposite end 94 that receives a pivot pin 96 that is connected between the handle exterior side pieces 59, 60. The pivot pin 96 is also disposed through an opening 100 in the firing trigger 20 and an opening 102 in the middle handle piece 104.
In addition, the handle 6 may include a reverse motor (or end-of-stroke sensor) 130 and a stop motor (or beginning-of-stroke) sensor 142. In various embodiments, the reverse motor sensor 130 may be a limit switch located at the distal end of the helical gear drum 80 such that the ring 84 threaded on the helical gear drum 80 contacts and trips the reverse motor sensor 130 when the ring 84 reaches the distal end of the helical gear drum 80. The reverse motor sensor 130, when activated, sends a signal to the motor 65 to reverse its rotation direction, thereby withdrawing the knife 32 of the end effector 12 following the cutting operation. The stop motor sensor 142 may be, for example, a normally-closed limit switch. In various embodiments, it may be located at the proximate end of the helical gear drum 80 so that the ring 84 trips the switch 142 when the ring 84 reaches the proximate end of the helical gear drum 80.
In operation, when an operator of the instrument 10 pulls back the firing trigger 20, the sensor 110 detects the deployment of the firing trigger 20 and sends a signal to the motor 65 to cause forward rotation of the motor 65 at, for example, a rate proportional to how hard the operator pulls back the firing trigger 20. The forward rotation of the motor 65 in turn causes the ring gear 78 at the distal end of the planetary gear assembly 72 to rotate, thereby causing the helical gear drum 80 to rotate, causing the ring 84 threaded on the helical gear drum 80 to travel distally along the helical gear drum 80. The rotation of the helical gear drum 80 also drives the main drive shaft assembly as described above, which in turn causes deployment of the knife 32 in the end effector 12. That is, the knife 32 and sled 33 are caused to traverse the channel 22 longitudinally, thereby cutting tissue clamped in the end effector 12. Also, the stapling operation of the end effector 12 is caused to happen in embodiments where a stapling-type end effector is used.
By the time the cutting/stapling operation of the end effector 12 is complete, the ring 84 on the helical gear drum 80 will have reached the distal end of the helical gear drum 80, thereby causing the reverse motor sensor 130 to be tripped, which sends a signal to the motor 65 to cause the motor 65 to reverse its rotation. This in turn causes the knife 32 to retract, and also causes the ring 84 on the helical gear drum 80 to move back to the proximate end of the helical gear drum 80.
The middle handle piece 104 includes a backside shoulder 106 that engages the slotted arm 90 as best shown in
Components of an exemplary closure system for closing (or clamping) the anvil 24 of the end effector 12 by retracting the closure trigger 18 are also shown in
In operation, when the yoke 250 rotates due to retraction of the closure trigger 18, the closure brackets 256, 258 cause the proximate closure tube 40 to move distally (i.e., away from the handle end of the instrument 10), which causes the distal closure tube 42 to move distally, which causes the anvil 24 to rotate about the pivot point 25 into the clamped or closed position. When the closure trigger 18 is unlocked from the locked position, the proximate closure tube 40 is caused to slide proximately, which causes the distal closure tube 42 to slide proximately, which, by virtue of the tab 27 being inserted in the window 45 of the distal closure tube 42, causes the anvil 24 to pivot about the pivot point 25 into the open or unclamped position. In that way, by retracting and locking the closure trigger 18, an operator may clamp tissue between the anvil 24 and channel 22, and may unclamp the tissue following the cutting/stapling operation by unlocking the closure trigger 20 from the locked position.
When the staple cartridge 34 is present, the sensor 136 is closed, which energizes a single pole, single throw relay 138. When the relay 138 is energized, current flows through the relay 136, through the variable resistor sensor 110, and to the motor 65 via a double pole, double throw relay 140, thereby powering the motor 65, and allowing it to rotate in the forward direction. When the end effector 12 reaches the end of its stroke, the reverse motor sensor 130 will be activated, thereby closing the switch 130 and energizing the relay 134. This causes the relay 134 to assume its energized state (not shown in
In other embodiments, rather than a proportional-type sensor 110, an on-off type sensor could be used. In such embodiments, the rate of rotation of the motor 65 would not be proportional to the force applied by the operator. Rather, the motor 65 would generally rotate at a constant rate. But the operator would still experience force feedback because the firing trigger 20 is geared into the gear drive train.
Additional configurations for motorized surgical instruments are disclosed in published U.S. application Pub. No. 2007/0175962 A1, entitled “Motor-driven surgical cutting and fastening instrument with tactile position feedback,” which is incorporated herein by reference.
In a motorized surgical instrument, such as one of the motorized endoscopic instruments described above or in a motorized circular cutter instrument, the motor may be powered by a number of battery cells connected in series. Further, it may be desirable in certain circumstances to power the motor with some fraction of the total number of battery cells. For example, as shown in
In such an embodiment, under the heaviest loads, the input voltage to the motor 65 may sag to about nine to ten volts. At this operating condition, the power pack 299 is delivering maximum power to the motor 65. Accordingly, as shown in
The switch 312 may be, for example, an electromechanical switch, such as a micro switch. In other embodiments, the switch 312 may be implemented with a solid-state switch, such as transistor. A second switch 314, such as a push button switch, may be used to control whether power is applied to the motor 65 at all. Also, a forward/reverse switch 316 may be used to control whether the motor 65 rotates in the forward direction or the reverse direction. The forward/reverse switch 316 may be implemented with a double pole—double throw switch, such as the relay 140 shown in
In operation, the user of the instrument 10 could select the desired power level by using some sort of switch control, such as a position-dependent switch (not shown), such as a toggle switch, a mechanical lever switch, or a cam, which controls the position of the switch 312. Then the user may activate the second switch 314 to connect the selected battery cells 310 to the motor 65. In addition, the circuit shown in
In other embodiments, as shown in
The primary power source 340 may charge the secondary accumulator devices 342. Once sufficiently charged, the primary power source 340 may be removed and the secondary accumulator devices 342 may be used to power the motor 65 during a procedure or operation. The accumulating devices 342 may take about fifteen to thirty minutes to charge in various circumstances. Supercapacitors have the characteristic they can charge and discharge extremely rapidly in comparison to conventional batteries. In addition, whereas batteries are good for only a limited number of charge/discharge cycles, supercapacitors can often be charged/discharged repeatedly, sometimes for tens of millions of cycles. For embodiments using supercapacitors as the secondary accumulator devices 342, the supercapacitors may comprise carbon nanotubes, conductive polymers (e.g., polyacenes), or carbon aerogels.
As shown in
The primary power source 340, the secondary accumulator devices 342, and the charge management circuit 344 may be part of a power pack in the pistol grip portion 26 of the handle 6 of the instrument 10, or in another part of the instrument 10. The power pack may be removable from the pistol grip portion 26, in which case, when the instrument 10 is to be used for surgery, the power pack may be inserted aseptically into the pistol grip portion 26 (or other position in the instrument according to other embodiments) by, for example, a circulating nurse assisting in the surgery. After insertion of the power pack, the nurse could put the replaceable primary power source 340 in the power pack to charge up the secondary accumulator devices 342 a certain time period prior to use of the instrument 10, such as thirty minutes. When the secondary accumulator devices 342 are charged, the charge management circuit 344 may indicate that the power pack is ready for use. At this point, the replaceable primary power source 340 may be removed. During the operation, the user of the instrument 10 may then activate the motor 65, such as by activating the switch 314, whereby the secondary accumulator devices 342 power the motor 65. Thus, instead of having a number of disposable batteries to power the motor 65, one disposable battery (as the primary power source 340) could be used in such an embodiment, and the secondary accumulator devices 342 could be reusable. In alternative embodiments, however, it should be noted that the secondary accumulator devices 342 could be non-rechargeable and/or non-reusable. The secondary accumulators 342 may be used with the cell selection switch 312 described above in connection with
The charge management circuit 344 may also include indicators (e.g., LEDs or LCD display) that indicate how much charge remains in the secondary accumulator devices 342. That way, the surgeon (or other user of the instrument 10) can see how much charge remains through the course of the procedure involving the instrument 10.
The charge management circuit 344, as shown in
The charge management circuit 344 may also comprise an i/o interface 352 for communicating with another device, such as described below. That way, the parameters stored in the memory 346 may be downloaded to another device. The i/o interface 352 may be, for example, a wired or wireless interface.
As mentioned before, the power pack may comprise the secondary accumulators 342, the charge management circuit 344, and/or the f/r switch 316. According to various embodiments, as shown in
As shown in
In addition, as shown in
The charger base 362 may also comprise a charge meter 374 for measuring the charge across the secondary accumulators 342. The charge meter 374 may be in communication with the processor(s) 366, so that the processor(s) 366 can determine in real-time the suitability of the power pack 299 for use to ensure high performance.
In another embodiment, as shown in
In other embodiments, different power converter topologies may be employed, including linear or switch-mode power converters. Other switch-mode topologies that may be employed include a flyback, forward, buck, boost, and SEPIC. The set point voltage for the power regulator 320 could be changed depending on how many of the battery cells are being used to power the motor 65. Additionally, the power regulator 320 could be used with the secondary accumulator devices 342 shown in
Batteries can typically be modeled as an ideal voltage source and a source resistance. For an ideal model, when the source and load resistance are matched, maximum power is transferred to the load.
Particularly for embodiments using a battery (or batteries) to power the motor 65 during a procedure, the control circuit 330 can monitor the output voltage and control the set point of the regulator 320 so that the battery operates on the “left” or power-increasing side of the power curve. If the battery reaches the peak power level, the control circuit 330 can change (e.g., lower) the set point of the regulator so that less total power is being demanded from the battery. The motor 65 would then slow down. In this way, the demand from the power pack would rarely if ever exceed the peak available power so that a power-starving situation during a procedure could be avoided.
In addition, according to other embodiments, the power drawn from the battery may be optimized in such a way that the chemical reactions within the battery cells would have time to recover, to thereby optimize the current and power available from the battery. In pulsed loads, batteries typically provide more power at the beginning of the pulse that toward the end of the pulse. This is due to several factors, including: (1) the PTC may be changing its resistance during the pulse; (2) the temperature of the battery may be changing; and (3) the electrochemical reaction rate is changing due to electrolyte at the cathode being depleted and the rate of diffusion of the fresh electrolyte limits the reaction rate. According to various embodiments, the control circuit 330 may control the converter 320 so that it draws a lower current from the battery to allow the battery to recover before it is pulsed again.
According to other embodiments, the instrument 10 may comprise a clutch-type torque-limiting device. The clutch-type torque-limiting device may be located, for example, between the motor 65 and the bevel gear 68, between the bevel gear 70 and the planetary gear assembly 72, or on the output shaft of the planetary gear assembly 72. According to various embodiments, the torque-limiting device may use an electromagnetic or permanent magnetic clutch.
The attractive force between the two disks 404, 406 and the corresponding torque capacity of the clutch 400 could be controlled by controlling the diameter of the disks 404, 406, the coefficient of friction between the contacting faces of magnetic disks 404 and 406, and by using magnetic materials for the disks 404, 406 that saturate at a known and controllable flux density. Therefore, even if there was an operating condition where more current was passed through the coil, the magnetic material of the disks 404, 406 would not generate a greater attractive force and subsequent limiting torque.
Utilization of such a clutch has many additional potential benefits. Being electrically controlled, the clutch 400 could be quickly deactivated by removing current from the wire to limit the amount of heat generated within the clutch 400 and within the motor 65. By disconnecting the motor from the rest of the drive train, via the clutch 400, most of the stored inertial energy in the drive train would be disconnected, limiting shock if the output were to be blocked suddenly. In addition, by being electrically controlled, some limited slipping could be designed-in to aid in reducing shocks when restarting the drive train under load. Further, because the magnetic saturation properties of one or more of the components (e.g., the magnetic disks 404, 406) within the clutch could be used to control the torque limit instead of coil current, the clutch 400 would be less sensitive to changes in system voltage. The torque limit in such embodiments would be primarily a function of the physical dimensions of the components of the clutch (e.g., the magnetic disks 404, 406) and would not require voltage regulators or other external components for proper operation.
In another embodiment, rather than using an electromagnetic clutch, the torque-limiting device may comprise a permanent magnet (not shown). The permanent magnet may be connected, for example, to the first, axially-movable, pole piece 408, and attract the axially-fixed second pole piece 410, or vice versa. In such embodiments, one of the disks 404, 406 could be made of a permanent magnet and the other one of a magnetic material like iron. In a slight variation, the stator 402 could be made in the form of a permanent magnet, causing the magnetic disks 404 and 406 to be attracted to each other. Because of the permanent magnet, the two disks 404, 406 would be engaged always. Using a permanent magnet would not provide as accurate as torque control as the electromagnetic clutch configuration described above, but it would have the advantages of: (1) not requiring controls or control logic to control the current through the coil; (2) being more compact that the electromagnetic clutch configuration; and (3) simplifying design of the instrument 10.
As mentioned previously, the end effector 12 may emit RF energy to coagulate tissue clamped in the end effector. The RF energy may be transmitted between electrodes in the end effector 12. A RF source (not shown), comprising, for example, an oscillator and an amplifier, among other components, which may supply the RF energy to the electrode, may be located in the instrument itself, such as in the handle 6 for a cordless instrument 10, or the RF source may be external to the instrument 10. The RF source may be activated as described further below.
According to various embodiments, the end effector 12 may comprise multiple sections (or segments) of electrodes. For example, as shown in the example of
The electrodes 500 may be energized simultaneously or in various orders, such as sequentially. For embodiments where the electrodes 500 are energized according to a sequence, the sequence may be automatic (controlled, for example, by a controller (not shown) in communication with the RF source) or by selection by the user. For example, the proximate electrodes 500 3 could be energized first; then the middle electrodes 500 2; then the distal electrodes 500 1. That way, the operator (e.g., the operating surgeon) can selectively coagulate areas of the staple line. The electrodes in such an embodiment could be controlled by a multiplexer and/or a multiple output generator, as described further below. That way, the tissue under each electrode 500 could be treated individually according to the coagulation needs. Each electrode in the pair may be connected to the RF source so that they are energized at the same time. That is, for the distal pair of active electrodes 500 1, each, being on opposite sides of the knife channel, may be energized by the RF source at the same time. Same for the middle pair of electrodes 500 2 and the proximate pair of electrodes 500 3, although, in an embodiment where the electrode pairs are energized in sequence, the distal pair is not energized at the same time as the middle and proximate pairs, and so on.
Further, various electrical parameters, such as impedance, delivered power or energy, etc., could be monitored and the output to particular electrodes 500 could be modified to produce the most desirable tissue effect. Additionally, another advantage is in the case of a metal staple or other electrically conductive object left from a previous instrument firing or surgical procedure that may cause a short of the electrodes. Such a short situation could be detected by the generator and/or multiplexer, and the energy could be modulated in a manner appropriate for the short circuit.
In addition, energizing the electrodes 500 in sequence reduces the instantaneous power required from the RF source in comparison to a design that would has one set of electrodes as long as the combined length of the three segmented electrodes 500 shown in
The electrodes 500 may be surrounded by an electrically insulating material 504, which may comprise a ceramic material.
In such an embodiment, the circuit board 570 may comprise multiple layers that provide electrical connections between the multiplexer 576 and the various electrode pairs. For example, as shown in
An advantage of having so many RF electrodes in the end effector 12, as shown in
Alternatively, actuation of the knife, staple drivers, and/or RF electrodes may be activated by voice or other sound commands detected by a microphone 542. In other embodiments, the handle 6 may comprise a RF or sonic transceiver 541, which may receive and/or transmit RF or sonic signals to activate the instrument. Also, as shown in
The instrument 10 shown in
As described above, the instrument 10 may comprise an articulation pivot 14 for articulating the end effector 12. A clinician or operator of the instrument 10 may articulate the end effector 12 relative to the shaft 8 by utilizing the articulation control 16, as described in more detail in published U.S. patent application Pub. No. 2007/0158385 A1, entitled “Surgical Instrument Having An Articulating End Effector,” by Geoffrey C. Hueil et al., which is incorporated herein by reference. In other embodiment, rather than a control device that is integrated with the instrument 10, the end effector 12 may be articulated by a separate instrument, such as gripper, that is inserted into the patient so that its operative portion is near the end effector 12 so that it can articulate the end effector 12 as desired. The separate instrument may be inserted through a different opening as the end effector 12, or through the same opening. Also, different operators can operate the separate instruments, or one person can operate both instruments, to articulate the end effector 12. In another passive articulation scenario, the end effector 12 may be articulated by carefully pushing it against other parts of the patient to achieve the desired articulation.
In another embodiment, the end effector 12 may be connected to the handle by a flexible cable. In such an embodiment, the end effector 12 could be positioned as desired and held in position by use of another instrument, e.g., a separate gripper instrument. In addition, in other embodiments, the end effector 12 could be positioned by a separate instrument and clamped by a second separate instrument. In addition, the end effector 12 could be made sufficiently small, such as 8 to 9 mm wide by 10 to 11 mm tall, so that a pull-to-close mechanism could be used to clamp the end effector from the handle 6. The pull-to-close mechanism could be adapted from that described in U.S. Pat. No. 5,562,701, entitled “Cable-Actuated Jaw Assembly For Surgical Instruments,” which is incorporated herein by reference. The cable 600 could be disposed in or along a flexible endoscope for use, for example, in upper or lower gastro-intestinal tract procedures.
In yet another embodiment, as shown in
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. In either case, however, the device can be reconditioned for reuse after at least one use. Reconditioning can include any combination of the steps of disassembly of the device, followed by cleaning or replacement of particular pieces, and subsequent reassembly. In particular, the device can be disassembled, and any number of the particular pieces or parts of the device can be selectively replaced or removed in any combination. Upon cleaning and/or replacement of particular parts, the device can 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 can 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.
Preferably, the various embodiments of the invention described herein will be processed before surgery. First, a new or used instrument is obtained and if necessary cleaned. The instrument can then be sterilized. In one sterilization technique, the instrument is placed in a closed and sealed container, such as a thermoformed plastic shell covered with a sheet of TYVEK. The container and instrument are then placed in a field of radiation that can penetrate the container, such as gamma radiation, x-rays, or high-energy electrons. The radiation kills bacteria on the instrument and in the container. The sterilized instrument can then be stored in the sterile container. The sealed container keeps the instrument sterile until it is opened in the medical facility.
It is preferred that the device is sterilized. This can be done by any number of ways known to those skilled in the art including beta or gamma radiation, ethylene oxide, steam and other methods.
While the present invention has been illustrated by description of several embodiments and while the illustrative embodiments have been described in considerable detail, it is not the intention of the applicant to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications may readily appear to those skilled in the art. The various embodiments of the present invention represent vast improvements over prior staple methods that require the use of different sizes of staples in a single cartridge to achieve staples that have differing formed (final) heights.
Accordingly, the present invention has been discussed in terms of endoscopic procedures and apparatus. However, use herein of terms such as “endoscopic” should not be construed to limit the present invention to a surgical stapling and severing instrument for use only in conjunction with an endoscopic tube (i.e., trocar). On the contrary, it is believed that the present invention may find use in any procedure where access is limited, including but not limited to laparoscopic procedures, as well as open procedures. Moreover, the unique and novel aspects of the various staple cartridge embodiments of the present invention may find utility when used in connection with other forms of stapling apparatuses without departing from the spirit and scope of the present invention.