Patent ID: 12257688

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

The following detailed description of example implementations refers to the accompanying drawings. The same reference numbers in different drawings may identify the same or similar elements.

An orthopedic rotary tool (e.g., a reamer, a drill, among other examples) can be used (e.g., by an operator, a surgeon, and/or a robot, among other examples) to perform one or more orthopedic techniques during an orthopedic procedure. For example, the operator may use the orthopedic rotary tool to cut, drill, and/or shape bone during the orthopedic procedure.

To cut, drill, and/or shape the bone during the orthopedic procedure, the operator may cause a component (e.g., edges or cutting flutes of a reamer, among other examples) of the orthopedic rotary tool to rotate and interact with the bone. As an example, the orthopedic rotary tool may include a motor to provide a rotational force that causes the component to rotate. As the component rotates, the operator causes the component to interact with the bone, and the rotational motion, combined with the component, creates a cutting action that removes bone material.

However, during the cutting process, the interaction between the component and the bone generates a reactionary torque (e.g., a reactionary force that opposes rotation of the component). In some cases, a high reactionary torque may be generated which requires the operator of the orthopedic rotary tool to exert a high counteracting force from his wrist to overcome the high reactionary torque and maintain control over movement associated with the orthopedic rotary tool. If the surgeon has to overcome high reactionary torque during orthopedic procedures, this introduces drawbacks and challenges. These include operator fatigue, wrist injury and reduced cutting precision of the orthopedic implement potentially resulting in suboptimal implant positioning and stability. Furthermore, existing techniques employed to mitigate high reactionary torque during orthopedic procedures generate excessive noise levels, which can lead to hearing damage of the operator.

Some implementations described herein relate to an orthopedic rotary tool with reduced reactionary torque. For example, the orthopedic rotary tool may include a motor, a drive shaft operatively coupled to the motor, an output anvil operatively coupled to the drive shaft, a rotating mass (e.g., a flywheel), a clutch operatively coupled to the rotating mass, and a controller. In some implementations, the controller may measure the rotational speed of the output anvil and based on comparison of that speed to a desired speed use a clutch to selectively couple the rotating mass to the output anvil to transmit additional torque from the rotating mass to the output anvil. As an example, if the controller determines that the output rotational speed of the output anvil drops below a threshold rotational speed, then the controller may cause the clutch to selectively couple the rotating mass to the output anvil to transmit additional torque from the rotating mass to the output anvil.

In this way, the orthopedic rotary tool may selectively couple a rotating mass to the output anvil to provide a torque that overcomes a high reactionary torque at the output anvil (e.g., via a clutch that can be mechanically and/or electronically controlled to selectively couple a rotating mass to the output anvil, as described in more detail elsewhere herein.

FIG.1is a diagram of an example orthopedic rotary tool1600with reduced reactionary torque.FIG.2is a diagrammatical cross-section of the orthopedic rotary tool1600ofFIG.1. As shown inFIGS.1-2, the orthopedic rotary tool1600includes a primary gear box1602, a one-way drive bearing1603, a rotating mass1604, a drive shaft1606, a slip clutch1608, a bypass shaft1610, an electronic clutch1612(e.g., a wrap spring clutch, among other examples), a rotational speed sensor1614a carriage plate driver1616, a gear carrier1618, a secondary gear box1620, and an output anvil1622.

FIG.3is a diagram of a magnetic slip clutch1608of the orthopedic rotary tool1600ofFIG.1.FIG.4is a partial diagrammatical cross-section of the magnetic slip clutch1608operatively coupled to the one-way bearing1603. As shown inFIGS.3-4, the orthopedic rotary tool1600includes magnets1802, a center drive1804, splined teeth1806, an airgap1808(e.g., that is positioned between the magnets1802and the splined teeth1806as shown inFIG.3), and a bypass shaft overrunning bearing1810. The bypass shaft overrunning bearing1810is used to drive a bypass shaft (such as the bypass shaft1610shown inFIG.2). The bypass shaft is a unique invention that enables the output anvil to be turned at a desired output rpm range and yet allow slippage at a design speed and as a result of said slippage to operatively couple additional torque to the output by using an alternate and parallel path. As an example, a design speed is a speed of the output anvil when the orthopedic rotary tool operates with no (or minimal) load when driven solely by the first drive path.

As further shown inFIG.3, the magnetic slip clutch1608is disposed within the rotating mass1604. Although the orthopedic rotary tool1600is shown and described as having the magnetic slip clutch1608disposed within the rotating mass1604, the orthopedic rotary tool1600may utilize any suitable slip or overload clutch, disposed in any suitable position associated with the orthopedic rotary tool1600.

Although the orthopedic rotary tool1600is described as using the magnetic slip clutch1608, the orthopedic rotary tool1600may use any suitable clutch, such as a friction clutch, hysteresis clutch, an eddy current clutch, and/or a spring ball relief clutch, among other examples. Different clutches are associated with different breakaway or slippage characteristics. One important distinction associated with this disclosure is that the bypass shaft rotational energy is operatively communicated from the motor to the anvil through a slip or breakaway clutch in which the torque transmitted to the operator is reduced when the torque reaches a slip torque (e.g., when the torque satisfies a torque threshold). In some implementations, the slippage or breakaway effect could be achieved by controlling or modulating an electrically activated clutch.

Accordingly, the “slip torque” of a clutch is associated with a maximum transmissible torque that may be transmitted before an angular rotation at an input side of the clutch exceeds (e.g., for a period of time) an angular rotation on an output side of the clutch.

In some implementations, an overload torque level (e.g., a torque level at the slip torque) may be approximately 25 inch-pounds (e.g., as measured, by a sensor device of the orthopedic rotary tool1600, at the output anvil1622) although a more preferable slippage would be about 10 inch-pounds.

In some implementations, the rotating mass1604may be operably coupled to the bypass shaft1610via the magnetic slip clutch1608. The bypass shaft1610may pass through a center of the electronic clutch1612and may engage a pinion in the secondary gearbox1620. During normal operation, the bypass shaft1610may engage the secondary gear box1620, which causes the output anvil1622to rotate at a design speed (e.g., between an rpm range of 100 and 500 and/or between a range of 280 and 340, among other examples).

In some implementations, if the output anvil1622encounters a high torque load (e.g., which causes excessive reactionary torque being transmitted to the operator of the orthopedic rotary tool1600), then the magnetic slip clutch1608may slip (e.g., or begin to slip), which limits the reactionary torque that is transmitted to the operator of the orthopedic rotary tool1600. In other words, the magnetic slip clutch1608may decouple the bypass shaft1610and the output anvil from the rotating mass1604(e.g., based on slipping). In some implementations, the magnetic slip clutch1608may slip based on a slip torque of 2 to 50 inch-pounds.

In this way, the reactionary torque transmitted to the operator of the orthopedic rotary tool1600may be limited. In some implementations, if the slip torque is exceeded, then the magnetic slip clutch1608slips, which causes a rotational speed associated with the output anvil1622to be reduced, temporarily. In other words, when the magnetic slip clutch1608slips, the output anvil1622slows down or stops based on the anvil torque exceeding the slip torque.

In some implementations, the rotational speed sensor1614is a Hall Effect sensor and may monitor the rotational speed of the output anvil1622. The Hall Effect sensor may send, and a controller (e.g., a control board and/or a control circuit, among other examples) associated with the orthopedic rotary tool1600may receive, an indication of the rotational speed of the output anvil1622. Although the orthopedic rotary tool1600is described as using the Hall effect sensor to monitor the rotational speed of the output anvil1622, the orthopedic rotary tool1600may use any suitable technique and/or sensor device to monitor the rotational speed of the output anvil1622.

In some implementations, the controller may control an electronic clutch1612, as described in more detail elsewhere herein. Accordingly, the controller may include various semiconductor components including but not limited to transistors, integrated circuits, and passive components such as inductors, capacitors etc.

In some implementations, the controller may cause the electronic clutch1612to be engaged based on the rotational speed of the anvil deviating from a design speed. Engaging the electronic clutch1612causes the rotating mass1604to be operatively coupled to the output anvil1622, as described in more detail elsewhere herein. Accordingly, for example, engaging the electronic clutch1612may increase a torque (e.g., may “boost” the torque) by enabling the rotational inertia of the rotating mass to be coupled to the output anvil.

In some implementations, a frequency and/or duty cycle of the electronic clutch1612can be optimized to provide the optimized operating characteristics associated with the orthopedic rotary tool1600(e.g., which may be based on operator preferences, orthopedic procedures, and/or orthopedic techniques, among other examples). As an example, the electronic clutch1612may be engaged at variable frequencies ranging from a single engagement up to 50 Hz.

In some implementations, the orthopedic rotary tool1600may include only the secondary (e.g., auxiliary) drive path (e.g., the orthopedic rotary tool1600may not include the bypass shaft1606). The frequency and/or duty cycle of the electronically activated clutch1612may be modulated based on an output rpm sensor to achieve a desired output rpm range. For example, in a no-load condition (e.g., when the orthopedic rotary tool1600is operating under no load), if the rpm sensor measures an output rpm of 1000 rpm, then the controller (e.g., based on an indication provided by the rpm sensor) may reduce the duty cycle and/or frequency of the electronic clutch1612to decrease the rpm to the desired output rpm range. As another example, under a high-load condition, (e.g., when the orthopedic rotary tool1600is operating under a high torque load), if the rpm sensor measures an output rpm of 25 rpm, then the controller (e.g., based on an indication provided by the rpm sensor) may increase the duty cycle and/or frequency of the electronic clutch1612to overcome the high torque load and increase the output rpm (e.g., of the output anvil1622).

In some implementations, the secondary drive path may be associated with engaging the electronic clutch1612. As an example, if the controller determines that the rotational speed of the output anvil1622has dropped below the desired design speed (e.g., when the magnetic slip clutch1608slips or begins slipping), then the controller may selectively activate the electronic clutch1612, which causes the rotating mass to be operatively coupled to the output anvil1622. Accordingly, a high rotational energy of the rotating mass1604may be transmitted to the output anvil1622to increase the rpm of the output anvil1622towards the desired output rpm range. In other words, the motor1624drives the rotating mass1604, which is then selectively coupled to and decoupled from the output anvil1622by the electronically activated clutch1612.

In some implementations, the electronic clutch1612may be “pulsed” (e.g., based on a frequency), which causes the rotating mass1604to be repeatedly coupled to, and decoupled from, the output anvil1622. As an example, the controller may selectively pulse the electronic clutch1612, which causes the rotating mass1604to be selectively coupled to, and decoupled from, the output anvil1622, and which increases the torque, transmitted to the output anvil1622, by at least 30%.

In some implementations, when the electronic clutch1612is activated, the rotating mass1604(e.g., a high-speed flywheel) may be operatively coupled (e.g., directly coupled) to the carriage plate driver1616, which results in a one to one coupling of the high speed flywheel to the output anvil. The inventors originally thought that coupling the high-speed flywheel through the gear box would multiply the output anvil torque by the gear ratio without any effect on the operator; however, it was unexpectedly discovered that this was not the case and in fact the gear ratio (if greater than 1:1) resulted in a significant torque coupled to the operator which was nearly equal to the gear ratio minus 1. As an example, if a 7:1 gear ratio was used to couple the flywheel, then the operator felt an increase of six times in the reactionary torque. Directly coupling the gear carrier1618to the output anvil1622, and, therefore, directly coupling the carriage plate driver1616to the output anvil1612, enables the gear ratio to be decreased from 7:1 to 1:1. This enables the rotating mass1604(e.g., the free spinning flywheel) to directly increase the torque on the output anvil1622with a minimal effect on the reactionary torque which turned into a huge benefit for the operator from a reactionary torque standpoint

In some implementations, a one-way overrun bearing (e.g., the bypass shaft overrun bearing1810shown and described in connection withFIG.3and/or as described in more detail elsewhere herein) may be installed between the bypass shaft1610and a center drive (e.g., the center drive1804shown and described in connection withFIG.3and/or as described in more detail elsewhere herein) to reduce reactionary torque (e.g., internal reactionary torque) and potential associated wear of one or more components of the orthopedic rotary tool1600(e.g., which is dependent on a construction of the clutch being used by the orthopedic rotary tool1600).

In some implementations, the activation of the electronic clutch1612may be associated with reducing the motor power and or speed by 10% or more such as to further decouple the reactionary torque communicated from the anvil to the operator or robot (it is understood that although the present disclosure refers to an operator, this function could be performed by a robot).

In some implementations, the electronic clutch1612may be activated in response to a 1% (or more) reduction of an output anvil rpm from the output anvil no-load rpm as detected by a sensor (e.g., the rotational speed sensor1614). For example, if the output anvil no-load rpm is 300 rpm, then the electronic clutch1612may be activated in response to the sensor detecting an output anvil rpm of 299 (e.g., a 1% reduction in rpm from 300 rpm).

In some implementations, the decoupling of the motor1624(e.g., by disengaging or reducing the power to the motor1624) reduces a passthrough torque (e.g., torque coupled from the output anvil1622back through to the motor1624, a motor mount and a handpiece of the orthopedic rotary tool1600). Furthermore, a rotational energy associated with the rotating mass1604increases by enabling access to the rotating inertia of the motor1624.

In some implementations, an amount of time that the rotating mass1604is engaged, via the electronic clutch1612(e.g., via activation of the electronic clutch1612), may be between a range (e.g., between approximately 2 milliseconds and 100 milliseconds or less than (or equal to) 50 milliseconds, among other examples). In some implementations, the rotating mass1604increases a peak output torque, as measured at the output anvil1622, by (or at least by) 100% over a main drive axis (e.g., the first drive path through the bypass shaft1610as described in more detail elsewhere herein) for a period of at least 2 milliseconds.

In some implementations, the electronic clutch1612engages (e.g., activates) in less than (or equal to) twenty milliseconds, where engagement of the electronic clutch1612is defined as moving from 10% to 80% of transmitted torque through the electronic clutch1612. The electronic clutch1612may be disengaged (e.g., may be deactivated) to allow the motor1624to drive reaccelerate the rotating mass1604.

In some implementations, if the controller determines that the output speed (e.g., of the output anvil1622) is in the desired output rpm range, then the controller enables the orthopedic rotary tool1600to function normally (e.g., the output anvil1622is driven by the bypass shaft1610), and the electronic clutch1612is deactivated (e.g., which causes the rotating mass1604to be decoupled from the output anvil1622). If the controller determines that the output speed (e.g., an output rotational speed of the output anvil1622) drops below an output speed threshold, then the controller may activate and deactivate (e.g., in a pulsed manner) the electronic clutch1612to overcome the excessive load torque encountered by the output anvil1622and increase the output speed.

FIG.8is a diagram of an example driven sun gear2000for a planetary gear box. As shown inFIG.8, the driven sun gear includes a sun gear2002, planet gear2004, a ring gear2006, and a gear carrier2008. In some implementations, the planetary gearbox operates via a fixed ring gear, a driven sun gear, and planet gears rotating around the sun gear. The planet gears2004translate around the sun gear2002and drive the output through a gear carrier2008. This configuration can create gear ratios from 3:1 to 10:1 or more. In this configuration, the input torque on the sun gear2002creates a reactionary force component on the ring gear2006. Because the ring gear2006is rigidly fixed to the housing, this reactionary force is transferred to the operator of the orthopedic rotary tool. For example, in a driven sun gear scenario, a torque applied to a sun gear2002is communicated to a planet gear2004. When a ring gear2006is added, the planet gear2004orbits around the sun gear2002and the carrier2008drives the output. The force vectors2010a,2010b, and2010care equal and opposite on the planet gear. The reactionary torque on the ring gear2006is Fplanet*Radiusring gear. It should be noted that, when using a planetary gear box, there are several configurations that may be used to deliver torque.

FIG.9is a diagram of an example driven gear carrier2100for a planetary gear box. As shown inFIG.9, the driven sun gear2100includes a gear carrier2102, a shaft2104, a planet2106, and a ring gear2108. As another example, a fixed ring gear and a driven gear carrier may be utilized. The gear carrier2102is driven by shafts2104coupled to the carriage plate driver, bypassing the sun gear and planet gears2106. In this example, the gear box behaves in a 1:1 gear ratio, allowing the reactionary torque to be carried by the shafts2104driving the gear carrier2102, which transmits the torque directly back to the slip clutch and subsequently to the motor.

In a second scenario, for example, the carrier2102is driven solely by a shaft2104that is connecting to a rotating mass with a large kinetic energy. The direct coupling of the carrier2102to the shaft2104results in a 1:1 ratio. Because there is no mechanical advantage of the gears, the reactionary forces on the planet gear2106and ring gear2108become negligible. Accordingly, in some implementations, high energy rotational mass may be clutched through a 1:1 gear ratio, as described in more detail elsewhere herein. This helps explain the unexpected discovery that directly coupling the flywheel in a ratio of nearly 1:1 to the output resulted in minimal reactionary torque fed back to the operator.

With reference toFIGS.1-4, using the magnetic slip clutch1608and the one way bearing1810on the bypass shaft1610greatly reduces contact wear between components. For example, an advantage of coupling the rotating mass1604through a 1:1 gear ratio on the secondary gearbox1620is that there will be no reactionary torque transmitted to the housing through the secondary gearbox ring gear. It is understood that coupling the electronic clutch1612to a 1:1 gear ratio is the same as (or similar to) coupling the electronic clutch1612directly to the output anvil1622. The one way bearing1810may reduce the wear which would occur in a contacting slip clutch such as a ball cup spring relief clutch or a friction clutch. It is noted that the magnetic slip clutch1608can be used independently of the one way bearing1810on the bypass shaft1610(e.g., the magnetic slip clutch1608may be used without the one-way bearing).

FIGS.10A-10Care diagrams of example orthopedic rotary tools1000,1030, and1040, respectively. Each of the orthopedic rotary tools1000,1030, and1040include a motor1002, a primary gearbox1004, a one-way drive bearing1006(which can be optional), a first drive1008, a secondary drive1010, an output anvil1012, a slip clutch1014, a bypass shaft1016, a secondary gearbox1018(e.g., that has a greater than a 1:1 gear ratio), a clutch1020, a gear ratio1022of less than 2:1, and a rotating mass1024. As shown inFIG.10A, the first drive1008includes the slip clutch1014, the bypass shaft1016, and the secondary gearbox1018, and the secondary drive1010includes the clutch1020, the gear ratio1022, and the rotating mass1024.

The motor1002of the orthopedic rotary tool1030ofFIG.10Bdrives the rotating mass1024and the slip clutch1014independently. The orthopedic rotary tool1030ofFIG.10Bfurther includes an optional one-way drive bearing1026after the secondary gearbox1018. The first drive1008includes the slip clutch1014, the bypass shaft1016, the secondary gearbox1018, and the optional one-way bearing1024. The secondary drive1010includes the one-way drive bearing1006, the rotating mass1024, the clutch1020, and the gear ratio1022.

The first drive1008and the secondary drive1010of the orthopedic rotary tool1040ofFIG.10Cinclude the same components asFIG.10B; however, the secondary gearbox1018of the orthopedic rotary tool1040ofFIG.10Cis positioned between the primary gearbox1004and the slip clutch1014.

As indicated above,FIGS.10A-10Care provided as examples. Other examples may differ from what is described with regard toFIGS.10A-10C. The number and arrangement of the various components shown inFIGS.10A-10Care provided as examples. In practice, there may be additional components, fewer components, different components, or differently arranged components than those shown inFIGS.10A-10C. Furthermore, components shown inFIGS.10A-10Cmay be implemented within a single orthopedic rotary tool. Additionally, or alternatively, a set of components (e.g., one or more components) shown inFIGS.10A-10Cmay perform one or more functions described as being performed by another set of components shown inFIGS.10A-10C.

FIG.11is partial diagram of an example of a direct coupling of the carriage plate driver1616to the output anvil1622via the gear carrier1618of the orthopedic rotary tool1600ofFIG.1, which enables a 1:1 gear ratio of the orthopedic rotary tool1600.

FIG.12Ais a diagram of an example orthopedic rotary tool1200.FIGS.12B-12Care partial diagrams of the orthopedic rotary tool1200ofFIG.12A. As shown inFIGS.12A-12C, the orthopedic rotary tool1200includes a motor1202, a drive shaft1204, a clutch driver1206(e.g., a spring-trip slip-clutch driver (STSCD)), one or more magnets1208(e.g., one or more STSCD magnets), a bypass drive1210, a bypass shaft1212, ball bearings1214, a flywheel1216, a flywheel slot1218, a wrap spring1220, a flywheel spring tang1222, a control spring tang1224, a wrap down hub1226, a carriage plate driver1228, carriage plate driver magnets1230, a bypass pinion1232, a one-way bearing1234, an rpm sensor1236, a primary gearbox1238, secondary gearbox1240, an output anvil1242, and a bypass sleeve bushing1244(e.g., that enables relative motion between the bypass shaft1212and the wrap down hub1226).

In some implementations, the orthopedic rotary tool1200may cause the output anvil1242to rotate using at least one of a first mode (e.g., associated with a first pathway) or a second mode (e.g., associated with a second pathway), as described in more detail elsewhere herein. As an example, when operating in the first mode, the orthopedic rotary tool1200may use the bypass drive1210to cause the output anvil1242to rotate. As another example, when operating in the second mode, the orthopedic rotary tool may use the flywheel1216to cause the output anvil1242to rotate.

In some implementations, an operator of the orthopedic rotary tool1200may cause the motor1202to rotate (e.g., by interacting with an operator interface of the orthopedic rotary tool1200). The motor1202drives the draft shaft1204, which, in turn, drives the clutch driver1206(e.g., the STSCD driver). When the orthopedic rotary tool1200operates in the first mode, the clutch driver1206drives the bypass drive1210through a slip clutch (e.g., a magnetic slip clutch). For example, the clutch driver1206may use the one or more magnets1208to drive the bypass drive1210, which, in turn drives the bypass shaft1212. The bypass shaft1212is operatively coupled to the bypass pinion1232. The bypass drive1210and the bypass shaft1212may drive the bypass pinion1232through the one-way bearing1234. The bypass pinion1232drives the output anvil1242through the secondary gearbox1240.

In some implementations, when a load torque on the output anvil1242is higher than a slip torque (e.g., a slip torque associated with the clutch driver1206, the one or more magnets1208, and the bypass drive1210), the bypass drive1210and the bypass shaft1212slip. This causes a rotational speed of the carriage plate driver1228to be reduced (e.g., the carriage plate driver1228will slow down or stop moving).

In some implementations, the carriage plate driver magnets1230may be disposed on the carriage plate driver1228(e.g., the carriage plate driver magnets1230may be regularly spaced on the carriage plate driver1228). The rpm sensor1236may be positioned to detect movement of the carriage plate magnets1230. The rpm sensor1236may detect a rotational speed of the carriage plate driver1228based on the movement of the carriage plate driver magnets1230. The rpm sensor1236may send, and a controller (e.g., associated with a control board) may receive, an indication of the rotational speed of the carriage plate driver1228. The controller may activate, based on determining that the rotational speed of the carriage plate driver1228satisfies (e.g., has dropped below) a rotational speed threshold, the second mode (e.g., the controller may cause the orthopedic rotary tool1200to operate in the second mode by engaging the flywheel1216).

As an example, the orthopedic rotary tool1200may drive the clutch driver1206which, in turn, drives the wrap spring1220through the flywheel spring tang1222and the control spring tang1224. The flywheel spring tang1222may be aligned within the flywheel slot1218and the control spring tang1224may be aligned within a slot of the clutch driver1206. As the clutch driver1206drives the control spring tang1224in a first direction, the control spring tang1224generates a radial force that unwinds coils of the wrap spring1220(e.g., the wrap spring1220expands). In other words, the control spring tang1224may cause the wrap spring1220to partially unwind when the control spring tang1224is driven in the first direction. In this way, because the wrap spring1220unwinds when the orthopedic rotary tool1200operates in the first mode (e.g., using the bypass drive1210and the bypass shaft1212to rotate the control spring tang1224in the first direction), the wrap spring1220does not interact with the wrap down hub1226during operation of the orthopedic rotary tool1200in the first mode.

Additionally, as the clutch driver1206drives the control spring tang1224in the first direction, the control spring tang1224causes the flywheel1216to rotate (e.g., accelerate) in the first direction, which enables the flywheel1216to generate and store the rotational kinetic energy (e.g., the flywheel1216may interact with ball bearings to rotate at a high speed with minimal friction).

In some implementations, the controller may activate the second mode (e.g., the controller may cause the orthopedic rotary tool1200to operate in the second mode by engaging the flywheel1216) based on determining that the rotational speed of the carriage plate driver1228satisfies (e.g., has dropped below) the rotational speed threshold. As an example, if the output anvil1242encounters an excessive load torque, then a rotational speed of the carriage plate driver1228will reduce (e.g., because of slippage associated with the bypass drive1210and the bypass shaft1212) and the controller may cause the orthopedic rotary tool1200to operate in the second mode to overcome the excessive load torque.

In some implementations, to operate in the second mode, the controller may reduce a rotational speed of the clutch driver1206(e.g., by causing a rotational speed of the motor1202to be reduced), which causes a rotational speed of the control spring tang1224to be reduced. In response to the rotational speed of the control spring tang1224being reduced, the flywheel1216will continue to rotate due to its high rotational inertia. The flywheel1216drives the flywheel spring tang1222, and the flywheel spring tang1222winds the coils of the wrap spring1220(e.g., the wrap spring1220contracts) to operatively couple the wrap spring1220to the wrap down hub1226. In other words, the flywheel spring tang1222may cause the wrap spring1220to operatively couple to the wrap down hub1226. This results in the flywheel1216being operatively coupled to the output anvil1242(e.g., via the wrap spring1220and the wrap down hub1226) in an approximate 1:1 gear ratio. In this way, when operating in the second mode, the flywheel1216applies a high rotary energy pulse to the output anvil1242to overcome the excessive torque load. After the high energy pulse has been applied to the output anvil, the controller can increase the rotational speed of the motor which releases the wrap spring1220from the wrap down hub1226and accelerates the flywheel (e.g., associated with the first mode of operation). The rpm sensor1236indicates to the controller when to shift between first mode and second mode continuously throughout the operational cycle of the tool.

FIG.13is a flowchart of an example process1300associated with operating an orthopedic rotary tool. As shown inFIG.13, process1300may include driving, by a motor and a first clutch, a first drive path that causes an output anvil to rotate at a speed (block1310). As an example, process1300may include driving, by the motor and the first clutch, the first drive path that causes the output anvil to rotate at the speed, as described in more detail elsewhere herein. As further shown inFIG.13, process1300may include selectively enabling, by the motor and a second clutch, a second drive path that causes a rotating mass to engage the output anvil and increase the speed (block1320). As an example, process1300may include selectively enabling, by the motor and the second clutch, the second drive path that causes the rotating mass to engage the output anvil and increase the speed, as described in more detail elsewhere herein.

In some implementations, the second drive path may be selectively enabled when the speed of the output anvil drops to less than a percentage of a design speed (e.g., less than 99% of the design speed). In some implementations, the first clutch may be a slip clutch and the second drive path may be selectively enabled when the slip clutch begins slipping. In some implementations, the second drive path may be selectively enabled based on at least one of a duty cycle or a frequency. In some implementation, selectively enabling the second drive path may causes an output torque at the anvil to increase by at least 30%. In some implementations, the engagement of the rotating mass to the output anvil may counteract a load torque received at the output anvil. In some implementations, the load torque may be at least one of approximately 2 to 50 inch-pounds.

AlthoughFIG.13shows example blocks of process1300, in some implementations, process1300may include additional blocks, fewer blocks, different blocks, or differently arranged blocks than those depicted inFIG.13. Additionally, or alternatively, two or more of the blocks of process1300may be performed in parallel. The process1300is an example of one process that may be performed by one or more devices described herein. These one or more devices may perform one or more other processes based on operations described herein, such as the operations described in connection withFIGS.1-13. Moreover, while the process1300has been described in relation to the devices and components of the preceding figures, the process1300can be performed using alternative, additional, or fewer devices and/or components. Thus, the process1300is not limited to being performed with the example devices, components, hardware, and software explicitly enumerated in the preceding figures.

As used herein, the term “component” is intended to be broadly construed as hardware, firmware, or a combination of hardware and software. It will be apparent that systems and/or methods described herein may be implemented in different forms of hardware, firmware, and/or a combination of hardware and software. The actual specialized control hardware or software code used to implement these systems and/or methods is not limiting of the implementations. Thus, the operation and behavior of the systems and/or methods are described herein without reference to specific software code—it being understood that software and hardware can be used to implement the systems and/or methods based on the description herein.

As used herein, satisfying a threshold may, depending on the context, refer to a value being greater than the threshold, greater than or equal to the threshold, less than the threshold, less than or equal to the threshold, equal to the threshold, not equal to the threshold, or the like.

Even though particular combinations of features are recited in the claims and/or disclosed in the specification, these combinations are not intended to limit the disclosure of various implementations. In fact, many of these features may be combined in ways not specifically recited in the claims and/or disclosed in the specification. Although each dependent claim listed below may directly depend on only one claim, the disclosure of various implementations includes each dependent claim in combination with every other claim in the claim set. As used herein, a phrase referring to “at least one of” a list of items refers to any combination of those items, including single members. As an example, “at least one of: a, b, or c” is intended to cover a, b, c, a-b, a-c, b-c, and a-b-c, as well as any combination with multiple of the same item.

When “a processor” or “one or more processors” (or another device or component, such as “a controller” or “one or more controllers”) is described or claimed (within a single claim or across multiple claims) as performing multiple operations or being configured to perform multiple operations, this language is intended to broadly cover a variety of processor architectures and environments. For example, unless explicitly claimed otherwise (e.g., via the use of “first processor” and “second processor” or other language that differentiates processors in the claims), this language is intended to cover a single processor performing or being configured to perform all of the operations, a group of processors collectively performing or being configured to perform all of the operations, a first processor performing or being configured to perform a first operation and a second processor performing or being configured to perform a second operation, or any combination of processors performing or being configured to perform the operations. For example, when a claim has the form “one or more processors configured to: perform X; perform Y; and perform Z,” that claim should be interpreted to mean “one or more processors configured to perform X; one or more (possibly different) processors configured to perform Y; and one or more (also possibly different) processors configured to perform Z.”

No element, act, or instruction used herein should be construed as critical or essential unless explicitly described as such. Also, as used herein, the articles “a” and “an” are intended to include one or more items and may be used interchangeably with “one or more.” Further, as used herein, the article “the” is intended to include one or more items referenced in connection with the article “the” and may be used interchangeably with “the one or more.” Furthermore, as used herein, the term “set” is intended to include one or more items (e.g., related items, unrelated items, or a combination of related and unrelated items), and may be used interchangeably with “one or more.” Where only one item is intended, the phrase “only one” or similar language is used. Also, as used herein, the terms “has,” “have,” “having,” or the like are intended to be open-ended terms. Further, the phrase “based on” is intended to mean “based, at least in part, on” unless explicitly stated otherwise. Also, as used herein, the term “or” is intended to be inclusive when used in a series and may be used interchangeably with “and/or,” unless explicitly stated otherwise (e.g., if used in combination with “either” or “only one of”).

In the preceding specification, various example embodiments have been described with reference to the accompanying drawings. It will, however, be evident that various modifications and changes may be made thereto, and additional embodiments may be implemented, without departing from the broader scope of the invention as set forth in the claims that follow. The specification and drawings are accordingly to be regarded in an illustrative rather than restrictive sense.