Patent Publication Number: US-2021170497-A1

Title: Intraosseous device couplers, drivers, kits, and methods

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 15/858,786, filed on Dec. 29, 2017, which is a divisional of U.S. patent application Ser. No. 13/835,383, filed on Mar. 15, 2013, now U.S. Pat. No. 9,883,853, the contents of which are herein incorporated by reference in their entirety. 
    
    
     BACKGROUND 
     1. Field of the Invention 
     The present invention relates generally to intraosseous (IO) access and, more particularly, but not by way of limitation, to couplers, drivers, IO devices (e.g., needle sets), and methods that can be used to facilitate IO access (e.g., to obtain bone marrow from the bone of a patient for biopsy and/or transplantation). 
     2. Description of Related Art 
     Examples of couplers, drivers, IO devices, and kits are disclosed, for example, in International Patent Application No. PCT/US2007/078207 (published as WO 2008/033874). 
     SUMMARY 
     This disclosure includes embodiments of couplers, drivers, IO devices, and kits. 
     Some embodiments of the present couplers comprise a drive hub having a first end and a second end configured to be coupled in fixed relation to a driveshaft of a driver having a housing such that at least a portion of the hub is disposed outside the housing of the driver; where the first end of the drive hub includes female threads configured to be coupled to an intraosseous (TO) device. In some embodiments, the second end of the drive hub comprises female threads configured to be coupled to the driveshaft of a driver. In some embodiments, the female threads in the second end of the drive hub are configured to tighten if a driver rotates the drive hub and an IO device coupled to the drive hub in a clockwise direction. 
     Some embodiments of the present couplers comprise a drive hub having a first end and a second end including a recess configured to receive a driveshaft of a driver; where the first end of the drive hub is configured to be coupled to an intraosseous (IO) device to resist rotation of the IO device relative to the drive hub; and where the second end of the drive hub is configured such that if a driveshaft is inserted into the recess, an interference fit between the drive hub and the driveshaft will resist rotation of the drive hub relative to the driveshaft. In some embodiments, the recess has a circular cross-sectional shape. In some embodiments, the recess is defined by a cylindrical wall. In some embodiments, the second end further includes a second recess surrounding at least a portion of the cylindrical wall. In some embodiments, the second end of the hub includes a plurality of tabs extending into the recess, the plurality of tabs being configured to deform if the driveshaft is inserted into the recess. In some embodiments, the plurality of tabs each has a triangular cross-sectional shape. In some embodiments, the recess has a circular central portion and one or more peripheral portions extending outwardly from the circular central portion. In some embodiments, the plurality of tabs extend into the peripheral portions of the openings. In some embodiments, the first end of the drive hub includes a recess and is configured such that if a hub of an IO device is inserted into the recess, an interference fit between the drive hub and the IO device will resist rotation of the IO device relative to the drive hub. 
     Some embodiments of the present couplers comprise a drive hub having a first end and a second end configured to be coupled in fixed relation to a driveshaft of a driver; where the first end of the drive hub has a recess configured to receive a portion of an intraosseous (IO) device; and where the first end of the drive hub is configured such that if a portion of the IO device is inserted into the recess, an interference fit between the drive hub and the IO device will resist rotation of the IO device relative to the drive hub. In some embodiments, the recess has a circular cross-sectional shape. In some embodiments, the recess is defined by a cylindrical wall. In some embodiments, the first end further includes a second recess surrounding at least a portion of the cylindrical wall. In some embodiments, the first end of the hub includes a plurality of tabs extending into the recess, the plurality of tabs configured to deform if the driveshaft is inserted into the recess. In some embodiments, the plurality of tabs each has a triangular cross-sectional shape. In some embodiments, the recess has a circular central portion and one or more peripheral portions extending outwardly from the circular central portion. In some embodiments, the plurality of tabs extend into the peripheral portions of the openings. In some embodiments, the second end of the drive hub includes a recess and is configured such that if the driveshaft is inserted into the recess, an interference fit between the drive hub and the driveshaft will resist rotation of the drive hub relative to the driveshaft. 
     Some embodiments of the present couplers comprise a drive hub having a first end and a second end including a recess configured to receive a driveshaft of a driver; and an adhesive disposed in the recess and configured to adhere to a driveshaft inserted into the recess; where the first end of the drive hub is configured to be coupled to an intraosseous (IO) device to resist rotation of the IO device relative to the drive hub; and where the recess has a cross-sectional shape corresponding to the cross-sectional shape of the driveshaft such that if the driveshaft is inserted into the second recess, the drive hub will resist rotating relative to the driveshaft. In some embodiments, the recess has a non-circular cross-sectional shape. In some embodiments, the first end of the drive hub includes a second recess configured to receive a hub of an IO device; the second recess has a cross-sectional shape corresponding to a cross-sectional shape of the hub of the IO device such that if the portion of the IO device is inserted into the recess, the drive hub will resist rotation of the IO device relative to the drive hub; and the coupler further comprises a second adhesive disposed in the second recess and configured to adhere to an IO device inserted into the second recess. 
     Some embodiments of the present couplers comprise a drive hub having a first end and a second end configured to be coupled in fixed relation to a driveshaft of a driver; where the first end of the drive hub has a recess configured to receive a portion of an intraosseous (IO) device; and where the recess has a cross-sectional shape corresponding to a cross-sectional shape of the portion of the IO device such that if the portion of the IO device is inserted into the recess, the drive hub will resist rotation of the IO device relative to the drive hub. 
     Some embodiments of the present couplers comprise a drive hub having a first end and a second end including a recess configured to receive a driveshaft of a driver; and a resilient clip biased toward an axis of rotation of the drive hub; where the first end of the drive hub is configured to be coupled to an intraosseous (IO) device to resist rotation of the IO device relative to the drive hub; and where the recess has a cross-sectional shape corresponding to a cross-sectional shape of the driveshaft such that if the driveshaft is inserted into the recess, the drive hub will resist rotating relative to the driveshaft. In some embodiments, the couplers comprise a hollow sleeve configured to be disposed around the recess such that a driveshaft inserted into the recess will be disposed in the hollow sleeve; where the resilient clip is unitary with the hollow sleeve. In some embodiments, the hollow sleeve and resilient clip comprise a single piece of sheet metal. In some embodiments, the distal end of the driveshaft has a non-circular cross-section. 
     Some embodiments of the present couplers comprise a drive hub having a first end and a second end including a recess configured to receive a driveshaft of a driver, the drive hub having a sidewall with at least one opening extending through the sidewall in communication with the recess, the at least one opening having an inner cross-sectional area at the recess that is smaller than an outer cross-sectional area spaced apart from the inner cross-sectional area; at least one ball movably disposed in the at least one opening in the drive hub; a resilient c-clip disposed around the drive hub such that the c-clip biases the at least one ball toward a rotational axis of the drive hub; where the first end of the drive hub is configured to be coupled to an intraosseous (IO) device to resist rotation of the IO device relative to the drive hub; and where the second end of the drive hub is configured such that if a driveshaft having at least one detent is inserted into the recess, the c-clip will (i) allow the at least one ball to move away from the rotational axis of the drive hub until the at least one detent aligns with the at least one ball, and (ii) press the at least one ball into the at least one detent when the at least one detent is aligned with the at least one ball to resist removal of the driveshaft from the recess. In some embodiments, the driveshaft and the recess each has a non-circular cross-sectional shape. In some embodiments, the drive hub has a circular outer cross-sectional shape. In some embodiments, the first end of the drive hub includes a second recess configured to receive a hub of an IO device, and the drive hub has at least one second opening extending through the sidewall in communication with the second recess, the at least one second opening having an inner cross-sectional area at the second recess that is smaller than an outer cross-sectional area spaced apart from the inner cross-sectional area; the coupler further comprising: at least one second ball movably disposed in the at least one second opening in the drive hub; a second resilient c-clip disposed around the drive hub such that the c-clip biases the at least one second ball toward a rotational axis of the drive hub; where the first end of the drive hub is configured such that if a hub of an IO device having at least one second detent is inserted into the recess, the second c-clip will (i) allow the at least one ball to move away from the rotational axis of the drive hub until the at least one second detent aligns with the at least one second ball, and (ii) press the at least one second ball into the at least one second detent when the at least one second detent is aligned with the at least one second ball to resist removal of the IO device from the recess. 
     Some embodiments of the present couplers comprise a drive hub having a first end and a second end configured to be coupled in fixed relation to a driveshaft of a driver, the first end including a recess configured to receive a hub of an IO device, the drive hub having a sidewall with at least one opening extending through the sidewall in communication with the recess, the at least one opening having an inner cross-sectional area at the recess that is smaller than an outer cross-sectional area spaced apart from the inner cross-sectional area; at least one ball movably disposed in the at least one opening in the drive hub; a resilient c-clip disposed around the drive hub such that the c-clip biases the at least one ball toward a rotational axis of the drive hub; where the second end of the drive hub is configured such that if a hub of an intraosseous (TO) device having at least one detent is inserted into the recess, the c-clip will (i) allow the at least one ball to move away from the rotational axis of the drive hub until the at least one detent aligns with the at least one ball, and (ii) press the at least one ball into the at least one detent when the at least one detent is aligned with the at least one ball to resist removal of the driveshaft from the recess. In some embodiments, the hub of the IO device and the recess each has a non-circular cross-sectional shape. In some embodiments, the drive hub has a circular outer cross-sectional shape. 
     Some embodiments of the present couplers comprise a drive hub having a first end and a second end configured to be coupled in fixed relation to a driveshaft of a driver, the first end including a recess configured to receive a hub of an IO device, the drive hub having a sidewall with at least one opening extending through the sidewall in communication with the recess, the at least one opening having an inner cross-sectional area at the recess that is smaller than an outer cross-sectional area spaced apart from the inner cross-sectional area; at least one ball movably disposed in the at least one opening in the drive hub; a collar movably disposed around the drive hub and having an interior surface defining at least one detent adjacent the drive hub; where the collar is movable between (i) a first position in which the at least one detent of the collar is aligned with the at least one opening such that the at least one ball can move away from the rotational axis of the drive hub to permit a hub of an intraosseous (IO) device having a detent to be inserted into or removed from the recess, and (ii) a second position in which the at least one detent of the collar is not aligned with the at least one opening such that if a hub of an IO device having at least one detent is disposed in the recess such that the at least one detent of the hub is aligned with the opening, the IO device is prevented from being removed from the recess. In some embodiments, the collar is biased toward the second position. In some embodiments, the hub of the IO device and the recess each has a non-circular cross-sectional shape. In some embodiments, the second end of the drive hub includes a second recess configured to receive a driveshaft of a driver, and the drive hub has at least one second opening extending through the sidewall in communication with the second recess, the at least one second opening having an inner cross-sectional area at the second recess that is smaller than an outer cross-sectional area spaced apart from the inner cross-sectional area; the coupler further comprising at least one second ball movably disposed in the at least one second opening in the drive hub; a second collar movably disposed around the drive hub and having an interior surface defining at least one second detent adjacent the drive hub; where the second collar is movable between (i) a first position in which the at least one second detent of the second collar is aligned with the at least one second opening such that the at least one second ball can move away from the rotational axis of the drive hub to permit a driveshaft having a detent to be inserted into or removed from the second recess, and (ii) a second position in which the at least one second detent of the collar is not aligned with the at least one second opening such that if driveshaft of a driver having at least one second detent is disposed in the second recess such that the at least one second detent is aligned with the opening, the driveshaft is prevented from being removed from the recess. 
     Some embodiments of the present couplers comprise a drive hub having a first end and a second end including a recess configured to receive a driveshaft of a driver, the drive hub having a sidewall with at least one opening extending through the sidewall in communication with the recess; at least one set screw with a spring-loaded ball, the at least one set screw disposed in the at least one opening in the drive hub such that the ball is biased in a direction toward an axis of rotation of the drive hub; where the first end of the drive hub is configured to be coupled to an intraosseous (IO) device to resist rotation of the IO device relative to the drive hub; and where the second end of the drive hub is configured such that if a driveshaft having at least one detent is inserted into the recess (i) the spring-loaded ball of the at least one set screw will move away from the rotational axis of the drive hub until the at least one detent aligns with the at least one ball, and (ii) the spring-loaded ball of the at least one set screw will move into the at least one detent when the at least one detent is aligned with the at least one ball to resist removal of the driveshaft from the recess. In some embodiments, the driveshaft and the recess each has a non-circular cross-sectional shape. In some embodiments, where the first end of the drive hub includes a second recess configured to receive a hub of an IO device, and the drive hub has at least one second opening extending through the sidewall in communication with the second recess; the coupler further comprising at least one second set screw with a spring-loaded ball, the at least one second set screw disposed in the at least one second opening in the drive hub such that the ball is biased in a direction toward an axis of rotation of the drive hub; where the second end of the drive hub is configured such that if a hub of an IO device having at least one second detent is inserted into the recess (i) the spring-loaded ball of the at least one second set screw will move away from the rotational axis of the drive hub until the at least one second detent aligns with the at least one ball, and (ii) the spring-loaded ball of the at least one second set screw will move into the at least one second detent when the at least one detent is aligned with the at least one second ball to resist removal of the IO device from the recess. 
     Some embodiments of the present couplers comprise a drive hub having a first end and a second end configured to be coupled in fixed relation to a driveshaft of a driver, the first end including a recess configured to receive a hub of an intraosseous (IO) device, the drive hub having a sidewall with at least one opening extending through the sidewall in communication with the recess; at least one set screw with a spring-loaded ball, the at least one set screw disposed in the at least one opening in the drive hub such that the ball is biased in a direction toward an axis of rotation of the drive hub; where the first end of the drive hub is configured such that if a hub of an IO device having at least one detent is inserted into the recess (i) the spring-loaded ball of the at least one set screw will move away from the rotational axis of the drive hub until the at least one detent aligns with the at least one ball, and (ii) the spring-loaded ball of the at least one set screw will move into the at least one detent when the at least one detent is aligned with the at least one ball to resist removal of the IO device from the recess. In some embodiments, the hub of the IO device and the recess each has a non-circular cross-sectional shape. 
     Some embodiments of the present couplers comprise a drive hub having a first end and a second end including a recess configured to receive a driveshaft of a driver, the drive hub having a sidewall with an opening extending through the sidewall in communication with the recess; a screw having an enlarged head and a threaded shaft with a distal end, the screw threaded into the opening with the distal end facing in a direction toward an axis of rotation of the drive hub; where the first end of the drive hub is configured to be coupled to an intraosseous (IO) device to resist rotation of the IO device relative to the drive hub; and where the screw is rotatable between (i) a first position in which the distal end does not extend into the recess to permit a driveshaft having a detent to be inserted into or removed from the recess, and (ii) a second position in which the distal end extends into the recess such that if a driveshaft having a detent is disposed in the recess such that the detent of the driveshaft is aligned with the opening, the driveshaft is prevented from being removed from the recess. In some embodiments, the driveshaft and the recess each has a non-circular cross-sectional shape. In some embodiments, the first end of the drive hub includes a second recess configured to receive a hub of an IO device, and the drive hub has a second opening extending through the sidewall in communication with the second recess; the coupler further comprising a second screw having an enlarged head and a threaded shaft with a distal end, the screw threaded into the second opening with the distal end facing in a direction toward an axis of rotation of the drive hub; where the second screw is rotatable between (i) a first position in which the distal end does not extend into the second recess to permit a hub of an IO device having a detent to be inserted into or removed from the recess, and (ii) a second position in which the distal end extends into the second recess such that if a hub of an IO device having a detent is disposed in the recess such that the detent of the hub is aligned with the opening, the IO device is prevented from being removed from the recess. 
     Some embodiments of the present couplers comprise a drive hub having a first end and a second end configured to be coupled in fixed relation to a driveshaft of a driver, the first end including a recess configured to receive a hub of an intraosseous (IO) device, the drive hub having a sidewall with an opening extending through the sidewall in communication with the recess; a screw having an enlarged head and a threaded shaft with a distal end, the screw threaded into the opening with the distal end facing in a direction toward an axis of rotation of the drive hub; where the screw is rotatable between (i) a first position in which the distal end does not extend into the recess to permit a hub of an IO device having a detent to be inserted into or removed from the recess, and (ii) a second position in which the distal end extends into the recess such that if a hub of an IO device having a detent is disposed in the recess such that the detent of the hub is aligned with the opening, the IO device is prevented from being removed from the recess. 
     Some embodiments of the present couplers comprise a drive hub having a first end and a second end including a recess configured to receive a driveshaft of a driver, the drive hub having a sidewall with an opening extending through the sidewall in communication with the recess; a pin having a distal end configured to be inserted into the opening such that the pin extends across a majority of a width of the recess; where the first end of the drive hub is configured to be coupled to an intraosseous (IO) device to resist rotation of the IO device relative to the drive hub; and where the pin is movable between (i) a first position in which the distal end does not extend into the recess to permit a driveshaft having a transverse passageway to be inserted into or removed from the recess, and (ii) a second position in which the pin extends into and across a majority of the recess such that if a driveshaft having a transverse passageway is disposed in the recess such that the transverse passageway is aligned with the opening, the pin extends into the transverse passageway to prevent the driveshaft from being removed from the recess. In some embodiments, the driveshaft and the recess each has a non-circular cross-sectional shape. In some embodiments, the first end of the drive hub includes a second recess configured to receive a hub of an IO device, and the drive hub has a second opening extending through the sidewall in communication with the second recess; the coupler further comprising a second pin having a distal end configured to be inserted into the second opening such that the pin extends across a majority of a width of the second recess; where the second pin is movable between (i) a first position in which the distal end does not extend into the second recess to permit a driveshaft having a transverse passageway to be inserted into or removed from the second recess, and (ii) a second position in which the second pin extends into and across a majority of the second recess such that if a hub of an IO device having a transverse passageway is disposed in the second recess such that the transverse passageway is aligned with the opening, the pin extends into the transverse passageway to prevent the IO device from being removed from the second recess. 
     Some embodiments of the present couplers comprise a drive hub having a first end and a second end configured to be coupled in fixed relation to a driveshaft of a driver, the first end including a recess configured to receive a hub of an intraosseous (IO) device, the drive hub having a sidewall with an opening extending through the sidewall in communication with the recess; a pin having a distal end configured to be inserted into the opening such that the pin extends across a majority of a width of the recess; where the pin is movable between (i) a first position in which the distal end does not extend into the recess to permit a hub of an IO device having a transverse passageway to be inserted into or removed from the recess, and (ii) a second position in which the pin extends into and across a majority of the recess such that if a hub of an IO device having a transverse passageway is disposed in the recess such that the transverse passageway is aligned with the opening, the pin extends into the transverse passageway to prevent the IO device from being removed from the recess. 
     Some embodiments of the present couplers comprise a drive hub having a first end and a second end configured to be coupled in fixed relation to a driveshaft of a driver; a resilient clamp having a substantially circular interior, the clamp configured to be movable between (i) a contracted position in which the interior has a first transverse dimension, and (ii) an expanded position in which the interior has a second transverse dimension that is larger than the first transverse dimension, where the resilient clamp is biased toward the contracted position; where the first end of the drive hub has a transverse dimension that is larger than the first transverse dimension of the clamp, and that is larger than a transverse dimension of the driveshaft; where the first end of the drive hub is configured to abut an intraosseous (IO) device such that the clamp can be disposed around the drive hub and the IO device to resist separation of the IO device from to the drive hub. In some embodiments, the drive hub has a cross-section with a circular central portion and a projection extending from the central portion in a direction away from a rotational axis of the drive hub. In some embodiments, the drive hub is not configured to receive a portion of the IO device. In some embodiments, the drive hub is configured to abut an IO device such that the clamp can be disposed around and in contact with the drive hub and the IO device to resist separation of the IO device from the drive hub. In some embodiments, the first end of the drive hub includes a sidewall defining a recess configured to receive a hub of the IO device, the sidewall having at least one slot extending through the sidewall in communication with the recess in the first end. In some embodiments, the second end of the drive hub includes a sidewall defining a recess configured to receive a driveshaft of a driver, the sidewall having at least one slot extending through the sidewall in communication with the recess in the second end, the coupler further comprising a second resilient clamp having a substantially circular interior, the second clamp configured to be movable between (i) a contracted position in which the interior has a first transverse dimension, and (ii) an expanded position in which the interior has a second transverse dimension that is larger than the first transverse dimension, where the second resilient clamp is biased toward the contracted position; where the second end of the drive hub has a transverse dimension that is larger than the first transverse dimension of the clamp, and that is larger than a transverse dimension of the driveshaft; where the recess in the second end of the drive hub is configured to receive a driveshaft of a driver such that the clamp can be disposed around the drive hub and the driveshaft to resist separation of the drive hub from the driveshaft. 
     Some embodiments of the present couplers comprise a drive hub having a first end and a second end including a sidewall defining a recess configured to receive a driveshaft of a driver, the sidewall having at least one slot extending through the sidewall in communication with the recess in the second end; a resilient clamp having a substantially circular interior, the clamp configured to be movable between (i) a contracted position in which the interior has a first transverse dimension, and (ii) an expanded position in which the interior has a second transverse dimension that is larger than the first transverse dimension, where the resilient clamp is biased toward the contracted position; where the second end of the drive hub has a transverse dimension that is larger than the first transverse dimension of the clamp; and where the recess is configured to receive a driveshaft of a driver such that the clamp can be disposed around the drive hub and the driveshaft to resist separation of the drive hub from the driveshaft. In some embodiments, the recess is configured to receive a driveshaft of a driver such that the clamp can be disposed around and in contact with the drive hub and the driveshaft to resist separation of the drive hub from the driveshaft. 
     Some embodiments of the present couplers comprise a drive hub having a first end and a second end configured to be coupled in fixed relation to a driveshaft of a driver, the first end including a plurality of movable prongs configured to grasp a hub of an intraosseous (IO) device; a collar movably disposed around the drive hub; where the collar is movable between (i) a first position in which the plurality of prongs can move away from the rotational axis of the drive hub to permit an IO device to be inserted into or removed from the plurality of prongs, and (ii) a second position in which the collar constrains the plurality of prongs such that if a hub of an IO device is disposed between the plurality of prongs, the prongs resist removal of the IO device from the plurality of prongs. In some embodiments, the collar is biased toward the second position. In some embodiments, the second end of the drive hub includes including a second plurality of movable prongs configured to grasp a driveshaft of a driver, the coupler further comprising a second collar movably disposed around the drive hub; where the second collar is movable between (i) a first position in which the second plurality of prongs can move away from the rotational axis of the drive hub to permit a driveshaft to be inserted into or removed from the second plurality of prongs, and (ii) a second position in which the second collar constrains the second plurality of prongs such that if a hub of an IO device is disposed between the second plurality of prongs, the second plurality of prongs resists removal of IO device from the second plurality of prongs. 
     Some embodiments of the present couplers comprise a drive hub having a first end and a second end including a recess configured to receive a driveshaft of a driver, the recess having a proximal end and a distal end; a magnetic ring disposed around a perimeter of the recess between the proximal end of the recess and the distal end of the recess; where the first end of the drive hub is configured to be coupled to an intraosseous (IO) device to resist rotation of the IO device relative to the drive hub. In some embodiments, the recess has a non-circular cross-sectional shape. In some embodiments, the magnetic ring defines a step within the recess. In some embodiments, the first end of the drive hub includes a second recess configured to receive a driveshaft of a driver, the recess having a proximal end and a distal end, the coupler further comprising a second magnetic ring disposed around a perimeter of the second recess between the proximal end of the second recess and the distal end of the second recess. In some embodiments, the recess has a non-circular cross-sectional shape. In some embodiments, the second magnetic ring defines a step within the second recess. In some embodiments, the second end of the drive hub comprises a flange extending outwardly relative to an axis of rotation of the drive hub. 
     Some embodiments of the present drivers comprise a housing; a power source; a driveshaft coupled to the power source such that the power source can cause the driveshaft to rotate; and a coupler of having any of the disclosed features or characteristics, where the drive hub is configured to be coupled to the driveshaft such that at least a portion of the drive hub is disposed outside the housing. In some embodiments, a portion of the driveshaft is tapered. In some embodiments, the drive hub is unitary with the driveshaft. In some embodiments, the power source comprises a spring. In some embodiments, the drivers further comprise an electric motor coupled to the driveshaft and the power source. In some embodiments, the driveshaft has a distal end including male threads corresponding to the female threads in the second end of the drive hub. In some embodiments, the driveshaft has a distal end with a non-circular cross-sectional shape. In some embodiments, the distal end of the driveshaft comprises one or more projections extending outward relative to an axis of rotation of the driveshaft. In some embodiments, the distal end of the driveshaft has a cross-section that is a different shape than a cross-section of the recess in the second end of the drive hub. In some embodiments, the driveshaft comprises a cross-section with a circular central portion and a projection extending from the central portion in a direction away from a rotational axis of the driveshaft. In some embodiments, the drivers comprise an element comprising at least one of a magnet and a magnetically-attractive material, the element coupled to the driveshaft and spaced apart from the distal end of the driveshaft; where the element of the driver is configured to magnetically couple to the magnetic ring of the coupler if the driveshaft is inserted into the recess in the second end of the coupler. In some embodiments, the element is disposed within the driveshaft. In some embodiments, the element comprises a ring disposed around the driveshaft. 
     Some embodiments of the present drivers comprise a housing having a body portion and a shroud portion, the body portion having a sidewall defining a distal end, and the shroud portion having a cylindrical sidewall extending from the distal end of the body portion, the shroud portion having an open distal end; a power source; and a driveshaft disposed in the body portion of the housing and coupled to the power source such that the power source can cause the driveshaft to rotate, the driveshaft having a distal end extending from the body portion and into the shroud portion; where the driver is configured to be coupled to an IO device having a hub with a recess sized to receive the distal end of the driveshaft, such that the distal end of the driveshaft extends into the recess and the hub of the IO device is at least partially disposed in the shroud portion of the housing. In some embodiments, the drivers comprise a plate having an opening, the plate disposed in the shroud portion of the housing with the driveshaft aligned with the opening such that the plate is movable within the shroud along a length of the driveshaft; and a spring disposed between the plate and the distal end of the body portion of the housing such that the spring biases the plate in a direction toward the open end of the shroud portion. In some embodiments, the shroud portion comprises a lip extending inward toward the driveshaft and configured to prevent the plate from exiting the shroud portion. In some embodiments, the shroud portion of the housing has one or more projections extending in a direction away from the driveshaft. In some embodiments, the one or more projections comprise two projections extending in opposite directions. In some embodiments, the shroud portion comprises one or more resilient portions and one or more substantially rigid portions, and the one or more projections extend from the one or more resilient portions such that the one or more projections are movable relative to the driveshaft. In some embodiments, the shroud portion has two elongated grooves in an outer surface of the cylindrical sidewall, the two elongated grooves extending in a direction that is substantially perpendicular to rotational axis of the driveshaft. 
     Some embodiments of the present kits comprise a driver having any of the disclosed features or characteristics and an intraosseous (IO) device comprising a first hub having a cannula coupled in fixed relation to the hub, the cannula having a distal end extending from a distal of the hub; where the IO device is configured to be coupled to the first end of the drive hub of the coupler. As described below, any couplers having the disclosed features or characteristics may be included. In some embodiments, the IO device is configured to be coupled to the first end of the drive hub such that the drive hub contacts the first hub of the IO device. In some embodiments, the IO device further comprises a second hub configured to be coupled to the first hub. In some embodiments, the second hub has a trocar with a distal end extending from the second hub, and the second hub is configured to be coupled to the first hub such that the trocar extends through a longitudinal passage of the trocar. In some embodiments, the IO device is configured to be coupled to the first end of the drive hub of the coupler such that the drive hub contacts the second hub of the IO device. In some embodiments, the second hub of the IO device is unitary with the drive hub of the coupler. In some embodiments, the second hub of the IO device comprises male threads corresponding to female threads of the drive hub. In some embodiments, the second hub of the IO device has a non-circular cross-sectional shape. In some embodiments, the second hub of the IO device comprises one or more projections extending outward relative to an axis of rotation of the IO device. In some embodiments, the second end of the drive hub has a cross-section that is a different shape than a cross-section of the recess in the first end of the drive hub. In some embodiments, the first hub is configured to be inserted into the recess in the first end of the drive hub of the coupler. In some embodiments, the second hub is configured to be inserted into the recess in the first end of the drive hub. In some embodiments, the second hub comprises a projection with at least one detent. In some embodiments, the second hub comprises a projection with a transverse passageway extending transversely across at least a portion of the projection. In some embodiments, the kits can comprise a sleeve configured to be rotatably coupled to one or more of the first hub and the second hub of the IO device, the sleeve including a proximal portion configured to fit over the shroud portion of the housing to couple the IO device to the driver. In some embodiments, the proximal portion of the sleeve comprises one or more L-shaped slots configured to receive the one or more projections if the proximal portion of the sleeve is disposed over the shroud portion of the housing such that the sleeve can be rotated relative to the shroud portion to resist removal of the IO device from the driver. In some embodiments, the proximal portion of the sleeve includes an interior surface defining one or more detents configured to receive the one or more projections of the shroud portion. In some embodiments, the kits can further comprise a sleeve rotatably coupled to one or more of the first hub and the second hub of the IO device, the sleeve including a proximal portion configured to fit over the shroud portion of the housing if the IO device is coupled to the driver; and a resilient U-shaped clip having two legs; where the proximal portion of the sleeve comprises two elongated openings configured to align with the elongated grooves in the shroud portion if the proximal portion of the sleeve is disposed on the shroud portion; and where the clip is configured to extend over the proximal portion of the sleeve with the two legs extending through the elongated openings in the sleeve and into the elongated grooves to resist removal of the sleeve and IO device from the driver. In some embodiments, the second hub comprises a cross-section with a circular central portion and a projection extending from the central portion in a direction away from a rotational axis of the second hub. 
     Any embodiment of any of the devices, systems, and methods can consist of or consist essentially of—rather than comprise/include/contain/have—any of the described steps, elements, and/or features. Thus, in any of the claims, the term “consisting of” or “consisting essentially of” can be substituted for any of the open-ended linking verbs recited above, in order to change the scope of a given claim from what it would otherwise be using the open-ended linking verb. 
     The feature or features of one embodiment may be applied to other embodiments, even though not described or illustrated, unless expressly prohibited by this disclosure or the nature of the embodiments. 
     Details associated with the embodiments described above and others are presented below. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The following drawings illustrate by way of example and not limitation. For the sake of brevity and clarity, every feature of a given structure is not always labeled in every figure in which that structure appears. Identical reference numbers do not necessarily indicate an identical structure. Rather, the same reference number may be used to indicate a similar feature or a feature with similar functionality, as may non-identical reference numbers. The embodiments of the present drivers, coupler assemblies, intraosseous (IO) devices, and their components shown in the figures are drawn to scale for at least the embodiments shown. 
         FIG. 1A  depicts a perspective view of one embodiment of the present intraosseous devices having a first embodiment of a cannula and a first embodiment of a stylet. 
         FIG. 1B  depicts a perspective view of a second embodiment of the present cannulas. 
         FIGS. 1C and 1D  depict a perspective views of a third embodiment of the present IO devices having a second embodiment of the present stylets disposed in the cannula of  FIG. 2 . 
         FIGS. 1E  and IF depict perspective views of a fourth embodiment of the present IO devices having a stylets, trocars, or inner penetrators disposed in a cannula or outer penetrator. 
         FIG. 2  depicts a cross-sectional side view of one embodiment of the present drivers. 
         FIGS. 3A-3C  depict various views of a first embodiment of the present couplers in combination with a powered driver and an IO device. 
         FIGS. 4A-4C  depict various views of a second embodiment of the present couplers in combination with a powered driver and an IO device. 
         FIGS. 5A-5D  depict various views of a third embodiment of the present couplers in combination with a powered driver and an IO device. 
         FIGS. 6A-6E  depict various views of a fourth embodiment of the present couplers in combination with a powered driver and an IO device. 
         FIGS. 7A-7C  depict various views of a fifth embodiment of the present couplers in combination with a powered driver and an IO device. 
         FIGS. 8A-8C  depict various views of a sixth embodiment of the present couplers in combination with a powered driver and an IO device. 
         FIGS. 9A-9C  depict various views of a seventh embodiment of the present couplers in combination with a powered driver and an IO device. 
         FIGS. 10A-10D  depict various views of an eighth embodiment of the present couplers in combination with a powered driver and an IO device. 
         FIGS. 11A-11D  depict various views of a ninth embodiment of the present couplers in combination with a powered driver and an IO device. 
         FIGS. 12A-12D  depict various views of a tenth embodiment of the present couplers in combination with a powered driver and an IO device. 
         FIGS. 13A-13C  depict various views of an eleventh embodiment of the present couplers in combination with a powered driver and an IO device. 
         FIGS. 14A-14B  depict side cross-sectional views of a powered driver for use with at least some embodiments of the present couplers. 
         FIGS. 15A-15C  depict various views of embodiment of a powered driver  200   m  for use with at least some embodiments of the present couplers. 
         FIGS. 16A-16C  depict various views of a twelfth embodiment of the present couplers in combination with a powered driver and an IO device. 
         FIGS. 17A-17D  depict various views of a thirteenth embodiment of the present couplers in combination with a powered driver and an IO device. 
         FIGS. 18A-18C  depict various views of a fourteenth embodiment of the present couplers in combination with a powered driver and an IO device. 
         FIGS. 19A-19C  depict various views of a fifteenth embodiment of the present couplers in combination with a powered driver and an IO device. 
         FIGS. 20A-20B  depict side cross-sectional views of a sixteenth embodiment of the present couplers in combination with a powered driver and an IO device. 
         FIGS. 21A-21C  depict various views of a seventeenth embodiment of the present couplers in combination with a powered driver and an IO device. 
         FIGS. 22A-22B  depict side cross-sectional views of an eighteenth embodiment of the present couplers in combination with a powered driver and an IO device. 
         FIGS. 23A-23B  depict perspective and side cross-sectional views, respectively, of a nineteenth embodiment of the present couplers in combination with a powered driver and an IO device. 
         FIGS. 24A-24B  depict perspective and side cross-sectional views, respectively, of a twentieth embodiment of the present couplers in combination with a powered driver and an IO device. 
         FIGS. 25A-25B  depict perspective and side cross-sectional views, respectively, of a twenty-first embodiment of the present couplers in combination with a powered driver and an IO device. 
         FIGS. 26A-26E  depict various views of a twenty-second embodiment of the present couplers in combination with a powered driver and an IO device. 
         FIGS. 27A-27C  depict various views of a twenty-third embodiment of the present couplers in combination with a powered driver and an IO device. 
         FIGS. 28A-28C  depict various views of a twenty-fourth embodiment of the present couplers in combination with a powered driver and an IO device. 
         FIGS. 29A-29D  depict various views of a twenty-fifth embodiment of the present couplers in combination with a powered driver and an IO device. 
         FIGS. 30A-30C  depict various views of a twenty-sixth embodiment of the present couplers in combination with a powered driver and an IO device. 
         FIGS. 31A-31D  depict various views of a twenty-seventh embodiment of the present couplers in combination with a powered driver and an IO device. 
         FIGS. 32A-32C  depict various views of a twenty-eighth embodiment of the present couplers in combination with a powered driver and an IO device. 
         FIGS. 33A-33B  depict cutaway perspective and side cross-sectional views, respectively, of a twenty-ninth embodiment of the present couplers in combination with a powered driver and an IO device. 
         FIGS. 34A-34C  depict various views of a thirtieth embodiment of the present couplers in combination with a powered driver and an IO device. 
         FIGS. 35A-35C  depict various views of a thirty-first embodiment of the present couplers in combination with a powered driver and an IO device. 
     
    
    
     DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS 
     The term “coupled” is defined as connected, although not necessarily directly, and not necessarily mechanically; two items that are “coupled” may be unitary with each other. The terms “a” and “an” are defined as one or more unless this disclosure explicitly requires otherwise. The term “substantially” is defined as largely but not necessarily wholly what is specified (and includes what is specified; e.g., substantially 90 degrees includes 90 degrees and substantially parallel includes parallel), as understood by a person of ordinary skill in the art. In any disclosed embodiment, the terms “substantially,” “approximately,” and “about” may be substituted with “within [a percentage] of” what is specified, where the percentage includes 0.1, 1, 5, and 10 percent. 
     The terms “comprise” (and any form of comprise, such as “comprises” and “comprising”), “have” (and any form of have, such as “has” and “having”), “include” (and any form of include, such as “includes” and “including”) and “contain” (and any form of contain, such as “contains” and “containing”) are open-ended linking verbs. As a result, a driver or coupler assembly that “comprises,” “has,” “includes” or “contains” one or more elements possesses those one or more elements, but is not limited to possessing only those elements. Likewise, a method that “comprises,” “has,” “includes” or “contains” one or more steps possesses those one or more steps, but is not limited to possessing only those one or more steps. 
     Further, a device or system (or an element of a device or system) that is configured in a certain way is configured in at least that way, but it can also be configured in other ways than those specifically described. 
     Various types of coupler assemblies incorporating teachings of the present disclosure may be satisfactorily used to releasably engage one end of a shaft extending from a driver with one end of an intraosseous device. For some embodiments, the powered driver may include a driveshaft having one end with a non-circular (e.g., generally hexagonal) cross section operable to be releasably engaged with a latch mechanism disposed proximate (e.g., in) one end of a coupler assembly. For some embodiments, a coupler assembly incorporating teachings of the present disclosure may be referred to as a “hands free” coupler, a quick disconnect or quick release coupler, and/or a port assembly. 
     A powered driver may be used to insert an IO device incorporating teachings of the present disclosure into a selected target area or target site in ten seconds or less. However, various teachings of the present disclosure are not limited to use with powered drivers. Manual drivers and spring powered drivers may also be used with IO devices incorporating teachings of the present disclosure. 
     Examples of manual drivers are shown in co-pending patent application Ser. No. 11/042,912 entitled Manual Intraosseous Device filed Jan. 25, 2005 (published as US 2005/0165404). The term “fluid” may be used in this application to include liquids such as, but not limited to, blood, water, saline solutions, IV solutions, plasma, or any mixture of liquids, particulate matter, dissolved medication, and/or drugs associated with biopsy or aspiration of bone marrow or communication of fluids with bone marrow or other target sites. The term “fluid” may also be used in this patent application to include any body fluids and/or liquids containing particulate matter such as bone marrow and/or cells that may be withdrawn from a target area. 
     The terms “harvest” and “harvesting” may be used in this application to include bone and/or bone marrow biopsy and bone marrow aspiration. Bone and/or bone marrow biopsy (sometimes referred to as “needle biopsy”) may be generally described as removing a relatively small piece or specimen of bone and/or bone marrow from a selected target area for biopsy purposes. Bone marrow aspiration (sometimes referred to as “bone marrow sampling”) may be generally described as removing larger quantities of bone marrow from a selected target area. Relatively large quantities of bone marrow may be used for diagnostic, transplantation, and/or research purposes. For example, some stem cell research techniques may require relatively large quantities of bone marrow. 
     The terms “insertion site,” “penetration site,” and “installation site” may be used in this application to describe a location on a bone at which an intraosseous device may be inserted or drilled into the bone and associated bone marrow. Insertion sites, penetration sites, and installation sites are generally covered by skin and soft tissue. 
     The term “intraosseous (IO) device” may be used in this application to include, but is not limited to, any hollow needle, hollow drill bit, penetrator assembly, bone penetrator, catheter, cannula, trocar, stylet, inner penetrator, outer penetrator, IO needle, biopsy needle, aspiration needle, IO needle set, biopsy needle set ,or aspiration needle set operable to provide access to an intraosseous space or interior portions of a bone. Such IO devices may be formed, at least in part, from metal alloys such as 304 stainless steel and other biocompatible materials associated with needles and similar medical devices. 
     Embodiments of the present coupler assemblies can be included in medical procedure trays, such as those disclosed in International Patent Application No. PCT/US2007/078207 (published as WO 2008/033874). 
     Referring now to the drawings, and more particularly to  FIG. 1A , shown therein and designated by the reference numeral  100  is one embodiment of the present intraosseous (IO) needle sets or aspiration needle sets. Aspiration needle set  100   a  comprises a hollow outer penetrator or cannula  110   a,  a corresponding inner penetrator or stylet (or trocar)  120 , and a hub assembly  130   a.  In the embodiment shown, first end  111   a  of cannula  110   a  and first end  121  of stylet  120  are operable or configured to penetrate a bone and associated bone marrow. Various features of first end  111   a  of cannula  110   a  and first end  121  of stylet  120  are shown in more detail in  FIGS. 1B-1D . First end  101  of IO needle set  100  corresponds generally with first end  111   a  of cannula  110   a  and first end  121  of stylet  120 . 
     In the embodiment shown, cannula  110   a  includes a plurality of markings  104  disposed on exterior portions of the cannula. Markings  104  may be referred to as “positioning marks” or “depth indicators,” and may be used to indicate the depth of penetration of needle set  100  into a bone and associated bone marrow. In some embodiments, cannula  110   a  may have a length of approximately sixty (60) millimeters and/or a nominal outside diameter of approximately 0.017 inches (e.g., corresponding generally to the dimensions of a sixteen (16) gauge needle). Cannula  110   a  and/or stylet  120  may be formed from stainless steel or other suitable biocompatible materials. In some embodiments, markings  104  are spaced at one (1) centimeter intervals on exterior portions of cannula  110   a.  In some embodiments, one or more side ports  106  may be formed in exterior portions of cannula  110   a  spaced from first end  111   a.    
     Hub assembly  130   a  may be configured and/or used to releasably dispose stylet  120  within the longitudinal bore or lumen of cannula  110   a.  In the embodiment shown, hub assembly  130   a  includes a first hub  140   a  and a second hub  150   a.  A second end of cannula  110   a , opposite from first end  111   a,  may be securely engaged with hub  140   a.  The second end of stylet  120 , opposite from first end  121 , may be securely engaged with the first end of hub  150   a.  As shown in  FIG. 1A , cannula  110   a  may extend longitudinally from first end  141  of hub  140   a . Stylet  120  may also extend from the first end of hub  150   a.  The second end of hub  140   a  may include a standard Luer lock fitting which may be releasably engaged with a corresponding Luer lock fitting disposed within the first end of second hub  150   a.  The Luer lock fitting disposed on the second end of hub  140   a  may be in fluid communication with the bore or passage in cannula  110   a,  and may be operable to be releasably engaged with a standard syringe type fitting and/or a standard intravenous (IV) connection. In the embodiment shown, hub  150   a  includes second end  152  that generally corresponds with second end  132  of hub assembly  130   a  and second end  102  of IO needle set  100 . Hub  140   a  may include first end  141  which may generally correspond with first end  131  of hub assembly  130   a.  Cannula  110   a  may extend longitudinally from first end  141  of hub  140   a  and first end  131  of hub assembly  130 . 
     In the embodiment shown, the second end of a hub assembly may be operable to be disposed within a receptacle formed in a coupler assembly, as described in more detail below. One feature of the present disclosure may include forming a hub assembly which may be releasably engaged within a first receptacle disposed in a first end of a coupler assembly (e.g., receptacle  263  proximate first end  261  of elongated core  260  as shown in  FIGS. 6A-6B  of International Patent Application No. PCT/US2007/078207 (published as WO 2008/033874)). The dimensions and configuration of receptacle  263  may be selected to prevent rotation of hub  150   a  relative to hub  140   a  if hub assembly  130   a  is disposed in receptacle  263  (e.g., while inserting (rotating) an IO device into a bone and associated bone marrow). A powered driver may be releasably engaged with a second receptacle disposed in a second end of the coupler assembly (e.g., receptacle  264  proximate second end  262  of elongated core  260  as shown in  FIGS. 6A-6B  of International Patent Application No. PCT/US2007/078207 (published as WO 2008/033874)). 
     In the embodiment shown, intraosseous device or aspiration needle set  100   a  includes first end  151  of hub  150   a  spaced from second end  142  of hub  140   a.  Portions of stylet  120  extending from first end  151  of hub  150   a  are shown slidably disposed within lumen or longitudinal bore  118  of cannula  110   a.  Hub assembly  130   a  may include first end  131  which may correspond generally with first end  141  of hub  140   a.  Hub assembly  130   a  may also include second end  132  which may correspond generally with second end  152  of hub  150   a  and second end  102  of hub assembly  130   a,  as shown. Cannula  110   a  may be attached to and extend from first end  141  of hub  140   a.  Second end  142  of hub  140   a  may include one-half a typical Luer lock connection or fitting operable to be releasably engaged with corresponding portions of a Luer lock connection or fitting disposed in first end  151  of second hub  150   a.  For embodiments such as the one shown in  FIG. 1A , first end  131  of hub assembly  130   a  may correspond with first end  141  of first hub  140   a.  Second end  152  of second hub  150   a  may correspond with second end  132  of hub assembly  130   a  and second end  102  of aspiration needle set  100   a.    
     At least one portion of hub assembly  130   a  may have a generally hexagonal cross section operable to be received within the generally hexagonal cross section of receptacle  263  disposed proximate first end  251  of coupler assembly  250 , as shown in  FIGS. 6A-6B  of International Patent Application No. PCT/US2007/078207 (published as WO 2008/033874). For some embodiments, portions of first hub  140   a  disposed adjacent to reduced outside diameter portion  143  may have generally hexagonal cross sections, as shown in  FIG. 1A . In other embodiments, various cross sections other than hexagonal may be satisfactorily used to releasably engage a powered driver with one end of a coupler assembly and an intraosseous device with an opposite end of the coupler assembly. Aspiration needle sets may include a trocar, stylet or penetrator in combination with an associated cannula, catheter or outer penetrator. However, biopsy needles formed in accordance with teachings of the present disclosure may or may not include a trocar, stylet or inner penetrator. 
     Hub  140   a  may include second end  142  with opening  144  formed therein. A passageway may extend from second end  142  towards first end  141  of hub  140   a,  as illustrated in  FIGS. 6A-6B  of International Patent Application No. PCT/US2007/078207 (published as WO 2008/033874). A passageway may be operable to communicate fluids with lumen  118  of cannula  100   a.  Second end  142  of hub  140  may include various features of a conventional Luer lock connection or fitting, including threads  148 , and corresponding threads  158  may be formed within first end  151  of hub  150   a,  as shown in  FIGS. 6A-6B  of International Patent Application No. PCT/US2007/078207 (published as WO 2008/033874). 
     For some applications hub  140   a  and hub  150   a  may, for example, be formed using injection molding techniques. For such embodiments hub  140   a  may include reduced outside diameter portion  143  disposed between first end  141  and second end  142 . In a similar manner a plurality of void spaces or cutouts  153  may be formed in hub  150   a  adjacent to and extending from second end  152  in the direction of first end  151 . The configuration and dimensions of reduced diameter portion  143  and/or cutouts  153  may be varied to optimize associated injection molding techniques and at the same time provide required configurations, dimensions and material strength to allow associated hub assembly  130   a  to function as described in this disclosure. 
     In some embodiments, tip  123  of stylet  120  may be disposed relatively close to a tip of cannula  110   a.  For some applications, first end  121  of trocar  120  and first end  111   a  of cannula  110   a  may be ground at the same time to form adjacent cutting surfaces. Grinding ends  111   a  and  121  at the same time may result in forming a single cutting unit to form generally matching cutting edges. Other types of cutting surfaces formed in accordance with teachings of the present disclosure may be discussed later (e.g., as described with reference to  FIGS. 1B-1D ). 
       FIGS. 1B-1D  show a second example of cutting surfaces and tips which may be formed adjacent to the ends of a cannula and/or an associated trocar in the present embodiments. In the embodiment shown, outer penetrator or cannula  110   b  may include first end  111   b  having a plurality of cutting surfaces  114   b  formed adjacent to opening  116  in first end  111 . Opening  116  may communicate with and form a portion of an associated longitudinal bore or lumen  118 . For some applications cutting surfaces  114   b  may be formed using electrical discharge machining (EDM) techniques or otherwise, as described in WO 2008/033874. In the embodiment shown, first end  111   b  has a generally tapered configuration or reduced outside diameter as compared with other portions of cannula  110   b  In other embodiments, first end  111   b  has an outside diameter that is equal to the outside diameter of other portions of cannula  110   b  (e.g., cannula  110   b  can have a constant outside diameter along the entire length of the cannula). Cutting surfaces  114   b  may, for example, be formed using machine grinding techniques. In some embodiments, such as the one shown, end  111   b  of cannula  110   b  may include six ground cutting surfaces  114   b  with respective crowns  115  therebetween. Forming a biopsy needle set and/or biopsy needle with tapered end  111   b  and a plurality of cutting surfaces  114   b  and crowns  115  may provide improved drilling performance (e.g., relative to others configurations) when the resulting biopsy needle set and/or biopsy needle is used with a powered driver in accordance with teachings of the present disclosure. For some applications, a helical groove  117  may be formed within longitudinal bore  118  proximate opening  116 . Helical groove  117  may assist with retaining a biopsy specimen or a bone marrow specimen within longitudinal bore  118 . For example, a single thread may be disposed within the longitudinal bore or lumen of the cannula such that the helical groove  117  is defined between turns of the thread. Various techniques and procedures may be satisfactorily used to place the single thread or otherwise form the helical groove, as described WO 2008/033874. 
     As shown in  FIG. 1C , a biopsy needle set  100   b  may include cannula or outer penetrator  110   b  with stylet or inner penetrator  120   b  slidably disposed therein. The proximal ends of cannula  110   b  and stylet  120   b  may be similar to those of cannula  110   a  and stylet  120  depicted in  FIG. 1A  (e.g., may include hubs  140   a  and  150   a,  respectively). For some applications first end  101  of biopsy needle set  100   b  may minimize damage to skin and soft body tissue at an insertion site. For some applications inner penetrator or trocar  120   b  may include first end  121  having a plurality of cutting surfaces  125  and  126  formed on exterior portions thereof extending from associated tip  123  towards second end of trocar or inner penetrator  120   b.  For some applications one or more cutting surfaces  125  may be formed having length  127  extending from tip  123  to associated cutting surfaces  114   b  in associated cannula  110   b.  One or more cutting surfaces  126  may be formed adjacent to each cutting surface  125  with second length  128 . First length  127  may be greater than second length  128 . As shown, lengths  127  and  128  are measured parallel to the central longitudinal axis of stylet  120   b.  The ratio of first length  127  and second length  128  may be varied in accordance with teachings of the present disclosure to provide optimum performance for penetrating a selected bone and associated bone marrow. Additional details of some embodiments of first end  101  are described in WO 2008/033874. 
       FIGS. 1E and 1F  depict perspective views of a fourth embodiment of the present IO devices having a stylets, trocars, or inner penetrators disposed in a cannula or outer penetrator. In the embodiment shown, device  100   a  is configured to provide access to a patient&#39;s circulatory system via the patient&#39;s bone (e.g., as opposed to extracting a bone-marrow sample). In the embodiment shown, device or penetrator assembly  100   c  may include first hub  140   c , connector or second hub  150   c,  outer penetrator  110   c,  and inner penetrator  120   c.  Penetrator assembly  100   c  may include an outer penetrator such as a cannula, hollow tube or hollow drill bit and an inner penetrator such as a stylet or trocar. Various types of stylets and/or trocars may be disposed within an outer penetrator. For some applications outer penetrator or cannula  110   c  may be described as a generally elongated tube sized to receive inner penetrator or stylet  120   c  therein. Portions of inner penetrator  120   c  may be disposed within longitudinal passageway  118  extending through outer penetrator  110   c.  The outside diameter of inner penetrator  120   c  and the inside diameter of longitudinal passageway  118  may be selected such that inner penetrator  120   c  may be slidably disposed within outer penetrator  110   c.    
     Metallic disc  170  may be disposed within opening  186  for use in releasably attaching connector  150   c  with a magnet disposed on a driveshaft (e.g., driveshaft  222  of driver  200  shown in  FIG. 2 ), such as, for example, on end of the driveshaft (e.g., end  224  of driveshaft  222 ). End  122  of inner penetrator  120   c  may be spaced from metallic disc  170  with insulating or electrically nonconductive material disposed therebetween. In other embodiments, disc  170  can be magnetic or magnetized to be attracted to a driveshaft (e.g.,  222 ) that is metallic). Tip  111   c  of outer penetrator  110   c  and/or tip  121  of inner penetrator  120   c  may be operable to penetrate bone and associated bone marrow. The configuration of tips  111   c  and/or  121  may be selected to penetrate a bone or other body cavities with minimal trauma. First end or tip  121  of inner penetrator  120   c  may be trapezoid shaped and may include one or more cutting surfaces. In one embodiment outer penetrator  110   c  and inner penetrator  120   c  may be ground together as one unit during an associated manufacturing process. Providing a matching fit allows respective tips  111   c  and  121  to act as a single drilling unit which facilitates insertion and minimizes damage as portions of penetrator assembly  100   c  are inserted into a bone and associated bone marrow. Outer penetrator  110   c  and/or inner penetrator  120   c  may be formed from stainless steel, titanium or other materials of suitable strength and durability to penetrate bone. 
     Hub  140   c  may be used to stabilize penetrator assembly  100   c  during insertion of an associated penetrator into a patient&#39;s skin, soft tissue and adjacent bone at a selected insertion site. Second end  142  of hub  140   c  may be operable for releasable engagement or attachment with associated connector  150   c.  First end  141  of hub  140   c  may have a size and configuration compatible with an associated insertion site for outer penetrator  110   c.  Connector  150   c  and attached inner penetrator  120   c  may be releasably engaged with each other by Luer type fittings, threaded connections or other suitable fittings formed on second end  142  of hub  140   c.  Outer penetrator  110   c  extends from first end  141  of hub  140   c.  For some applications connector  150   c  may be described as a generally cylindrical tube defined in part by second end  152  and first end  151 . The exterior of connector  150   c  may include an enlarged tapered portion adjacent to end  181 . A plurality of longitudinal ridges  190  may be formed on the exterior of connector  150   c  to allow an operator to grasp associated penetrator assembly  100   c  during attachment with a driveshaft. Longitudinal ridges  190  also allow connector  150   c  to be grasped for disengagement from hub  140   c  when outer penetrator  110   c  has been inserted into a bone and associated bone marrow. 
     First end  151  of connector  150   c  may include opening  185  sized to receive second end  142  of hub  140   c  therein. Threads  158  may be formed in an opening adjacent to first end  151  of connector  150   c,  as shown. Threaded fitting  158  may be used in releasably attaching connector  150   c  with threaded fitting  148  adjacent to second end  142  of hub  140   c.  Second end  142  of hub  140   c  may include a threaded connector  148  or other suitable fittings formed on the exterior thereof. Second end  142  may have a generally cylindrical pin type configuration compatible with releasably engaging second end or box end  182  of connector  150   c.  For some applications end  141  of hub  140   c  may have the general configuration of a flange. Angular slot or groove  188  sized to receive one end of protective cover or needle cap  234  may be formed in end  202 . Slot or groove  204  may be used to releasable engage a needle cover (not expressly shown) with penetrator assembly  100   c.    
     For some applications a penetrator assembly may include only a single, hollow penetrator. For other applications a penetrator assembly may include an outer penetrator such as a cannula, hollow needle or hollow drill bit and an inner penetrator such as a stylet, trocar or other removable device disposed within the outer penetrator. Penetrator  110   c  is one example of a single, hollow penetrator or cannula. The size of a penetrator may vary depending upon the intended application for the associated penetrator assembly. Penetrators may be relatively small for pediatric patients, medium size for adults and large for oversize adults. By way of example, a penetrator may range in length from five (5) mm to thirty (30) mm. The diameter of a penetrator may range from eighteen (18) gauge to ten (IO) gauge. The length and diameter of the penetrator used in a particular application may depend on the size of a bone to which the apparatus may be applied. Penetrators may be provided in a wide variety of configurations depending upon intended clinical purposes for insertion of the associated penetrator. For example, there may be one configuration for administering drugs and/or fluids to a patient&#39;s bone marrow and an alternative configuration for sampling bone marrow and/or blood from a patient. 
     For some applications connector  150   c  may be described as having a generally cylindrical configuration defined in part by second end  152  and first end  151 . Exterior portions of connector  150   c  may include an enlarged tapered portion adjacent to end  181 . A plurality of longitudinal ridges  190  may be formed on the exterior of connector  150   c  to allow an operator to grasp associated penetrator assembly  100   c  during attachment with a driveshaft. Longitudinal ridges  190  also allow connector  150   c  to be grasped for disengagement from hub  140   c  when outer penetrator  110   c  has been inserted into a bone and associated bone marrow. Second end  152  of connector of  150   c  may included opening  186  sized to receive portions driveshaft  52  therein. A plurality of webs  136  may extend radially outward from connector receptacle  186 . Webs  136  cooperate with each other to form a plurality of openings  138  adjacent to second end  152 . Opening  186  and openings  138  cooperate with each other to form portions of a connector receptacle operable to receive respective portions of a connector (not expressly shown) therein. 
       FIG. 2  depicts a cross-sectional view of one embodiment of a driver that can be used with embodiments of the present drivers, coupler assemblies, and kits. In the embodiment shown, powered driver  200  may be used to insert one of the present intraosseous devices into a bone and associated bone marrow. Powered driver  200  may include housing  210  having a general configuration similar to a small pistol defined in part by handle  214 . Various components associated with powered driver  200  may be disposed within housing  210  (e.g., handle  214 ). For example a power source such as battery pack  216  may be disposed within handle  214 . Housing  210  may be formed from relatively strong, heavy duty polymeric materials such as polycarbonate or other satisfactory materials. For some applications housing  210  may be formed in two halves (not expressly shown) which may be joined together with a fluid tight seal to protect various components of powered driver  200  disposed therein. 
     Motor  218  and gear assembly  220  may be disposed within portions of housing  210  adjacent to handle  214 . Motor  218  and gear assembly  220  may be generally aligned with each other. Motor  218  may be rotatably engaged with one end of gear assembly  220 . Driveshaft  222  may be rotatably engaged with and extend from another end of gear assembly  220  opposite from motor  218 . For some applications both motor  218  and gear assembly  220  may have generally cylindrical configurations. Distal end or first end  211  of housing  210  may include an opening with portions of driveshaft  222  extending through the opening, as shown. For some applications, end  224  or the portion of driveshaft  222  extending from first end  211  of housing  210  may have a generally hexagonal cross section with surfaces  226  disposed thereon. Receptacle  263  disposed in second end  252  of coupler assembly  250  may have a matching generally hexagonal cross section, as shown in  FIGS. 6A-6C  of International Patent Application No. PCT/US2007/078207 (published as WO 2008/033874). 
     Surfaces  226  may extend generally parallel with each other and parallel with respect to a longitudinal axis or rotational axis of driveshaft  222 . One or more tapered surfaces  228  may also be formed on end  224  to assist with releasably engaging powered driver  200  with coupler assembly  250 . Embodiments of powered driver  200  include speed reduction ratios, for example, of between 60:1 and 80:1, resulting in driveshaft RPMs that are reduced relative to motor RPMs. Coupler assemblies having corresponding openings or receptacles may be releasably engaged with end  224  extending from first end  211  of powered driver  200 . For example, end  224  extending from first end  211  of housing  210  may be releasably engaged with receptacle  264  disposed proximate second end  252  of coupler assembly  250 , as shown in  FIGS. 6A-6B . 
     For some applications thrust bearing  241  may be disposed between first end or distal end  211  of housing  210  and adjacent portions of gear assembly  220 . Thrust bearing  242  may be disposed between second end or proximal end  212  of housing  210  and adjacent portions of motor  218 . Thrust bearings  241  and  242  may limit longitudinal movement of motor  218 , gear assembly  220  and driveshaft  222  within associated portions of housing  210 . Trigger assembly  244  may also be disposed within housing  210  proximate handle  214 . Trigger assembly  244  may include trigger or contact switch  246 . Motor  218  may be energized and deenergized by alternately depressing and releasing trigger  246 . Electrical circuit board  247  may also be disposed within housing  210 . Electrical circuit board  247  may be electrically coupled with trigger assembly  244 , motor  218 , power supply  216  and indicator light  248 . For some applications indicator light  248  may be a light emitting diode (LED) or a small more conventional light bulb. For some applications indicator light  248  may be activated when ninety percent (90%) of electrical storage capacity of battery pack  216  has been used. The configuration and dimensions of an intraosseous device formed in accordance with teachings of the present disclosure may vary depending upon respective intended applications for each intraosseous device. For example the length of a biopsy needle formed in accordance with teachings of the present disclosure may vary from approximately five (5) millimeters to thirty (30) millimeters. 
     Couplers and coupler assemblies incorporating teachings of the present disclosure may function as “quick release mechanisms” operable to engage and disengage an IO device from a powered driver (e.g., a driver disposed within a flexible containment bag or sterile sleeve). In applications involving a flexible containment bag or sterile sleeve, such coupler assemblies may allow rotation of an IO device (e.g., biopsy needle or needle set) without damage to the flexible containment bag or sterile sleeve, and one end of the coupler assembly may be operable to form a fluid seal or fluid barrier with adjacent portions of the containment bag or sterile sleeve. A coupler assembly incorporating teachings of the present disclosure may also be described as a port assembly attached to a containment bag. Such port assemblies may allow easy engagement or disengagement of a powered driver from an IO device and at the same time allow the powered driver to “power in and power out” an IO device from an insertion site.  FIGS. 3A-35C  depict various embodiments of the present couplers in conjunction with drivers and/or IO devices; because the drivers and/or IO devices are similar in many respects to driver  200  of  FIGS. 2  and IO devices  100   a - 100   c  of  FIGS. 1A-1F , the differences in the drivers and/or IO devices are primarily described below. 
       FIGS. 3A-3C  depict various views of a first embodiment  300   a  of the present couplers in combination with a powered driver  200   a  and an IO device  100   d  that is configured to provide access to an interior of a bone (e.g., similar in some respects to IO device  100   c ). In the embodiment shown, coupler  300   a  comprises a drive hub  304   a  having a first end  308   a  and a second end  312   a  configured to be coupled in fixed relation to a driveshaft  222   a  (of a driver  200   a  having a housing  210   a ) such that at least a portion of the drive hub is disposed outside the housing of the driver. In the embodiment shown, first end  308   a  of drive hub  304   a  includes female threads  316   a  configured to be coupled to an intraosseous (IO) device  100   d,  as shown. More particularly, in the embodiment shown, hub assembly  130   d  (and more specifically second hub  150   d,  in the depicted embodiment) of IO device  100   d  includes male threads  320   a  corresponding to female threads  316   a.  In the embodiment shown, threads  316   a  (and  320   a ) are configured to tighten if the driver rotates drive hub  304   a  and IO device  100   d  (coupled to the drive hub) in a clockwise direction. In the embodiment shown, drive hub  304   a  is unitary with driveshaft  222   a  (drive hub  304   a  and driveshaft  222   a  comprise a single piece of material). In other embodiments, drive hub  304   a  may be coupled to driveshaft  222   a  in any manner (e.g., welding, threads, press-fit, and/or the like) that permits the function described in this disclosure. 
       FIGS. 4A-4C  depict various views of a second embodiment  300   b  of the present couplers in combination with a powered driver  200   b  and an IO device  100   e  that is configured for obtaining a sample of bone and/or bone marrow (e.g., similar in some respects to IO devices  100   a  and/or  100   b ). Coupler  300   b  is similar in some respects to coupler  300   a.  In the embodiment shown, coupler  300   b  comprises a drive hub  304   b  having a first end  308   b  and a second end  312   b  configured to be coupled in fixed relation to a driveshaft  222   b  (of a driver  200   b  having a housing  210   b ) such that at least a portion of the drive hub is disposed outside the housing of the driver. In the embodiment shown, first end  308   b  of drive hub  304   b  includes female threads  316   b  configured to be coupled to an intraosseous (IO) device  100   e,  as shown. More particularly, in the embodiment shown, hub assembly  130   e  (and more specifically first hub  140   e,  in the depicted embodiment) of IO device  100   e  includes male threads  320   b  corresponding to female threads  316   b.  Coupler  300   b  differs from coupler  300   a,  for example, in that drive hub  304   b  includes a recess  324   b  that is sized to receive a second hub (not shown, but similar to second hub  150   a  of IO device  100   a ). In the embodiment shown, threads  316   b  (and  320   b ) are configured to tighten if the driver rotates drive hub  304   b  and IO device  100   e  (coupled to the drive hub) in a clockwise direction. Coupler  300   b  further differs from coupler  300   a,  for example, in that second end  312   b  of drive hub  304   b  includes female threads  328   a  configured to be coupled to driveshaft  222   b  of driver  200   b.  In the embodiment shown, driveshaft  222   b  has a distal end  224   b  and includes male threads  332   b  adjacent corresponding to female threads  328   b . In the embodiment shown, second end  312   b  of drive hub  304   b  comprises a flange  334   b  extending outwardly relative to an axis of rotation of the drive hub, as shown. Flange  334   b  may, for example, be used to connect coupler  300   b  to a containment bag or the like (e.g., as disclosed WO 2008/033874). 
       FIGS. 5A-5D  depict various views of a third embodiment  300   c  of the present couplers in combination with a powered driver  200   c  and an IO device  100   f  that is configured to provide access to an interior of a bone (e.g., similar in some respects to IO device  100   c ). In the embodiment shown, coupler  300   c  comprises a drive hub  304   c  having a first end  308   c  and a second end  312   c  including a recess  336   c  configured to receive driveshaft  222   c  of driver  200   c.  In this embodiment, second end  312   c  is configured such that if driveshaft  222   c  is inserted into recess  336   c,  an interference fit between drive hub  304   c  and driveshaft  222   c  will resist rotation of the drive hub relative to the driveshaft (and/or resist removal of drive hub  304   c  from driveshaft  222   c ). For example, in the embodiment shown, driveshaft  222   c  is substantially rigid (e.g., comprises a metal such as stainless steel) and has a transverse dimension that is larger than a corresponding transverse dimension of recess  336   c  such that as driveshaft  222   c  is inserted into recess  336   c,  drive hub  304   c  will deflect slightly and impart a compressive force on driveshaft  222   c.  Drive hub  304   c  can comprise, for example, a resilient material such as a resilient polymer, or any other material permitting the described function. In some embodiments, the driveshaft and the recess have dissimilar cross-sectional shapes. For example, in the embodiment shown ( FIG. 5D ), driveshaft  222   c  has a hexagonal cross-sectional shape and recess  336   c  has a circular cross-sectional shape. In other embodiments, the driveshaft and recess can have similar cross-sectional shapes (e.g., driveshaft  222   c  can have a circular cross-sectional shape. To facilitate insertion of driveshaft  222   c  into recess  336   c,  one or both of driveshaft  222   c  and recess  336   c  can be tapered (e.g., driveshaft  222   c  can have a transverse dimension that is relatively smaller at distal end  224   c  and increases along a portion of driveshaft  222   c  approaching housing  210   c , and/or recess  336   c  can have a relatively larger transverse dimension (e.g., diameter) at second end  312   c  that increases along a portion of recess  336   c  approaching first end  308   c ). In the embodiment shown, first end  308   c  is configured to be coupled to IO device  100   f  (e.g., to resist rotation of the IO device relative to the drive hub). For example, in the embodiment shown, drive hub  304   c  is unitary with a portion of hub assembly  130   f  (and more specifically unitary with second hub  150   f,  in the depicted embodiment). 
       FIGS. 6A-6E  depict various views of a fourth embodiment  300   d  of the present couplers in combination with a powered driver  200   d  and an IO device  100   g  that is configured for obtaining a sample of bone and/or bone marrow (e.g., similar in some respects to IO devices  100   a  and/or  100   b ). In the embodiment shown, coupler  300   d  comprises a drive hub  304   d  having a first end  308   d  and a second end  312   d  including a recess  336   d  configured to receive driveshaft  222   d  of driver  200   d.  In this embodiment, second end  312   d  is configured such that if driveshaft  222   d  is inserted into recess  336   d,  an interference fit between drive hub  304   d  and driveshaft  222   d  will resist rotation of the drive hub relative to the driveshaft (and/or resist removal of the drive hub from driveshaft). For example, in the embodiment shown, driveshaft  222   d  is substantially rigid (e.g., comprises a metal such as stainless steel) and has a transverse dimension that is larger than a corresponding transverse dimension of recess  336   d  such that as driveshaft  222   d  is inserted into recess  336   d,  drive hub  304   d  will deflect slightly and impart a compressive force on driveshaft  222   d.  Drive hub  304   d  can comprise, for example, a resilient material such as a resilient polymer, or any other material permitting the described function. In some embodiments, the driveshaft and the recess have dissimilar cross-sectional shapes. For example, in the embodiment shown ( FIG. 6E ), driveshaft  222   d  has a hexagonal cross-sectional shape and recess  336   d  has a circular cross-sectional shape. In other embodiments, the driveshaft and recess can have similar cross-sectional shapes (e.g., driveshaft  222   d  can have a circular cross-sectional shape). To facilitate insertion of driveshaft  222   d  into recess  336   d,  one or both of driveshaft  222   d  and recess  336   d  can be tapered (e.g., driveshaft  222   d  can have a transverse dimension that is relatively smaller at distal end  224   d  and increases along a portion of driveshaft  222   d  approaching housing  210   d,  and/or recess  336   d  can have a relatively larger transverse dimension (e.g., diameter) at second end  312   d  that increases along a portion of recess  336   d  approaching first end  308   d ). Further, in this embodiment driveshaft  222   d  comprises an enlarged cap member  223   d  that can comprise a resilient material (e.g., a resilient polymer) to further facilitate insertion of driveshaft  222   d  into recess  336   d.    
     Coupler  300   d  further differs from coupler  300   c,  for example, in that first end  308   d  includes a second recess  340   d  that is sized to receive a hub (e.g., first hub  140   g ) of IO device  100   g,  and first end  308   d  is configured such that if hub  140   g  is inserted into recess  340   d  , an interference fit between drive hub  308   d  and hub  140   g  will resist rotation of IO device  100   g  relative to drive hub  304   d.  As described above for drive hub  304   d  and driveshaft  222 , drive hub  304   d  can comprise, for example, a resilient material such as a resilient polymer, or any other material permitting the described function. In some embodiments, hub  140   g  and recess  340   d  have dissimilar cross-sectional shapes. For example, in the embodiment shown ( FIG. 6D ), hub  140   g  has a hexagonal cross-sectional shape and recess  340   d  has a circular cross-sectional shape. In other embodiments, the driveshaft and recess can have similar cross-sectional shapes (e.g., hub  140   g  can have a circular cross-sectional shape). To facilitate insertion of hub  140   g  into recess  340   d,  one or both of hub  140   g  and recess  340   d  can be tapered (e.g., hub  140   g  can have a transverse dimension that is relatively smaller at second end  142  and increases along a portion of hub  140   g  approaching first end  141 , and/or recess  340   d  can have a relatively larger transverse dimension (e.g., diameter) at first end  308   d  that increases along a portion of recess  340   d  approaching second end  312   d ). Coupler  300   d  further differs from coupler  300   c,  for example, in that drive hub  304   d  includes a recess  324   d  that is sized to receive a second hub (not shown, but similar to second hub  150   a  of IO device  100   a ) in combination with first hub  140   g  of IO device  100   g.    
       FIGS. 7A-7C  depict various views of a fifth embodiment  300   e  of the present couplers in combination with a powered driver  200   e  and an IO device  100   h  that is configured to provide access to an interior of a bone (e.g., similar in some respects to IO device  100   c ). In the embodiment shown, coupler  300   e  comprises a drive hub  304   e  having a first end  308   e  and a second end  312   e  including a recess  336   e  configured to receive driveshaft  222   e  of driver  200   e.  In this embodiment, second end  312   e  is configured such that if driveshaft  222   e  is inserted into recess  336   e,  an interference fit between drive hub  304   e  and driveshaft  222   e  will resist rotation of the drive hub relative to the driveshaft (and/or resist removal of drive hub  304   e  from driveshaft  222   e ). For example, in the embodiment shown, driveshaft  222   e  is substantially rigid (e.g., comprises a metal such as stainless steel), and drive hub  304   e  includes a plurality of tabs or ribs  344   e  (e.g., with a triangular cross-sectional shape, as shown) extending into recess  336   e.  In this embodiment, tabs  344   e  are configured to deform if the driveshaft is inserted into the recess. In the embodiment shown, recess  336   e  has at least one transverse dimension that is larger than a transverse dimension of driveshaft  222   e;  however, tabs  344   e  extend inward and a transverse distance between opposing tabs  344   e  is less than a transverse dimension of driveshaft  222   e,  such that tabs  344   e  will deflect and/or compress and impart a compressive force on driveshaft  222   e . Drive hub  304   e  can comprise, for example, a resilient material such as a resilient polymer, or any other material permitting the described function. In the embodiment shown, first end  308   e  is configured to be coupled to IO device  100   h  (e.g., to resist rotation of the IO device relative to the drive hub). For example, in the embodiment shown, drive hub  304   e  is unitary with a portion of hub assembly  130   h  (e.g., unitary with second hub  150   h ). While not shown in  FIGS. 7A-7C , other embodiments can comprise a second recess in first end  308   e  with tabs extending into the recess to form an interference fit with a hub of an IO device (e.g., similar to coupler  100   d ). 
       FIGS. 8A-8C  depict various views of a sixth embodiment  300   f  of the present couplers in combination with a powered driver  200   f  and an IO device  100   i  that is configured to provide access to an interior of a bone (e.g., similar in some respects to IO device  100   c ). In the embodiment shown, coupler  300   f  comprises a drive hub  304   f  having a first end  308   f  and a second end  312   f  including a recess  336   f  configured to receive driveshaft  222   f  of driver  200   f.  In this embodiment, second end  312   f  is configured such that if driveshaft  222   f  is inserted into recess  336   f,  an interference fit between drive hub  304   f  and driveshaft  222   f  will resist rotation of the drive hub relative to the driveshaft (and/or resist removal of drive hub  304   f  from driveshaft  222   f ). For example, in the embodiment shown, driveshaft  222   f  comprises one or more barbs  348   f  (e.g., an annular barb surrounding the perimeter of the driveshaft, or one or more discrete barbs disposed around the driveshaft) with a transverse dimension between outermost portions of barb(s)  348   f  that is larger than a corresponding transverse dimension of recess  336   f  such that as driveshaft  222   f  is inserted into recess  336   f,  drive hub  304   f  will deflect slightly and impart a compressive force on barb(s)  348   f  In the embodiment shown, driveshaft  222   f  is substantially rigid (e.g., comprises a metal such as stainless steel). Drive hub  304   f  can comprise, for example, a resilient material such as a resilient polymer, or any other material permitting the described function. In some embodiments, the driveshaft and the recess have similar cross-sectional shapes. For example, in the embodiment shown ( FIG. 5D ), driveshaft  222   f  has an annular barb  348   f  with a circular cross-sectional shape and recess  336   f  has a circular cross-sectional shape. In other embodiments, the driveshaft and recess can have dissimilar cross-sectional shapes (e.g., driveshaft  222   f  can have a plurality of discrete barbs) and recess  336   f  can have a circular cross-sectional shape. To facilitate insertion of driveshaft  222   f  into recess  336   f,  one or both of driveshaft  222   f  and recess  336   f  can be tapered (e.g., driveshaft  222   f  can have a transverse dimension that is relatively smaller at distal end  224   f  and increases along a portion of driveshaft  222   f  approaching housing  210   f,  as shown, and/or recess  336   f  can have a relatively larger transverse dimension (e.g., diameter) at second end  312   f  that increases along a portion of recess  336   f  approaching first end  308   f ). In the embodiment shown, first end  308   f  is configured to be coupled to IO device  100   i  (e.g., to resist rotation of the IO device relative to the drive hub). For example, in the embodiment shown, drive hub  304   f  is unitary with a portion of hub assembly  130   i  (e.g., unitary with second hub  150   i ). 
       FIGS. 9A-9C  depict various views of a seventh embodiment  300   g  of the present couplers in combination with a powered driver  200   g  and an IO device  100   j  that is configured for obtaining a sample of bone and/or bone marrow (e.g., similar in some respects to IO devices  100   a  and/or  100   b ). In the embodiment shown, coupler  300   g  comprises a drive hub  304   f  having a first end  308   f  and a second end  312   f  including a recess  336   f  configured to receive driveshaft  222   g  of driver  200   g.  In this embodiment, second end  312   g  is configured such that if driveshaft  222   g  is inserted into recess  336   g,  an interference fit between drive hub  304   g  and driveshaft  222   g  will resist rotation of the drive hub relative to the driveshaft (and/or resist removal of the drive hub from driveshaft). For example, in the embodiment shown, driveshaft  222   g  comprises one or more barbs  348   g  (e.g., an annular barb surrounding the perimeter of the driveshaft, or one or more discrete barbs disposed around the driveshaft) with a transverse dimension between outermost portions of barb(s)  348   g  that is larger than a corresponding transverse dimension of recess  336   g  such that as driveshaft  222   g  is inserted into recess  336   g,  drive hub  304   g  will deflect slightly and impart a compressive force on barb(s)  348   g.  In the embodiment shown, driveshaft  222   g  is substantially rigid (e.g., comprises a metal such as stainless steel). Drive hub  304   g  can comprise, for example, a resilient material such as a resilient polymer, or any other material permitting the described function. In some embodiments, the driveshaft and the recess have similar cross-sectional shapes. For example, in the embodiment shown ( FIG. 5D ), driveshaft  222   g  has an annular barb  348   g  with a circular cross-sectional shape and recess  336   g  has a circular cross-sectional shape. In other embodiments, the driveshaft and recess can have dissimilar cross-sectional shapes (e.g., driveshaft  222   g  can have a plurality of discrete barbs) and recess  336   g  can have a circular cross-sectional shape. To facilitate insertion of driveshaft  222   g  into recess  336   g,  one or both of driveshaft  222   g  and recess  336   g  can be tapered (e.g., driveshaft  222   g  can have a transverse dimension that is relatively smaller at distal end  224   g  and increases along a portion of driveshaft  222   g  approaching housing  210   g,  as shown, and/or recess  336   g  can have a relatively larger transverse dimension (e.g., diameter) at second end  312   g  that increases along a portion of recess  336   g  approaching first end  308   g ). 
     Drive hub  304   g  differs from drive hub  304   f,  for example, in that recess  336   g  is defined by a cylindrical wall  352   g  that is, in turn, at least partially (e.g., up to entirely, as shown) surrounded by a second (e.g., annular) recess  356   g  that permits wall  352   g  to flex to facilitate insertion of driveshaft. Drive hub  304   g  further differs from drive hub  304   f,  for example, in that first end  308   g  includes a second recess  340   g  that is sized to receive a hub (e.g., first hub  140   j ) of IO device  100   g,  and first end  308   g  is configured such that if hub  140   j  is inserted into recess  340   g,  an interference fit between drive hub  308   g  and hub  140   j  will resist rotation of IO device  100   j  relative to drive hub  304   g.  As described above, drive hub  304   g  can comprise, for example, a resilient material such as a resilient polymer, or any other material permitting the described function. In some embodiments, hub  140   j  and recess  340   g  have dissimilar cross-sectional shapes. For example, in the embodiment shown, hub  140   j  has a hexagonal cross-sectional shape and recess  340   g  has a circular cross-sectional shape. In other embodiments, the driveshaft and recess can have similar cross-sectional shapes (e.g., hub  140   j  can have a circular cross-sectional shape). To facilitate insertion of hub  140   j  into recess  340   g,  one or both of hub  140   j  and recess  340   g  can be tapered (e.g., hub  140   j  can have a transverse dimension that is relatively smaller at second end  142  and increases along a portion of hub  140   j  approaching first end  141 , and/or recess  340   g  can have a relatively larger transverse dimension (e.g., diameter) at first end  308   g  that increases along a portion of recess  340   g  approaching second end  312   g ). In the embodiment shown, drive hub  304   g  also includes a recess  324   g  configured to receive a portion of hub  140   j  (e.g., a hose fitting with an annular barb, as shown; or Luer-lock fitting threads  148  as in hub  140   a ). In other embodiments, recess  324   g  can be sized to receive a second hub (not shown but similar, for example, to second hub  150   a ). In the embodiment shown, recess  324   g  is defined by a cylindrical wall  360   g  that is, in turn, at least partially (e.g., up to entirely, as shown) surrounded by a second (e.g., annular) recess  364   g  that permits wall  360   g  to flex to facilitate insertion of driveshaft. 
       FIGS. 10A-10D  depict various views of an eighth embodiment  300   h  of the present couplers in combination with a powered driver  200   h  and an IO device  100   k  that is configured to provide access to an interior of a bone (e.g., similar in some respects to IO device  100   c ). In the embodiment shown, coupler  300   h  comprises a drive hub  304   h  having a first end  308   h  and a second end  312   h  including a recess  336   h  configured to receive driveshaft  222   h  of driver  200   h.  In this embodiment, second end  312   h  is configured such that if driveshaft  222   h  is inserted into recess  336   h,  an interference fit between drive hub  304   h  and driveshaft  222   h  will resist rotation of the drive hub relative to the driveshaft (and/or resist removal of drive hub  304   h  from driveshaft  222   h ). For example, in the embodiment shown, driveshaft  222   h  is substantially rigid (e.g., comprises a metal such as stainless steel), and drive hub  304   h  includes a plurality of tabs or ribs  344   h  (e.g., with a triangular cross-sectional shape, as shown) extending into recess  336   h.  In this embodiment, tabs  344   e  are configured to deform if the driveshaft is inserted into the recess. In the embodiment shown, recess  336   h  has at least one transverse dimension that is larger than a transverse dimension of driveshaft  222   h;  however, tabs  344   h  extend inward and a transverse distance between opposing tabs  344   h  is less than a transverse dimension of driveshaft  222   h,  such that tabs  344   h  will deflect and/or compress and impart a compressive force on driveshaft  222   h.  Drive hub  304   h  can comprise, for example, a resilient material such as a resilient polymer, or any other material permitting the described function. In the embodiment shown, first end  308   h  is configured to be coupled to IO device  100   k  (e.g., to resist rotation of the IO device relative to the drive hub). For example, in the embodiment shown, drive hub  304   h  is unitary with a portion of hub assembly  130   k  (e.g., unitary with second hub  150   k ). 
     Coupler  300   h  differs from coupler  300   e,  for example, in the drive hub  304   h  defines a recess  336   h  that has a depth that is at least 50% greater (e.g., 100% greater) than the length of driveshaft  222   h  that is received in recess  336   h,  resulting in added length of sidewall  352   h  to increase flexibility of sidewall  352   h  and thereby facilitate insertion of driveshaft  222   h  into recess  352   h.  Driveshaft  222   h  differs from driveshaft  222   e,  for example, in that driveshaft  222   h  (e.g., distal end  224   h ) comprises one or more (e.g., a plurality of, as shown) projections  368   h  extending outward relative to an axis of rotation of the driveshaft. In the embodiment shown, projections  368   h  are configured to be aligned with tabs  344   h,  as shown, to deform tabs  344   h  to create the interference fit between the driveshaft and the drive hub. In the embodiment shown, recess  336   h  has a circular cross-sectional shape. However, in other embodiments, recess  336   h  has a cross-sectional shape that is similar to the cross-sectional shape of driveshaft  222   h  (having a circular central portion and one or more peripheral portions (e.g., corresponding to projections  368   h ) extending outwardly from the circular central portion; and, in such embodiments, tabs  344   h  can each extend into the peripheral portion(s) of the recess). While not shown in  FIGS. 10A-10D , other embodiments can comprise a second recess in first end  308   h  with tabs extending into the recess to form an interference fit with a hub of an IO device (e.g., similar to coupler  100   d ). 
       FIGS. 11A-11D  depict various views of a ninth embodiment  300   i  of the present couplers in combination with a powered driver  200   i  and an IO device  100   l  that is configured to provide access to an interior of a bone (e.g., similar in some respects to IO device  100   c ). In the embodiment shown, coupler  300   i  comprises a drive hub  304   i  having a first end  308   i  and a second end  312   i  including a recess  336   i  configured to receive driveshaft  222   i  of driver  200   i.  In the embodiment shown, coupler  300   i  further comprises an adhesive  372   i  disposed in the recess and configured to adhere to driveshaft  222   i  if driveshaft  222   i  is inserted into recess  336   i  (e.g., to resist (e.g., interfere with the) removal of driveshaft  222   i  from recess  336   i ). In the embodiment shown, recess  336   i  has a cross-sectional shape corresponding to the cross-sectional shape of driveshaft  222   i  such that if the driveshaft is inserted into the second recess, the drive hub will resist rotating relative to the driveshaft. For example, in the embodiment shown, recess  336   i  and driveshaft  222   i  each has a cross-sectional shape of a circle with a portion removed to result in two opposing flat sides  376   i  and  380   i,  respectively. Adhesive  372   i  can comprise a double-sided tape and/or a liquid or gel adhesive disposed in the recess (e.g., at sides  376   i  and/or at the end of distal end of recess  336   i  (farthest from second end  312   i )). In other embodiments, the driveshaft and recess can have dissimilar cross-sectional shapes (e.g., recess  336   i  can have a circular cross-sectional shape). To facilitate insertion of driveshaft  222   i  into recess  336   i,  one or both of driveshaft  222   i  and recess  336   i  can be tapered (e.g., driveshaft  222   i  can have a transverse dimension that is relatively smaller at distal end  224   i  and increases along a portion of driveshaft  222   i  approaching housing  210   i,  and/or recess  336   i  can have a relatively larger transverse dimension (e.g., diameter) at second end  312   i  that increases along a portion of recess  336   i  approaching first end  308   i ). In the embodiment shown, first end  308   i  is configured to be coupled to IO device  1001  (e.g., to resist rotation of the IO device relative to the drive hub). For example, in the embodiment shown, drive hub  304   i  is unitary with a portion of hub assembly  130   l  (e.g., unitary with second hub  150   l ). 
       FIGS. 12A-12D  depict various views of a tenth embodiment  300   j  of the present couplers in combination with a powered driver  200   j  and an IO device  100   m  that is configured for obtaining a sample of bone and/or bone marrow (e.g., similar in some respects to IO devices  100   a  and/or  100   b ). In the embodiment shown, coupler  300   j  comprises a drive hub  304   j  having a first end  308   j  and a second end  312   j  including a recess  336   j  configured to receive driveshaft  222   j  of driver  200   j.  In the embodiment shown, coupler  300   j  further comprises an adhesive  372   j  disposed in the recess and configured to adhere to driveshaft  222   j  if driveshaft  222   j  is inserted into recess  336   j  (e.g., to resist removal of driveshaft  222   j  from recess  336   j ). In the embodiment shown, recess  336   j  has a cross-sectional shape corresponding to the cross-sectional shape of driveshaft  222   j  such that if the driveshaft is inserted into the second recess, the drive hub will resist rotating relative to the driveshaft. For example, in the embodiment shown, recess  336   j  and driveshaft  222   j  each has a cross-sectional shape of a circle with a portion removed to result in two opposing flat sides  376   j  and  380   j,  respectively. Further, in this embodiment driveshaft  222   d  comprises an enlarged cap member  223   j  (on which flats  380   j  are disposed) that can comprise a resilient material (e.g., a resilient polymer) to further facilitate insertion of driveshaft  222   j  into recess  336   j.  Adhesive  372   j  can comprise a double-sided tape and/or a liquid or gel adhesive disposed in the recess (e.g., at sides  376   j  and/or at the end of distal end of recess  336   j  (farthest from second end  312   j )). In other embodiments, the driveshaft and the corresponding recess can have dissimilar cross-sectional shapes (e.g., recess  336   j  can have a circular cross-sectional shape). To facilitate insertion of driveshaft  222   j  into recess  336   j,  one or both of driveshaft  222   j  and recess  336   j  can be tapered (e.g., driveshaft  222   j  can have a transverse dimension that is relatively smaller at distal end  224   j  and increases along a portion of driveshaft  222   j  approaching housing  210   j,  and/or recess  336   j  can have a relatively larger transverse dimension (e.g., diameter) at second end  312   j  that increases along a portion of recess  336   j  approaching first end  308   j ). 
     Drive hub  304   j  differs from drive hub  304   i,  for example, in that first end  308   j  includes a second recess  340   j  that is sized to receive a hub (e.g., first hub  140   m ) of IO device  100   m.  In the embodiment shown, coupler  300   j  further comprises an adhesive  384   j  disposed in recess  340   j  and configured to adhere to hub  140   m  if hub  140   m  is inserted into recess  340   j  (e.g., to resist removal of IO device  100   m  from recess  340   j ). In the embodiment shown, recess  340   j  has a cross-sectional shape corresponding to the cross-sectional shape of hub  140   m  such that if hub  140   m  is inserted into the second recess, the drive hub will resist rotating relative to hub  140   m.  For example, in the embodiment shown, recess  340   j  and hub  140   m  each has a cross-sectional shape of a circle with a portion removed to result in two opposing flat sides  388   j  and  392   j,  respectively. Adhesive  384   j  can comprise a double-sided tape and/or a liquid or gel adhesive disposed in the recess (e.g., at sides  388   j ). In other embodiments, hub  140   m  and the corresponding recess can have dissimilar cross-sectional shapes (e.g., recess  340   j  can have a circular cross-sectional shape). To facilitate insertion of hub  140   m  into recess  340   j,  one or both of hub  140   m  and recess  340   j  can be tapered (e.g., hub  140   m  can have a transverse dimension that is relatively smaller at second end  142  and increases along a portion of hub  140   m  approaching first end  141 , and/or recess  340   j  can have a relatively larger transverse dimension (e.g., diameter) at first end  308   j  that increases along a portion of recess  340   j  approaching second end  312   j ). Coupler  300   j  further differs from coupler  300   i,  for example, in that drive hub  304   j  includes a recess  324   j  that is sized to receive a second hub (not shown, but similar to second hub  150   a  of IO device  100   a ) in combination with first hub  140   m  of IO device  100   m.    
       FIGS. 13A-13C  depict various views of an eleventh embodiment  300   k  of the present couplers in combination with a powered driver  200   k  and an IO device  100   n  that is configured to provide access to an interior of a bone (e.g., similar in some respects to IO device  100   c ). In the embodiment shown, coupler  300   k  comprises a drive hub  304   k  having a first end  308   k  and a second end  312   k  configured to be coupled in fixed relation to driveshaft  222   k  of driver  200   k  (e.g., second end  312   k  is unitary with driveshaft  222   k  in the embodiment shown). In this embodiment, first end  308   k  includes a recess  340   k  configured to receive a portion of hub assembly  130   n  (e.g., hub  150   n ) of IO device  100   n.  In the embodiment shown, recess  340   k  has a cross-sectional shape (e.g., hexagonal) corresponding to the cross-sectional shape (e.g., hexagonal) of the portion of the IO device such that if the portion of the IO device is inserted into the recess, the drive hub will resist rotation of the IO device relative to the drive hub. To facilitate insertion of hub  150   n  into recess  340   k,  one or both of hub  150   n  and recess  340   k  can be tapered (e.g., hub  150   n  can have a transverse dimension that is relatively smaller at second end  142  and increases along a portion of hub  150   n  approaching first end  141 , and/or recess  340   k  can have a relatively larger transverse dimension (e.g., diameter) at first end  308   k  that increases along a portion of recess  340   k  approaching second end  312   k ). 
       FIGS. 14A-14B  depict side cross-sectional views of a powered driver  2001  for use with at least some embodiments of the present couplers. In the embodiment shown, driver  200   l  comprises: a housing  210   l  having a body portion  213   l  and a shroud portion  396   l . In this embodiment, body portion  213   l  has a sidewall  400   l  defining distal end  211  of the body portion, and shroud portion  396   l  has a cylindrical sidewall  404   l  extending from distal end  211  of the body portion. In the embodiment shown, shroud portion  396   l  has an open distal end  408   l . In the embodiment shown, driveshaft  222   l  has a distal end  224   l  extending from body portion  213   l  (e.g., past distal end  211  and into shroud portion  396   l ). In this embodiment, driver  200   l  is configured to be coupled to an IO device (e.g.,  100   c ) having a hub (e.g.,  140   c  and/or  150   c ) with a recess  186  sized to receive distal end  224   l  of the driveshaft, such that the distal end of the driveshaft extends into recess  186  and the hub (e.g.,  140   c  and/or  150   c ) of the IO device is at least partially disposed in the shroud portion of the housing. For example, in this embodiment, if IO device  100   c  is coupled to driver  200   l , first end  141  of hub  140   c  is even with or extends outwardly past distal end  408   l.    
       FIGS. 15A-15C  depict various views of another embodiment of a powered driver  200   m  for use with at least some embodiments of the present couplers. Driver  200   m  is similar in many respects to driver  200   l , and therefore the differences in driver  200   m  will primarily be described here. In the embodiment shown, driver  200   m  comprises a plate  412   m  having an opening  416   m  that is disposed in a shroud portion  396   m  with driveshaft  222   m  aligned with opening  416   m  such that the plate is movable with shroud portion  396   m  along a length of the driveshaft. Shroud portion  396   m  that is similar to shroud portion  396   l , with the exception that shroud portion  396   m  comprises a lip  420   m  extending inward toward the driveshaft and configured to prevent the plate from exiting the shroud portion, as shown. In this embodiment, driver  200   m  also comprises a spring  424   m  disposed between plate  412   m  and distal end  211  of body portion  213   m  of housing  210   m  such that the spring biases the plate in a direction toward open end  408   m  of the shroud portion. 
       FIGS. 16A-16C  depict various views of a twelfth embodiment  300   n  of the present couplers in combination with a powered driver  200   n  and an IO device  100   o  that is configured to provide access to an interior of a bone (e.g., similar in some respects to IO device  100   c ). In the embodiment shown, coupler  300   n  comprises a drive hub  304   n  having a first end  308   n  and a second end  312   n  including a recess  336   n  configured to receive a driveshaft  222   n  of a driver  200   n.  In the embodiment shown, coupler  300   n  further comprises one or more (e.g., two, as shown) resilient clips  428   n  biased toward an axis of rotation of the drive hub (e.g., and of driveshaft  222   n ). For example, in this embodiment, coupler  300   n  comprises a hollow sleeve  332   n  configured to be disposed around recess  336   n  such that driveshaft  222   n,  if inserted into the recess, will also be disposed in the hollow sleeve. In this embodiment, resilient clips  428   n  are unitary with sleeve  432   n  (e.g., comprise a single piece of sheet metal). As described above for other embodiments, recess  336   n  has a cross-sectional shape corresponding to the cross-sectional shape of driveshaft  222   n  such that if the driveshaft is inserted into the recess, drive hub  304   n  will resist rotating relative to the driveshaft. For example, in this embodiment, both of recess  336   n  and driveshaft  222   n  have non-circular (e.g., elongated) cross-sectional shapes. In the embodiment shown, first end  308   n  is configured to be coupled to IO device  100   o  (e.g., to resist rotation of the IO device relative to the drive hub). For example, in the embodiment shown, drive hub  304   n  is unitary with a portion of a hub assembly (e.g., unitary with second hub  150   o ). 
       FIGS. 17A-17D  depict various views of a thirteenth embodiment  300   o  of the present couplers in combination with a powered driver  200   o  and an IO device  100   p  that is configured to provide access to an interior of a bone (e.g., similar in some respects to IO device  100   c ). In the embodiment shown, coupler  300   o  comprises a drive hub  304   o  having a first end  308   o  and a second end  312   o  configured to be coupled in fixed relation to a driveshaft  222   o  of driver  200   o  (e.g., drive hub  304   o  can be unitary with driveshaft  222   o,  as shown). In this embodiment, first end  308   o  includes a recess  340   o  configured to receive a hub (e.g., second hub  150   p ) of IO device  100   p.  In the embodiment shown, drive hub  304   o  has a sidewall  436   o  with at least one (e.g., two, as shown) opening  440   o  extending through the sidewall in communication with recess  340   o.  In this embodiment, each opening  440   o  has an inner cross-sectional area at recess  340   o  that is smaller than an outer cross-sectional area spaced apart from the inner cross-sectional area. In the embodiment shown, coupler  300   o  also comprises a ball  444   o  movably disposed in each opening  440   o;  and a resilient c-clip  448   o  disposed around the drive hub such that c-clip  448   o  biases ball(s)  444   o  toward a rotational axis of the drive hub (and of the driveshaft). In the embodiment shown, ball(s)  444   o  each has a maximum cross-sectional area that is larger than the inner cross-sectional area of the respective opening  440   o  to prevent the ball from falling into recess  340   o  if driveshaft  222   o  is not disposed in recess  340   o.  In this embodiment, second end  312   o  of drive hub  304   o  is configured such that if a hub (e.g., second hub  150   p ) of IO device  100   p  (which, in this embodiment, has at least one detent  452   o  configured to align with openings  440   o ) is inserted into recess  340   o,  the c-clip will: (i) allow ball(s)  444   o  to move away from the rotational axis of the drive hub until detent(s)  452   o  align with ball(s)  444   o , and (ii) press ball(s)  444   o  into detent(s)  452   o  when detent(s)  452   o  align with ball(s)  444   o  to resist removal of the driveshaft from the recess. In some embodiments, hub  150   p  and/or recess  340   o  have non-circular cross-sectional shapes (e.g., to resist rotation of hub  150   p  relative drive hub  304   o ). In the embodiment shown, drive hub  304   o  has a circular outer cross-sectional shape. In the embodiment shown, hub  150   p  includes a projection  456   o  that includes detent(s)  452   o.    
       FIGS. 18A-18C  depict various views of a fourteenth embodiment  300   p  of the present couplers in combination with a powered driver  200   p  and an IO device  100   q  that is configured for obtaining a sample of bone and/or bone marrow (e.g., similar in some respects to IO devices  100   a  and/or  100   b ). In the embodiment shown, coupler  300   p  comprises a drive hub  304   p  having a first end  308   p  and a second end  312   p  configured to be coupled in fixed relation to a driveshaft  222   p  of driver  200   p  (e.g., drive hub  304   p  can be unitary with driveshaft  222   p,  as shown). In this embodiment, first end  308   p  includes a recess  340   p  configured to receive a hub (e.g., first hub  140   q ) of IO device  100   q.  In the embodiment shown, drive hub  304   p  has a sidewall  436   p  with at least one (e.g., two, as shown) opening  440   p  extending through the sidewall in communication with recess  340   p.  In this embodiment, each opening  440   p  has an inner cross-sectional area at recess  340   p  that is smaller than an outer cross-sectional area spaced apart from the inner cross-sectional area. In the embodiment shown, coupler  300   p  also comprises a ball  444   p  movably disposed in each opening  440   p;  and a resilient c-clip  448   p  disposed around the drive hub such that c-clip  448   p  biases ball(s)  444   p  toward a rotational axis of the drive hub (and of the driveshaft). In the embodiment shown, ball(s)  444   p  each has a maximum cross-sectional area that is larger than the inner cross-sectional area of the respective opening  440   p  to prevent the ball from falling into recess  340   p  if hub  140   q  is not disposed in recess  340   p.  In this embodiment, second end  312   p  of drive hub  304   p  is configured such that if a hub (e.g., first hub  140   q ) of IO device  100   q  (which, in this embodiment, has at least one detent  452   q  configured to align with openings  440   p ) is inserted into recess  340   p,  the c-clip will: (i) allow ball(s)  444   p  to move away from the rotational axis of the drive hub until detent(s)  452   p  align with ball(s)  444   p,  and (ii) press ball(s)  444   p  into detent(s)  452   p  when detent(s)  452   p  align with ball(s)  444   p  to resist removal of hub  140   q  from the recess. In some embodiments, hub  140   q  and/or recess  340   p  have non-circular cross-sectional shapes (e.g., to resist rotation of hub  140   q  relative to drive hub  304   p ). In the embodiment shown, drive hub  304   p  has a circular outer cross-sectional shape. 
     Coupler  300   p  differs from coupler  300   o,  for example, in that first end  308   p  includes a recess  336   p  configured to receive driveshaft  222   p  of driver  200   p.  In the embodiment shown, drive hub  304   p  has a sidewall  460   p  with at least one (e.g., two, as shown) opening  464   p  extending through the sidewall in communication with recess  336   p,  with each opening  464   p  having an inner cross-sectional area at recess  336   p  that is smaller than an outer cross-sectional area spaced apart from the inner cross-sectional area (e.g., at the outer surface of sidewall  460   p ). In the embodiment shown, coupler  300   p  also comprises at least one (e.g., two, as shown) second ball  468   p  each movably disposed in an opening  464   p;  and a second resilient c-clip  472   p  disposed around the drive hub such that the c-clip biases ball(s)  468   p  toward a rotational axis of the drive hub (and of the driveshaft). In the embodiment shown, ball(s)  468   p  each has a maximum cross-sectional area that is larger than the inner cross-sectional area of the respective opening  464   p  to prevent the ball from falling into recess  336   p  if driveshaft  222   p  is not disposed in recess  340   p . In this embodiment, second end  312   p  of the drive hub is configured such that if driveshaft  222   p  (which has at least one detent  476   p ) is inserted into recess  336   p,  the c-clip will: (i) allow ball(s)  468   p  to move away from the rotational axis of the drive hub until detent(s)  476   p  aligns with ball(s)  468   p,  and (ii) press ball(s)  468   p  into detent(s)  476   p  when detent(s)  476   p  align with ball(s)  468   p  to resist removal of the driveshaft from the recess. In some embodiments, driveshaft  222   p  and/or recess  336   p  have non-circular cross-sectional shapes (e.g., to resist rotation of drive hub  304   p  relative to driveshaft  222   p ). In the embodiment shown, drive hub  304   p  has a circular outer cross-sectional shape. Coupler  300   p  further differs from coupler  300   o,  for example, in that drive hub  304   p  includes a recess  324   p  that is sized to receive a second hub (not shown, but similar to second hub  150   a  of IO device  100   a ). 
       FIGS. 19A-19C  depict various views of a fifteenth embodiment  300   q  of the present couplers in combination with a powered driver  200   q  and an IO device  100   r  that is configured to provide access to an interior of a bone (e.g., similar in some respects to IO device  100   c ). In the embodiment shown, coupler  300   q  comprises a drive hub  304   q  having a first end  308   q  and a second end  312   q  configured to be coupled in fixed relation to a driveshaft  222   q  of driver  200   q  (e.g., drive hub  304   q  can be unitary with driveshaft  222   q,  as shown). In this embodiment, first end  308   q  includes a recess  340   q  configured to receive a hub (e.g., second hub  150   r ) of IO device  100   r.  In the embodiment shown, drive hub  304   q  has a sidewall  436   q  with at least one (e.g., two, as shown) opening  440   q  extending through the sidewall in communication with recess  340   q.  In this embodiment, each opening  440   q  has an inner cross-sectional area at recess  340   q  that is smaller than an outer cross-sectional area spaced apart from the inner cross-sectional area. In the embodiment shown, coupler  300   q  also comprises a ball  444   q  movably disposed in each opening  440   q;  and a collar  480   q  movably disposed around the drive hub and having an interior surface  484   q  defining at least one detent  488   q  adjacent the drive hub. In this embodiment, collar  480   q  is movable between: (i) a first position ( FIG. 19B ) in which detent(s)  488   q  of collar  480   q  is aligned with opening(s)  440   q  such that ball(s)  444   q  can move away from the rotational axis of the drive hub to permit a hub (e.g.,  150   r ) of IO device  100   r  having a detent  352   q  to be inserted into or removed from recess  340   q  (this first position and other such similar positions described in this disclosure may also be characterized as positions that allow the hub to move within the recess without interference from the positive detenting structure (e.g., ball  444   q  in this embodiment), and (ii) a second position ( FIG. 19C ) in which detent(s)  488   q  of collar  480   q  do not align with opening(s)  440   q  such that if a hub (e.g.,  150   r ) of IO device  100   r  having detent(s)  352   q  is disposed in recess  340   q  such that detent(s)  352   q  of hub  150   r  align with opening(s)  440   q,  IO device  100   r  is prevented from being removed from recess  340   q  (this second position and other such similar positions described in this disclosure may also be characterized as positions that cause the positive detenting structure (e.g., ball  444   q  in this embodiment) to be sufficiently disposed in the detent (e.g., detent(s)  352   q  in this embodiment) such that the hub cannot move completely in and out of the recess due to interference with the positive detenting structure). In some embodiments, hub  150   r  and/or recess  340   q  have non-circular cross-sectional shapes (e.g., to resist rotation of hub  150   r  relative to drive hub  304   q ). In the embodiment shown, hub  150   r  includes a projection  356   q  that includes detent(s)  352   q.  In the embodiment shown, coupler  300   q  comprises a spring  492   q  that biases collar  480   q  toward the second position ( FIG. 19C ). While not shown in  FIGS. 19A-19D , other embodiments can comprise a second recess in second end  312   q  with openings, balls, and a second collar to engage corresponding detents in a driveshaft of a driver (e.g., similar to coupler  300   p ). 
       FIGS. 20A-20B  depict side cross-sectional views of a sixteenth embodiment  300   r  of the present couplers in combination with a powered driver  200   r  and an IO device  100   s  that is configured to provide access to an interior of a bone (e.g., similar in some respects to IO device  100   c ). In the embodiment shown, coupler  300   r  comprises a drive hub  304   r  having a first end  308   r  and a second end  312   r  configured to be coupled in fixed relation to a driveshaft  222   r  of driver  200   r  (e.g., drive hub  304   r  can be unitary with driveshaft  222   r,  as shown). In this embodiment, first end  308   r  includes a recess  340   r  configured to receive a hub  130   s  (e.g., second hub  150   s ) of IO device  100   s.  In the embodiment shown, drive hub  304   r  has a sidewall  436   r  with at least one (e.g., two, as shown) opening  440   r  extending through the sidewall in communication with recess  340   r.  In the embodiment shown, coupler  300   r  also comprises at least one set screw  496   r  with a spring-loaded ball  444   r,  with set screw(s)  496   r  disposed in opening(s)  440   r  such that ball  440   r  is biased in a direction toward an axis of rotation of the drive hub. In this embodiment, second end  312   r  of drive hub  304   r  is configured such that if a hub (e.g., hub  150   s ) of IO device  100   s  having at least one detent  452   r  is inserted into recess  340   r : (i) spring-loaded ball(s)  444   r  will move away from the rotational axis of the drive hub until detent(s)  452   r  align with ball(s)  444   r,  and (ii) ball(s)  444   r  will move into detent(s)  452   r  when detent(s) align with ball(s)  444   r  to resist removal of the IO device from recess  340   r.  In some embodiments, hub  150   s  and/or recess  340   s  have non-circular cross-sectional shapes (e.g., to resist rotation of hub  150   s  relative to drive hub  304   r ). In the embodiment shown, hub  150   s  includes a projection  456   r  that includes detent(s)  452   r.    
       FIGS. 21A-21C  depict various views of a seventeenth embodiment  300   s  of the present couplers in combination with a powered driver  200   s  and an IO device  100   t  that is configured for obtaining a sample of bone and/or bone marrow (e.g., similar in some respects to IO devices  100   a  and/or  100   b ). In the embodiment shown, coupler  300   s  comprises a drive hub  304   s  having a first end  308   s  and a second end  312   s  configured to be coupled in fixed relation to a driveshaft  222   s  of driver  200   s.  In this embodiment, first end  308   s  includes a recess  340   s  configured to receive a hub (e.g., first hub  140   t ) of IO device  100   t.  In the embodiment shown, drive hub  304   s  has a sidewall  436   s,  a distal portion of which has at least one (e.g., two, as shown) opening  440   s  extending through the sidewall in communication with recess  340   s.  In the embodiment shown, coupler  300   s  also comprises at least one set screw  496   s  with a spring-loaded ball  444   s  (these and others like them in this disclosure may also be characterized collectively as a spring-loaded ball plunger and a set screw), with set screw(s)  496   s  disposed in opening(s)  440   s  such that ball  444   s  is biased in a direction toward an axis of rotation of the drive hub. In this embodiment, second end  312   s  of drive hub  304   s  is configured such that if a hub (e.g., hub  140   t ) of IO device  100   t  having at least one detent  352   s  is inserted into recess  340   s : (i) spring-loaded ball(s)  444   s  will move away from the rotational axis of the drive hub until detent(s)  352   s  align with ball(s)  444   s,  and (ii) ball(s)  444   s  will move into detent(s)  352   s  when detent(s) align with ball(s)  444   s  to resist removal of the IO device from recess  340   s.  In some embodiments, hub  140   t  and/or recess  340   s  have non-circular cross-sectional shapes (e.g., to resist rotation of hub  140   t  relative to drive hub  304   s ). In the embodiment shown, hub  140   t  includes a projection  456   s  that includes detent(s)  452   s.    
     Coupler  300   s  differs from coupler  300   r,  for example, in that second end  312   s  includes a recess  336   s  configured to receive driveshaft  222   s  of driver  200   s.  In the embodiment shown, a proximal portion of sidewall  3460   s  (the proximal portion having a cross-sectional area that is smaller than a cross-sectional area of the distal portion referenced above) has at least one (e.g., two, as shown) opening  464   s  extending through the sidewall in communication with recess  336   s.  In the embodiment shown, coupler  300   s  also comprises at least one set screw  496   s  with a spring loaded ball  444   s,  with set screw(s)  496   s  disposed in opening(s)  464   s  such that ball(s)  444   s  are biased in a direction toward an axis of rotation of the drive hub. In this embodiment, second end of drive hub  304   s  is configured such that if driveshaft  222   s  (which has at least one detent  476   s ) is inserted into recess  336   s : (i) ball(s)  444   s  of screw(s)  496   s  will move away from the rotational axis of the drive hub until detent(s)  476   s  aligns with ball(s)  444   s,  and (ii) ball(s)  444   s  of screw(s)  496   s  will move into detent(s)  476   s  when detent(s)  476   s  align with ball(s)  444   s  to resist removal of driveshaft  222   s  from recess  336   s.  In some embodiments, driveshaft  222   s  and/or recess  336   s  have non-circular cross-sectional shapes (e.g., to resist rotation of drive hub  304   s  relative to driveshaft  222   s ). In the embodiment shown, drive hub  304   s  has a circular outer cross-sectional shape. Coupler  300   s  further differs from coupler  300   r,  for example, in that drive hub  304   s  includes a recess  324   s  that is sized to receive a second hub (not shown, but similar to second hub  150   a  of IO device  100   a ). 
       FIGS. 22A-22B  depict side cross-sectional views of an eighteenth embodiment  300   t  of the present couplers in combination with a powered driver  200   t  and an IO device  100   u  that is configured to provide access to an interior of a bone (e.g., similar in some respects to IO device  100   c ). In the embodiment shown, coupler  300   t  comprises a drive hub  304   t  having a first end  308   t  and a second end  312   t  configured to be coupled in fixed relation to a driveshaft  222   t  of driver  200   t  (e.g., drive hub  304   t  can be unitary with driveshaft  222   t,  as shown). In this embodiment, first end  308   t  includes a recess  340   t  configured to receive a hub (e.g., second hub  150   u ) of IO device  100   u.  In the embodiment shown, drive hub  304   t  has a sidewall  436   t  with at least one opening  440   t  extending through the sidewall in communication with recess  340   t.  In the embodiment shown, coupler  300   t  also comprises a screw  500   t  having an enlarged head  504   t  and a threaded shaft  508   t  with a distal end  512   t,  the screw threaded into opening  440   t  with the distal end facing in a direction toward an axis of rotation of the drive hub. In this embodiment, screw  500   t  is rotatable between: (i) a first position in which distal end  512   t  does not extend into recess  340   t  to permit hub  150   u  of IO device  100   u  having a detent  452   t  to be inserted into or removed from recess  340   t;  and (ii) a second position in which distal end  512   t  extends into second recess  340   t  such that if hub  150   u  of IO device  100   u  having detent(s)  452   t  is disposed in recess  340   t  such that detent  452   t  is aligned with opening  440   t  (and thereby screw  500   t ), IO device  100   u  is prevented from being removed from recess  340   t  (e.g., as shown in  FIG. 22B ). In some embodiments, hub  150   u  and/or recess  340   t  have non-circular cross-sectional shapes (e.g., to resist rotation of hub  150   u  relative to drive hub  304   t ). In the embodiment shown, hub  150   u  includes a projection  456   t  that includes detent(s)  452   t.    
       FIGS. 23A-23B  depict perspective and side cross-sectional views, respectively, of a nineteenth embodiment  300   u  of the present couplers in combination with a powered driver  200   u  and an IO device  100   v  that is configured for obtaining a sample of bone and/or bone marrow (e.g., similar in some respects to IO devices  100   a  and/or  100   b ). In the embodiment shown, coupler  300   u  comprises a drive hub  304   u  having a first end  308   u  and a second end  312   u  configured to be coupled in fixed relation to a driveshaft  222   u  of driver  200   u  (e.g., drive hub  304   u  can be unitary with driveshaft  222   u,  as shown). In this embodiment, first end  308   u  includes a recess  340   u  configured to receive a hub (e.g., first hub  140   v ) of IO device  100   v.  In the embodiment shown, drive hub  304   u  has a sidewall  436   u,  a distal portion of which has at least one opening  440   u  extending through the sidewall in communication with recess  340   u.  In the embodiment shown, coupler  300   u  also comprises a screw  500   u  having an enlarged head  504   u  and a threaded shaft  508   u  with a distal end  512   u,  the screw threaded into opening  440   u  with the distal end facing in a direction toward an axis of rotation of the drive hub. In this embodiment, screw  500   u  is rotatable between: (i) a first position in which distal end  512   u  does not extend into recess  340   u  to permit hub  130   v  (e.g., hub  150   v ) of IO device  100   v  having a detent  452   u  to be inserted into or removed from recess  340   u;  and (ii) a second position in which distal end  512   u  extends into second recess  340   u  such that if hub  150   v  of IO device  100   v  having detent(s)  452   u  is disposed in recess  340   u  such that detent  452   u  is aligned with opening  440   u  (and thereby screw  500   u ), IO device  100   v  is prevented from being removed from recess  340   u  (e.g., as shown in  FIG. 23B ). In some embodiments, hub  150   v  and/or recess  340   u  have non-circular cross-sectional shapes (e.g., to resist rotation of hub  150   v  relative to drive hub  304   u ). In the embodiment shown, hub  150   v  includes a projection  456   u  that includes detent(s)  452   u.    
     Coupler  300   u  differs from coupler  300   t,  for example, in that second end  312   u  includes a recess  336   u  configured to receive driveshaft  222   u  of driver  200   u.  In the embodiment shown, a proximal portion of sidewall  346   u  (the proximal portion having a cross-sectional area that is smaller than a cross-sectional area of the distal portion referenced above) has at least one (e.g., two, as shown) opening  464   u  extending through the sidewall in communication with recess  336   u.  In the embodiment shown, coupler  300   u  also comprises a second screw  500   u  having an enlarged head  504   u  and a threaded shaft  508   u  with a distal end  512   u,  the second screw threaded into opening  464   u  with the distal end facing in a direction toward an axis of rotation of the drive hub. In this embodiment, the second screw is rotatable between: (i) a first position in which distal end  512   u  does not extend into recess  336   u  to permit driveshaft  222   u  (which has a detent  476   u ) to be inserted into or removed from recess  336   u,  and (ii) a second position in which distal end  512   u  extends into recess  336   u  such that if driveshaft  222   u  having detent  476   u  is disposed in recess  336   u  such that detent  476   u  is aligned with opening  464   u  (and thereby screw  500   u ), driveshaft  222   u  is prevented from being removed from recess  336   u.  In some embodiments, driveshaft  222   u  and/or recess  336   u  have non-circular cross-sectional shapes (e.g., to resist rotation of drive hub  304   u  relative to driveshaft  222   u ). Coupler  300   u  further differs from coupler  300   t,  for example, in that drive hub  304   u  includes a recess  324   u  that is sized to receive a second hub (not shown, but similar to second hub  150   a  of IO device  100   a ). 
       FIGS. 24A-24B  depict perspective and side cross-sectional views, respectively, of a twentieth embodiment of the present couplers  300   v  in combination with a powered driver  200   v  and an IO device  100   w  that is configured to provide access to an interior of a bone (e.g., similar in some respects to IO device  100   c ). In the embodiment shown, coupler  300   v  comprises a drive hub  304   v  having a first end  308   v  and a second end  312   v  configured to be coupled in fixed relation to a driveshaft  222   v  of driver  200   v  (e.g., drive hub  304   v  can be unitary with driveshaft  222   v,  as shown). In this embodiment, first end  308   v  includes a recess  340   v  configured to receive a hub (e.g., second hub  150   w ) of IO device  100   w.  In the embodiment shown, drive hub  304   v  has a sidewall  436   v  with at least one (e.g., two, as shown) opening  440   v  extending through the sidewall in communication with recess  340   v.  In the embodiment shown, coupler  300   v  also comprises a pin  520   v  having a distal end  524   v  configured to be inserted into opening  440   v  such that pin  520   v  extends across a majority (e.g., all) of a width of recess  340   v  (e.g., and through a second opening  440   v  on an opposite side of opening  340   v,  as shown). In this embodiment, pin  520   v  is movable between: (i) a first position in which distal end  524   v  does not extend into recess  340   v  to permit a hub  150   w  of IO device  100   w  (which has a transverse passageway  528   w ) to be inserted into or removed from recess  340   v,  and (ii) a second position in which pin  520   v  extends into and across a majority (e.g., all) of recess  340   v  (as shown in  FIG. 24B ) such that if hub  150   w  of IO device  100   v  having transverse passageway  528   w  is disposed in recess  340   v  such that transverse passageway  528   w  is aligned with opening  440   v,  pin  520   v  extends into (e.g., through) transverse passageway  528   w  to prevent IO device  100   w  from being removed from recess  340   v . In some embodiments, such as the one shown, hub  150   w  and/or recess  340   v  have non-circular cross-sectional shapes (e.g., to resist rotation of hub  150   w  relative to drive hub  304   v ). In the embodiment shown, hub  150   w  includes a projection  456   v  that includes transverse passageway  528   w.    
       FIGS. 25A-25B  depict perspective and side cross-sectional views, respectively, of a twenty-first embodiment  300   w  of the present couplers in combination with a powered driver  200   w  and an IO device  100   x  that is configured for obtaining a sample of bone and/or bone marrow (e.g., similar in some respects to IO devices  100   a  and/or  100   b ). In the embodiment shown, coupler  300   w  comprises a drive hub  304   w  having a first end  308   w  and a second end  312   w  configured to be coupled in fixed relation to a driveshaft  222   w  of driver  200   w.  In this embodiment, first end  308   w  includes a recess  340   w  configured to receive a hub (e.g., first hub  140   x ) of IO device  100   x.  In the embodiment shown, drive hub  304   w  has a sidewall  436   w,  a distal portion of which has at least one (e.g., two, as shown) opening  440   w  extending through the sidewall in communication with recess  340   w.  In the embodiment shown, coupler  300   w  also comprises a pin  520   w  having a distal end  524   w  configured to be inserted into opening  440   w  such that pin  520   w  extends across a majority (e.g., all) of a width of recess  340   w  (e.g., and through a second opening  440   w  on an opposite side of opening  340   w,  as shown). In this embodiment, pin  520   w  is movable between: (i) a first position in which distal end  524   w  does not extend into recess  340   w  to permit a hub  150   x  (e.g., hub  130   x ) of IO device  100   x  (which has a transverse passageway  528   x ) to be inserted into or removed from recess  340   w,  and (ii) a second position in which pin  520   w  extends into and across a majority (e.g., all) of recess  340   w  (as shown in  FIG. 25B ) such that if hub  150   x  of IO device  100   x  having transverse passageway  528   x  is disposed in recess  340   w  such that transverse passageway  528   x  is aligned with opening  440   w , pin  520   w  extends into (e.g., through) transverse passageway  528   x  to prevent IO device  100   x  from being removed from recess  340   w.  In some embodiments, such as the one shown, hub  150   x  and/or recess  340   w  have non-circular cross-sectional shapes (e.g., to resist rotation of hub  150   x  relative to drive hub  304   x ). In the embodiment shown, hub  150   x  includes a projection  456   w  that includes transverse passageway  528   x.    
     Coupler  300   w  differs from coupler  300   v,  for example, in that second end  312   w  includes a recess  336   w  configured to receive driveshaft  222   w  of driver  200   w.  In the embodiment shown, a proximal portion of sidewall  436   w  of drive hub  304   w  (the proximal portion having a cross-sectional area that is smaller than a cross-sectional area of the distal portion referenced above) includes at least one (e.g., two, as shown) opening  464   w  extending through the sidewall in communication with recess  336   w.  In the embodiment shown, coupler  300   w  also comprises a second a pin  520   w  having a distal end  524   w  configured to be inserted into opening  464   w  such that pin  520   w  extends across a majority (e.g., all) of a width of recess  340   w  (e.g., and through a second opening  464   w  on an opposite side of opening  340   v,  as shown). In this embodiment, pin  520   v  is movable between: (i) a first position in which distal end  524   w  does not extend into recess  336   w  to permit a driveshaft  222   w  driver  200   w  (which has a transverse passageway  532   w ) to be inserted into or removed from recess  336   w,  and (ii) a second position in which pin  520   w  extends into and across a majority (e.g., all) of recess  340   w  (as shown in  FIG. 25B ) such that if driveshaft  222   w  of driver  200   w  having transverse passageway  532   w  is disposed in recess  336   w  such that transverse passageway  532   w  is aligned with opening  464   w,  pin  520   w  extends into (e.g., through) transverse passageway  532   w  to prevent IO device  100   x  from being removed from recess  336   w.  In some embodiments, such as the one shown, driveshaft  222   w  and/or recess  336   w  have non-circular cross-sectional shapes (e.g., to resist rotation of drive hub  304   w  relative to driveshaft  222   w ). Coupler  300   w  also differs from coupler  300   v,  for example, in that drive hub  304   w  includes a recess  324   w  that is sized to receive a second hub (not shown, but similar to second hub  150   a  of IO device  100   a ). 
       FIGS. 26A-26E  depict various views of a twenty-second embodiment  300   x  of the present couplers in combination with a powered driver  200   x  and an IO device  100   y  that is configured to provide access to an interior of a bone (e.g., similar in some respects to IO device  100   c ). In the embodiment shown, driver  200   x  is similar in some respects to driver  200   l  described above with reference to  FIGS. 14A-14B . For example, driver  200   x  comprises a housing  210   x  having a body portion  213   x  and a shroud portion  396   x.  In this embodiment, body portion  213   x  has a sidewall  400   x  defining distal end  211  of the body portion, and shroud portion  396   x  has a cylindrical sidewall  404   x  extending from distal end  211  of the body portion. In the embodiment shown, shroud portion  396   x  has an open distal end  408   x.  In the embodiment shown, driveshaft  222   x  has a distal end  224   x  extending from body portion  213   x  (e.g., past distal end  211  and into shroud portion  396   x ). However, driver  200   x  differs from driver  200   l , for example, in that shroud portion  396   x  includes one or more (e.g., two, as shown) projections  536   x  extending (e.g., in opposite directions) from sidewall  404   x  (e.g., and away from driveshaft  222   x ). In this embodiment, projections  536   x  are shaped as short, circular cylinders. 
     In the embodiment shown, coupler  300   x  comprises a hollow sleeve  544   x  configured to be rotatably coupled to a hub (e.g., a first hub and/or a second hub) of IO device  100   y.  In this embodiment, sleeve  544   x  includes a proximal portion  548   x  configured to fit over shroud portion  396   x  of housing  210   x  (as shown, for example, in  FIG. 26B ) to couple the IO device to the driver and resist removal of IO device from the driver. In this embodiment, proximal portion  548   x  of sleeve  544   x  comprises one or more (e.g., two, as shown) L-shaped slots  552   x  each configured to receive a projection  536   x  if proximal portion  544   x  of the sleeve is disposed over shroud portion  396   x  such that sleeve  544   x  can be rotated in direction  556   x  relative to shroud portion  396   x  to resist removal of the IO device from the driver (e.g., to lock the sleeve relative to the driver by seating projections  536   x  in lateral legs  560   x  of slots  552   x,  as shown in  FIG. 26E ). In this embodiment, distal end  561   x  of sleeve  544   x  includes an openings  564   x  (e.g., with a circular cross-section, as shown) through which a portion of IO device  100   y  can extend such that the driver can rotate the IO device while sleeve  544   x  is coupled in fixed relation to the driver. In the embodiment shown, IO device  100   y  comprises an elongated hub assembly  130   y  having a first end  131  with a circular cross-section sized to correspond to that of opening  564   x  (e.g., that is smaller than a portion of hub  130   y  configured to be disposed immediately inside sleeve  544   x ). In this embodiment, hub  130   y  also comprises a flange  568   x  with a circular cross-section that is larger than opening  564   x  such that first end  131  can “snap” into opening  564   x  to (i) maintain its longitudinal position relative to sleeve  544   x,  (ii) create a tortuous path through opening to reduce the likelihood of contaminants traveling through opening  546   x  while IO device  100   y  is coupled to sleeve  544   x,  and (iii) permit IO device  100   y  to rotate relative sleeve  544   x.    
       FIGS. 27A-27C  depict various views of a twenty-third embodiment  300   y  of the present couplers in combination with a powered driver  200   y  and IO device  100   z  that is configured to provide access to an interior of a bone (e.g., similar in some respects to IO device  100   c ). In the embodiment shown, driver  200   y  is similar in some respects to driver  200   x.  For example, driver  200   y  comprises a housing  210   y  having a body portion  213   y  and a shroud portion  396   y.  In this embodiment, body portion  213   y  has a sidewall  400   y  defining distal end  211  of the body portion, and shroud portion  396   y  has a cylindrical sidewall  404   y  extending from distal end  211  of the body portion. In the embodiment shown, shroud portion  396   y  has an open distal end  408   y.  In the embodiment shown, driveshaft  222   y  has a distal end  224   y  extending from body portion  213   y  past distal end  211  and into shroud portion  396   y.  In the embodiment shown, shroud portion  396   y  includes one or more (e.g., two, as shown) projections  536   y  extending (e.g., in opposite directions) from sidewall  404   y  (e.g., and away from driveshaft  222   y ). Driver  200   y  differs from driver  200   x,  for example, in that shroud portion  396   y  (e.g., sidewall  404   y ) comprises one or more (e.g., two, as shown) resilient portions  572   y  and one or more substantially rigid portions  576   y,  with projections  536   y  extending from resilient portions  572   y  such that the projections are movable relative to driveshaft  222   y.  In this embodiment, resilient portions  572   y  and substantially rigid portions  576   y  comprise the same material, and resilient portions are created by the placement of slots  580   y  between portions  572   y  and  576   y  such that resilient portions  572   y  have less curvature than substantially rigid portions  576   y,  and thereby have less resistance at distal end  408   y  to bending toward driveshaft  222   y  (but still enough resistance to bending to bias resilient portions  572   y  toward a position in which portions  572   y  are substantially aligned with portions  576   y ). 
     In the embodiment shown, coupler  300   y  comprises a hollow sleeve  544   y  configured to be rotatably coupled to a hub  130   z  (e.g., first hub  140   z  and/or second hub  150   z ) of IO device  100   z.  In this embodiment, sleeve  544   y  includes a proximal portion  548   y  configured to fit over shroud portion  396   y  of housing  210   y  (as shown, for example, in  FIG. 27B ) to couple the IO device to the driver and resist removal of IO device from the driver. In this embodiment, proximal portion  548   y  includes an interior surface  584   y  defining one or more detents  588   y  configured to receive projections  536   y  of shroud portion  396   y  to resist removal of the IO device from the driver. In this embodiment, sleeve  544   y  can be pressed directly over shroud portion  396   y  (e.g.,  FIG. 27B  to  FIG. 27C ) such that proximal portion  548   y  will depress projections  536   y  (and resilient portions  572   y ) until detent(s)  588   y  align with detent(s)  588   y,  at which point, resilient portions  572   y  will return to their resting positions and extend projections  536   y  into detent(s)  588   y.  In this embodiment, distal end  560   y  of sleeve  544   y  includes an openings  564   y  (e.g., with a circular cross-section, as shown) through which a portion of IO device  100   z  can extend such that the driver can rotate the IO device while sleeve  544   y  is coupled in fixed relation to the driver. In the embodiment shown, IO device  100   z  comprises an elongated hub assembly  130   z  having a first end  131  with a circular cross-section sized to correspond to that of opening  564   y  (e.g., that is smaller than a portion of hub  130   z  configured to be disposed immediately inside sleeve  544   x ). In this embodiment, hub  130   z  also comprises a flange  568   y  with a circular cross-section that is larger than opening  564   y  such that first end  131  can “snap” into opening  564   y  to (i) maintain its longitudinal position relative to sleeve  544   y,  (ii) create a tortuous path through opening to reduce the likelihood of contaminants traveling through opening  546   y  while IO device  100   z  is coupled to sleeve  544   y,  and (iii) permit IO device  100   z  to rotate relative sleeve  544   y.    
       FIGS. 28A-28C  depict various views of a twenty-fourth embodiment  300   z  of the present couplers in combination with a powered driver  200   z  and an IO device  100   aa  that is configured to provide access to an interior of a bone (e.g., similar in some respects to IO device  100   c ). In the embodiment shown, driver  200   z  is similar in some respects to driver  200   y.  For example, driver  200   z  comprises: a housing  210   z  having a body portion  213   z  and a shroud portion  396   z.  In this embodiment, body portion  213   z  has a sidewall  400   z  defining distal end  211  of the body portion, and shroud portion  396   z  has a cylindrical sidewall  404   z  extending from distal end  211  of the body portion. In the embodiment shown, shroud portion  396   z  has an open distal end  408   z.  In the embodiment shown, driveshaft  222   z  has a distal end  224   z  extending from body portion  213   z  past distal end  211  and into shroud portion  396   z ). In the embodiment shown, shroud portion  396   z  includes one or more (e.g., two, as shown) projections  536   z  extending (e.g., in opposite directions) from sidewall  404   z  (e.g., and away from driveshaft  222   z ). Driver  200   z  differs from driver  200   y,  for example, in that shroud portion  396   z  (e.g., sidewall  404   z ) comprises one includes two elongated grooves  592   z  in an outer surface of cylindrical sidewall  404   z,  with grooves  592   z  extending in a direction that is substantially perpendicular to the rotational axis of the driveshaft, as shown. In other embodiments, grooves  592   z  can be disposed or orientated at any suitable angle relative to driveshaft  222   z.    
     In the embodiment shown, coupler  300   z  comprises a hollow sleeve  544   z  configured to be rotatably coupled to a hub (e.g., a first hub and/or a second hub) of IO device  100   aa . In this embodiment, sleeve  544   z  includes a proximal portion  548   z  configured to fit over shroud portion  396   z  of housing  210   z  (as shown, for example, in  FIG. 28B ) to couple the IO device to the driver and resist removal of IO device from the driver. In this embodiment, proximal portion  548   z  of the sleeve comprises two elongated openings  596   z  that are configured to align with grooves  592   z  in shroud portion  396   z  if proximal portion  548   z  is disposed on shroud portion  396   z.  In this embodiment, coupler  300   z  also comprises a resilient U-shaped clip  600   z  having two legs  604   z,  and clip  600   z  is configured to extend over proximal portion  548   z  with legs  604   z  extending through elongated openings  596   z  and into elongated grooves  592   z  to resist removal of the sleeve and IO device from the driver (as shown in  FIGS. 28B and 28C ). 
       FIGS. 29A-29D  depict various views of a twenty-fifth embodiment of the present couplers  300   aa  in combination with a powered driver  200   aa  and an IO device  100   bb  that is configured to provide access to an interior of a bone (e.g., similar in some respects to IO device  100   c ). In the embodiment shown, coupler  300   aa  comprises a drive hub  304   aa  having a first end  308   aa  and a second end  312   aa  configured to be coupled in fixed relation to driveshaft  222   aa  of a driver  200   aa  (e.g., second end  312   aa  is unitary with driveshaft  222   aa  in the embodiment shown). In the embodiment shown, coupler  300   aa  also comprises a resilient clamp  608   aa  having a substantially circular interior  612   aa , and configured to be movable between (i) a contracted position ( FIG. 29C ) in which the interior has a first transverse dimension  616   aa , and (ii) an expanded position ( FIG. 29D ) in which the interior has a second transverse dimension  620   aa  that is larger than first transverse dimension  616   aa . In this embodiment, clamp  608   aa  is biased toward the contracted position of  FIG. 29C . In the embodiment shown, drive hub  304   aa  has a transverse dimension  624   aa  that is larger than dimension  616   aa  and that is larger than a transverse dimension (e.g., diameter) of driveshaft  222   a.  In this embodiment, first end  308   aa  of drive hub  304   aa  is configured to abut IO device  100   bb  (e.g., a hub  150   bb ) such that clamp  608   aa  can be disposed around drive hub  304   aa  and IO device  100   bb  (e.g., around hub  150   bb ) to resist separation of the IO device (and, more specifically, hub  150   bb , in this embodiment) from the driver (and, more specifically, drive hub  304   aa , in this embodiment), as shown in  FIG. 29A . 
     In the embodiment shown, hub  150   bb  of IO device  100   bb  has a cross-section with a circular central portion and a projection  628   aa  extending from the central portion in a direction away from a rotational axis of the drive hub, as shown. In this embodiment, clamp  608   aa  includes a slot  632   aa  between opposing portions of the clamp such that projection  628   aa  can be aligned with (disposed in) slot  632   aa  to resist rotation of hub  150   bb  relative to clamp  608   aa . In some embodiments, drive hub  304   aa  can have a cross-section similar to that of hub  150   bb  (e.g., having a circular central portion and a projection of the same size(s) as those of hub  150   bb ), such that the projection of drive hub  304   aa  can align with (disposed in) a second slot  636   aa  of clamp  608   aa  to resist rotation of drive hub  304   aa  relative to clamp  608   aa . In the embodiment shown, drive hub  304   a  is not configured to receive a portion of IO device  100   bb  (e.g., adjacent ends of the drive hub and IO device abut each other without overlapping longitudinally, as shown). As shown in  FIG. 29A , drive hub  304   aa  is configured to abut IO device  100   bb  such that clamp  608   aa  can be disposed around and in contact with drive hub  304   aa  and IO device  100   bb  to resist separation of the IO device from the drive hub. 
       FIGS. 30A-30C  depict various views of a twenty-sixth embodiment  300   bb  of the present couplers in combination with a powered driver  200   bb  and an IO device  100   cc  that is configured for obtaining a sample of bone and/or bone marrow (e.g., similar in some respects to IO devices  100   a  and/or  100   b ). In the embodiment shown, coupler  300   bb  comprises a drive hub  304   bb  having a first end  308   bb  and a second end  312   bb . In this embodiment, first end  308   bb  of drive hub  304   bb  includes a sidewall  640   bb  defining a recess  340   bb  configured to receive a hub (e.g., first hub  140   cc ) of IO device  100   cc . In this embodiment, sidewall  640   bb  has at least one (e.g., two, as shown) slot  644   bb  extending through the sidewall in communication with recess  340   bb . Clamp  608   bb  (which is substantially similar to clamp  608   aa  described above) is configured to fit over sidewall  640   bb  and slot  644   bb  permits the sidewall to flex inwardly to clamp hub  140   cc . In the embodiment shown, hub  140   cc  of IO device  100   cc  has a cross-section with a circular central portion and projections  628   bb  extending from the central portion in a direction away from a rotational axis of the drive hub, as shown. In this embodiment, projections  628   bb  can be aligned with (e.g., disposed in) slots  644   bb  to resist rotation of hub  140   cc  relative to drive hub  304   bb . In this embodiment, the transverse dimension of drive hub  304   bb  is greater than the contracted transverse dimension of clamp  608   bb  such when clamp  608   bb  is disposed around first end  308   bb  of drive hub  304   bb , clamp  608   bb  will contact and apply a compressive force to projections  628   bb  (as well as to sidewall  640   bb ) to resist separation of the IO device (and, more specifically, hub  140   cc , in this embodiment) from the driver (and, more specifically, drive hub  304   bb , in this embodiment). 
     In the embodiment shown, second end  312   bb  of drive hub  304   bb  includes sidewall  648   bb  defining a recess  336   bb  configured to receive driveshaft  222   bb  of driver  200   bb . In this embodiment, sidewall  648   bb  has at least one (e.g., two, as shown) slot  652   bb  extending through the sidewall in communication with recess  336   bb . Coupler  300   bb  also comprises a clamp  656   bb  (which is substantially similar to clamp  608   aa  described above) that is configured to fit over sidewall  648   bb  and slot  652   bb  may permit the sidewall to flex inwardly to clamp hub  140   cc . In the embodiment shown, driveshaft  222   bb  of driver  200   bb  has a cross-section with a circular central portion and projections  660   bb  extending from the central portion in a direction away from a rotational axis of the drive hub, as shown. In this embodiment, projections  660   bb  can be aligned with (disposed in) slots  652   bb  to resist rotation of drive hub  304   bb  relative to driveshaft  222   bb . In this embodiment, the transverse dimension of driveshaft  222   bb  is greater than the contracted transverse dimension of clamp  656   bb  such that when clamp  656   bb  is disposed around second end  312   bb  of drive hub  304   bb , clamp  656   bb  will contact and apply a compressive force to projections  660   bb  to resist separation of drive hub  304   bb  from driveshaft  222   b.  Coupler  300   bb  also includes a recess  324   bb  that is sized to receive a second hub (not shown, but similar to second hub  150   a  of IO device  100   a ). 
       FIGS. 31A-31D  depict various views of a twenty-seventh embodiment  300   cc  of the present couplers in combination with a powered driver  200   cc  and an IO device  100   dd  that is that is configured to provide access to an interior of a bone (e.g., similar in some respects to IO device  100   c ). In the embodiment shown, coupler  300   cc  comprises a drive hub  304   cc  having a first end  308   cc  and a second end  312   cc  configured to be coupled in fixed relation to driveshaft  222   cc  of driver  200   cc  (e.g., second end  312   cc  is unitary with driveshaft  222   cc  in the embodiment shown). In the embodiment shown, first end  308   aa  includes a plurality of movable prongs  664   cc  configured to grasp a hub (e.g., second hub  150   dd ) of IO device  100   dd ; and a collar  668   cc  that is movably disposed around drive hub  304   cc , as shown. In this embodiment, collar  668   cc  is movable between: (i) a first position ( FIGS. 31B and 31C ) in which prongs  664   cc  can move away from the rotational axis of the drive hub to permit IO device  100   dd  to be inserted into or removed from the prongs, and (ii) a second position ( FIG. 31D ) in which collar  668   cc  constrains prongs  664   cc  such that if hub  150   dd  is disposed between prongs  664   cc , prongs  664   cc  resist removal of the IO device from the plurality of prongs. In some embodiments, collar  668   cc  is biased toward the second position (e.g., by a spring (not shown) disposed between collar  668   cc  and housing  210   cc  of driver  200   cc ). In the embodiment shown, hub  150   dd  of IO device  100   dd  comprises a projection  456   cc  with one or more detents  452   cc  that are configured to receive a portion of prongs  664   cc , as shown in  FIG. 31D . While not shown in  FIGS. 31A-31D , other embodiments can comprise a second plurality of prongs and a second collar at second end  312   cc  to engage a driveshaft of a driver (e.g., with corresponding detents). 
       FIGS. 32A-32C  depict various views of a twenty-eighth embodiment  300   dd  of the present couplers in combination with a powered driver  200   dd  and an IO device  100   ee  that is configured to provide access to an interior of a bone (e.g., similar in some respects to IO device  100   c ). In the embodiment shown, coupler  300   dd  comprises a drive hub  304   dd  having a first end  308   dd  and a second end  312   dd  including a recess  336   dd  configured to receive driveshaft  222   dd  of driver  200   dd , with recess  336   dd  having a proximal end at second end  312   dd  and a distal end closer to first end  308   dd . In this embodiment, coupler  300   dd  also comprises a ring  672   dd  that comprises at least one of a magnetically-chargeable (e.g., iron) and a magnetically-attractive material (e.g., a permanent magnet). Ring  672   dd  is disposed around a perimeter of recess  336   dd  between the proximal and distal ends of the recess, as shown. In this embodiment, driver  200   dd  also comprises a ring  676   dd  that comprises at least one of a magnetically-chargeable (e.g., iron) and a magnetically-attractive material (e.g., a permanent magnet). Ring  676   dd  is disposed around and coupled in fixed relation to driveshaft  222   dd , as shown. Ring  672   dd  and ring  676   dd  are configured to be magnetically attracted to each other when driveshaft  222   dd  is inserted into recess  336   dd  ( FIG. 32C ) to resist separation of drive hub  304   dd  from driveshaft  222   dd . For example, ring  672   dd  and ring  676   dd  can both comprise magnetically-attractive materials, or one can comprise a magnetically-attractive material and the other can comprise a magnetically-chargeable material. In this embodiment, first end  308   dd  of drive hub  304   dd  is configured to be coupled to an intraosseous (IO) device (e.g., to resist rotation of the IO device relative to the drive hub). For example, in the embodiment shown, drive hub  304   dd  is unitary with a portion of the hub assembly of the IO device (e.g., unitary with second hub  150   ee ). In some embodiments, driveshaft  222   dd  and/or recess  336   dd  have non-circular cross-sectional shapes (e.g., to resist rotation of drive hub  304   dd  relative to driveshaft  222   dd ). As shown, recess  336   dd  and ring  672   dd  are configured such that ring  672   dd  defines a step within the recess between the proximal and distal ends of the recess. 
       FIGS. 33A-33B  depict cutaway perspective and side cross-sectional views, respectively, of a twenty-ninth embodiment  300   ee  of the present couplers in combination with a powered driver  200   ee  and an IO device  100   ff  that is configured to provide access to an interior of a bone (e.g., similar in some respects to IO device  100   c ). In the embodiment shown, coupler  300   ee  comprises a drive hub  304   ee  having a first end  308   ee  and a second end  312   ee  including a recess  336   ee  configured to receive driveshaft  222   ee  of driver  200   ee , with recess  336   ee  having a proximal end at second end  312   ee  and a distal end closer to first end  308   ee . In this embodiment, coupler  300   ee  also comprises a ring  672   ee  that comprises at least one of a magnetically-chargeable (e.g., iron) and a magnetically-attractive material (e.g., a permanent magnet). Ring  672   ee  is disposed around a perimeter of recess  336   ee  between the proximal and distal ends of the recess, as shown. In this embodiment, driver  200   ee  also comprises an element  680   ee  that comprises at least one of a magnetically-chargeable (e.g., iron) and a magnetically-attractive material (e.g., a permanent magnet). As shown, element  680   ee  is disposed within the perimeter of driveshaft  222   ee  and spaced apart from the distal end  224   ee  of the driveshaft, as shown. Ring  672   ee  and element  680   ee  are configured to be magnetically attracted to each other when driveshaft  222   ee  is inserted into recess  336   ee  ( FIG. 33B ) to resist separation of drive hub  304   ee  from driveshaft  222   ee . For example, ring  672   ee  and element  680   ee  can both comprise magnetically-attractive materials, or one can comprise a magnetically-attractive material and the other can comprise a magnetically-chargeable material. In this embodiment, first end  308   ee  of drive hub  304   ee  is configured to be coupled to an intraosseous (IO) device (e.g., to resist rotation of the IO device relative to the drive hub). For example, in the embodiment shown, drive hub  304   ee  is unitary with a portion of the hub assembly of the IO device (e.g., unitary with second hub  150   ff ). In some embodiments, driveshaft  222   ee  and/or recess  336   ee  have non-circular cross-sectional shapes (e.g., to resist rotation of drive hub  304   ee  relative to driveshaft  222   ee ). 
       FIGS. 34A-34C  depict various views of a thirtieth embodiment  300   ff  of the present couplers in combination with a powered driver  200   ff  and an IO device  100   gg  that is configured for obtaining a sample of bone and/or bone marrow (e.g., similar in some respects to IO devices  100   a  and/or  100   b ). In the embodiment shown, coupler  300   ff  comprises a drive hub  304   ff  having a first end  308   ff  and a second end  312   ff  including a recess  336   ff  configured to receive driveshaft  222   ff  of driver  200   ff , with recess  336   ff  having a proximal end at second end  312   ff  and a distal end closer to first end  308   ff . In this embodiment, coupler  300   ff  also comprises a ring  672   ff  that comprises at least one of a magnetically-chargeable (e.g., iron) and a magnetically-attractive material (e.g., a permanent magnet). Ring  672   ff  is disposed around a perimeter of recess  336   ff  between the proximal and distal ends of the recess, as shown. In this embodiment, driver  200   ff  also comprises a ring  676   ff  that comprises at least one of a magnetically-chargeable (e.g., iron) and a magnetically-attractive material (e.g., a permanent magnet). Ring  676   ff  is disposed around and coupled in fixed relation to driveshaft  222   ff , as shown. Ring  672   ff  and ring  676   ff  are configured to be magnetically attracted to each other when driveshaft  222   ff  is inserted into recess  336   ff  ( FIG. 34C ) to resist separation of drive hub  304   ff  from driveshaft  222   ff . For example, ring  672   ff  and ring  676   ff  can both comprise magnetically-attractive materials, or one can comprise a magnetically-attractive material and the other can comprise a magnetically-chargeable material. In some embodiments, driveshaft  222   ff  and/or recess  336   ff  have non-circular cross-sectional shapes (e.g., to resist rotation of drive hub  304   ff  relative to driveshaft  222   ff ). As shown, recess  336   ff  and ring  672   ff  are configured such that ring  672   ff  defines a step within the recess between the proximal and distal ends of the recess. Further, in this embodiment driveshaft  222   ff  comprises an enlarged cap member  223   ff  (on which ring  672   ff  is disposed) that can comprise a resilient material (e.g., a resilient polymer) to further facilitate insertion of driveshaft  222   ff  into recess  336   ff.    
     Coupler  300   ff  differs from coupler  300   dd , for example, in that first end  308   ff  includes a recess  340   ff  configured to receive a hub (e.g., first hub  140   gg ) of IO device  100   gg , with recess  340   ff  having a distal end at first end  308   ff  and a proximal end closer to second end  312   ff . In this embodiment, coupler  300   ff  also comprises a ring  684   ff  that comprises at least one of a magnetically-chargeable (e.g., iron) and a magnetically-attractive material (e.g., a permanent magnet). Ring  684   ff  is disposed around a perimeter of recess  340   ff  between the proximal and distal ends of the recess, as shown. In this embodiment, driver  200   ff  also comprises a ring  688   ff  that comprises at least one of a magnetically-chargeable (e.g., iron) and a magnetically-attractive material (e.g., a permanent magnet). Ring  688   ff  is disposed around and coupled in fixed relation to hub  140   gg , as shown. Ring  684   ff  and ring  680   ff  are configured to be magnetically attracted to each other when hub  140   gg  is inserted into recess  340   ff  ( FIG. 34C ) to resist separation of hub  140   gg  from drive hub  304   ff . For example, ring  684   ff  and ring  684   ff  can both comprise magnetically-attractive materials, or one can comprise a magnetically-attractive material and the other can comprise a magnetically-chargeable material. In some embodiments, hub  140   gg  and recess  340   ff  have non-circular cross-sectional shapes (e.g., to resist rotation of hub  140   gg  relative to drive hub  304   ff ). As shown, recess  340   ff  and ring  684   ff  are configured such that ring  684   ff  defines a step within the recess between the proximal and distal ends of the recess. Coupler  300   ff  also includes a recess  324   ff  that is sized to receive a second hub (not shown, but similar to second hub  150   a  of IO device  100   a ). 
       FIGS. 35A-35C  depict various views of a thirty-first embodiment  300   gg  of the present couplers in combination with a powered driver  200   gg  and an IO device  100   hh  that is configured for obtaining a sample of bone and/or bone marrow (e.g., similar in some respects to IO devices  100   a  and/or  100   b ). In the embodiment shown, coupler  300   gg  comprises a drive hub  304   gg  having a first end  308   gg  and a second end  312   gg  including a recess  336   gg  configured to receive driveshaft  222   gg  of driver  200   gg , with recess  336   gg  having a proximal end at second end  312   gg  and a distal end closer to first end  308   gg . In this embodiment, coupler  300   gg  also comprises a ring  672   gg  that comprises at least one of a magnetically-chargeable (e.g., iron) and a magnetically-attractive material (e.g., a permanent magnet). Ring  672   gg  is disposed around a perimeter of recess  336   gg  between the proximal and distal ends of the recess, as shown. In this embodiment, driver  200   ff  also comprises at least one (e.g., two, as shown) element  680   gg  that comprises at least one of a magnetically-chargeable (e.g., iron) and a magnetically-attractive material (e.g., a permanent magnet). As shown, elements  680   gg  are disposed within the perimeter of driveshaft  222   gg  and spaced apart from the distal end  224   gg  of the driveshaft, as shown. Ring  672   gg  and elements  680   gg  are configured to be magnetically attracted to each other when driveshaft  222   ff  is inserted into recess  336   ff  ( FIG. 35B ) to resist separation of drive hub  304   gg  from driveshaft  222   gg . For example, ring  672   gg  and element  680   gg  can both comprise magnetically-attractive materials, or one can comprise a magnetically-attractive material and the other can comprise a magnetically-chargeable material. In some embodiments, driveshaft  222   gg  and/or recess  336   gg  have non-circular cross-sectional shapes (e.g., to resist rotation of drive hub  304   gg  relative to driveshaft  222   gg ). Further, in this embodiment driveshaft  222   gg  comprises an enlarged cap member  223   gg  (in which elements  680   gg  are disposed) that can comprise a resilient material (e.g., a resilient polymer) to further facilitate insertion of driveshaft  222   gg  into recess  336   gg.    
     Coupler  300   gg  differs from coupler  300   ee , for example, in that first end  308   gg  includes a recess  340   gg  configured to receive a hub (e.g., first hub  140   hh ) of IO device  100   hh , with recess  340   gg  having a distal end at first end  308   gg  and a proximal end closer to second end  312   gg . In this embodiment, coupler  300   gg  also comprises a ring  684   gg  that comprises at least one of a magnetically-chargeable (e.g., iron) and a magnetically-attractive material (e.g., a permanent magnet). Ring  684   gg  is disposed around a perimeter of recess  340   gg  between the proximal and distal ends of the recess, as shown. In this embodiment, driver  200   gg  also comprises at least one (e.g., two, as shown) element  692   gg  that comprises at least one of a magnetically-chargeable (e.g., iron) and a magnetically-attractive material (e.g., a permanent magnet). As shown, elements  692   gg  are disposed within the perimeter of hub  140   hh . Ring  684   gg  and elements  692   gg  are configured to be magnetically attracted to each other when driveshaft  222   gg  is inserted into recess  340   gg  ( FIG. 35B ) to resist separation of hub  140   hh  from drive hub  304   gg . For example, ring  684   gg  and elements  692   gg  can both comprise magnetically-attractive materials, or one can comprise a magnetically-attractive material and the other can comprise a magnetically-chargeable material. In some embodiments, hub  140   hh  and/or recess  340   gg  have non-circular cross-sectional shapes (e.g., to resist rotation of hub  140   hh  relative to drive hub  304   gg ). Coupler  300   gg  also includes a recess  324   gg  that is sized to receive a second hub (not shown, but similar to second hub  150   a  of IO device  100   a ). 
     The above specification and examples provide a complete description of the structure and use of exemplary embodiments. Although certain embodiments have been described above with a certain degree of particularity, or with reference to one or more individual embodiments, those skilled in the art could make numerous alterations to the disclosed embodiments without departing from the scope of this invention. As such, the various illustrative embodiments of the present devices are not intended to be limited to the particular forms disclosed. Rather, they include all modifications and alternatives falling within the scope of the claims, and embodiments other than the one shown may include some or all of the features of the depicted embodiment. For example, components may be combined as a unitary structure, and/or connections may be substituted (e.g., threads may be substituted with press-fittings or welds). Further, where appropriate, aspects of any of the examples described above may be combined with aspects of any of the other examples described to form further examples having comparable or different properties and addressing the same or different problems. Similarly, it will be understood that the benefits and advantages described above may relate to one embodiment or may relate to several embodiments. 
     The claims are not intended to include, and should not be interpreted to include, means-plus- or step-plus-function limitations, unless such a limitation is explicitly recited in a given claim using the phrase(s) “means for” or “step for,” respectively.