Multi-joint fixture system

Abstract

A multi-joint fixture including a proximal base unit, one or more arms serially connected by electromagnetically lockable ball joints, and a distal hub. The ball joints unlock when not powered. A centering mechanism biases the ball joints toward a neutral position. A control system activates the electromagnetic brake with a high-then-low voltage profile. A headpiece attaches to the hub and holds a drape that covers the fixture. A connector connects a surgical device to the headpiece. A switch on the hub can be actuated via actuators on the headpiece or connector.

1 . A ball joint, comprising:
 a ball; and   a body containing a portion of the ball;   a brake element; and   an electromagnetic brake mechanism configured to actuate the brake element between a locked state wherein the brake element presses against the ball with a force adequate to fix the orientation of the ball, and an unlocked state wherein the brake element does not press against the ball with a force as high as that of the locked state.   
   
   
       2 . The ball joint of  claim 1 , wherein:
 the electromagnetic brake mechanism is configured to actuate the brake element to the locked state when the electromagnet is energized; and   the electromagnetic brake mechanism is configured to actuate the brake element to the unlocked state when the electromagnet is not energized.   
   
   
       3 . The ball joint of  claim 1 , wherein:
 the electromagnetic brake mechanism is configured to actuate the brake element to the unlocked state when the electromagnet is energized; and   the electromagnetic brake mechanism is configured to actuate the brake element to the locked state when the electromagnet is not energized.   
   
   
       4 . The ball joint of  claim 1 , wherein the electromagnetic brake mechanism includes a paired electromagnet and draw-plate, electromagnet and draw-plate each being positioned along an electromagnet axis and establishing a closable gap between them that is normal to the electromagnet axis. 
   
   
       5 . The ball joint of  claim 4 , wherein a spherical portion of the ball and the brake element are each concentric with the electromagnet axis. 
   
   
       6 . The ball joint of  claim 4 , wherein:
 the ball joint defines a ball axis passing through a spherical portion of the ball;   the brake element is concentric with the ball axis; and   the ball axis and the electromagnet axis are parallel to, and offset from, one another.   
   
   
       7 . The ball joint of  claim 4 , and further comprising a lever arm connecting the brake element to the paired electromagnet and draw-plate, and being configured to use leverage to react against the brake element with a greater force than against the paired electromagnet and draw-plate. 
   
   
       8 . The ball joint of  claim 4 , wherein the brake element and paired electromagnet and draw-plate act upon one another with equal force. 
   
   
       9 . The ball joint of  claim 1 , and further comprising a centering mechanism configured to bias ball toward a neutral position. 
   
   
       10 . The ball joint of  claim 9 , wherein:
 the ball includes a spherical portion and a shaft extending from the spherical portion; and   the centering mechanism includes a spring spiraling in three dimensions to connect the shaft to the body.   
   
   
       11 . A ball joint locking system, comprising:
 the ball joint of  claim 1 ; and   a control system configured to actuate the electromagnetic brake mechanism with a voltage profile characterized by a first, transient portion and a second, steady-state portion, the transient portion voltage being significantly greater than the steady-state portion voltage.   
   
   
       12 . A system for holding an instrument, comprising:
 a base unit;   a hub configured to detachably hold the instrument; and   a group of one or more arms serially connected by a plurality of joints between the base unit and the hub, one or more of the plurality of joints being the ball joint of  claim 1 ;   a control system configured to actuate the electromagnetic brake mechanism with a voltage profile characterized by a first, transient portion and a second, steady-state portion, the transient portion voltage being significantly greater than the steady-state portion voltage; and   a system cart, wherein, the system cart houses the control system and one or more storage compartments configured to house the group of one or more arms serially connected by the plurality of joints when not in use.   
   
   
       13 . A multi-joint fixture for holding an instrument, comprising:
 a base unit;   a first arm;   a first joint adjustably connecting a proximal end of the first arm to the base unit;   a second arm;   a second joint adjustably connecting a proximal end of the second arm to a distal end of the first arm;   a hub configured to detachably hold the instrument; and   a third joint adjustably connecting the hub to a distal end of the second arm;   wherein at least one of the group comprising the first ball joint, the second ball joint and the third ball joint is a ball joint as defined in  claim 1 .   
   
   
       14 . The multi-joint fixture of  claim 13 , and further comprising a switch carried proximate the hub, the switch being configured to control actuation of the electromagnetic brake mechanism. 
   
   
       15 . A jointed arm; comprising:
 an arm generally extending along a longitudinal arm axis from a proximal end to a distal end; and   the ball joint of  claim 1 ;   wherein the body extends distally along the longitudinal axis from the distal end of the arm;   wherein the ball has a spherical portion lying along the longitudinal axis and a shaft extending out of the body in a direction perpendicular to the longitudinal axis; and   wherein the electromagnetic brake mechanism includes a paired electromagnet and draw-plate lying along the longitudinal axis;   
   
   
       16 . A multi-joint fixture for holding an instrument, comprising:
 a base unit;   a hub configured to detachably hold the instrument; and   a group of one or more arms serially connected by a plurality of non-separable joints between the base unit and the hub, one or more of the joints having a brake mechanism configured to lock the orientation of the joint when the brake mechanism is actuated;   wherein the electromagnetic brake mechanism is only configured to actuate the brake mechanism when the system is powered.   
   
   
       17 . A multi-joint fixture for holding an instrument, comprising:
 a base unit;   a hub configured to detachably hold the instrument; and   a group of one or more arms serially connected by a plurality of joints between the base unit and the hub, one or more of the joints having a brake mechanism configured to unlock the orientation of the joint when the brake mechanism is actuated;   wherein the electromagnetic brake mechanism is only configured to actuate the brake mechanism when the system is powered.   
   
   
       18 . A multi-joint fixture for holding an instrument, comprising:
 a base unit;   a hub configured to detachably hold the instrument; and   a group of one or more arms serially connected by a plurality of joints between the base unit and the hub, one or more of the joints having a brake mechanism configured to lock the orientation of the joint when the brake mechanism is actuated;   wherein the brake mechanism includes a brake element, a driver configured to actuate the brake element, and a lever arm connecting the driver to the brake element, and being configured to use leverage to react against the brake element with a greater force than against the driver.   
   
   
       19 . A multi-joint fixture for holding an instrument, comprising:
 a base unit;   a hub configured to detachably hold the instrument; and   a group of one or more arms serially connected by a plurality of joints between the base unit and the hub, the joints having a brake mechanism configured to lock the orientation of the joint when the brake mechanism is actuated;   wherein one or more of the joints include a centering mechanism configured to bias the joint toward a neutral position.   
   
   
       20 . A control system configured to actuate an electromagnetic brake mechanism via an electronic brake circuit, comprising:
 a control circuit configured to create a voltage profile across the brake circuit in response to an activation signal;   wherein the voltage profile is characterized by a first, transient portion and a second, steady-state portion, the transient portion having a voltage significantly greater than the steady-state portion voltage.   
   
   
       21 . A multi-joint fixture for holding an instrument, comprising:
 a base unit;   a hub configured to detachably hold the instrument; and   a group of one or more arms serially connected by a plurality of joints between the base unit and the hub, one or more of the joints having a brake mechanism configured to lock the orientation of the joint when the brake mechanism is actuated; and   a switch carried proximate the hub, the switch being configured to control actuation of brake mechanism.   
   
   
       22 . The multi-joint fixture of  claim 21 , wherein every joint has a brake mechanism configured to lock the orientation of the joint when the brake mechanism is actuated, and wherein the switch controls actuation of the brake mechanism of each joint. 
   
   
       23 . A surgical-instrument adaptor for use with a surgical instrument and an apparatus having a hub and a switch to be actuated, comprising:
 a first connector configured for connection to the surgical instrument;   a second connector configured for a quickly detachable connection to the hub; and   a switch actuator in actuation communication with the switch.   
   
   
       24 . The surgical-instrument adaptor of  claim 23 , wherein the switch actuator includes a body configured to physically actuate against an actuator on the hub. 
   
   
       25 . A surgical instrument for use with a hub, comprising:
 a surgical-instrument portion configured for use in surgery;   a connector configured for a quickly detachable connection to the hub; and   a switch actuator in actuation communication with the switch.   
   
   
       26 . A multi-joint fixture for holding a sterile instrument having a connector, comprising:
 a proximal base unit;   a distal first hub;   a group of one or more arms serially connected by a plurality of joints extending distally from the base unit to the hub, one or more of the joints having a brake mechanism configured to lock the orientation of the one or more joints when the brake mechanism is actuated; and   a surgical drape including a sterile curtain sealed to a headpiece, the headpiece being detachably connected to the first hub, and the sterile curtain being extended over the first hub, the group of one or more arms, and the base unit, isolating them from instruments external to the sterile curtain;   wherein the headpiece forms a second hub configured to receive the instrument connector.   
   
   
       27 . The multi-joint fixture of  claim 26 , wherein the first hub includes a switch configured to control the actuation of the brake mechanism of the one or more joints, and wherein the headpiece has an actuator configured to control the actuation of the brake mechanism of the one or more joints. 
   
   
       28 . The multi-joint fixture of  claim 27 , and further comprising a connector connected to the instrument, wherein the connector includes an actuator configured to control the actuation of the brake mechanism of the one or more joints. 
   
   
       29 . The multi-joint fixture of  claim 28 , wherein the headpiece actuator is configured to actuate the switch, and the connector actuator is configured to actuate the headpiece actuator. 
   
   
       30 . The multi-joint fixture of  claim 27 , wherein the sterile instrument includes an actuator configured to control the actuation of the brake mechanism of the one or more joints. 
   
   
       31 . The multi-joint fixture of  claim 30 , wherein the headpiece actuator is configured to actuate the switch, and the sterile instrument actuator is configured to actuate the headpiece actuator. 
   
   
       32 . The multi-joint fixture of  claim 26 , wherein the brake mechanism of each of the one or more joints is an electromagnetic brake mechanism.