Grasp assist system

{
  "publication_number": "US10888487B1",
  "country": "US",
  "kind": "B1",
  "title": "Grasp assist system",
  "abstract": "A grasp assist system includes a glove having a glove palm and fingers, with the glove worn on a user's hand. A sensor measures flexion of the glove fingers, and thus a change of position and/or attitude of the fingers is determined. Finger saddles at least partially surround a phalange of a respective one of the user's fingers. The system uses one or more tendon actuators to pull on flexible tendons. Each tendon connects to a respective finger saddle. A controller is in communication with the actuators and sensor(s). The glove may use feedback from optional contact sensors to adjust tension, and may have a built-in restorative force. In executing a control method, the controller selectively applies tension to the tendons in response to finger flexion, via the tendon actuators, at a level sufficient for moving the user's fingers when the user executes a hand maneuver.",
  "claims": [
    "1. A grasp assist system comprising: a glove having a glove palm and a plurality of glove fingers, wherein the glove is configured to be worn on a hand and fingers of a user; a flexion sensor configured to output flexion signals indicative of a level of flexion of the hand and fingers of the user; a plurality of finger saddles, each of which is positioned to at least partially surround a phalange of a respective one of the fingers of the user when the user wears the glove; one or more tendon actuators; a plurality of flexible tendons each connected to and driven by at least one of the one or more tendon actuators, wherein each of the flexible tendons is also connected to a respective one of the finger saddles; a set of contact sensors connected to at least some of the glove fingers and configured to detect contact between the glove and an object during execution of a hand maneuver; and a controller in communication with the one or more tendon actuators and the flexion sensor, wherein the controller is configured, in response to the flexion signals, to selectively apply tension to the plurality of flexible tendons via the one or more tendon actuators at a tension level sufficient for moving the fingers of the user and the glove fingers, wherein the controller is in communication with the set of contact sensors and is configured to adjust the tension to the plurality of flexible tendons, via the one or more tendon actuators, in response to the contact, and wherein the controller is configured to execute a first operating mode in which closure of the glove as a whole occurs in response to flexion of any one of the fingers of the user, and a second operating mode in which closure of a particular glove finger of the plurality of glove fingers occurs in response to detection of flexion of a finger of the user corresponding to the particular glove finger.",
    "2. The grasp assist system of claim 1, wherein the flexion sensor includes a plurality of string potentiometers extending along a posterior of the glove fingers.",
    "3. The grasp assist system of claim 1, wherein the glove includes a restraint layer to which is attached a palm bar spanning a width of the glove palm, a hardware layer containing the one or more tendon actuators, and an outer layer surrounding the restraint layer and the hardware layer.",
    "4. The grasp assist system of claim 3, further comprising: a ratchet mechanism connected to an opposite side of the restraint layer relative to the palm bar, the palm bar defining passages circumscribing the flexible tendons, wherein distal ends of the palm bar are mechanically coupled to the ratchet mechanism such that a rotation of the ratchet mechanism adjusts a fit of the glove to the hand of the user.",
    "5. The grasp assist system of claim 4, further comprising: a conduit manifold connected to a palm-side of the restraint layer adjacent to the palm bar, wherein each tendon of the plurality of flexible tendons is contained within respective conduits to form a Bowden cable system in which each of the respective conduits is received within the conduit manifold.",
    "6. The grasp assist system of claim 1, wherein the glove is configured to provide a built-in restorative force such that, when the hand of the user is in a relaxed state, the built-in restorative force assists in a return of the flexible tendons to a relaxed default position.",
    "7. The grasp assist system of claim 6, wherein the glove is configured to be pressurized by an external pressure supply, and wherein pressurization of the glove by the external pressure supply provides the built-in restorative force.",
    "8. A grasp assist system comprising: a glove having a glove palm and a plurality of glove fingers, wherein the glove is configured to be worn on a hand and fingers of a user and includes a pressurizable bladder layer, a restraint layer to which is attached a palm bar spanning a width of the glove palm, a hardware layer, and an outer layer surrounding the restraint layer and the hardware layer; a flexion sensor configured to output flexion signals indicative of a level of flexion of the hand and fingers of the user, the flexion sensor including a plurality of string potentiometers extending along a posterior side of the glove fingers; a plurality of flexible finger saddles, each of which at least partially surrounds a phalange of a respective finger of the user when the user wears the glove; one or more tendon actuators contained within the hardware layer; a plurality of flexible tendons each connected to and driven by at least one of the one or more tendon actuators, wherein each of the flexible tendons is connected to a respective one of the finger saddles and to a respective one of the tendon actuators, wherein pressurization of the bladder layer provides a built-in restorative force such that, when the hand of the user is in a relaxed state, the built-in restorative force assists in a return of the flexible tendons to a relaxed default position; a conduit manifold connected to a palm-side of the restraint layer adjacent to the palm bar, wherein each tendon of the plurality of flexible tendons is contained within respective conduits to form a Bowden cable system in which each of the conduits is received within the conduit manifold; a ratchet mechanism connected to an opposite side of the restraint layer relative to the palm bar, the palm bar defining passages circumscribing the conduits with tendons therein, wherein distal ends of the palm bar are mechanically coupled to the ratchet mechanism such that a rotation of the ratchet mechanism adjusts a fit of the glove; and a controller positioned in communication with the one or more tendon actuators and the flexion sensor, wherein the controller is configured, in response to the flexion signals, to selectively apply tension to the plurality of flexible tendons via the one or more tendon actuators at a tension level sufficient for moving the fingers of the user and the glove fingers.",
    "9. The grasp assist system of claim 8, further comprising: a set of contact sensors connected to at least some of the glove fingers and configured to detect contact with an object during execution of a hand maneuver, wherein the controller is in communication with the set of contact sensors and is configured to adjust the tension to the plurality of flexible tendons, via the one or more tendon actuators, in response to the contact.",
    "10. The grasp assist system of claim 9, wherein the controller is configured to execute a first operating mode in which closure of the glove as a whole occurs in response to flexion of any one of the fingers of the user, and a second operating mode in which closure of a particular glove finger of the plurality of glove fingers occurs in response to detection of flexion of a finger of the user corresponding to the particular glove finger.",
    "11. The grasp assist system of claim 9, wherein the controller includes a human machine interface programmed to allow the user to selectively enable or disable grasp assistance, and to selectively vary an amount of tension to be applied to the tendons by the tendon actuators."
  ],
  "description_excerpt": "The present disclosure relates to a glove-based grasp assist system and a control method for the same.\n\nA glove-based grasp assist system and related control method are disclosed herein. The grasp assist system selectively assists the natural hand and finger motion of a human operator/user using a tendon drive system. Such assistance may be desirable when helping the user overcome the bending stiffness of certain types of specialized work or recreational gloves, e.g., gloves for use in aerospace applications, recreational diving, industrial work applications, or rehabilitation or treatment of users having limited finger strength and dexterity.\n\nA power-actuated glove is worn over the user's hand to form a core element of the disclosed system. Power assist capabilities of the system are selectively provided by one or more connected glove actuators, which bend the user's fingers via applied tension to one or more flexible artificial tendons when the user executes a hand maneuver. As used herein, the term “hand maneuver” refers to any user-initiated, muscle-based motion of the user's hands involving manual flexing of the user's fingers and/or thumb, regardless of whether the user actually grasps or otherwise makes contact with an external object during the grasp maneuver. In other words, the user decides when and how far to move his or her fingers/thumb. The system automatically assists in moving the user's fingers via tendon tensioning in response to such user-initiated motion.",
  "cpc": [
    "A61H 1/0288",
    "A41D 19/0006",
    "A41D 19/0024",
    "A41D 19/0044",
    "A41D 19/015",
    "A41D 19/01547",
    "A41D 2500/50",
    "A41D 2600/20",
    "A61H 2201/14",
    "A61H 2201/1409",
    "A61H 2201/165",
    "A61H 2201/169",
    "A61H 2201/5035",
    "A61H 2201/5058",
    "A61H 2201/5061",
    "A61H 2205/067",
    "B25J 13/02",
    "B32B 2307/3065",
    "B32B 2307/558",
    "B32B 2307/7265",
    "B32B 25/08",
    "B32B 25/20",
    "B32B 27/08",
    "B32B 27/322",
    "B32B 27/36",
    "B64G 6/00",
    "G06F 3/014",
    "G06F 3/016"
  ],
  "ipc": [
    "A41D 19/015",
    "A61H 1/02"
  ],
  "assignees": [
    "National Aeronautics and Space Administration NASA"
  ],
  "inventors": [
    "Jonathan M. Rogers",
    "Benjamin J. Peters",
    "Evan Laske",
    "Emily R. McBryan"
  ],
  "filing_date": "2018-04-05",
  "publication_date": "2021-01-12",
  "grant_date": "2021-01-12",
  "priority_date": "2017-04-06",
  "application_number": "US-201815946503-A",
  "family_id": "74067007",
  "cited_by_count": 18,
  "citations": [
    "US3564614A",
    "US6312398B1",
    "US6413229B1",
    "US7410338B2",
    "US8029414B2",
    "US20080071386A1",
    "US20180168830A1",
    "US8255079B2",
    "US8467903B2",
    "US20110113631A1",
    "US20110185473A1",
    "US20130231595A1",
    "WO2012165880A2",
    "US9067325B2",
    "US9149933B2",
    "WO2015134336A2",
    "US20170168565A1",
    "US20160052130A1",
    "US20190060099A1"
  ]
}