Arthrometer with gravity switches and adjustable limit signaling

• US 5,394,888 A
• Filed: 12/17/1992
• Issued: 03/07/1995
• Est. Priority Date: 12/17/1992
• Status: Expired due to Fees

• Current Assignee: Kevin R. Stone, Knapp, William R., Perry A. Klebahn
• Original Assignee: Kevin R. Stone, Knapp, William R., Perry A. Klebahn
• Inventors: Stone, Kevin R., Knapp, William R., Klebahn, Perry A.
• Primary Examiner(s): Apley, Richard J.
• Assistant Examiner(s): Mollo, Jeanne M.
• Application Number:
  US07/992,059
• Time in Patent Office: 810 Days
• Field of Search: 482/909, 128/782, 340/573, 340/689, 73/379.01, 73/865.4, 33/373, 33/384, 200/220, 200/230
• US Class Current: 600/595
• CPC Class Codes: A61B 5/1071 measuring angles, e.g. using goniometers A61B5/1123 takes precedence
• CPC Class Codes: A61B 5/4528 Joints A61B5/4533, A61B5/4538 take precedence
• CPC Class Codes: A61B 5/6828 Leg
• CPC Class Codes: A61B 5/6831 Straps, bands or harnesses
• CPC Class Codes: Y10S 482/909 Mechanical indicator

Abstract

An apparatus for measuring the angle of flexure between an elongated body limb and the portion of the body to which the limb is affected. The apparatus can be used to monitor flexure between a thigh and lower portion of a human leg. The apparatus is useful during the performance of rehabilitative knee-bends includes means for coupling the apparatus to the thigh, and two gravity actuated switches for monitoring the angle between a long axis of the thigh and a vertical axis. The apparatus indicates when the extreme points of the knee-bend have been crossed.

Claims

1. An arthrometer for monitoring an angle of flexure of an elongated body limb with respect to the portion of the body to which the limb is attached, comprising:

A. an elongated housing extending along a principal axis,

B. means for detachably coupling said housing to the limb whereby said principal axis is at a fixed orientation with respect to a central axis of the limb,

C. first limit sensor affixed to said housing including;

i. a first gravity-actuated switch coupled to said housing and responsive to orientation relative to a vertical axis, so that said first switch is in a first state when said first switch is oriented within a first range of orientations, and said first switch is in a second state when said first switch is oriented within a second range of orientations,

ii. first switch positioning assembly including first venier means for adjustably orienting said first switch with respect to said principal axis whereby said first switch is in its first state when said principal axis is oriented within a first predetermined range of orientations measured with respect to the vertical axis and in its second state otherwise, and

D. second limit sensor affixed to said housing including;

i. a second gravity-actuated switch coupled to said housing and responsive to orientation relative to the vertical axis, so that said second switch is in a first state when said second switch is oriented within a third range of orientations, and said second switch is in a second state when said second switch is oriented within a fourth range of orientations, and

ii. second switch positioning assembly including second vernier means for adjustably orienting said second switch with respect to said principal axis whereby said second switch is in its first state when said principal axis is oriented within a second predetermined range of orientations measured with respect to the vertical axis and in its second state otherwise,

wherein said first and second switches are mercury switches, and

wherein said first switch positioning assembly includes;

i. first adjustment member and means for rotatably coupling said first adjustment member to said housing about an axis substantially perpendicular to said principal axis,

ii. a first elongated adjustment arm extending between two ends thereof along a first arm axis, and means for rotatably coupling one of said ends to said housing about an axis substantially perpendicular to said principal axis, and means for slidably and rotatably coupling the other of said ends to said first adjustment member along a slide axis substantially parallel to said first arm axis and about an axis substantially perpendicular to said principal axis,

iii. means for rigidly affixing said first switch to said first arm in a first predetermined orientation with respect to arm first arm axis, and

wherein said second switch positioning assembly includes;

i. second adjustment member and means for rotatably coupling said second adjustment member to said housing about an axis substantially perpendicular to said principal axis,

ii. a second elongated adjustment ann extending between two ends thereof along a second arm axis, and means for rotatably coupling one of said ends to said housing about an axis substantially perpendicular to said principal axis, and means for slidably and rotatably coupling the other of said ends to said second adjustment member along a slide axis substantially parallel to said second arm axis and about an axis substantially perpendicular to said principal axis, and

iii. means for rigidly affixing said second switch to said second arm in a second predetermined orientation with respect to said second arm axis.