Device for measuring the position and/or motion of a body part

• US 4,586,515 A
• Filed: 12/16/1983
• Issued: 05/06/1986
• Est. Priority Date: 04/16/1982
• Status: Expired due to Fees

• Current Assignee: Meinhard Berger
• Original Assignee: Meinhard Berger
• Inventors: Berger, Meinhard
• Primary Examiner(s): Howell, Kyle L.
• Assistant Examiner(s): Shay, David
• Application Number:
  US06/567,402
• Time in Patent Office: 872 Days
• Field of Search: 128/782, 128/774, 128/779, 280/289 WC, 400/87, 350/321, 351/200, 351/209, 3/1.1, 273/190 A
• US Class Current: 600/595
• CPC Class Codes: A61B 5/1121 Determining geometric values, e.g. centre of rotation or angular range of movement
• CPC Class Codes: A61B 5/1126 using a particular sensing technique
• CPC Class Codes: A61B 5/4504 Bones A61B5/4547 takes precedence
• CPC Class Codes: A61B 5/4528 Joints A61B5/4533, A61B5/4538 take precedence
• CPC Class Codes: G01B 9/10 Goniometers for measuring angles between surfaces

Abstract

In the diagnostic evaluation of the measurement of head rotations for the functional examination of the cervical portion of the spine and the upper dorsal column it is to be noted that the head rotates not only with reference to that axial system which corresponds to the measuring system arranged between the holder and the supporting device, but also performs a three-dimensional movement in space. When tilting the head, e.g., the same not only rotates about a horizontal, frontal axis (parallel ear-to-ear) but also moves forward and downward. Even more complex are rotary or lateral tilting movements of the head which, beyond a certain extend of displacement, proceed only with a three-dimensional motion of the head. Yet the rotations of the head in a broader sense, including the ancillary movements referred to, are what permits more accurate conclusions as to the function of the spine. Analogous conditions apply to other sequences of movement with multijointed motion progressions, e.g. of the extremities.

It is therefore essential to the invention that not only the rotary movements of the holder are measured by the measuring system arranged between the holder and the supporting device but that also the motion of this measuring system or the holder in space is taken into consideration in the measurement or in the evaluation of the measuring results. This can be done, preferably, by an additional measuring system arranged, say, in the region of the supporting device for detecting the movements of the holder in space and/or mathematically in the evaluation by a data processor.

Claims

1. A method for the diagnosis of nuerological and orthopedic motion disorders of a body part which comprises the steps of:

affixing to said body part a single articulation consisting of three rotary displacement sensors having mutually orthogonal axes and each consisting of two relatively rotatable members defining the respective axis such that a first member of a first of said sensors is rigidly connected to said body part, a second member of said first sensor is rigidly connected to a first member of a second of said sensors, a second member of said second sensor is rigidly connected to a first member of a third of said sensors and a second member of said third sensor is rotatable relative to said first member of said third sensor about an axis of said third sensor;

spacially positioning said second member of said third sensor by fixing it against rotation but enabling linear displacement of said second member of said third sensor while permitting pendular displacement of said axis of said third sensor with respect to a reference point in space about two pendular axes neither of which is parallel to said linear displacement of said second member;

measuring linear displacement of said second member of said third sensor with a fourth motion sensor;

measuring angular displacement of said axis of said third sensor about said reference point with fifth and sixth motion sensors respectively responsive to displacement about said pendular axis; and

causing said body part to move and detecting outputs of said sensors as an indication of the motion pattern of said body part in space to a diagnose a motion disorder.

2. An apparatus for the diagnosis of neurological and orthopedic motion disorders of a body part which comprises:

a holder adapted to be affixed to a body part, motion of which is to be monitored for diagnosis of a neurological or orthopedic motion disorder;

a sensing system forming a single three-axis articulation affixed to said holder, said sensing system comprising;

three rotary displacement sensors having mutually orthogonal axes and each consisting of two relatively rotatable members defining the respective axis,

a first member of a first of said sensors being rigidly connected to said holder,

a second member of said first sensor being rigidly connected to a first member of a second of said sensors,

a second member of said second sensor being rigidly connected to a first member of a third of said sensors and a second member of said third sensor being rotatable relative to said first member of said third sensor about an axis of said third sensor;

a longitudinally shiftable support element connected to said second member of said third sensor and restricting angular displacement of said second member of said third sensor while guiding said sensing means linearly with respect to a reference point spaced from said holder;

means for mounting said support element to permit pendular displacement of said support element about two different pendular axes neither of which are parallel to the linear displacement of said element with respect to said reference point;

a fourth sensor responsive to linear displacement of said sensing system in the direction of said linear displacement; and

fifth and sixth sensors respectively responsive to angular displacement of said element about said pendular axes whereby outputs of said sensors can be monitored to provide an indication of motion disorders of a body part engageable in said holder.

3. The apparatus defined in claim 2 wherein said rotary displacement sensors are rotary potentiometers.

4. The apparatus defined in claim 3 wherein said holder is a helmet which can receive a head of a patient having a motion disorder to be diagnosed and each of said potentiometers has a housing and a shaft, a housing of a first potentiometer forming said first sensor being connected to said helmet, the shaft of said first potentiometer being connected to the shaft of a second potentiometer forming said second sensor, the housing of said second potentiometer being connected to the shaft of a third potentiometer forming said third sensor, and the housing of said third potentiometer being fixed to said element.

5. The apparatus defined in claim 3 wherein the shaft of a first potentiometer forming said first sensor is connected to said helmet, the housing of said first potentiometer is connected with the shaft of a second potentiometer forming said second sensor, the housing of said second potentiometer being connected to the shaft of a third potentiometer forming said third sensor and the housing of said third potentiometer being connected to said element.

6. The apparatus defined in claim 5, further comprising a fourth potentiometer having a shaft connected with the shaft of said third potentiometer and a housing connected with said element, one of said first and fourth potentiometers having its shaft arrestable with respect to the respective housing.

7. The apparatus defined in claim 2 wherein said element is a rod freely vertically movable in a weight-relieving mode.

8. The apparatus defined in claim 7, further comprising means for guiding said rod while preventing rotation thereof.

9. The apparatus defined in claim 2 wherein said fourth, fifth and sixth sensors form a kinematic chain articulating said element about said reference point.