Diagnostic force analysis system

• US 4,195,643 A
• Filed: 12/27/1976
• Issued: 04/01/1980
• Est. Priority Date: 12/27/1976
• Status: Expired due to Term

• Current Assignee: Massachusetts Institute of Technology
• Original Assignee: Massachusetts Institute of Technology
• Inventors: Pratt, George W. Jr.
• Primary Examiner(s): Michell, Robert W.
• Assistant Examiner(s): Jaworski, Francis J.
• Application Number:
  US05/754,370
• Time in Patent Office: 1,191 Days
• Field of Search: 128/2 S, 128/2.05 D, 128/2.05 E, 128/2.05 P, 128/2.05 V, 128/2 P, 128/2.1 P, 128/779, 73/719-722, 73/172, 73/1 B, 73/780, 73/769, 177/210 R, 177/210 C, 177/210 EM
• US Class Current: 600/592
• CPC Class Codes: A61B 2503/40 Animals
• CPC Class Codes: A61B 2562/0252 Load cells
• CPC Class Codes: A61B 2562/0261 Strain gauges
• CPC Class Codes: A61B 2562/043 in a linear array
• CPC Class Codes: A61B 5/1036 Measuring load distribution, e.g. podologic studies
• CPC Class Codes: A61B 5/1102 Ballistocardiography
• CPC Class Codes: A61B 5/1116 Determining posture transitions
• CPC Class Codes: A61B 5/224 Measuring muscular strength
• CPC Class Codes: A61B 5/4082 Diagnosing or monitoring movement diseases, e.g. Parkinson, Huntington or Tourette
• CPC Class Codes: A61B 5/7257 using Fourier transforms
• CPC Class Codes: G01L 1/146 for measuring force distributions, e.g. using force arrays G01L1/148 takes precedence

Abstract

A system operable to measure the time varying forces transmitted by a body and to combine the forces transmitted by different parts of the body. The system can be employed to measure physiological forces associated with motion of the body such as the gait of humans or animals. It can also be employed to measure forces internally generated by the body at rest such as ballistocardiographic and posture control forces. The posture control forces can be used as a measure of lameness. The Fourier transform of the force ballistocardiogram and posture control forces are found to contain information related to physiological condition. In some configurations the system employs ceramic capacitors as piezoelectric force transducers in a special circuit. The use of ceramic capacitors as pyroelectric bolometers is also discussed.

Claims

1. A method of using diagnostic apparatus for measuring the relationship between distress level and physiological force due to pain developed by a live being, that comprises the steps of

providing a force plate system comprising at least one force plate to receive said physiological forces supporting at least some portion of a live being on said at least one force plate operable to produce an analog output signal comprising a dc component and an ac component;

providing analyzer means connected to said analog output signal distinguishing between the dc component and the ac component thereby to produce an output signal derived from the ac component that quantifies said distress level;

including the further step of preparing from the output signal a force amplitude hisogram over a predetermined time interval having a width indicating the level of distress due to pain.

2. A method as set forth in claim 1, including repeating said steps for individual limbs of a live being and comparing the respective histograms to detect lameness due to pain.

3. A method of using diagnostic apparatus for measuring the relationship between distress level and physiological force due to pain developed by a live being, that comprises the steps of

providing a force plate system comprising at least one force plate to receive said physiological forces supporting at least some portion of a live being on said at least one force plate operable to produce an analog output signal comprising a dc component and an ac component;

providing analyzer means connected to receive said analog output signal distinguishing between the dc component and the ac component thereby to produce an output signal derived from the ac component that quantifies said distress level;

including the further step of preparing a root means square average of the output signal as a measure of distress level indicating pain.

4. In a method as set forth in claim 3, including repeating said steps for individual limbs of a live being and comparing the respective root mean square averages to detect lameness due to pain.