Method and system for the derivation of human gait characteristics and detecting falls passively from floor vibrations

• US 7,857,771 B2
• Filed: 03/26/2004
• Issued: 12/28/2010
• Est. Priority Date: 04/03/2003
• Status: Expired due to Fees

• Current Assignee: University of Virginia Patent Foundation (University of Virginia)
• Original Assignee: University of Virginia Patent Foundation (University of Virginia)
• Inventors: Kell, Steven W., Dalal, Siddharth, Felder, Robin A., Alwan, Majd
• Primary Examiner(s): Hindenburg; Max
• Assistant Examiner(s): Pani; John
• Application Number:
  US10/550,157
• Publication Number:
  US 20060195050A1
• Time in Patent Office: 2,468 Days
• Field of Search: 600/587, 600/592, 600/595, 702/142, 702/149, 702/160, 340/573.1, 340/566, 340/573.7, 367/135, 367/136
• US Class Current: 600/595
• CPC Class Codes: A61B 2562/02 Details of sensors specially adapted for in-vivo measurements
• CPC Class Codes: A61B 2562/0219 Inertial sensors, e.g. accelerometers, gyroscopes, tilt switches
• CPC Class Codes: A61B 5/0002 Remote monitoring of patients using telemetry, e.g. transmission of vital signals via a communication network A61B5/07 takes precedence; transmission systems for measured values G08C; transmission H04B; transmission of digital information H04L; wireless communication networks H04W
• CPC Class Codes: A61B 5/0017 transmitting optical signals transmission by light H04B10/00
• CPC Class Codes: A61B 5/1038 Measuring plantar pressure during gait
• CPC Class Codes: A61B 5/1117 Fall detection
• CPC Class Codes: G01P 3/50 for measuring linear speed G01P3/56 takes precedence
• CPC Class Codes: G06F 2218/00 Aspects of pattern recognition specially adapted for signal processing
• CPC Class Codes: G06V 40/20 Movements or behaviour, e.g. gesture recognition recognition of facial expressions G06V40/16

Abstract

The gait monitor system and method provides various basic gait parameters including step count, cadence, and step duration, in addition to its ability to distinguish between normal, limping and shuffling gait modes, as well as determine falls. Moreover, this gait monitor may be provided with additional sensors, e.g. beam break at the beginning and end of a corridor to estimate average walking velocity (with the distance between the beams known or determined); this enables the calculation of additional gait characteristics such as average step length and average stride length. These parameters can additionally be used to detect various gait anomalies and other diagnostic information.

Claims

1. A gait monitoring system for monitoring gait characteristics of a subject, said system comprising:

a sensor module configured to touch an upper surface of a floor, the sensor module configured to while touching the upper surface of the floor detect at least one of floor acceleration, floor vibration, and floor deflection and to provide at least one of an acceleration, vibration, and deflection signal, wherein the subject can walk on the upper surface of the floor in proximity to said sensor module; and

a processor that is configured to analyze the acceleration, vibration, and deflection signal and to determine gait characteristics based on the signal,

wherein, the processor is configured to determine the gait characteristics based on the at least one signal from a single sensor module; and

the processor is configured to detect a fall of a human being by distinguishing between steps of the human being and the fall of the human being and comparing the data to a threshold.

2. The system of claim 1, further comprising:

an output module for receiving data indicative of the gait characteristics.

3. The system of claim 2, wherein said output module comprises at least one of display, alarm, memory storage, communication device, printer, buzzer, PDA, lap top computer, computer, audio or visual alarm, and light.

4. The system of claim 3, wherein said communication device comprises at least one of modem, pager, network interface, Ethernet card, serial communications port, parallel communications port, telephone, and PCMCIA slot and card.

5. The system of claim 1, wherein said sensor module and processor module are in wireless communication.

6. The system of claim 5, wherein said wireless communication comprises at least one of RF link, an infrared, cellular phone link, optical and electromagnetic.

7. The system of claim 1, wherein said sensor module and processor module are in a hard wired communication.

8. The system of claim 7, wherein said hard wired communication comprises at least one of electronic, integrated circuit, electromagnetic, wire, cable, fiber optics, a phone line, twisted pair, and coaxial.

9. The system of claim 1, further comprising:

a rate-of-travel detector to determine the rate-of-travel of the subject.

10. The system of claim 9, wherein said rate-of-travel detector comprises at least one of a plurality of beam breaks, floor switches, and door switches.

11. The system of claim 9, wherein said rate-of-travel detector comprises at least one of ultrasonic communication, IR communication, laser communication, ground radar communication, wide band radar communication, and doppler communication.

12. The system of claim 1, wherein said gait characteristics of the subject includes at least two of step count, pace, normal gait condition, limp, shuffle, and falls.

13. The system of claim 1, further comprising an archival storage module.

14. The system of claim 13, wherein the processor module is configured to perform at least two of longitudinal analysis of gait characteristics, pattern recognition, and identification determination, wherein identification determination associates gait characteristics with a particular subject and said archival storage module stores the at least two of longitudinal analysis of gait characteristics, pattern recognition, and identification determination.

15. The system of claim 1, further comprising:

a second processor module, wherein said second processor module is configured to analyze gait characteristics, pattern recognition, and identification determination data, the identification determination data associating gait characteristics with a particular subject.

16. The system of claim 1, wherein the subject is one of a human and an animal.

17. The system of claim 1, further comprising a fall module configured to:

provide notification of a fall based on the data.

18. The system of claim 1, further comprising a step module configured to process data received from said sensor module.

19. The system of claim 1, further comprising:

a second processor module in communication with said system.

20. A method for monitoring gait characteristics of a subject, said method comprising:

detecting at least one of a floor acceleration, a floor vibration, and a floor deflection to provide at least one of an acceleration, vibration, and deflection signal, wherein said detecting is provided by a sensor module touching an upper surface of a floor, and wherein the subject walks on the upper surface of the floor in proximity to said sensor module;

using a processor analyzing the at least one signal; and

determining gait characteristics based on the at least one signal,

wherein, the gait characteristics are determined based on the at least one signal from a single sensor module; and

the analyzing further includes detecting a fall of a human being by distinguishing between steps of the human being and the fall of the human being and comparing the data to a threshold.

21. The method of claim 20, further comprising:

outputting data indicative of the gait characteristics.

22. The method of claim 21, wherein said outputting is provided by an output module that comprises at least one of display, alarm, memory storage, communication device, printer, buzzer, PDA, lap top computer, computer, audio or visual alarm, and light.

23. The method of claim 22, wherein said communication device comprises at least one of modem, pager, network interface, Ethernet card, serial communications port, parallel communications port, telephone, and PCMCIA slot and card.

24. The method of claim 20, further comprising:

detecting rate-of-travel of the subject to determine the rate-of-travel of the subject.

25. The method of claim 24, wherein said detecting the rate-of-travel is provided by a rate-of-travel detector.

26. The method of claim 24, wherein said detecting the rate-of-travel comprises at least one of ultrasonic communication, IR communication, laser communication, ground radar communication, wide band radar communication, and doppler communication.

27. The method of claim 20, wherein the gait characteristics of the subject includes at least two of step count, pace, normal gait condition, limp, shuffle, and falls.

28. The method of claim 20, further comprising:

storing archival information or data.

29. The method of claim 28, wherein the storing of archival information or data is provided by an archival storage module that stores at least two of longitudinal analysis of gait characteristics, pattern recognition, and identification determination, the identification determination associating gait characteristics with a particular subject.

30. The method of claim 29, further comprising:

analyzing the gait characteristics, pattern recognition, and identification determination data.

31. The method of claim 20, wherein the subject is one of a human and animal.

32. The method of claim 20, further comprising:

automatically identifying signals indicative of a human body falling to determine fall data.

33. The method of claim 20, further comprising:

analyzing step data from the at least one signal.

34. The method of claim 20, wherein the distinguishing between steps of a human being and a fall of a human being is based on filtering out a frequency corresponding to at least one of walking modes and dropped objects.

35. A computer program product comprising non-transitory computer usable medium having computer logic embedded thereon for enabling at least one processor in a computer system to monitor gait characteristics of a subject, said computer logic configured to cause the computer system to:

receive at least one of a floor acceleration, a floor vibration, and a floor deflection signal, wherein said at least one signal is provided by a sensor module touching an upper surface of a floor, and wherein the subject can walk on the upper surface of the floor in proximity to said sensor module; and

analyze the at least one signal; and

determine gait characteristics based on the at least one signal,

wherein, the gait characteristics are determined based on the at least one signal from a single sensor module; and

the analyzing further including detecting a fall of a human being by distinguishing between steps of the human being and the fall of the human being and comparing the data to a threshold.

36. The computer program product of claim 35, wherein the distinguishing between steps of a human being and a fall of a human being is based on filtering out a frequency corresponding to at least one of walking modes and dropped objects.

37. A gait monitoring system, said system comprising:

a sensor device comprising;

a housing configured to be placed on a floor surface in a freestanding position; and

a sensor configured to;

touch the floor surface;

detect while touching the floor surface at least one of floor acceleration, floor vibration, and floor deflection; and

generate a signal based on the detected at least one of floor acceleration, floor vibration, and floor deflection;

a processor unit configured to communicate with the sensor device and determine gait characteristics based on the signal, the determining gait characteristics including identifying at least two of a normal gait characteristic, limping, shuffling, and falling of a human being by comparing the signal to respective characteristic patterns; and

an output device configured to output the determined gait characteristics, the output including different outputs for the at least two of normal gait characteristic, abnormal gait characteristic and human body fall.

38. The system of claim 37, wherein the processor unit is configured to determine the gait characteristics based on the signal from a single sensor device.

39. The system of claim 37, wherein the processor unit is configured to identify the human body fall based on filtering out a frequency corresponding to at least one of walking modes and dropped objects.