System and method for measuring gait kinematics information

• US 7,237,446 B2
• Filed: 09/16/2005
• Issued: 07/03/2007
• Est. Priority Date: 09/16/2005
• Status: Active Grant

• Current Assignee: IDT Technology Limited (IDT International Limited)
• Original Assignee: IDT Technology Limited (IDT International Limited)
• Inventors: Chan, Raymond, Leong, Mun Hoong
• Primary Examiner(s): Williams; Hezron
• Assistant Examiner(s): Shah; Samir M.
• Application Number:
  US11/228,121
• Publication Number:
  US 20070062279A1
• Time in Patent Office: 655 Days
• Field of Search: 734/88, 738/654, 735/09, 735/11
• US Class Current: 73/865.4
• CPC Class Codes: A63B 2071/0663 worn on the wrist, e.g. wrist bands
• CPC Class Codes: A63B 2220/40 Acceleration
• CPC Class Codes: A63B 2225/15 with identification means that can be read by electronic means
• CPC Class Codes: A63B 2225/20 with means for remote communication, e.g. internet or the like
• CPC Class Codes: A63B 2225/50 Wireless data transmission, e.g. by radio transmitters or telemetry
• CPC Class Codes: A63B 2230/04 heartbeat characteristics, e.g. ECG, blood pressure modulations
• CPC Class Codes: A63B 69/0028 for running, jogging or speed-walking movable endless bands A63B22/02
• CPC Class Codes: A63B 71/06 Indicating or scoring devices for games or players , or for other sports activities
• CPC Class Codes: G01C 22/006 Pedometers

Abstract

A system for measuring gait kinematics information during exercise of a subject comprising a fixing member adapted for fixing onto the trunk of the body of the subject; an acceleration sensor attached to the fixing member for sensing the vertical acceleration of the trunk of the body of the subject; and a microprocessor coupled to the acceleration sensor adapted to receive the vertical acceleration data from the acceleration sensor, and to compute and derive the speed and distance traversed by the subject, and to communicate the speed and distance information. In the preferred embodiment, a heart-rate monitoring device is also provided.

Claims

1. A system for measuring gait kinematics information during exercise of a subject comprising:

a fixing member adapted for fixing onto the trunk of the body of the subject;

an acceleration sensor attached to the fixing member for sensing the vertical acceleration of the trunk of the body of said subject; and

a microprocessor coupled to said acceleration sensor, said microprocessor configured to receive vertical acceleration data from said acceleration sensor, to compute and derive the speed and distance traversed by said subject using the algorithm of the form

$D_{\mathrm{Tc}}=\frac{K_a*\left(1-K_t\right)*S_{T_c}}{K_{\mathrm{cal}}}$ $V_{\mathrm{Tc}}=\frac{K_a*\left(1-K_t\right)*S_{T_c}}{K_{\mathrm{cal}}*T_c}$

 

Wherein;

D_Tc is the actual distance,

V_Tc is the actual speed,

S_Tc is the acceleration signal-changing rate,

K_t is the time shift compensation factor,

K_a is the amplitude shift compensation factor,

K_cal is the calibration constant,

and to communicate said speed and distance information to a receiving device.

2. The system according to claim 1, further comprising a wireless transmission unit coupled to said microprocessor for transmitting said gait kinematics information;

and said receiving device comprising a receiving unit for receiving said gait kinematics information.

3. The system according to claim 2, wherein said receiving device is adapted for attachment to the wrist of said subject and comprises a wireless receiver and a display unit for displaying said gait kinematics information.

4. The system according to claim 2, wherein said receiving device is adapted for wearing on the ear of said subject and comprises a wireless receiver and an earplug for audibly transmitting said gait kinematics information to said subject.

5. The system according to claim 2, wherein said wireless transmission unit is a radio-frequency transmitter, infra-red transmitter or sonar transmitter.

6. The system according to claim 1, further comprising a heart-rate monitoring device fixed onto said fixing member and coupled to said microprocessor.

7. The system according to claim 6, wherein said heart rate monitoring device comprises a set of electrodes that measure the electrocardiogram (ECG) signal of said subject, said heart rate monitoring device further capable of converting said ECG signal to digital pulses and means to communicate said digital pulses as a heart-rate value to said subject.

8. The system according to claim 6, further comprising a wireless transmission unit coupled to said microprocessor for transmitting said gait kinematics information;

and said receiving device comprising a receiving unit for receiving said gait kinematics information.

9. The system according to claim 8, wherein said receiving device is adapted for attachment to the wrist of said subject and comprises a wireless receiver and a display unit for displaying said gait kinematics information.

10. The system according to claim 8, wherein said receiving device is adapted for wearing on the ear of said subject and comprises a wireless receiver and an earplug for audibly transmitting said gait kinematics information to said subject.

11. The system according to claim 8, wherein said gait kinematics information is transmitted in a data packet from said transmission unit to said receiving unit of said receiving device.

12. The system according to claim 11, wherein said data packet further comprises ID and error-correction bits so as to combat data transmission error during wireless transmission.

13. The system according to claim 8, wherein said wireless transmission unit is a radio-frequency transmitter, infra-red transmitter or sonar transmitter.