Portable ranging system for analyzing gait
First Claim
1. A portable ranging system comprising:
- circuitry, said circuitry responsive to actuation for initiating a count;
an infrared emitter, said infrared emitter responsive to said circuitry for emitting high-intensity infrared light to flood a ranging area with infrared light;
an ultrasound emitter,an infrared receiver within the ranging area, said infrared receiver responsive to said infrared light for causing said ultrasound emitter to emit an ultrasound pulse; and
an ultrasound receiver, said ultrasound receiver responsive to said ultrasound pulse to cause said circuitry to terminate the count, said circuitry using the count to compute the distance between the ultrasound emitter and the ultrasound receiver.
1 Assignment
0 Petitions
Accused Products
Abstract
A portable ranging system for analyzing gait is disclosed comprising a transponder having an infrared receiver and an ultrasound emitter, a base unit having an infrared emitter and an ultrasound receiver, and a computer terminal. During gait analysis, the transponder is worn by a subject at approximately the level of the body center of mass. As the subject walks away from the base unit, the base unit continuously causes, at a constant sampling rate, the ultrasound emitter to emit ultrasound pulses. These ultrasound pulses are received by the ultrasound receiver of the base unit. The computer terminal, by counting during the flight of each ultrasound pulse, is able to calculate the time of flight of each ultrasound pulse, and thus calculate and display in real time the forward progression of the subject. At the end of the walking trial, the computer terminal displays the instantaneous velocity profile, or gait velocigram (GVG), for that trial. From the GVG, the computer terminal calculates and displays gait parameters such as gait speed, cadence, step time, step length, peak-to-peak variation, and time to achieve steady state walking. From the displayed data, gait pathologies can be readily identified.
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Citations
84 Claims
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1. A portable ranging system comprising:
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circuitry, said circuitry responsive to actuation for initiating a count; an infrared emitter, said infrared emitter responsive to said circuitry for emitting high-intensity infrared light to flood a ranging area with infrared light; an ultrasound emitter, an infrared receiver within the ranging area, said infrared receiver responsive to said infrared light for causing said ultrasound emitter to emit an ultrasound pulse; and an ultrasound receiver, said ultrasound receiver responsive to said ultrasound pulse to cause said circuitry to terminate the count, said circuitry using the count to compute the distance between the ultrasound emitter and the ultrasound receiver. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A portable ranging system comprising:
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circuitry, said circuitry responsive to actuation to initiate a count; a base unit having an infrared emitter and an ultrasound receiver, said base unit responsive to the actuation of the circuitry for causing the infrared emitter to emit high-intensity infrared light to flood a ranging area with infrared light; a transponder having an infrared receiver and an ultrasound emitter, said transponder responsive to receipt of the infrared light for causing the ultrasound emitter to emit an ultrasound pulse; and said base unit responsive to receipt of the ultrasound pulse to cause said circuitry to terminate the count, said circuitry using the count to compute the distance between the transponder and the base unit. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18)
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19. In a portable ranging system having circuitry, a base unit, and a transponder, the method of computing the velocity of the transponder as it moves relative to the base unit within a ranging area, the method comprising the steps of:
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(a) counting by the circuitry in response to an actuation of the circuitry, (b) triggering by the circuitry the base unit in response to the actuation of said circuitry; (c) flooding by the base unit the ranging area with infrared light in response to said triggering; (d) receiving by the transponder the infrared light; (e) emitting by the transponder an ultrasound pulse in response to said step of receiving by the transponder of the infrared light; (f) receiving by the base unit the ultrasound pulse; (g) signalling by the base unit said circuitry in response to said step of receiving by the base unit the ultrasound pulse; (h) terminating by said circuitry said counting in response to said step of signalling; (i) repeating steps (a) through (h) for each of a plurality of constant time periods; (j) computing using count data from said counting the distance of the transponder from the base unit for each of the plurality of constant time periods; and (k) differentiating the distance data computed in step (j) to obtain the velocity. - View Dependent Claims (20)
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21. A portable ranging system comprising:
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circuitry, said circuitry responsive to actuation for initiating a count; an infrared emitter, said infrared emitter responsive to said circuitry for emitting high-intensity infrared light to flood a ranging area with infrared light; an ultrasound emitter; an infrared receiver, said infrared receiver responsive to infrared light for causing said ultrasound emitter to emit an ultrasound pulse; an ultrasound receiver, said ultrasound receiver responsive to a signal for causing said circuitry to terminate the count, said circuitry using the count to compute the distance between the ultrasound emitter and the ultrasound receiver; and means for ensuring that the signal is the ultrasound pulse. - View Dependent Claims (22, 23, 24, 25, 26, 27, 28, 29, 30, 31)
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32. A portable ranging system comprising:
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circuitry, said circuitry responsive to actuation for initiating a count; a base unit having an infrared emitter and an ultrasound receiver, said base unit causing the infrared emitter to emit high-intensity infrared light for flooding a ranging area with infrared light; a transponder having an infrared receiver and an ultrasound emitter, said transponder responsive to receipt of the infrared light for causing the ultrasound emitter to emit an ultrasound pulse; means responsive to the circuitry for preventing noise received and/or present in the system from falsely triggering the receipt of an ultrasound pulse, and for causing said circuitry to terminate the count upon receipt of the ultrasound pulse; and said circuitry using the count to compute the distance between the transponder and the base unit. - View Dependent Claims (35, 36, 37, 38, 39)
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33. A portable ranging system comprising:
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processing circuitry; control circuitry, said control circuitry causing the initiation of a count by the processing circuitry; an infrared emitter, said infrared emitter responsive to said control circuitry for flooding a ranging area with infrared light, an infrared receiver for receiving the infrared light; an ultrasound emitter for emitting an ultrasound pulse within the ranging area; an ultrasound receiver, said ultrasound receiver responsive to said ultrasound pulse to cause the processing circuitry to terminate the count, said processing circuitry performing a count and the control circuitry triggering the infrared emitter during each of a plurality of constant time periods as one of the ultrasound emitter or ultrasound receiver moves relative to the other within the ranging area; and said processing circuitry using the count to compute the distance between the one of the ultrasound emitter and the ultrasound receiver that is moving and the other for each of the plurality of constant time periods, said processing circuitry using the distance computed for each of the plurality of time periods to compute the velocity of the one of the ultrasound emitter or the ultrasound receiver that is moving. - View Dependent Claims (34)
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40. In a portable ranging system having circuitry, a base unit, and a transponder, the method of computing the velocity of the transponder as it moves relative to the base unit within a ranging area, the method comprising the steps of:
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(a) counting by the circuitry in response to an actuation of the circuitry, (b) triggering by the circuitry the base unit in response to the actuation of the circuitry; (c) emitting by the base unit within the ranging area infrared light in response to said step of triggering; (d) receiving by the transponder the infrared light; (e) emitting by the transponder an ultrasound pulse in response to said step of receiving by the transponder the infrared light; (f) receiving by the base unit of signals; (g) determining by the base unit that one of the signals received is the ultrasound pulse; (h) signalling by the base unit said circuitry in response to said step of determining; (i) terminating by said circuitry said counting in response to said step of signalling; (j) repeating steps (a) through (i) for each of a plurality of constant time periods; (k) computing by the circuitry using count data the distance of the transponder from the base unit for each of the plurality of constant time periods; and (l) differentiating the distance data computed in step (k) to obtain the velocity. - View Dependent Claims (41)
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42. A portable ranging system comprising:
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processing circuitry; control circuitry, said control circuitry causing the initiation of a count by the processing circuitry; an infrared emitter, said infrared emitter responsive to said control circuitry for emitting high-intensity infrared light to flood a ranging area with infrared light, an infrared receiver for receiving the infrared light; an ultrasound emitter for emitting an ultrasound pulse within the ranging area; an ultrasound receiver, said ultrasound receiver responsive to said ultrasound pulse to cause the processing circuitry to terminate the count; and said processing circuitry using the count to compute the distance between the ultrasound emitter and the ultrasound receiver. - View Dependent Claims (43, 44)
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45. A portable ranging system comprising:
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circuitry, said circuitry responsive to actuation for initiating a count; an infrared emitter, said infrared emitter responsive to said circuitry for emitting infrared light in a ranging area; an ultrasound emitter; an infrared receiver, said infrared receiver responsive to infrared light for causing said ultrasound emitter to emit an ultrasound pulse; an ultrasound receiver, said ultrasound receiver responsive to a signal for causing said circuitry to terminate the count, said circuitry performing a count and triggering the infrared emitter during each of a plurality of constant time periods as one of the ultrasound emitter or ultrasound receiver moves relative to the other within the ranging area, said circuitry using the count to compute the distance between the one of the ultrasound emitter and the ultrasound receiver that is moving and the other for each of the plurality of constant time periods, said circuitry using the distance computed for each of the plurality of time periods to compute the velocity of the one of the ultrasound emitter or the ultrasound receiver that is moving; and means for ensuring that the signal is the ultrasound pulse. - View Dependent Claims (46, 47, 48)
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49. A portable ranging system comprising:
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circuitry, said circuitry responsive to actuation for initiating a count; a base unit having an infrared emitter and an ultrasound receiver, said base unit causing the infrared emitter to emit infrared light within a ranging area; a transponder worn by a subject who is walking, said transponder having an infrared receiver and an ultrasound emitter, said transponder responsive to receipt of the infrared light for causing the ultrasound emitter to emit an ultrasound pulse; and means for preventing noise received and/or present in the system from falsely triggering the receipt of an ultrasound pulse, and for causing said circuitry to terminate the count upon receipt of the ultrasound pulse, said circuitry performing a count and triggering said base unit to cause the infrared emitter to emit infrared light within the ranging area during each of a plurality of constant time periods as the transponder moves relative to the base unit within the ranging area; said circuitry using the count to compute the distance between the transponder and the base unit for each of the plurality of constant time periods, and said circuitry computing a plurality of gait parameters for the walking subject. - View Dependent Claims (50, 51)
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52. In a portable ranging system having control circuitry, processing circuitry, thresholding circuitry, an ultrasound emitter, and an ultrasound receiver, the method of computing the velocity of one of the ultrasound emitter or ultrasound receiver as the one moves relative to the other, said method comprising the steps of:
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(a) causing by said control circuitry the triggering of the processing circuitry and the ultrasound emitter; (b) counting by the processing circuitry in response to said triggering; (c) emitting by the ultrasound emitter an ultrasound pulse in response to said triggering; (d) receiving by the ultrasound receiver signals; (e) comparing by the thresholding circuitry the signals received by the ultrasound emitter to a time varying adaptive threshold; (f) signalling by the thresholding circuitry the processing circuitry when a signal received is greater than the time varying adaptive threshold; (g) terminating by the processing circuitry said counting in response to said step of signalling; and (h) repeating steps (a) through (g) for each of a plurality of constant time periods; (i) calculating using count data from said counting the distance of the ultrasound emitter from the ultrasound receiver for each of the plurality of constant time periods; (j) differentiating the distance data calculated in step (i) to obtain velocity. - View Dependent Claims (53)
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54. A portable ranging system comprising:
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processing circuitry; an ultrasound emitter; control circuitry, said control circuitry causing the initiation of a count by the processing circuitry and for causing the ultrasound emitter to emit an ultrasound pulse; an ultrasound receiver; means for analyzing signals received at the ultrasound receiver for determining that the ultrasound pulse has been received, and for causing said processing circuitry to terminate the count upon receipt of the ultrasound pulse, said processing circuitry performing a count and the control circuitry causing the ultrasound emitter to emit an ultrasound pulse during each of a plurality of constant time periods as one of the ultrasound emitter or ultrasound receiver moves relative to the other within the ranging area, and said processing circuitry using the count to compute the distance between the one of the ultrasound emitter and the ultrasound receiver that is moving and the other for each of the plurality of constant time periods, said processing circuitry using the distance computed for each of the plurality of time periods to compute the velocity of the one of the ultrasound emitter or the ultrasound receiver that is moving.
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55. A portable ranging system comprising:
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circuitry, said circuitry responsive to actuation for initiating a count; an infrared emitter, said infrared emitter responsive to said circuitry for flooding a ranging area with infrared light; an ultrasound emitter, an infrared receiver within the ranging area, said infrared receiver responsive to said infrared light for causing said ultrasound emitter to emit an ultrasound pulse; and an ultrasound receiver, said ultrasound receiver responsive to said ultrasound pulse to cause said circuitry to terminate the count, said circuitry performing a count and triggering the infrared emitter during each of a plurality of constant time periods as one of the ultrasound emitter or ultrasound receiver moves relative to the other within the ranging area, said circuitry using the count to compute the distance between the one of the ultrasound emitter and the ultrasound receiver that is moving and the other for each of the plurality of constant time periods, said circuitry using the distance computed for each of the plurality of time periods to compute the velocity of the one of the ultrasound emitter or the ultrasound receiver that is moving. - View Dependent Claims (56)
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57. A portable ranging system comprising:
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circuitry, said circuitry responsive to actuation to initiate a count; a base unit having an infrared emitter and an ultrasound receiver, said base unit responsive to the actuation of the circuitry for causing the infrared emitter to flood a ranging area with infrared light; a transponder worn by subject who is walking, said transponder having an infrared receiver and an ultrasound emitter, said transponder responsive to receipt of the infrared light for causing the ultrasound emitter to emit an ultrasound pulse; and said base unit responsive to receipt of the ultrasound pulse to cause said circuitry to terminate the count, said circuitry performing a count and triggering said base unit to cause the infrared emitter to flood the ranging area during each of a plurality of constant time periods as the transponder moves relative to the base unit within the ranging area, said circuitry using the count to compute the distance between the transponder and the base unit for each of the plurality of constant time periods, and said circuitry computing a plurality of gait parameters for the walking subject. - View Dependent Claims (58, 59)
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60. A portable ranging system comprising:
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an infrared emitter for emitting an infrared pulse for each of a plurality of time periods; an ultrasound emitter; an infrared receiver, said infrared receiver responsive to the infrared pulse received for causing the ultrasound emitter to emit an ultrasound pulse for each of the plurality of time periods; an ultrasound receiver for receiving the ultrasound pulse for each of the plurality of time periods; circuitry for determining an elapsed time from emission of the infrared pulse to receipt of the ultrasound pulse for each of the plurality of time periods as one of the ultrasound emitter or ultrasound receiver moves relative to the other; and said circuitry using the elapsed time for each of the plurality of time periods to calculate at least one of a plurality of parameters for the one of the ultrasound emitter or ultrasound receiver that moves, said plurality of parameters comprised of mean velocity, mean acceleration, instantaneous forward velocity, maximum velocity, minimum velocity, and peak to peak velocity variation. - View Dependent Claims (61, 62, 63, 64)
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65. A portable ranging system comprising:
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a base unit having an infrared emitter and an ultrasound receiver, said infrared emitter for emitting an infrared pulse for each of a plurality of time periods; a transponder having an infrared receiver and an ultrasound emitter, said infrared receiver responsive to the infrared pulse for causing the ultrasound emitter to emit an ultrasound pulse for each of the plurality of time periods, said ultrasound receiver for receiving the ultrasound pulse for each of the plurality of time periods; circuitry for determining an elapsed time from emission of the ultrasound pulse to receipt of the ultrasound pulse for each of the plurality of time periods; and said circuitry using the elapsed time for each of the plurality of time periods to calculate at least one of a plurality of parameters for the transponder as it moves, said plurality of parameters comprised of mean velocity, mean acceleration, instantaneous forward velocity, maximum velocity, minimum velocity, and peak to peak velocity variation. - View Dependent Claims (66, 67, 68, 69, 70, 71, 72, 73)
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74. A portable ranging system comprising:
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an ultrasound emitter for emitting an ultrasound pulse for each of a plurality of time periods; an ultrasound receiver for receiving the ultrasound pulse for each of the plurality of time periods; circuitry for determining an elapsed time from emission of the ultrasound pulse to receipt of the ultrasound pulse for each of the plurality of time periods as one of the ultrasound emitter or ultrasound receiver moves relative to the other; and said circuitry using the elapsed time for each of the plurality of time periods to calculate at least one of a plurality of parameters for the one of the ultrasound emitter or ultrasound receiver that moves, said plurality of parameters comprised of mean velocity, mean acceleration, instantaneous forward velocity, maximum velocity, minimum velocity, and peak to peak velocity variation. - View Dependent Claims (75, 76, 77, 78, 79, 80, 81, 82, 83)
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84. A portable ranging system comprising;
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processing circuitry; an ultrasound emitter, control circuitry, said control circuitry responsive to actuation for causing the initiation of a count by the processing circuitry and for causing the ultrasound emitter to emit an ultrasound pulse; an ultrasound receiver; circuitry for comparing signals received at the ultrasound receiver to a time varying adaptive threshold and for causing said processing circuitry to terminate the count when the signal received is greater than the threshold, said processing circuitry performing a count and said control circuitry causing the ultrasound emitter to emit an ultrasound pulse during each of a plurality of constant time periods as one of the ultrasound emitter or ultrasound receiver moves relative to the other within the ranging area; and said processing circuitry using the count to compute the distance between the one of the ultrasound emitter and the ultrasound receiver that is moving for each of the plurality of constant time periods, said processing circuitry using the distance computed for each of the plurality of time periods to compute the velocity of the one of the ultrasound emitter or the ultrasound receiver that is moving.
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Specification