Movement function assessment system and movement function measurement apparatus
The present invention addresses the problem of limiting power consumption and radio wave interference when assessing the movements of multiple sites of a living body. The present invention is a movement function assessment system provided with: a movement function measurement apparatus for calculating movement data on the basis of the relative distances of pairs of transmission coils and reception coils attached to movable portions of a living body; and an assessment apparatus for assessing the movement function of the living body on the basis of the movement data received from the movement function measurement apparatus. A control unit of the movement function measurement apparatus performs the switching of the multiple transmission coils by a switching unit (1) and the switching of the multiple reception coils by a switching unit (2) so that the paired transmission coils and reception coils are operated sequentially.
1. A movement function measurement apparatus, comprising:
an alternating current generating unit configured to generate an alternating current of a predetermined frequency;
a plurality of oscillation coils;
a first switching unit connected with the alternating current generating unit, the first switching unit being configured to connect the alternating current generating unit with each of the plurality of oscillation coils one by one so that the alternating current of the predetermined frequency generated by the alternating current generating unit flows through each of the plurality of oscillation coils in sequence;
a plurality of detection coils, each of which is:
paired with a corresponding one of the plurality of oscillation coils; and
configured to output a detection signal, represented as a magnetic field waveform having a plurality of cycles over a period of time, based on a detection of a magnetic field generated by the corresponding one of the plurality of oscillation coils;
a second switching unit configured to connect with each of the plurality of detection coils one by one so that the detection signal from each of the plurality of detection coils is output to the second switching unit in sequence;
an amplification/filter unit connected with the plurality of detection coils through the second switching unit;
a detection unit connected with the amplification/filter unit, the detection unit being configured to perform detection by using reference signals from the alternating current generating unit; and
a control unit configured to control the first switching unit and the second switching unit so that the magnetic field, generated by the corresponding one of the plurality of oscillation coils connected with the first switching unit, is detected by one of the plurality of detection coils which is paired with the corresponding one of the plurality of oscillation coils, connected with the second switching unit,
wherein the movement function measurement apparatus is configured to calculate movement data including at least one of a distance data, velocity data, an acceleration data, and jerk data based on a relative distance between each of the coil pairs of the oscillation coils and the detection coils attached to movable portions of a biological object, the relative distance being obtained by converting a voltage value generated by each detection coil, and
wherein, for each said magnetic field waveform obtained from a corresponding detection coil, the detection unit:
deletes a noise component contained in at least a first cycle in a period of time after the second switching unit is connected with the corresponding detection coil, and
detects remaining cycles in the period of time as a signal component.
2. The movement function measurement apparatus according to claim 1 , wherein
the detection unit deletes, among the magnetic field waveforms obtained from each of the plurality of the detection coils, predetermined cycles thereof immediately after the second switching unit is connected with the each of the plurality of the detection coils.
3. The movement function measurement apparatus according to claim 2 , wherein
the movement function measurement apparatus further includes a down-sampling unit configured to perform down-sampling of output data from the detection unit at a predetermined ratio.
4. The movement function measurement apparatus according to claim 2 , wherein
the control unit controls the first switching unit and the second switching unit so that the alternating current flows through the each of the plurality of oscillation coils from the alternating current generating unit during a time width T 1 , and that the each of the coil pairs of the oscillation coils and the detection coils is functioned once for every cycle of a time width T 2 , in which
the control unit stops the alternating current generating unit during a time width T 3 (T 2 −T 1 *N), wherein a number of the coil pairs of the oscillation coils and the detection coils is N, so that neither of the coil pairs of the oscillation coils and the detection coils is functioned.
5. The movement function measurement apparatus according to claim 2 , further comprising:
an analog/digital conversion unit provided between the amplification/filter unit and the detection unit, the analog/digital conversion unit being configured to convert analog data received from the amplification/filter unit into digital data to transmit the digital data to the detection unit.
6. The movement function measurement apparatus according to claim 1 , wherein
the movement function measurement apparatus further includes a down-sampling unit configured to perform down-sampling of output data from the detection unit at a predetermined ratio.
7. The movement function measurement apparatus according to claim 1 , wherein
the control unit controls the first switching unit and the second switching unit so that the alternating current flows through the each of the plurality of oscillation coils from the alternating current generating unit during a time width T 1 , and that the each of the coil pairs of the oscillation coils and the detection coils is functioned once for every cycle of a time width T 2 , in which
the control unit stops the alternating current generating unit during a time width T 3 (T 2 −T 1 *N), wherein a number of the coil pairs of the oscillation coils and the detection coils is N, so that neither of the coil pairs of the oscillation coils and the detection coils is functioned.
8. The movement function measurement apparatus according to claim 1 , further comprising:
an analog/digital conversion unit provided between the amplification/filter unit and the detection unit, the analog/digital conversion unit being configured to convert analog data received from the amplification/filter unit into digital data to transmit the digital data to the detection unit.
9. A movement function assessment system, comprising:
the movement function measurement apparatus according to any one of claims 1 - 8 ; and
an assessment apparatus configured to assess a movement function of the biological object based on the movement data received from the movement function measurement apparatus.
10. The movement function assessment system according to claim 9 , further comprising:
a data communication unit provided between the movement function measurement apparatus and the assessment apparatus, the data communication unit having a communication function to deliver by radio or cable the movement data on the plurality of the detection coils calculated by the movement function measurement apparatus all together to the assessment apparatus.