JP2000175979A - Joint training device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a joint training device of reliability and safety, whose angle detecting part is durable to avoid generation of malfunction by the erroneous detection of the angle. SOLUTION: The joint training device for making the legs of a patient execute bending and stretching exercise is provided with a driving force transmitting means transmitting the driving force of the means 3 to a leg bending and stretching mechanism by making a moving piece along a rotary shaft 21 driven by the means 3. In the joint training device detecting the bending and stretching angle of the legs by detecting the rotation of the shaft 21, a mechanism detecting means 50 detecting the rotation of the shaft 21 is made a noncontacting optical type. In addition, the means 3 is forcedly stopped in the case of generating deviation between the rotation of the shaft 21 and that of the means 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a joint training apparatus for training the movement of a joint so as not to cause contracture (stiffening) of a muscle after an operation on a knee joint or the like.

[0002]

2. Description of the Related Art Conventionally, Japanese Patent Application Laid-Open No.
One disclosed in Japanese Patent No. 4989 is known. This is, as shown in FIGS.
The internal housing 2 is slidably inserted in the front-rear direction, and a feed screw 4 driven by a motor 3 is disposed in the internal housing 2 in the front-rear direction. The idle woma 5 reciprocating in the front-rear direction along the housing 2 is screwed into the upper and lower thighs of the patient's leg a between the idle wok 5 and the inner housing 2 by bending and extending along with the reciprocating movement of the idle wok 5. A link mechanism 6 for bending and extending the a1 and the lower leg a2 is provided.

[0003] This joint training apparatus also has a motor 3
A control circuit 7 is provided for controlling the extension angle of the leg a (the angle at which the leg a extends) and the bending angle (the angle at which the leg a bends), and the speed setting and changing of the bending and stretching motion by operating the operation panel 8. I can do it.

[0004] As shown in FIG. 9, the joint training apparatus controls the extension angle and the like of the legs by controlling the motor 3 by the control circuit 7. This type of joint training device operates the control circuit 7 by converting an alternating current into a direct current. In addition to the operation panel 8, there is a remote control type operation unit that can set the extension angle and the like at hand of the patient. The patient operates the activation / operation switch 49 and the operation angle change switch of the operation unit. 17, the joint training apparatus can be operated.

Conventionally, a potentiometer 39 has been used for detecting the angle of the flexion / extension movement of the leg of the joint training apparatus. The rotation obtained by reducing the rotation of the motor 3 to 1/20 by the speed reducer 23 is transmitted to the feed screw 4 and the worm wheel 52. This rotation is performed by the worm wheel 52 for 2
The rotation decelerated to 1/0 is transmitted to the potentiometer 39. The output of the potentiometer 39 was taken into the control circuit 7 to calculate the angle. If the potentiometer 39 is used, a value corresponding to the rotation is output, and the value can be stored even when the power is turned off.

[0006]

However, since the winding resistor and the output terminal of the potentiometer 39 are in contact with each other, poor contact occurs due to wear of the winding resistance during use. This contact failure causes erroneous angle detection. As described above, the potentiometer 39 is not suitable for use in which the potentiometer 39 is constantly rotated for a long period of time. Also, 1
It is difficult to detect a detection angle abnormality using only one angle detector.

The present invention has been made in view of such inconvenience, and provides a highly reliable and safe joint training apparatus in which the angle detecting section has high durability and does not cause malfunction due to erroneous angle detection. .

[0008]

According to the first aspect of the present invention, a moving body (22) reciprocates along a driving means (3) and a rotating shaft (21) rotated by the driving means (3). Leg bending and stretching mechanism (100) for bending and stretching the leg (a) of the patient
A mechanism detecting means (50) for detecting rotation of the rotating shaft (21), and a control means (16) for controlling the driving means (3) in accordance with an output signal of the mechanism detecting means (50). In the provided joint training apparatus (D), the mechanism detecting means (50) is of a non-contact optical type.

According to the present invention, the mechanism detecting means (50)
Since there is no contact portion, there is no wear due to sliding, and poor contact due to wear can be prevented. Therefore, the durability of the mechanism detecting means (50) is improved, malfunction is prevented, and the reliability of the joint training apparatus (D) is improved.

According to a second aspect of the present invention, in the joint training apparatus (D) according to the first aspect, the joint training apparatus (D) detects a shift between the rotation of the rotating shaft (21) and the driving means (3). Displacement detecting means for detecting the rotation of the driving means (3).
8) detecting a shift between the rotation of the rotating shaft (21) and the rotation of the driving means (3) based on the output signal of 8) and the output signal of the mechanism detecting means (50), and
When the output of the deviation detecting means has reached a predetermined value,
The driving means (3) is forcibly stopped.

According to the present invention, the speed reducer (23) or the like is interposed between the driving means (3) and the rotating shaft (21) rotated by the driving means (3), or the mechanism detecting means (50). )
When the worm wheel (52) is provided at the input portion of the worm wheel (52), the portion of the speed reducer (23) or the worm wheel (5)
In the case of part (2), when the actual bending angle (θ) and the angle calculated based on the output signal from the mechanism detecting means (50) are shifted due to loosening or slipping, the driving means (3) ) To prevent accidents from occurring.

According to a third aspect of the present invention, in the joint training apparatus (D) according to the second aspect, there is provided an alarm unit which emits an alarm sound when the driving unit (3) is forcibly stopped. .

[0013] According to the present invention, it is possible to notify a person other than the patient that the joint training apparatus (D) has stopped.

According to a fourth aspect of the present invention, in the joint training apparatus (D) according to any one of the first to third aspects, a position detecting means (53) for detecting that the moving body (22) has reached a predetermined position. Wherein the control means (16) forcibly stops the driving means (3) in response to an output signal of the position detection means (53).

According to the present invention, the mechanism detecting means (50)
Even when the joint training apparatus (D) malfunctions due to a cause other than the difference between the rotation of the rotating shaft based on the output of the drive detection means (38) and the rotation of the drive means (3), the drive means ( 3) Forcibly stop to prevent accidents from occurring.

According to a fifth aspect of the present invention, in the joint training apparatus (D) according to the second or third aspect, the joint training apparatus (D) includes an output signal of the mechanism detecting means (50) and the drive detecting means (D). 38) first storage means (35) for storing moving body data of the moving body (22) corresponding to the output signal of (38), and position detection for detecting that the moving body (22) has reached a predetermined position. Means (53), second storage means (34) storing moving body data corresponding to the predetermined position of the moving body (22), and moving body data stored in the second storing means. Correction means for correcting the moving object data stored in the first storage means (35) based on the output signal of the position detection means (53). (34) Ete, this replaced data introduced into the displacement detecting means, Suspended said drive means based on an output signal of said deviation detecting means (3)
Is controlled to be drivable.

According to the present invention, when the driving means (3) is forcibly stopped, the speed reducer (23) and the mechanism detecting means (5) are provided.
After repairing the looseness of the worm wheel (52) for inputting the rotation of the rotating shaft (21) to 0), the mechanism detecting means (50)
Of the rotation shaft (21) based on the output of the
8) The data remaining in the RAM (35) is forcibly rewritten to data having no deviation from the rotation of the driving means (3) based on the output of (8), and the driving means (3) operates normally. be able to.

[0018]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 to 3 show a joint training apparatus D according to an embodiment of the present invention. As shown in FIG. 1, this joint training apparatus D includes an upper thigh a1 and a lower thigh a1 of a patient's leg a.
2 is a device for performing a bending / extending motion between a predetermined extension angle θ1 and a bending angle θ2. The device D includes an external housing 19 having a cavity formed therein, and an external housing 1
And an internal housing 20 which is inserted into the cavity 9 and is slidably provided in the front-rear direction. The internal housing 20 includes a drive motor 3 as a drive unit for driving the joint training device D.
(See FIG. 2), a speed reducer 23 for transmitting the driving force by reducing the rotation of the output shaft of the drive motor 3, and a leg bending / stretching mechanism 100 for bending / stretching the leg a of the patient.
Further, the leg bending and stretching mechanism 100 is interlocked with a reciprocating motion of the drive force transmission mechanism 200 including a feed screw 21 as a rotation shaft for transmitting the drive force of the drive motor 3 and an idle top 22 as a moving body, and an idle bear 22. Link mechanism 1 that moves
4 is provided. The feed screw 21 is attached to the inner casing 20 so as to extend in the front-rear direction.
Reciprocates along the feed screw as the feed screw 21 rotates. Further, the link mechanism 14 is connected to the idle top 22 and moves in conjunction with the movement of the idle top 22.
Further, the joint training apparatus D includes a control circuit 16 that freely sets the extension angle θ1 and the bending angle θ2, the speed of the bending and extension movement, and controls the motor 3 to perform a desired bending and extension movement.

The outer housing 19 is a tubular body having a substantially rectangular cross section, and its rear end is closed by an end plate and its front end is open. The inner housing 20 is a box that is slightly smaller than the outer housing 19, and its front and rear portions are closed by end plates. The inner housing 20 is inserted into the cavity of the outer housing 19 from the front end. A guide rail (not shown) is provided in the front-rear direction inside both side walls in the left-right direction perpendicular to the front-rear direction of the outer casing 19, and a projection slidably engaged with the guide rail is provided on the inner casing 20 in the left-right direction. The inner housing 20 is slidable with respect to the outer housing 19.

Although not shown, a stopper is provided at the front end of the outer casing 19 to prevent the inner casing 20 from slipping out. Further, a slit (not shown) is provided in the front-rear direction so that the link mechanism 14 does not interfere with the inner housing 20 and the outer housing 19.

At the rear of the inner casing 20, a speed reducer 23 is provided, which accommodates a plurality of gears in a box-shaped casing, and a feed screw 21 is provided so as to penetrate into the speed reducer 23. ing. The feed screw 21 is formed with a helical thread over substantially the entire region in the longitudinal direction, and the gear of the speed reducer 23 is meshed with this thread to feed the feed screw 21.
The rotation of the drive motor 3 is decelerated and transmitted. In addition,
The drive motor 3 is moved from a direction orthogonal to the axial direction of the feed screw 21.
Is provided such that its output shaft is inserted into the speed reducer 23. The front end of the feed screw 21 is rotatably supported by a front end plate of the internal housing 20 via a bearing (not shown). Reduction gear 23 used in this embodiment body
Transmits the rotation of the output shaft of the drive motor 3 (see FIG. 2) to the feed screw 21 at a speed reduced to 1/20. However,
The reduction ratio is not limited to this, and may be another value.

Further, the feed screw 21 is screwed with an idler top 22 which moves in the axial direction. Idocoma 2
Numeral 2 reciprocates along the axial direction with the rotation of the feed screw 21, converts the rotational motion of the feed screw 21 into a linear motion, and transmits the driving force to the link mechanism 14.

The link mechanism 14 corresponds to the upper thigh a1 and the lower thigh a2 of the leg, respectively, and the first link 2 has one end rotatably connected to each other by an upper support pin 28.
4 and a second link 25. Further, a third link 26 whose one end is rotatably connected to the other end of the first link 24 and the intermediate support pin 30, and one end is rotated to the center of the second link 25 by the intermediate support pin 31. And a fourth link 27 that is freely connected. The other ends of the link 26 and the link 27 are connected by a lower support pin 29 facing the upper support pin 28. These links 24, 25, 26, and 27 are connected in the overall shape like a pantograph. And the second link 25
The other end of the lower support pin 29 is connected by a connection pin 32 to an idle top 22 that reciprocates along a feed screw 21.
Is connected to the front of the internal housing 20.

Although not shown in the figure, the link mechanism 14 is disposed on the left and right sides of the apparatus D, and the left and right sides are interconnected by the lower support pin 29 and the connection pin 32. In addition, the second link 25 has a leg t
A fixing frame 25a is attached so as to easily fix the foot, and a lower end thereof is provided with a step 25b for placing the foot a4.
Is provided. The second links 25 are provided on the left and right, but they are connected by a belt (not shown), and the belt supports the upper thigh a1. Further, the fixed frame 25a, the step 25b, and the second link 25
A pad and a belt (both not shown) for fixing the leg a to the link mechanism 14 are provided.

The operation of the present joint training apparatus D is performed by a control panel 37 including a start / stop switch 43 for starting and stopping, and an operation angle setting switch (not shown) for setting an operation angle.

This joint training apparatus D is provided with a non-contact optical encoder 50 as a mechanism detecting means for detecting the rotation of the feed screw 21 as shown in FIG. The non-contact optical encoder 50 is attached to a bracket 231 at the rear of the speed reducer 23, and is provided such that its input shaft is arranged in a direction orthogonal to the axial direction of the feed screw 21. A worm wheel 52 is attached to the tip of the input shaft so as to rotate while meshing with the thread of the feed screw 21 and transmitting the rotation of the feed screw 21 to the non-contact optical encoder 50. At the rear of the drive motor 3, an input shaft is directly connected to the drive motor 3, and an encoder 38 is provided as drive detection means for detecting rotation of the output shaft.

As shown in FIG. 3, the encoders 50 and 38 are provided with a disk-shaped slit plate S which rotates together with these input shafts. On the periphery of the slit plate S, a plurality of slits S1 ‥ are formed concentrically over the entire circumference.
S1, S2 ‥ S2 are formed in two layers. Note that the interval between the slits S1 of the outer slits S1１S1 is substantially the same as the width of the inner slit S2, and the outer slits S1 ‥ S1 are circular with respect to the inner slits S2 ‥ S2. The slits are arranged so as to be shifted by half a slit S1 in the circumferential direction. Also, each slit S1 ‥ S in the radial direction
At a position of 1, S2 ‥ S2, a light projector (not shown) and light receivers M and N for receiving light emitted from the light projector are provided with a slit plate S interposed therebetween.

Each of the light receivers M and N emits a constant voltage signal when receiving light from the light emitter. Therefore,
When the slit plate S rotates and the light emitted from the light emitter is intermittently cut off, the voltage signal emitted from the light receiver is as shown in FIG.
It becomes a pulse signal as shown in FIG. By counting the number of pulses, the amount of rotation of the feed screw can be specified.
Further, since the slits S1 and S2 are arranged in the circumferential direction shifted by half the slit S1, a phase difference of 1/4 pitch occurs between the voltage signals of the light receiver M and the light receiver N. If it is determined which phase of the light receiver M and the light receiver N is advanced, the direction of rotation of the encoder can also be determined.

As shown in FIG. 5, the inner casing 20 is provided with rails 56, 56 extending in the front-rear direction provided on both left and right sides thereof, and an idle frame 22 moving in the front-rear direction along the feed screw 21. Have been. Idocoma 22
In each of the left and right ends, engaging portions 551 and 551 which are engaged with and slide on the rails 56 and 56 are bolted to the front surface thereof. A light shielding plate 57 made of a T-shaped band plate is provided at a substantially central portion in the left-right direction of the rear end surface so as to protrude rearward. When the idle top 22 moving along the feed screw 21 reaches the rearmost position within the movable range, the rear end of the light shielding plate 57 is formed by a slit formed in the rear end plate of the internal housing 20. 541.

On the other hand, on the outer wall surface of the end plate at the rear part of the inner casing 20, an origin sensor 53 as position detecting means for detecting that the idle top 22 has reached the rearmost position within the movable range thereof is provided. Is provided. Origin sensor 53
Is mounted so that the light projecting portion 531 and the light receiving portion 532 are arranged side by side in the left-right direction and the slit 541 is interposed therebetween, and the rear end of the light shielding plate 57 is located between the light projecting portion and the light receiving portion. When it reaches, the voltage is turned ON or OFF to send a signal to the control circuit.

The above-described signals from the non-contact optical encoder 50, the encoder 38 directly connected to the drive motor 3, and the origin sensor 53 are input to the control circuit 16 disposed at the lower rear part of the outer casing 19. The control circuit 16 controls the joint training apparatus D according to these signals.

As shown in FIG. 6, the control circuit 16 includes a CPU (central processing circuit) 33 for performing various calculations and operation controls necessary for the operation of the joint training apparatus mainly composed of a microprocessor, and a joint training circuit. RO in which programs and data for controlling basic operations such as device startup are written
M34, a RAM 35 in which programs and data necessary for the operation of the joint training apparatus are written as needed, an AD converter 42 for converting an analog value of an external device into a digital value and taking it into the CPU 33, and a digital output value of the CPU 33 A DA converter 41 for converting the value into a value and transmitting a signal to an external device, a motor drive circuit 40 for appropriately transmitting a drive signal to the drive motor 3, and an LED drive circuit 48 for changing the lighting content of the LED according to the control content A switch input circuit 47 for starting / stopping the apparatus, and loading the set values into the CPU 33; and an alarm drive circuit 60 for controlling an alarm buzzer to emit an alarm sound. The control circuit 16 includes the AC power supply 3
By the DC constant voltage device 362 activated by 61
It operates with a constant DC voltage applied. Also, RAM3
5, a backup battery 51 is provided.
The written data is not erased even if 6 is cut off.

The control circuit 16 calculates the bending / extension angle of the leg through the rotation state of the feed screw 21 by a signal from the non-contact encoder 50, and compares the calculated bending angle with the preset extension angle or bending angle. Thus, the drive motor is controlled so as not to exceed the set angle.

The speed reducer 23, the feed screw 21, and the worm wheel 52 are interposed between the non-contact optical encoder 50 and the drive motor 3 to be controlled. Therefore, while the device is in use, the loosening of the bolts to which the gear of the speed reducer 23 is attached, the thread of the feed screw 21 and the worm wheel 52 are set, and the input of the non-contact encoder 50 of the worm wheel 52 is performed. A slip or the like with respect to the shaft may occur, and a deviation may occur between the bending / extension angle calculated based on the signal transmitted from the non-contact optical encoder 50 and the actual bending / extension angle of the leg. In this device, in such a case, the control circuit 16 controls to forcibly stop the drive motor 3 and issue a command to the alarm buzzer 61 to emit an alarm sound. The determination of the angle shift is performed by reading the signal from the non-contact optical encoder 50 and the signal from the encoder 38 directly connected to the motor into the CPU 33,
These are stored in the RAM 35 as a storage device. Then, an arithmetic program for calculating the angle difference recorded in the ROM 34 is read into the CPU 33, and the angle is calculated from the data stored in the RAM 35 according to this program, and then the angle is calculated by calculating. And RO
Data of the allowable value of the preset angle difference from M34,
This is performed by reading a program for comparing the calculated value of the angle difference with the allowable value data and determining whether the angle difference has reached the allowable value. When the angle difference reaches the allowable value, the CPU 33 outputs a signal for forcibly stopping the drive motor 3 to the DA converter.

In this joint training apparatus, the drive motor 3 which is forcibly stopped is operated as usual. When a signal is output from the photoelectric switch described above,
The CPU 33 executes a correction program recorded in the ROM 34 based on this signal. In the correction program, the angle data stored in the RAM 35 at the time when the allowable value is reached is rewritten to the preset angle data. That is, the two angle data obtained based on the outputs of the two encoders 50 and 38 stored in the RAM 35 at the time of the forcible stop are converted into an angle of -10 degrees formed when the nut is located at the rearmost position. Force rewriting. Then, the angle is calculated based on the rewritten new data, the angle deviation is set to zero, and the normal operation state is set within the allowable value range.

In this joint training apparatus, the origin sensor 53 is also used as a switch for forcibly stopping. It malfunctions for some reason other than the case where the difference between the bending angle and the actual bending angle due to the output from the non-contact optical encoder 50 and the actual bending angle is different, and even if the patient reaches the preset expansion angle, the patient further expands the bending angle. Even when the drive motor 3 is driven in the direction in which the nut is moved and the light shielding plate 57 is moved to a position where the origin sensor 53 is operated, the drive motor 3 is forcibly stopped.

[0038]

As described above, according to the present invention, the mechanism detecting means is a non-contact optical type, so that there is no occurrence of contact failure due to wear, erroneous detection is prevented, and durability and reliability are improved. Also, when detecting the leg flexion / extension angle, not only the mechanism detection means for detecting the rotation of the rotating shaft rotated by the driving means, but also the drive detection means for detecting the rotation of the output shaft of the driving means, The malfunction is confirmed based on the output signals of the two detection means. If the malfunction is found, the driving means is forcibly stopped to prevent the occurrence of an accident, thereby improving the safety of the joint training apparatus. Improve. Further, an alarm means is provided to notify a person around the patient that the device has stopped.

Further, position detecting means for detecting that the moving body of the driving force transmitting means has reached a predetermined position is provided.
The driving means is forcibly stopped even if it malfunctions due to a cause other than the rotational deviation of both the driving means and the rotating shaft, thereby improving safety. Further, since the correction means is provided, the drive means which has been forcibly stopped can be operated in a normal state according to the output signal of the position detection means.

[Brief description of the drawings]

FIG. 1 is a partially cutaway side view showing a joint training apparatus according to one embodiment of the present invention.

FIG. 2 is a perspective view showing a mounting portion of a mechanism detecting means used in the joint training apparatus shown in FIG.

FIG. 3 is a perspective view showing a slit plate and a light receiver inside the mechanism detecting means of FIG. 2;

FIG. 4 is a diagram showing a waveform of an output signal of a detection means provided with the slit plate and the light receiver of FIG. 3;

FIG. 5 is a plan view of an internal housing of the joint training apparatus of FIG. 1;

FIG. 6 is a block diagram of a control system of the joint training device.

FIG. 7 is a side view showing an extended state of the conventional joint training apparatus.

FIG. 8 is a side view showing a bending state of the conventional joint training apparatus.

FIG. 9 is a block diagram of a control system of a conventional joint training apparatus.

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 leg flexion / extension mechanism 14 link mechanism 16 control means (control circuit) 200 driving force transmission means 21 rotating shaft (feed screw) 22 moving body (idcoma) 23 reduction gear 38 drive detection means (encoder) 50 mechanism detection means (non-contact optics) 52) Worm wheel 53 Position detecting means (origin sensor)

Claims (5)

[Claims] 1. A drive unit, a leg bending / extension mechanism for causing a movable body to reciprocate along a rotation axis rotated by the drive unit to cause a patient's leg to bend / extend, and a mechanism for detecting rotation of the rotation shaft. A joint training apparatus comprising: a detecting unit; and a control unit that controls the driving unit in accordance with an output signal of the mechanism detecting unit, wherein the mechanism detecting unit is a non-contact optical type. . 2. The joint training apparatus according to claim 1, further comprising: a shift detecting unit configured to detect a shift between the rotation axis and the driving unit. The shift detecting unit detects a rotation of the driving unit. Detecting the deviation between the rotation of the rotating shaft and the rotation of the driving unit based on the output signal of the mechanism detection unit and the output signal of the mechanism detection unit. The control unit detects that the output signal of the deviation detection unit has reached a predetermined value. 2. The joint training apparatus according to claim 1, wherein said driving means is forcibly stopped. 3. The joint training apparatus according to claim 2, further comprising an alarm unit that emits an alarm sound when the driving unit is forcibly stopped. 4. The joint training device includes position detecting means for detecting that the moving body has reached a predetermined position, and the control means forcibly drives the driving means in accordance with an output signal of the position detecting means. The joint training device according to claim 1, wherein the joint training device is stopped. 5. The joint training apparatus according to claim 1, wherein the first storage unit stores moving object data of the moving object corresponding to an output signal of the mechanism detecting unit and an output signal of the driving detecting unit; Position detecting means for detecting arrival at a predetermined position; second storage means for storing moving body data corresponding to the predetermined position of the moving body;
Correction means for correcting the moving body data stored in the storage means, wherein the control means converts the moving body data stored in the first storage device based on an output signal of the position detection means. It is possible to replace the moving body data stored in the second storage means, introduce the replaced data into the displacement detection means, and drive the driving means forcibly stopped based on an output signal of the displacement detection means. The joint training apparatus according to claim 2, wherein the joint training apparatus is controlled to: