JPH08294503A - Motor-driven artificial hand - Google Patents

Abstract

PURPOSE: To provide a motor-driven artificial hand capable of feedback comfortable to a wearing person. CONSTITUTION: This motor-driven artificial hand 25 is provided with a sensation feedback part 4 for feeding back reaction force to the wearing person 25 as a body feeling based on reaction force detection signals (f) from a reaction force detector 12 for detecting the reaction force of a finger part 5. The sensation feedback part 4 is provided with an arithmetic operation processing part 30 for operationally amplifying the reaction force detection signals (f) of the reaction force detector 12 and outputting reaction force feedback signals (e) and a body feeling device 31 for converting the reaction force feedback signals (f) to body feeling stimuli and making the wearing person 25 feel them. The arithmetic operation processing part 30 is provided with an output arithmetic operation part 32 for setting the amplification ratio of the reaction force detection signals (f) and a state signal arithmetic operation part 33 for outputting the state signals (g) of the muscle of the wearing person 25 and the output arithmetic operation part 32 sets the amplification ratio to a high position accompanying the increase in the state signals (g), performs amplification by the amplification ratio and outputs the reaction force feedback signals (e).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an electric prosthesis,
In particular, it relates to sensory feedback control for providing comfortable feedback to the wearer.

[0002]

2. Description of the Related Art With the increasing importance of social welfare in recent years,
There is a growing need for rehabilitation for people whose limbs have been amputated due to traffic and occupational accidents. Due to this need, various electric prostheses have been developed as a substitute for the function of the hand lost by amputation. There is. As a specific electric prosthesis, a detector that detects the gripping force of the hand part that is opened and closed, and a gripping force detection signal from this detector are amplified at a constant amplification rate to sense the prosthesis wearer's sense. Some devices are provided with a sensory feedback unit that feeds back to the container as a sensation.

Further, as the functions required of the current electric prosthesis, not only the motion control function of the hand and the like to be opened and closed is sophisticated, but also the wearer can easily control the electric prosthesis. Is desired. To that end, it has the same dynamic characteristics as the human hand and has sensory feedback, i.e. the human sensory organs are more sensitive as the person is in tension and so-called nerve-focused. There is a need for an electric prosthesis with sensory feedback that is adapted to the characteristics of high sensitivity and low sensitivity in the relaxed state.

[0004]

However, in the conventional electric prosthesis, since the feedback signal of the grasping force of the prosthesis is amplified at a constant amplification rate and transmitted to the sensation device, the wearer of the prosthesis is soft. If you try to grab an object and get tense, or if you try to grab an object in the lillux state, if the prosthesis holding force is the same, the amount of sensory feedback will be the same. However, there was a problem that it was annoying when in a relaxed state.

A conventional electric prosthetic hand feedback device feeds back the grip force of the prosthetic hand.
The open / closed state of the prosthesis depends on the wearer's vision. For this reason, when using an object under conditions where it is not possible to effectively check the open / closed state of the artificial hand, such as in the dark, when grasping an object,
There is a problem that it is difficult to operate because the open / closed state of the prosthesis cannot be grasped.

The present invention has been made in order to solve such a problem, and provides an electric prosthesis that enables comfortable tactile feedback for the wearer. Specifically, (1) Wearing According to the person's tension or relaxed state, even with the same gripping force, provision of an electric prosthetic hand that enables the wearer to perform sensory feedback according to the state,
(2) An object of the present invention is to provide an electric prosthesis that can appropriately feed back the opening / closing operation of the prosthesis to the wearer.

[0007]

In order to solve the above problems, in the electric prosthesis of the present invention, in claim 1, the reaction force detection from the reaction force detector for detecting the reaction force of the hand portion which is opened and closed. An electric prosthesis having a sensation hood back section for feeding back the reaction force as a sensation to the sensory organs of a prosthetic hand wearer based on a signal, wherein the sensation feedback section is
An arithmetic processing unit that arithmetically amplifies a reaction force detection signal from the reaction force detector and outputs a reaction force feedback signal, and a sensation that the reaction force feedback signal is converted into a bodily sensation and is sensed by a sensory organ of a prosthetic wearer. A device, the arithmetic processing unit includes an output arithmetic unit that sets an amplification ratio of the reaction force detection signal, and a state signal arithmetic unit that outputs a state signal of the muscle of the artificial hand wearer, and the output arithmetic unit The unit sets the amplification ratio to a high value as the status signal increases, and outputs the reaction force feedback signal amplified at this amplification ratio.

In claim 2, in addition to the one in claim 1,
The muscle state signal uses either a composite signal of the myoelectric signals of the flexor muscle and the extensor muscle of the artificial arm wearer, or a higher myoelectric signal of the myoelectric signals of the flexor muscle and the extensor muscle.

According to a third aspect of the present invention, the normal mode signal is output to the arithmetic processing unit when the muscle state signal is lower than a predetermined high reference value. Also, a mode selection unit is provided for outputting a high sensitivity mode signal when the muscle state signal is equal to or higher than the high reference value, and the output operation unit is configured to output the high sensitivity mode signal from the mode selection unit. A predetermined amplification ratio higher than the amplification ratio in the normal mode signal is set, and the reaction force feedback signal amplified at this amplification ratio is output.

In the fourth aspect, in addition to the third aspect,
The high-sensitivity mode signal is to be released by a release signal, the release signal, after the elapse of a set time, or when the muscle state signal is again continued for a predetermined time above the high reference value, or, One of the times when the muscle state signal is maintained at a value equal to or lower than the low reference value for a predetermined time is selected and used.

According to a fifth aspect of the present invention, according to each of the first and second aspects, the arithmetic processing section inputs / outputs the reaction force detection signal by characteristic conversion based on an exponential function and outputs the converted signal to the output arithmetic section. A characteristic conversion unit is provided.

According to a sixth aspect of the present invention, the opening / closing angle and opening / closing speed of the hand portion are fed back to the sensory organs of the prosthetic wearer as a sensation on the basis of a pulse signal from a pulse generator that detects the amount of movement of the hand portion that is opened and closed. An electric prosthesis having a sensation feedback unit that operates, wherein the sensation feedback unit calculates an opening / closing angle and an opening / closing speed of a hand part based on a pulse signal from the pulse generator; And an arithmetic processing unit that receives an angle signal and a speed signal from the speed calculation unit and outputs a pulsed open / closed state feedback signal, and a pulse of this open / closed state feedback signal is converted into a vibration stimulus to a sensory organ of a prosthetic wearer. And a sensation device for sensation, wherein the arithmetic processing unit has an amplitude that increases in proportion to one of an angle signal and a velocity signal, and an angle signal. Are those set the frequency increases in proportion to the other speed signals, and outputs a closing state feedback signal that is set to the amplitude value and frequency.

[0013]

As described above, according to the electric prosthesis of the present invention, in claim 1, the amplification ratio of the reaction force feedback signal is set to a high value with the increase of the muscle state signal from the state signal calculating section. The sensitivity of the reaction force feedback signal can be increased according to the tension state of the wearer of the prosthetic hand, and sensory feedback according to the wearer's state is possible.

According to a second aspect of the present invention, the muscular state signal is either a composite signal of the myoelectric signals of the flexor and extensor muscles of the wearer of the prosthetic hand, or a higher level of the myoelectric signals of the flexor and extensor muscles. By using such a configuration, the accuracy of the muscle state signal can be improved.

In the third aspect, when the high sensitivity mode signal is output, a predetermined amplification rate higher than the amplification rate in the normal mode signal is set, so that the wearer of the artificial hand performs, for example, fine work and continues the operation. In a tense state, the reaction force of the artificial arm can be continuously sensed with high sensitivity without being affected by the temporary displacement of the muscle.

According to the present invention, the release signal for releasing the high-sensitivity mode signal is output after the set time elapses or by the displacement of the muscle state signal. , Can be easily changed to the normal mode.

According to the present invention, the input / output characteristic conversion section of the arithmetic processing section characteristic-converts the reaction force detection signal from the reaction force detector based on the exponential function and outputs it to the output calculation section. In addition to changing the sensitivity according to the tension state, it is possible to output a reaction force feedback signal according to the characteristics of the human sense organ to the sensible device.

In the sixth aspect, since the open / close state feedback signal is used as a pulse signal and the amplitude value and the frequency thereof are set and output according to the angle signal and the speed signal of the artificial hand, the artificial hand can be used even in darkness. The prosthesis wearer can recognize the opening / closing operation of the.

[0019]

【Example】

Embodiment 1 Hereinafter, an electric prosthetic hand that is Embodiment 1 of the present invention will be described with reference to the drawings. FIG. 1 is a schematic configuration diagram showing a configuration of an electric prosthesis according to the first embodiment, and FIG. 2 is an enlarged view of main parts showing a configuration of the prosthesis with an electric prosthesis according to the first embodiment.

In FIG. 1, reference numeral 1 denotes an electric artificial hand, which is mainly composed of an artificial hand 2 which is opened and closed, a control device 3 which controls the opening and closing operation of the artificial hand 2, and a sensory feedback section 4. There is.

The artificial hand 2 comprises a hand portion 5, a hand body portion 6 and an opening / closing mechanism 7 for opening and closing the hand portion 5. As shown in FIG. 2, the hand portion 5 is composed of a thumb 8, an index finger 9 and a middle finger 10 which are rotatably attached to a hand body 6, and the thumb 9 and the middle finger 10 are linked to each other by a link mechanism 11. In addition to being capable of opening and closing operations such as bending and extension in cooperation with 8, the strain gauges 12 serving as reaction force detectors are provided on the inner and outer portions of the fingers 8 to 10, respectively. Further, as shown in FIG. 2, the opening / closing mechanism 7 is installed inside the hand main body portion 6, and is connected to the DC motor 14 connected to the pulse generator 13 (pulse encoder) and the DC motor 14. A ball screw 16 that is rotatable via a gear mechanism 15, and the moving body 1 of the ball screw 16
The link rod 18 connected to 7 is connected to the link mechanism 11, and the rotational movement of the DC motor 14 is
-Each finger 8 of the hand portion 5 via the link mechanism 11 by expansion and contraction of the link rod 18 which is converted into a linear motion of the moving body 17 via the ball screw 16 and moves following the linear motion of the moving body 17. It is opened and closed by rotating 10 to 10.

The control device 3 is installed in an artificial limb (not shown) which is continuously provided on the artificial hand 2, and the myoelectric signal detecting section 20 is provided.
And a nerve-muscle control system simulation unit 21 and a drive control unit 22. The myoelectric signal detection unit 20 is used by the prosthetic hand wearer 2
5 from the extensor and flexor muscles in the vicinity of the artificial arm wearing part 25
The current value that changes depending on the degree of tension / relaxation of the person is detected and processed to calculate each myoelectric signal (extensor myoelectric signal Ae ″, flexor myoelectric signal Af ″), and the nerve-muscle control system simulator 21
Output to.

The nerve-muscle control system simulating section 21 receives the respective myoelectric signals (extensor myoelectric signal Ae ", flexor myoelectric signal Af") and drives the DC motor 14 based on the following concept. The control signal c for controlling is output to the drive controller 22.

That is, as shown in FIG. 3, a command from the human brain is transmitted to the α motor neuron of the spinal cord and further transmitted to the muscle, causing contraction, but the muscle length and its velocity are detected in the muscle. There is a muscular spindle that does, and its output is fed back to α motor neurons. That is, there is a closed loop (stretch reflex system) composed of muscle spindle-α motor neuron-muscle. It is said that this system plays an important role in position control, and the excellent motor function of the human hand is exerted by the feedback control by this stretch reflex system and the viscoelasticity of the muscle itself. This motor function is regarded as a system of one degree of freedom consisting of a pair of flexor muscles and extensor muscles as shown in FIG. 4, the joint angle is θ, the torques by the flexor muscles and extensor muscles are Af ′ and Ae ′, respectively. When the torque due to the external force applied to P is P, it is expressed by P = Af'-Ae '(1).

Here, in order to facilitate understanding, the torque generated in the muscle is decomposed into each component and expressed. Torque Af 'due to flexor is expressed by the sum of contraction torque Af and torque FAf (θ) due to stretching reflex system / muscle viscoelasticity, and Af' = Af + FAf (θ) ... ... (2). The same applies to the extensor muscle, and Ae ′ = Ae + FAe (θ) (3).

As a result, the finger torque P is calculated by the equations (1) to
From (3), P = Af−Ae + F (θ) (4) where F (θ) = FAf (θ) −FAe (θ) · It can be expressed as (5).

Assuming that the flexor and extensor muscles have the same mechanical characteristics, P (s) = Af (s) −Ae (s) + Gx (s) θ (s) ... (6) Gx (s) = Gm (s) + exp (-Ls) Gn (s) ... (7) Here, Gm (s) is a transfer function representing the viscoelasticity of the flexor muscle and the extensor muscle, and Gn (s) is a transfer function representing the stretch reflex system. Further, L is a dead time that represents the delay of the nervous system. Gx (s) is a complicated transfer function including dead time, but Gx (s) is referred to the tension response when the muscle is stretched.
(S) is approximated by a simple first-order lead / first-order lag system. That is, the transfer function Gx (s) is Gx (s) = K (1 + τ2 · s) / (1 + τ1 · s) (8) where K = K0 + a (Af + Ae) ......... (9) The gain K is not constant, but is proportional to the sum of contraction torques generated by flexor and extensor muscles. Incidentally, K0 is a gain during relaxation, and a is a constant.

When the above equation (6) is solved for θ, θ (s) = [P (s) −Af (s) + Ae (s)] / Gx (s) · (10). This indicates that the joint angle θ of the finger may be controlled so as to have the value on the right side of Expression (10). And
The value on the right side of the equation (10) is calculated from the contraction torques Af and Ae of the flexor muscle and the extensor muscle and the finger torque P. Further, since the contraction torques Af and Ae cannot be directly measured, they are estimated by using the myoelectric signals of the remaining muscles.

That is, full-wave rectification of myoelectric signals of residual muscles,
The estimated values Af ″ and Ae ″ are obtained by smoothing (myoelectric signal detection unit 20 in FIG. 1). Next, the finger torque P of the artificial hand 2
Is calculated, and the value on the right side is calculated from the finger torque P and the estimated values Af ″ and Ae ″ using the equation (10). Let this be θ ′ (the nerve-muscle control system simulating unit 21 in FIG. 1), and this θ ′
Is given as a target value of the drive control unit 22 and a control signal c.
Then, the drive control unit 22 inputs the pulse signal p from the pulse generator (encoder) 13 connected to the DC motor 14, and the opening / closing operation angle θ ″ of each of the fingers 8 to 10 of the artificial hand 2 is θ ″. The drive signal d is sent to the DC motor 4 to drive it so that = θ ', and the opening / closing operation angle of each finger 8 to 10 of the artificial hand 2 is controlled.

The sensory feedback section 4 is provided with the fingers 8-10.
Reaction force detection signal f from the strain gauge 12 for detecting the reaction force of the
It is composed of an arithmetic processing unit 30 that amplifies and outputs a reaction force feedback signal e, and a sensation device 31 that converts the reaction force feedback signal e into a sensory stimulus and causes the sensory organs of the wearer 25 of the prosthetic hand to experience it. . This arithmetic processing unit 30
An output calculation unit 32 that sets an amplification rate of a reaction force detection signal f from the strain gauge 12 that detects a reaction force applied to each of the fingers 8 to 10 when the fingers 8 to 10 grip an object, and a control device 3. Each myoelectric signal of the prosthetic hand wearer 25 (extensor myoelectric signal Ae ″, flexor myoelectric signal A detected by the myoelectric signal detector 20 of FIG.
f ″) is input to perform predetermined arithmetic processing and outputs the result to the output arithmetic unit 32. The state signal arithmetic unit 33 includes the state signal arithmetic unit 33. When the myoelectric signals (extensor muscle signal Ae ″, flexor myoelectric signal Af ″) of the prosthesis wearer 25 detected in step S4 are input, the extensor muscle signal Ae ″ and the flexor myoelectric signal Af ″ are added to combine. A signal is calculated and output as a muscle state signal g
2 is output. In addition, the higher level signal of the extensor muscle signal Ae ″ and the flexor myoelectric signal Af ″ is the muscle state signal g.
May be output. The output calculation unit 32 includes a reaction force detection signal f from the strain gauge 12 and a state signal calculation unit 33.
When the state signal g of the muscle from is input, the reaction force detection signal f
The amplification rate is set to a high value as the muscle state signal g increases, and the amplification rate is output to the sensible device 31 as a reaction force feedback signal e.

As a result, when the muscle state signal g output from the myoelectric signal detecting section 33 and corresponding to the degree of tension or the degree of relaxation of the prosthetic hand wearer 25 becomes large, the amplification ratio set in the output computing section 32. Is also set to a large value, and the sensitivity of the reaction force feedback signal e output from the arithmetic processing unit 30 to the sensation device 31 is increased. On the other hand, when the wearer 25 of the artificial hand is in a relaxed state and the muscle state signal g calculated by the state signal calculation unit 33 becomes small, the amplification ratio set by the output calculation unit 32 is set to a small value. The sensitivity of the reaction force feedback signal g output from the arithmetic processing unit 30 to the sensation device 31 is reduced.

The sensation device 31 is, for example, a prosthetic hand wearer 25.
The reaction force feedback signal g output from the arithmetic processing unit 30, which is attached to the skin surface of the arm or the like serving as a sensory organ of
Based on the above, the pressing force for pressing the skin is output, and the pressing surface presses the skin surface so that the prosthetic wearer 25 can feel it.

As described above, according to the electric artificial hand 1 of the first embodiment, the opening / closing mechanism of the artificial hand 2 is operated (the DC motor 14 is driven) to close the fingers 8 to 10 of the hand portion 5. Even if the reaction force detection signal f, which is the reaction force from the object detected by the strain gauge 12 when the object is gripped, has a predetermined value, the output calculation unit 32 outputs the signal from the state signal calculation unit 33. A reaction force feedback signal e with an increase in the muscle state signal g
Since the amplification ratio is set to a high value, the sensitivity of the anti-feedback signal e can be changed according to the tension state or the relaxation state of the prosthetic hand wearer 25, and the tension state of the prosthetic hand wearer 25 can be changed to the prosthetic hand wearer 25 via the sensation device 31. Alternatively, it becomes possible to experience the bodily stimulus (compression) according to the relaxed state.

The state signal g of the muscle to be calculated and compared by the state signal calculating unit 33 is a combined signal of the myoelectric signals Ae "and Af" of the flexor and extensor, or each of the flexor and extensor. Since one of the higher-order myoelectric signals of the myoelectric signals Ae ″ and Af ″ is used, the accuracy of the muscle state signal g can be increased, and the prosthetic wearer 25 can be placed in the tensioned state or the relaxed state. It is possible to accurately experience the corresponding bodily stimulus (compression).

Next, a modification of the electric prosthesis 1 according to the first embodiment will be described with reference to FIGS. In FIG. 5, as a first modified example of the electric prosthetic hand 1 of the first embodiment, the arithmetic processing unit 30 is provided with a mode selection unit 40. The mode selection unit 40 includes an output calculation unit 32 and a state signal calculation unit 3
3 and the output signal calculation unit 32 and the status signal calculation unit 33 are connected to each other. In addition, the mode selection unit 4
0 is the normal mode I when the muscle state signal g output from the state signal calculation unit 33 is lower than a predetermined high reference value H.
Output the normal mode signal i of
The high-sensitivity mode signal k of the high-sensitivity mode K is output to the output calculation unit 32 on condition that the muscle state signal g is equal to or higher than the high reference value H and the release signal j output after the elapse of the predetermined time T is not input. It is a thing. This high reference value H is set to a value when the prosthetic hand wearer 25 is in a tense state, that is, when the prosthetic hand wearer 25 is in a tense state when gripping the object with the prosthetic hand 2.

Then, regarding the operation of the first modification,
Describing based on the flowchart of FIG. 6, similarly to the above description, when the fingers 8 to 10 of the hand portion 5 hold the object, the reaction force detection signal f detected by the strain gauge 12 is detected by the sensory feedback unit 4. The signal is output to the arithmetic processing unit 30 and also myoelectric signals (extensor muscle signal Ae ″, flexor muscle signal A
The muscle state signal g calculated and compared by the state signal calculation unit 33 based on f ″) is output to the mode selection unit 40, and the muscle state signal g is read (step # 1).

The mode selecting section 40, which has read the muscle state signal g, processes it as follows and outputs the normal mode signal i or the high sensitivity mode signal k to the output calculating section 32.

(A) The muscle state signal g output from the state signal calculator 33 is compared with the high reference value H (step #
2) When the muscle state signal g is equal to or less than the high reference value H, the normal mode I is set, and the muscle state signal g output from the state signal calculation unit 33 is output as the normal mode signal i. 32 (step # 3), and when the muscle state signal g is higher than the high reference value H, the high sensitivity mode K
Then, a predetermined high sensitivity signal k equal to or higher than the high reference value H is output to the output calculation unit 32 (step # 4). Then, the mode selection unit 40 inputs the muscle state signals g sequentially output from the state signal calculation unit 33, repeats steps # 1 to # 4, and outputs the normal mode signal to the output calculation unit 32. i or the high sensitivity mode signal k is output.

(B) At this time, when the mode selection unit 40 sets the high sensitivity mode K, the mode selection unit 40 switches to the high sensitivity mode K regardless of the muscle state signal g output from the state signal calculation unit 32 thereafter. Maintain and maintain a high predetermined amplification rate, but for a predetermined time T after changing to high sensitivity mode K
(Eg, 30 minutes, 1 hour, etc.) elapses, or the muscle state signal g output from the state signal calculator 32 is maintained at a value equal to or higher than the high reference value H for a predetermined time S (eg, 2 seconds). Or the muscle state signal g is low reference value R (prosthetic hand wearer 25
It shows the value when in a relaxed state. ) Depending on which of the following values has been continued for a predetermined time S,
When the release signal j is input, the high sensitivity mode K is released by the input of the release signal j, and the normal mode I is set (step # 5). The condition for outputting the release signal j may be only one of the above conditions, or may be a condition that any one of the above conditions is satisfied.

Then, the arithmetic processing unit 30 sets the amplification ratio of the reaction force detection signal f based on the reaction force detection signal f and the normal mode signal i or the high sensitivity mode signal k of the mode selection unit 40. The signal amplified by this amplification ratio is output to the sensible device 31 as a reaction force feedback signal e (step # 6).

Then, the sensible device 31 which receives the reaction force feedback signal e presses the skin surface, which is the sensory organ of the artificial hand wearer 25, with the pressing force corresponding to the reaction force feedback signal e, and wears the artificial hand wearer. Experience 25.

As described above, according to the first modification of the electric prosthesis of the first embodiment, the same effect as that of the first embodiment can be obtained, and the mode selecting section 40 outputs the high sensitivity mode signal k. When outputting to the output calculation unit 32, the output calculation unit 32 sets a predetermined amplification ratio higher than the amplification ratio when the normal mode signal i is output.
However, for example, when performing a fine work or the like, and when the tension state continues, the reaction force of the artificial hand 2 is continuously received with high sensitivity without being affected by the temporary displacement of the muscle.
It becomes possible to experience the number five.

According to the first modification, the release signal j for releasing the high-sensitivity mode signal k in the high-sensitivity mode K is output after the elapse of the set time T or by the displacement of the muscle state signal g. With this configuration, the prosthetic hand wearer 25 can easily change to the normal mode I without being particularly conscious of it.

Further, in FIG. 7, as a second modification of the electric prosthetic hand 1 of the first embodiment, the input / output characteristic conversion unit 50 is provided in the arithmetic processing unit 30. The input / output characteristic conversion unit 50 is connected to the strain gauge 12 and the output calculation unit 32, respectively. When the reaction force detection signal f from the strain gauge 12 is input, the reaction force detection signal f is based on an exponential function. Output conversion section 32 of calculation processing section 30
Is output to In addition, this exponential function is determined by the characteristics that human sensory organs are less likely to capture the variation as the reaction force increases, and that the sensation becomes almost constant when the reaction force exceeds a certain level. Is. Then, the output calculation unit 31 of the calculation processing unit 30 detects the reaction force whose characteristic is converted by the characteristic-converted reaction force detection signal f and the muscle state signal g which is calculated and compared by the state signal calculation unit 33. Signal f
Is calculated, and the reaction force feedback signal e calculated by this amplification ratio is output to the sensible device 31.

As described above, according to the second modification of the electric prosthesis of the first embodiment, the input / output characteristic conversion unit 50 of the arithmetic processing unit 30 uses the reaction force detection signal f from the strain gauge 12 based on the exponential function. Since the characteristics are converted and output to the output calculation unit 32, in addition to the conversion of the sensitivity according to the tension state of the prosthetic hand wearer 25, the reaction force feedback signal e according to the characteristics of the human sense organ is sent to the sensation device 31. Can and experience device 3
1 changes the pressing force for pressing the skin on the basis of the reaction force feedback signal e output from the arithmetic processing unit 30 so that the prosthetic wearer 25 is in the tension / relaxed state and the characteristics of the human sense organ. It is possible to experience the bodily stimulus (compression) according to the.

In the electric prosthesis 1 of the first embodiment,
As shown in FIG. 8, the third modification may have the first modification and the second modification shown in FIGS. 5 and 7, respectively.

Embodiment 2 An electric prosthetic hand which is Embodiment 2 of the present invention will be described below with reference to the drawings. FIG. 9 is a schematic configuration diagram showing the configuration of the electric prosthesis according to the second embodiment. In FIG. 9 of the second embodiment, the same reference numerals as those in FIGS. 1 and 2 of the first embodiment indicate the same components (members), and thus the description thereof will be omitted.

The electric prosthesis 100 of the second embodiment is based on the pulse signal p from the pulse generator 13 and is used by the prosthetic wearer 2
5 is made to experience a sensational stimulus, and the hand portion 5
It is intended to recognize the opening / closing operation of.

In FIG. 9, 101 is a sensation feedback unit, which is an angle and speed calculation unit 102 for calculating the opening / closing angle θ ₀ and the opening / closing speed V of the hand portion 5 based on the pulse signal p from the pulse generator 13. An arithmetic processing unit 103 that inputs the angle signal m and the speed signal n from the angle and speed calculation unit 102 and outputs a pulsed open / closed state feedback signal q, and the open / closed state feedback signal q.
It is configured by a sensation device 104 that converts the sensation into a sensation stimulus and causes the sensory organs of the prosthetic hand wearer 25 to experience the sensation. When the pulse signal p from the pulse generator 13 is input, the angle / velocity calculation unit 102 calculates an opening / closing angle θ ₀ of the hand portion 5 and outputs the angle signal m to the calculation processing unit 103 as an opening / closing angle calculation unit 105. When the pulse signal p from the pulse generator 13 is input, the opening / closing speed calculation unit 10 that calculates the opening / closing speed V of the hand portion 5 and outputs it as the speed signal n to the calculation processing unit 103.
It consists of 6. Further, the arithmetic processing unit 103 receives an angle signal m and a velocity signal n output from the angle and velocity arithmetic unit 102, and performs an input / output characteristic conversion unit 107 that performs characteristic conversion of each of the signals m and n based on a proportional function. , The angle signal m whose characteristics are respectively converted by the input / output characteristic conversion unit 107.
Amplitude value calculation unit 108 that sets the amplitude value based on the above, and frequency calculation unit 10 that sets the frequency based on the speed signal n.
9 and an output calculation unit 110 that synthesizes the amplitude value and the frequency and outputs a pulsed open / closed state feedback signal q to the sensation device 104. The frequency may be set by the angle signal m, and the amplitude value may be set by the speed signal n.

The sensation device 104 is, for example, a prosthetic hand wearer 2
It is attached to the skin surface of the arm etc.
Based on the open / closed state feedback signal q output from the arithmetic processing unit 103, a vibration stimulus that vibrates the skin is output, and the vibration stimulus presses the skin surface so that the prosthetic wearer 25 can experience it.

Next, the operation of the electric prosthesis 100 will be described.

First, when the fingers 8 to 10 of the artificial hand 2 are opened and closed, the pulse generator 13 to which the DC motor 14 is connected.
The pulse signal p from is transmitted to the angle and speed calculation unit 102. Then, in the angle and speed calculation unit 102, the opening / closing angle calculation unit 105 and the opening / closing speed calculation unit 106 calculate the rotation angle and rotation speed of the DC motor 14, that is, the opening / closing angle θ ₀ of the hand portion 5 and the opening / closing speed V. , And outputs to the arithmetic processing unit 103 as an angle signal m and a speed signal n.

Then, the arithmetic processing unit 103, to which the angle signal m and the velocity signal n are input, receives the input / output characteristic conversion unit 10.
7. The amplitude value calculation unit 108 and the frequency calculation unit 109 set the amplitude value and the frequency that increase in proportion to the angle signal m and the speed signal n, and the output calculation unit 110.
Then, the amplitude value and the frequency are combined and an open / close state feedback signal q is sent to the sensible device 104.

Then, the sensible device 104, to which the open / closed state feedback signal q is input, vibrates and stimulates the skin surface, which is a sensory organ of the prosthetic hand wearer 25, at the frequency corresponding to the open / closed state feedback signal q. Make person 25 experience.

As described above, according to the electric artificial hand 1 of the second embodiment, when the opening / closing mechanism of the artificial hand 2 is operated (DC motor is driven), the fingers 8 to 10 of the hand portion 5 are opened / closed. Based on the pulse signal p from the pulse generator 13, the angle / speed calculator 102 calculates the opening / closing angle θ ₀ and the opening / closing speed V of the hand portion 5 into an angle signal m and a speed signal n. Then, based on each angle signal m and velocity signal n, an amplitude value and a frequency that increase in proportion to each signal are set, and at the same time, artificial sensation (vibration) is experienced by the prosthetic hand wearer 25 according to the amplitude and frequency. Since it is configured to be performed, the prosthetic hand wearer 25 can recognize the opening / closing operation of the prosthetic hand 2 even in darkness, and the operability of the prosthetic hand wearer 25 can be improved.

In the first and second embodiments, the arithmetic processing units 30 and 103 are individually provided, but the present invention is not limited to this, and each arithmetic processing unit 3 is not limited to this.
By providing 0 and 103 at the same time, the artificial hand wearer 25
It is possible to experience a tactile stimulus (compression) according to the tension state or a relaxed state, and recognize the opening / closing operation of the artificial hand 2 by the tactile stimulus (vibration) even in the dark or the like. Therefore, the operability of the wearer 25 of the prosthetic hand can be improved.

[0057]

As described above, according to the electric prosthesis of the present invention,
Even if the reaction force detection signal detected by the reaction force detector when the hand is opened and closed is the same regardless of the tension state or the relaxed state of the wearer of the artificial hand, this reaction force detection signal is Since the output calculation unit of the input calculation processing unit sets the amplification rate of the reaction force feedback signal to a high value as the muscle state signal from the state signal calculation unit increases, the sensitivity of the reaction force feedback signal is changed. It is possible for the wearer of the artificial hand to experience the sensation stimulus according to the tension state or the relaxed state.

As the muscle state signal, either the composite signal of the myoelectric signals of the flexor and extensor or the higher myoelectric signal of the myoelectric signals of the flexor and extensor is used.
The accuracy of the muscle state signal can be increased, and the prosthetic wearer can accurately experience the sensory stimulus according to the tension state or the relaxed state.

Further, when the mode selection unit outputs the high sensitivity mode signal to the output calculation unit, the output calculation unit sets a predetermined amplification ratio higher than that at the time of outputting the normal mode signal. When performing work, etc., if you continue to be in a tense state, you can continue to experience the reaction force of the hand part with high sensitivity without being affected by the temporary displacement of the muscles and make the wearer experience it. It will be possible.

Further, since the release signal for releasing the high sensitivity mode signal of the high sensitivity mode is output after the elapse of the set time or by the displacement of the muscle state signal, the artificial arm wearer is particularly conscious of it. Even without it, it is possible to easily change to the normal mode.

Further, the input / output characteristic conversion unit of the arithmetic processing unit is
The reaction force detection signal from the reaction force detector is converted to characteristics based on the exponential function and output to the output calculation unit, so in addition to changing the sensitivity according to the tension state of the artificial hand wearer, the characteristics of human sensory organs can be changed. A corresponding reaction force feedback signal can be sent to the sensory device.

Further, when the hand portion is opened / closed, the angle / speed calculator calculates the opening / closing angle and the opening / closing speed of the hand portion based on the pulse signal from the pulse generator to obtain an angle signal and a speed signal. A configuration in which an arithmetic processing unit sets an amplitude value that increases in proportion to each signal based on each angle signal and a velocity signal and a frequency, and causes a prosthetic wearer to experience a tactile sensation according to the amplitude and frequency. Therefore, the opening / closing operation of the hand portion can be recognized by the wearer of the artificial hand even in the dark, and the operability of the wearer of the artificial hand can be improved.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing a configuration of an electric prosthesis according to a first embodiment of the present invention.

FIG. 2 is an enlarged view of a main part showing the configuration of the prosthetic hand of the electric prosthetic hand according to the first embodiment of the present invention.

FIG. 3 is a schematic diagram for explaining control of the control device for the electric prosthesis according to the first embodiment of the present invention.

FIG. 4 is a schematic diagram for explaining control of the control device for the electric prosthesis according to the first embodiment of the present invention.

FIG. 5 is a schematic configuration diagram showing a configuration of a first modified example of the electric prosthesis according to the first embodiment of the present invention.

FIG. 6 is a flowchart for explaining the operation of the first modified example of the electric prosthesis according to the first embodiment of the present invention.

FIG. 7 is a schematic configuration diagram showing a configuration of a second modified example of the electric prosthesis according to the first embodiment of the present invention.

FIG. 8 is a schematic configuration diagram showing a configuration of a third modified example of the electric prosthesis according to the first embodiment of the present invention.

FIG. 9 is a schematic configuration diagram showing a configuration of an electric prosthesis according to a second embodiment of the present invention.

[Explanation of symbols]

 1, 100 Electric prosthetic hand 4, 101 Sensory feedback unit 5 Hand part 12 Strain gauge 13 Pulse generator (encoder) 25 Prosthetic hand wearer 30, 103 Arithmetic processing unit 31, 104 Sensation device 32, 110 Output computing unit 33 State signal computing unit 40 mode selection unit 50, 107 input / output characteristic conversion unit Ae ″ extensor myoelectric signal Af ″ flexor myoelectric signal

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Isao Kishimoto 60, 646 Ishimori, Jinno-cho, Kakogawa-shi, Hyogo (72) Inventor Taka Takashi Kobayashi 5-2 C-1404 Kashinodai, Nishi-ku, Kobe-shi, Hyogo

Claims (6)

[Claims] 1. A sensory hood back section that feeds back the reaction force as a sensation to the sensory organs of a wearer of a prosthetic hand based on a reaction force detection signal from a reaction force detector that detects the reaction force of the hand portion that is opened and closed. An electric prosthesis equipped with the sensory feedback unit, wherein the sensation feedback unit arithmetically amplifies the reaction force detection signal from the reaction force detector and outputs a reaction force feedback signal; It has a sensation device for converting into a sensory sensation of a prosthetic wearer, and the arithmetic processing unit outputs an output arithmetic unit that sets the amplification ratio of the reaction force detection signal, and a state signal of the muscle of the prosthetic wearer. A state signal calculation unit for outputting, and the output calculation unit sets the amplification ratio to a high value as the state signal increases, and outputs a reaction force feedback signal amplified at this amplification ratio. Electric Dynamic prosthetic hand. 2. The muscle state signal is either a composite signal of the respective myoelectric signals of the flexor and extensor muscles of the prosthetic wearer, or a higher myoelectric signal of the myoelectric signals of the flexor muscles and extensor muscles. The electric prosthesis according to claim 1, which is used. 3. The arithmetic processing unit outputs a normal mode signal when the muscle state signal is lower than a predetermined high reference value, and has high sensitivity when the muscle state signal is equal to or higher than the high reference value. A mode selection unit that outputs a mode signal is provided, and when the high-sensitivity mode signal is output from the mode selection unit, the output calculation unit has a predetermined amplification ratio that is higher than the amplification ratio in the normal mode signal. Is set, and the reaction force feedback signal amplified at this amplification ratio is output, and the electric prosthetic hand according to claim 1 or 2, respectively. 4. The high-sensitivity mode signal is released by a release signal, and the release signal is maintained after a set time has passed or when the muscle state signal is again maintained at a high reference value or higher for a predetermined time. 4. The electric prosthesis according to claim 3, which is selected and used when the muscle condition signal is maintained at a value equal to or lower than the low reference value for a predetermined time. 5. The input / output characteristic conversion unit for converting the characteristic of the reaction force detection signal based on an exponential function and outputting it to the output calculation unit is provided in the arithmetic processing unit. Alternatively, the electric prosthesis according to claim 2. 6. A sensory feedback unit that feeds back the opening / closing angle and opening / closing speed of the hand portion as a sensation to the sensory organs of a prosthetic wearer based on a pulse signal from a pulse generator that detects the amount of movement of the hand portion that is opened and closed. An electric prosthesis provided with, wherein the sensory feedback unit calculates an opening / closing angle and an opening / closing speed of a hand part based on a pulse signal from the pulse generator, and an angle and speed calculating unit, and the angle and speed calculating unit. Processing unit that outputs a pulsed open / closed state feedback signal in response to an angle signal and a velocity signal from the body, and a sensation device that converts the pulse of the open / closed state feedback signal into a vibration stimulus to allow the sensory organs of a prosthetic wearer to experience it. And the arithmetic processing unit has an amplitude that increases in proportion to one of the angle signal and the velocity signal, and the other of the angle signal and the velocity signal. Set the frequency increases proportionally, and outputs the amplitude value and the on-off state feedback signal set to a frequency electric prosthetic hand.