CN111991693B

CN111991693B - Limb rehabilitation robot

Info

Publication number: CN111991693B
Application number: CN202010686636.1A
Authority: CN
Inventors: 刘艳红; 秦云辉; 霍本岩; 杨磊; 关元
Original assignee: Zhengzhou University
Current assignee: Zhengzhou University
Priority date: 2020-07-16
Filing date: 2020-07-16
Publication date: 2023-03-14
Anticipated expiration: 2040-07-16
Also published as: CN111991693A

Abstract

The invention relates to a limb rehabilitation robot, which comprises a functional electrical stimulation device and a robot body; the functional electrical stimulation device is used for generating electrical stimulation signals; the robot body comprises a mechanical arm for supporting the whole limb, and the mechanical arm comprises a front end arm and a rear end arm; the front end arm and the rear end arm are respectively used for fixing corresponding parts of limbs; the extension directions of the front end arm and the rear end arm are consistent, three-dimensional force sensors are arranged at the opposite positions of the two arms, and the two arms are connected through the three-dimensional force sensors. The invention utilizes the three-dimensional force sensor to collect the feedback of the muscle after receiving the electric stimulation, greatly reduces the difficulty of signal processing, reduces the complexity of operation and improves the efficiency compared with the collection of the electromyographic signals.

Description

Limb rehabilitation robot

Technical Field

The invention belongs to the field of instruments for passive exercise, and particularly relates to a limb rehabilitation robot for rehabilitation training by using electric stimulation.

Background

Cerebral apoplexy is a common cerebrovascular disease in the middle-aged and the elderly, has the characteristics of high morbidity, high disability rate and high mortality, is a main reason for long-term paralysis and different degrees of movement dysfunction, and poses a great threat to human health.

Stroke is also a common disease, for stroke patients, motor nerve signal interruption or nerve modulation is caused by central nerve injury, and limb muscles receive abnormal nerve signals or do not receive motor signals, so that the function of activated contraction is lost, and the limb cannot be controlled by the brain to realize autonomous movement.

The functional electrical stimulation is used as a neuromuscular stimulation treatment method, can activate nerves and muscles, is used for treating patients with cerebral apoplexy and apoplexy, and can effectively realize the rehabilitation of muscle strength and motor function of the patients. For example, the functional electrical stimulation method includes applying an electrode pad to the skin, and controlling the generation of an electrical signal of a certain intensity to stimulate the skin.

For closed loop control, it is necessary to detect the response of the limb to the electrical stimulation. In the prior art, the response of the limb to the electrical stimulation is mainly obtained in two ways, for example, chinese patent document CN105031812, "a functional electrical stimulation closed-loop control system for myoelectric signal feedback", where the myoelectric signal is collected by a myoelectric signal collector (surface electrode) to detect the response of the limb to the electrical stimulation.

However, the electromyographic signals are complex and contain a large amount of bioelectrical information of the human body, and the difficulty in extracting effective signals is high; and a large number of surface electrodes need to be pasted on the skin when the electromyographic signals are collected, so that the operation is complicated and the efficiency is low.

Disclosure of Invention

The invention aims to provide a limb rehabilitation robot, which aims to solve the problem that the difficulty in extracting effective signals is high in the existing method.

Based on the above purpose, a limb rehabilitation robot comprises a functional electrical stimulation device and a robot body;

the functional electrical stimulation device is used for generating electrical stimulation signals;

the robot body comprises a mechanical arm for supporting the whole limb, and the mechanical arm comprises a front end arm (10) and a rear end arm (6); the front end arm (10) and the rear end arm (6) are respectively used for fixing corresponding parts of limbs; the extending directions of the front end arm (10) and the rear end arm (6) are consistent, a three-dimensional force sensor (9) is arranged at the opposite position of the two arms, and the two arms are connected through the three-dimensional force sensor (9).

Furthermore, the front end arm (10) and the rear end arm (6) are strip-shaped, and brackets are respectively arranged on the outer sides of the front end arm and the rear end arm.

Furthermore, the three-dimensional force sensor (9) is respectively connected with the front end arm (10) and the rear end arm (6) through two connecting pieces (8).

Furthermore, the length directions of the two connecting pieces (8) are perpendicular to the extending direction of the two arms, and the installation position of the three-dimensional force sensor (9) is staggered with the positions of the two arms.

Furthermore, a rotating shaft (5) is installed at the rear end of the rear end arm (6), and two ends of the rotating shaft (5) are respectively rotatably assembled on the two mounting plates (4 and 7), so that the mechanical arm can rotate around the axis of the rotating shaft (5) to adjust the angle of the mechanical arm.

Furthermore, the device also comprises a motor which is in transmission connection with the rotating shaft (5).

Furthermore, the functional electrical stimulation control device comprises an upper computer (16), a controller (13) and a motor sheet (15).

The invention is mainly characterized in that the mechanical arm is divided into two parts, namely a front end arm and a rear end arm, a three-dimensional force sensor is arranged between the front end arm and the rear end arm, and the feedback of the muscle after receiving electric stimulation is collected by the three-dimensional force sensor.

Drawings

Fig. 1 is an overall structure diagram of an upper limb rehabilitation robot;

1 is L type cantilever, 2 is the fixing base, 3 is the connecting seat, 4, 7 are the mounting panel, 5 are the pivot, 6 are the rear end arm, 8 are first, the second connecting piece, 9 are three-dimensional force sensor, 10 are the front end arm, 11, 12 are the bracket, 13 are the controller, 14 are the electro stimulator, 15 are the electrode slice, 16 are the host computer.

Detailed Description

The following provides a robot for upper limb rehabilitation training. It will be appreciated by those skilled in the art that it may also be applied to lower limb rehabilitation training, with appropriate adaptation.

As shown in fig. 1, an upper limb rehabilitation robot includes a functional electrical stimulation control device and a robot body:

the functional electrical stimulation control device includes: an upper computer 16, which is used for operating and observing relevant feedback by an operator, a controller 13 (adopting an NI myRIO controller and a LabVIEW platform) generates a PWM signal and inputs the PWM signal into a multi-channel electric stimulator 14, the electric stimulator 14 amplifies the PWM signal to a voltage range of 90V-120V to form voltage pulse, and the voltage pulse electrically stimulates muscle fixing positions through an electrode plate 15 stuck on the surface of the muscle of a human body. Generally, a plurality of electrode pads 15 are required to be arranged to form an electrical stimulation array. The controller 13 is also used for receiving signals collected by the three-dimensional force sensor 9 and regulating the output of the PWM signals to the electrical stimulator 14 by combining with a control program.

The robot body mainly includes: the mechanical arm is used for supporting the whole upper limb and comprises a front end arm 10 and a rear end arm 6, wherein a bracket 12 for fixing a wrist is arranged on the front end arm 10; a bracket 11 for fixing the biceps brachii is mounted on the rear end arm 6. The extension directions of the front end arm 10 and the rear end arm 6 are consistent, and a first connecting piece 8 and a second connecting piece 8 are respectively arranged and fixed at the opposite positions of the two arms; the length directions of the first connecting piece 8 and the second connecting piece 8 are vertical to the extending directions of the two arms, and a three-dimensional force sensor 9 is arranged between the first connecting piece 8 and the second connecting piece 8; the three-dimensional force sensor 9 is installed at a position staggered with the two arms so as to be convenient to install. Considering that the sum of the mass of the mechanical arm and the upper limb of the human body is about 5kg, the stress value of the pressure sensor is 50N under the condition of no electric stimulation, and the electric stimulation output value of most people is found to be within 30N through statistics, so that the range of the sensor selected here is 100N, and meanwhile, the requirement of converting the force signal into a voltage signal is considered to be identified by an analog input (ADC) of the controller. Considering that the resolution of the controller (13) ADC is 12 bits, the maximum input voltage is 5V. From this, the minimum resolution voltage of the ADC is

v is the minimum resolvable voltage of the ADC. The sensitivity of the pressure sensor is therefore chosen to be 1mV. The three-dimensional force sensor converts pressure or tension signals into electric signals, the electric signals are expanded to a range of 0V-2.5V-5V through the sensor transmitter, and when the sensor is not stressed, voltage output values of the three-dimensional force sensor in three directions are all 2.5V. When the sensor is stressed, the voltage value in the stress direction changes. The parameters of the finally selected three-dimensional pressure sensor are as follows:

TABLE 1.1 three-dimensional force sensor parameter Table

The robot body still includes: one end of the L-shaped cantilever 1 and one end of the L-shaped cantilever 1 are fixed on a support frame (not shown) of the equipment through a fixing seat 2 and are used for supporting the whole mechanical arm. The other end of the L-shaped cantilever 1 is fixedly provided with a connecting seat 3, and two mounting plates 4 and 7 are fixed on the connecting seat 3; the rear end of the rear end arm 6 is provided with a rotating shaft 5, and the two ends of the rotating shaft 5 are respectively assembled on the two mounting plates 4 and 7 in a rotating manner, so that the mechanical arm can rotate around the axis of the rotating shaft 5 to adjust the angle of the mechanical arm, and a patient is in a relatively comfortable state. A motor is arranged on the mounting plate 4 or 7 (the motor is arranged between the mounting plates 4 and 7), and the motor is connected with the rotating shaft 5 through belt transmission to provide power for the rotation of the mechanical arm.

As another embodiment, the motor may be connected to the rotating shaft 5 through a gear transmission. In addition, the motor may be disposed not only between the mounting plates 4, 7 but also outside the mounting plate 4 or the mounting plate 7 (in this case, the motor may directly drive the rotating shaft 5).

When the system is used, the weight of the arm of a user is measured, the output value of the three-dimensional force sensor is initialized to zero according to the weight, the pasting position (generally, the biceps brachii muscle position) of the electrode slice of a patient is wiped with alcohol, the skin resistance is reduced, and the electrode slice is pasted to the proper position of the muscle; rehabilitation training is then started. Relevant software program parts of the robot are compiled on LabVIEW and deployed in the controller 13, and the intensity of the electric stimulation signal is controlled by the duty ratio of the PWM wave, so that safe electric stimulation on the human body is realized. The electrical stimulation acts on an upper limb system of a human body, the magnitude of the generated force is collected by the three-dimensional force sensor 9 and fed back to the controller 13, and the controller 13 makes strategy adjustment so as to achieve high-precision output force control. The controller 13 is in communication connection with the upper computer 16, and final data are displayed on an upper computer interface.

In the above embodiment, the front and rear arms are bar-shaped, and the wrist and biceps brachii muscle of the upper limb are fixed by fixing the bracket thereto. As another embodiment, the front and rear arms may be configured to be cylindrical to accommodate the arms of the patient.

Claims

1. A limb rehabilitation robot comprises a functional electrical stimulation device and a robot body;

the functional electrical stimulation device is used for generating electrical stimulation signals; it is characterized in that the preparation method is characterized in that,

the robot body comprises a mechanical arm for supporting the whole limb, and the mechanical arm comprises a front end arm (10) and a rear end arm (6); the front end arm (10) and the rear end arm (6) are respectively used for fixing corresponding parts of limbs; the extension directions of the front end arm (10) and the rear end arm (6) are consistent, three-dimensional force sensors (9) are arranged at the opposite positions of the two arms, and the two arms are connected through the three-dimensional force sensors (9); the three-dimensional sensor is used for collecting the force generated by the electric stimulation signal acting on the upper limb system of the human body and feeding the collected force back to the controller of the functional electric stimulation device, and the controller adjusts the strength of the generated electric stimulation signal according to the fed-back force.

2. The limb rehabilitation robot according to claim 1, wherein the front arm (10) and the rear arm (6) are bar-shaped and have brackets provided on their outer sides, respectively.

3. The limb rehabilitation robot according to claim 1, characterized in that the three-dimensional force sensor (9) is connected to the front arm (10) and the rear arm (6) by two connectors (8).

4. The limb rehabilitation robot according to claim 3, wherein the length direction of the two connecting pieces (8) is perpendicular to the extending direction of the two arms, and the installation position of the three-dimensional force sensor (9) is staggered with the positions of the two arms.

5. The limb rehabilitation robot according to claim 1, wherein a rotating shaft (5) is mounted at the rear end of the rear arm (6), and two ends of the rotating shaft (5) are respectively and rotatably mounted on the two mounting plates (4, 7), so that the mechanical arm can rotate around the axis of the rotating shaft (5) to adjust the angle of the mechanical arm.

6. A limb rehabilitation robot according to claim 5, characterized by further comprising a motor in transmission connection with the rotating shaft (5).

7. The limb rehabilitation robot of claim 1, wherein the FES control device comprises an upper computer (16), a controller (13) and a motor sheet (15).