TW201808378A - Gait-adaptive control system and method for wearable drop foot electrical stimulator - Google Patents

Abstract

The invention presents a gait-adaptive automated control system and method for a wearable electrical stimulator as a gait-corrective device for drop-foot patients. The wearable electrical stimulation control system includes a first inertial sensor, a second inertial sensor, a microcontroller and an electrical stimulator. The first inertial sensor is mounted on a leg and senses a first locomotion data of the leg. The second inertial sensor is mounted on a foot and senses a second locomotion data of the foot. The microcontroller receives the first locomotion data and the second locomotion data, and outputs a command with stimulation parameters modulated by real-time changes in gait phases, calculated using the first locomotion data and the second locomotion data. The electrical stimulator corrects drop foot by generating electrical pulses with stimulation parameters given in the command in order to stimulate the calf.

Description

Wearable foot-foot electric stimulation control system and method adaptive to instant gait

The invention relates to a wearable foot electric stimulation control system and a wearable foot electric stimulation control method which are adaptive to an instant gait, and particularly relates to a method for assisting a foot-hanging patient to generate an electric stimulation parameter by adjusting an electric stimulation parameter in real time. A smooth, stable gait wearable foot electric stimulation control system and a wearable foot electric stimulation control method.

Drop foot is a common clinical phenomenon in medicine, and its official name is the equinus foot. The normal ankle joint can perform dorsiflexion, plantar flexion, inversion, eversion, and the like. When the dorsiflexion is worse, there will be a foot-hanging phenomenon. Normal gait requires a good ankle function, and once a foot-hanging phenomenon occurs, there will be various compensatory gait. For example, hip-hiking is to improve the pelvis to avoid foot mopping; steppage gait is to use more hip flexion and knee flexion to extend the foot off time; The foot may have a vaulting to help the foot off the ground. In patients with mild symptoms, there may be situations where the forefoot hits the ground or the foot slaps. Some patients do not consciously stumble over the above situations. Therefore, walking is not only energy-intensive but also dangerous for patients with foot-hanging feet. This is a problem that must be addressed.

When the patient's ankle dorsiflexion is completely lost, the patient is usually advised clinically to consider an ankle aid or a functional electrical stimulator. Functional electrical stimulation can stimulate the contraction of the tibialis anterior muscle through functional current, and induce the foot to actively make a hooking action, which can improve the gait of stroke patients. Clinically, in order to assist patients with foot-hanging to improve the drop foot phenomenon during locomotion and to assist in gait adjustment during walking, it is one of the common methods to use functional skin electrical stimulation to stimulate contraction of the tibialis anterior muscle. . Transcutaneous surface functional electrical stimulation (sFES) is a method for clinically utilizing surface electrical stimulation of a motor nerve that is not controlled by the brain to induce contractile response of muscles innervated by motor nerves. This method can help patients who cannot control their muscles due to external injury to restore their body functions in order to improve their daily activities. At present, the existing foot electric stimulator mostly uses a foot switch or an inertial sensing unit (IMU) including a gyroscope as a basis for judging the timing of starting and closing the electrical stimulation. However, existing products lack a control method for automatically adjusting electrical stimulation parameters according to actual gait changes, and it is often difficult to assist a patient to produce a steady gait that is close to normal walking.

The invention provides a wearable foot-foot electric stimulation control system and a wearable foot-foot electric stimulation control method which are adaptive to the instant gait, so that the foot-footed patient can produce a smoother and smoother gait.

The invention provides a wearable foot-foot electric stimulation control system adaptive to an instant gait, which is suitable for a foot-hanging patient, including a first inertial sensor, a second inertial sensor, a microcontroller and an electrical stimulator. The first inertial sensor is disposed on the lower leg and senses first locomotion data of the lower leg. A second inertial sensor is disposed on the foot and senses second motion pose data of the foot. The microcontroller is coupled to the first inertial sensor and the second inertial sensor, and the microcontroller receives the first motion posture data and the second motion posture data, and analyzes the step according to the first motion posture data and the second motion posture data. After the state phase, the stimulation parameters are calculated by the closed loop feedback control method, and finally the control command including the stimulation parameters is output. The electrical stimulator is coupled to the microcontroller, and the electrical stimulator outputs a pulse wave according to the control command to stimulate the lower leg, thereby correcting the patient's gait.

In an embodiment of the invention, the microcontroller calculates the calf angle according to the first motion posture data and calculates the foot angle according to the second motion posture data, and the closed loop feedback control method is based on the calf angle, the foot angle, and the gait stage. Calculate the stimulation parameters.

In an embodiment of the invention, the gait phase includes a support period and a swing period, and the swing period includes a pre-swing period, an initial swing period, a middle swing period, and a swing period.

In an embodiment of the present invention, the wearable foot electrical stimulation control system further includes a graphical user interface coupled to the microcontroller, the graphical user interface providing an initial setting of the electrical stimulator and recording The first motion posture data, the second motion posture data, the gait phase, and an intensity of the pulse wave, a frequency, and a pulse width.

In an embodiment of the invention, the first inertial sensor and the second inertial sensor each include an accelerometer and a gyroscope.

The present invention provides a wearable foot-foot electrical stimulation control method that is adaptive to an immediate gait, suitable for a foot-footed patient, including sensing a first motion profile data of the lower leg by a first inertial sensor disposed on the lower leg. The wearable foot electrical stimulation control method further includes sensing the second motion posture data of the foot by the second inertial sensor disposed on the foot. The wearable foot electric stimulation control method further includes receiving, by the microcontroller, the first motion posture data and the second motion posture data, and analyzing the gait phase according to the first motion posture data and the second motion posture data, and then closing the loop. The feedback control method calculates the stimulation parameters and finally outputs a control command including the stimulation parameters. The wearable foot electrical stimulation control method further includes outputting a pulse wave according to the control command by the electrical stimulator to stimulate the tibialis anterior muscle to generate an ankle dorsiflexion motion.

In an embodiment of the invention, the microcontroller calculates the calf angle according to the first motion posture data and calculates the foot angle according to the second motion posture data, and the closed loop feedback control method is based on the calf angle, the foot angle, and the gait stage. Calculate the stimulation parameters.

In an embodiment of the invention, the gait phase includes a support period and a swing period, and the swing period includes a pre-swing period, an initial swing period, a middle swing period, and a swing period.

In an embodiment of the present invention, the wearable electrical stimulation control method further includes providing an initial setting of the electrical stimulator through the graphical user interface and recording the first motion posture data, the second motion posture data, the gait phase, and The intensity, frequency and pulse width of the pulse wave.

In an embodiment of the invention, the first inertial sensor and the second inertial sensor each include an accelerometer and a gyroscope.

Based on the above, the wearable electrical stimulation control system and the wearable electrical stimulation control method adaptive to the instant gait of the present invention can calculate the gait phase by measuring the angles of the lower leg and the foot, and output in different gait phases. Pulse waves with corresponding parameters stimulate the contraction of the tibialis anterior muscle, enabling patients with foot-foot to produce a smoother, smoother gait by more precise gait phase determination.

The above described features and advantages of the invention will be apparent from the following description.

1 is a block diagram of a wearable foot-foot electrical stimulation control system in accordance with an embodiment of the present invention. 2 is a schematic diagram of a wearable foot-foot electrical stimulation control system in accordance with an embodiment of the present invention.

Referring to FIG. 1 and FIG. 2 simultaneously, the wearable electrical stimulation control system 100 of the present invention includes a first inertial sensor 110, a second inertial sensor 120, a microcontroller 130, and an electrical stimulator 140. The microcontroller 130 is coupled to the first inertial sensor 110 and the second inertial sensor 120 , and the electrical stimulator 140 is coupled to the microcontroller 130 . The first inertial sensor 110 may include an accelerometer 111 and a gyroscope 112, and the second inertial sensor 120 may include an accelerometer 121 and a gyroscope 122. The microcontroller 130 can be a microprocessor, a programmable controller, an Application Specific Integrated Circuits (ASIC), a Programmable Logic Device (PLD), or the like. The electrical stimulator 140 includes a pulse wave generator 143, and the pulse wave generator 143 can generate an electrical stimulation pulse wave that is conducted by the wire to the first electrode sheet 141 and the second electrode sheet 143. It should be noted that although the first inertial sensor 110 in this embodiment may include an accelerometer (for example, a three-axis accelerometer) 111 and a gyroscope 112, the present invention is not limited thereto. In another embodiment, the first inertial sensor 110 (and the second inertial sensor 120) may also include any sensed component that can measure the acceleration value and the angular velocity value.

The first inertial sensor 110 can be placed on the calf 201 (eg, the inside of the lower leg) where the patient has a foot-hanging symptom and senses the first locomotion data of the calf 201. The second inertial sensor 120 can be disposed on the foot 202 and sense the second motion pose data of the foot 202. The first motion posture data and the second motion posture data include acceleration values and angular velocity values obtained from the accelerometer 111, the accelerometer 121 and the gyroscope 112, and the gyroscope 122. The microcontroller 130 may receive the first motion posture data and the second motion posture data and output a control instruction according to the first motion posture data and the second motion posture data. It should be noted that the microcontroller 130 can be connected to the first inertial sensor 110, the second inertial sensor 120, and the electrical stimulator by using a wired or wireless manner, and the first inertial sensor 110 and the microcontroller The 130 and the electrical stimulator 140 can also be integrally disposed on the lower leg 201.

When the electrical stimulator 140 receives the control command, the pulse generator 143 may output an electrical stimulation pulse according to the control command to stimulate the lower leg 201. Specifically, the pulse generator 143 may output an electrical stimulation pulse wave to the first electrode sheet 141 according to the control command to stimulate the common nerve 210 of the calf 201, and the electrical stimulation pulse wave may also be output to the second electrode sheet 142 to stimulate. The tibialis anterior muscle 220 of the lower leg 201, and the electrical stimulation pulse waves output to the first electrode piece 141 and the second electrode piece 142 may have the same or different strengths. It should be noted that the first electrode piece 141 and the second electrode piece 142 may be attached to the skin of the lower leg 201 to conduct electrical stimulation pulse waves, and the pulse wave generator 143 may generate a specific intensity according to the control instruction of the microcontroller 130 (intensity). A biphasic pulse train of frequency and pulse width to properly stimulate the common peroneal nerve 210, induce contraction of the tibialis anterior muscle 220, and produce a dorsiflexion.

In order to provide an electric stimulation pulse wave more accurately when the patient walks to generate a smoother gait, the microcontroller 130 may calculate the angles of the calf 201 and the foot 202 according to the first motion posture data and the second motion posture data, respectively. The gait phase is calculated according to the angles of the calf 201 and the foot 202, and the control command is output according to the gait phase. In detail, the microcontroller 130 can determine the stance phase or the swing phase that is currently in the gait phase based on the angles of the lower leg 201 and the foot 202. The microcontroller 130 controls the electrical stimulator 140 to output an electrical stimulation pulse only during the swing period. In addition, the swing period can be subdivided into four sub-stages: pre-swing, initial swing, mid-swing, and terminal swing. The pre-swing period and the late swing period may represent a state in which the foot portion 202 is partially attached and partially suspended, and the initial swing period and the middle swing period may represent a state in which the foot portion 202 is completely suspended. The microcontroller 130 can control the electrical stimulator 140 to output an electrical stimulation pulse wave when detecting the early swing period, and control the electrical stimulator 140 to stop outputting the electrical stimulation pulse wave when the late swing is detected to assist the patient in making the swing period. Proper squat dorsiflexion to overcome the symptoms of the foot.

During the swing period, the microcontroller 130 may further calculate the current required electrical stimulation current intensity to induce the contraction of the tibialis anterior muscle 220 to the required intensity according to the sub-stage of the subdivision and the angle of the lower leg 201 and the foot 202 as feedback parameters. In turn, a smooth, smooth gait is produced. That is to say, the microcontroller 130 adjusts the electrical stimulation intensity of the electrical stimulator 140 in real time according to the first motion posture data and the second motion posture data of the instant feedback at each gait stage of each step of the patient.

The wearable footstep electrical stimulation control system 100 of the present invention also includes a graphical user interface 150. The graphical user interface 150 can be a software module running on a personal computer, a notebook computer, a smart phone, a tablet or other mobile device and coupled to the microcontroller 130 via wireless communication, for example, via Bluetooth wireless transmission. Communication with the microcontroller 130 is performed. The graphical user interface 150 can provide initial settings for the electrical stimulator 140 and record the relationship between the first motion profile data, the second motion profile data, the intensity, frequency, and pulse width of the pulse wave and the various gait phases.

In the present embodiment, the first inertial sensor 110 and the second inertial sensor 120 are connected to the microcontroller 130 in a wired manner, but the invention is not limited thereto. For example, in another embodiment, the first inertial sensor 110 and the second inertial sensor 120 can be integrated with the communication chip and transmit the first motion posture data and the second motion posture data to the micro control through wireless communication. 130. As such, the convenience of the patient using the wearable electrical stimulation control system 100 of the present invention can be increased. In addition, the first inertial sensor 110, the second inertial sensor 120, the microcontroller 130, and the electrical stimulator 140 of the present invention can be powered by a rechargeable battery (eg, a lithium ion battery) to achieve wearability. Sex and portability.

3 is a flow chart of a wearable electrical stimulation control method in accordance with an embodiment of the present invention.

Referring to FIG. 3, in step S301, the first motion posture data of the lower leg is sensed by the first inertial sensor disposed on the lower leg.

In step S303, the second motion posture data of the foot is sensed by the second inertial sensor disposed at the foot.

In step S305, the first motion posture data is received by the microcontroller to calculate the calf angle and receive the second motion posture data to calculate the foot angle.

In step S307, the instant gait phase is calculated by the calf angle and the foot angle.

In step S309, the appropriate electrical stimulation parameters are adjusted by the small leg angle, the foot angle and the gait phase in a closed loop feedback control method, and a control command including the electrical stimulation parameter is output.

In step S311, the pulse wave is output by the electrical stimulator according to the control command to stimulate the lower leg.

After step S311, the patient may generate a squatting dorsiflexion motion, and at this time, return to step S301 and S303 to sense the motion posture data again, and use the motion posture data as a feedback parameter to calculate the output pulse wave of the next gait phase. strength.

In summary, the wearable electrical stimulation control system and the wearable electrical stimulation control method of the present invention can calculate the gait phase by measuring the angles of the lower leg and the foot, and output corresponding electrical stimulation pulses in different gait phases. The wave stimulates the common peroneal nerve and the tibialis anterior muscle of the lower leg, so that the foot of the foot can more accurately simulate the dorsiflexion of the normal person in each gait stage, thereby producing a smoother and smoother gait.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention, and any one of ordinary skill in the art can make some changes and refinements without departing from the spirit and scope of the present invention. The scope of the invention is defined by the scope of the appended claims.

100‧‧‧Wearing Electrical Stimulation Control System
110‧‧‧First inertial sensor
111, 121‧‧ ‧ accelerometer
112, 122‧‧‧Gyro
120‧‧‧Second inertial sensor
130‧‧‧Microcontroller
140‧‧‧Electro-stimulator
141‧‧‧First electrode
142‧‧‧Second electrode
143‧‧‧ Pulse generator
150‧‧‧ graphical user interface
201‧‧‧ calf
202‧‧‧ Foot
210‧‧‧腓腓总
220‧‧‧ 胫 anterior muscle
S301, S303, S305, S307, S309, S311‧‧‧ steps of the wearable electrical stimulation control method

1 is a block diagram of a wearable foot-foot electrical stimulation control system in accordance with an embodiment of the present invention. 2 is a schematic diagram of a wearable foot-foot electrical stimulation control system in accordance with an embodiment of the present invention. 3 is a flow chart of a wearable foot electrical stimulation control method in accordance with an embodiment of the present invention.

Claims (10)

A wearable foot electric stimulation control system adapted to an immediate gait, suitable for a foot-hanging patient, comprising: a first inertial sensor disposed on a lower leg and sensing a first motion posture data of the lower leg a second inertial sensor, disposed at a foot and sensing a second motion posture data of the foot; a microcontroller coupled to the first inertial sensor and the second inertial sensor, The microcontroller receives the first motion posture data and the second motion posture data, and analyzes the one-step phase in real time according to the first motion posture data and the second motion posture data, and calculates a stimulation parameter by using a closed loop feedback control method. And outputting a control command including the stimulation parameter; and an electrical stimulator coupled to the microcontroller, the electrical stimulator outputting a pulse wave according to the control command to stimulate the lower leg. The wearable foot-foot electric stimulation control system adapted to the instant gait according to claim 1, wherein the microcontroller calculates a calf angle according to the first motion posture data and according to the second motion posture data A foot angle is calculated, and the closed loop feedback control method calculates the stimulation parameter according to the calf angle, the foot angle, and the gait phase. The wearable foot-foot electrical stimulation control system adapted to the instant gait according to claim 2, wherein the gait phase comprises a support period and a swing period, the swing period includes a swing period and a swing Initial, mid-swing and late swing. The wearable foot-foot electric stimulation control system adapted to the instant gait as described in claim 1 further includes a graphical user interface coupled to the microcontroller, the graphical user interface providing the electrical stimulation An initialization of the device sets and records the first motion posture data, the second motion posture data, the gait phase, and an intensity, a frequency, and a pulse width of the pulse wave. The wearable electrical stimulation control system adapted to the instant gait according to claim 1, wherein the first inertial sensor and the second inertial sensor each comprise an accelerometer and a gyroscope. A wearable foot electric stimulation control method adapted to an instant gait, suitable for a foot-hanging patient, comprising: sensing a first movement of the lower leg by a first inertial sensor disposed on a lower leg Attitude data; sensing a second motion posture data of the foot by a second inertial sensor disposed at a foot; receiving the first motion posture data and the second motion posture by a microcontroller Data, according to the first motion posture data and the second motion posture data, analyzing the one-step phase in real time, calculating a stimulation parameter by a closed loop feedback control method, and outputting a control instruction including the stimulation parameter; and using an electrical stimulation The device outputs a pulse according to the control command to stimulate the lower leg. The wearable electrical stimulation control method adapted to the instant gait according to claim 6, wherein the microcontroller calculates a calf angle according to the first motion posture data and calculates a foot according to the second motion posture data. a portion angle, and the closed loop feedback control method calculates the stimulation parameter according to the calf angle, the foot angle, and the gait phase. The wearable foot electric stimulation control method adapted to the instant gait according to claim 7, wherein the gait phase comprises a support period and a swing period, the swing period includes a swing period and a swing Initial, mid-swing and late swing. The wearable foot electric stimulation control method adapted to the instant gait as described in claim 6 further includes providing an initial setting of the electrical stimulator and recording the first motion through a graphical user interface. The attitude data, the second motion attitude data, the gait phase, and an intensity of the pulse wave, a frequency, and a pulse width. The wearable foot electric stimulation control method adapted to the instant gait according to claim 6 , wherein the first inertial sensor and the second inertial sensor each comprise an accelerometer and a gyroscope instrument.