JP2014213147A - System and method for measuring walking function recovery state - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a system and method for measuring walking function recovery state, capable of objectively evaluating the walking function by highly efficiently measuring the dorsiflexion and plantar flexion of a user's leg during walking.SOLUTION: The measuring system of walking function recovery state includes: a leg orthosis comprising a support, and a leg holding part journaled to the lower end and swinging according to the dorsiflexion and plantar flexion operations of the leg; a force sensor that is fitted to the support for detecting force applied to a part adjacent to a journal part according to the dorsiflexion and plantar flexion operations of the leg; and a data analysis part that receives an output of the force sensor when the user performs a plurality of steps of walking operations to analyze a recovery state of the user's walking function. The data analysis part defines timing when a sensor output X is maximized in a direction of the plantar flexion, as a sole grounding period of each step. The sensor output X is divided into respective step outputs Xn, with a period from one sole grounding period to a next sole grounding period defined as one period Tn of the walking. The system extracts data of specific phases d1-d2 during a period from a start point to a terminal point of each step output Xn.

Description

  The present invention relates to a measurement system and a measurement method of a recovery function of a walking function used for rehabilitation or the like of a person with a walking disability.

  2. Description of the Related Art Conventionally, as disclosed in, for example, Patent Literature 1, a multi-link type mechanism that is worn along a foot from a patient's waist is provided, and a foot orthosis in which a plurality of sensors are attached to various places is provided. There was a walking ability measuring device for analyzing the output and evaluating the user's walking ability. This measuring apparatus is an apparatus for performing evaluation while paying attention to the swing amplitude of the user's foot (how much the foot tip swings back and forth from the waist). The plurality of sensors are a load sensor that measures the force that the sole of the foot receives from the floor and a foot position sensor that measures the position of the foot in the front-rear direction relative to the waist. The walking ability can be evaluated by recognizing the position of the first foot and the position of the second foot and calculating the walking ability index using the average and variance as variables.

JP 2012-85891 A

  Although various methods have been proposed for evaluating the recovery status of gait function, there is no one that has been widely recognized because of its current effectiveness.

  As a result of the inventor's examination, it is effective to focus on the recovery status of the force to move the foot in the dorsiflexion direction and the force to move in the sole flexion direction for each stance phase and swing phase in the walking cycle. I understood. As shown in FIG. 6, the stance phase is a period in which the foot is on the ground, and is generally a period from the plantar contact period to the heel-off period. The swing phase is a period in which the foot is away from the ground, and generally refers to the period from the fingertip separation period to the heel contact period.

  However, there is no device in the world that can accurately measure the dorsiflexion or plantar flexion force of a foot while walking, and the walking ability measurement device of Patent Document 1 is not a device that can handle this evaluation method.

  The present invention has been made in view of the above-described background art, and can accurately measure the force of dorsiflexion and plantar flexion of a foot while walking, and enables an objective evaluation of walking function. An object of the present invention is to provide a function recovery status measurement system and method.

The present invention is composed of a column attached to the user's lower leg side, and a foot holding unit pivotally attached to the lower end of the column, according to the dorsiflexion and plantar flexion motion of the user's foot. The leg holding part swings around the pivot part, and the force applied to the part near the pivot part according to the dorsiflexion and bottom flexion movement of the user's foot. And a data analysis unit that receives the output of the force sensor unit when a user performs a plurality of steps of walking motion and analyzes the recovery status of the walking function. Recognizes the timing at which the sensor output is maximized in the plantar flexion direction as the plantar contact period of each step, and sets the sensor from one plantar contact period to the next plantar contact period as one cycle of walking. The output is divided into each step output, and specific phase data from the start point to the end point of each step output This is a system for measuring the recovery status of walking function to be extracted.

  It is preferable that the support column is made of metal, is attached to an end portion of the foot holding unit, the force sensor unit is a strain gauge, and detects an elastic strain in which a portion in the vicinity of the shaft attachment portion is curved in the front-rear direction. .

Further, the present invention is composed of a strut attached to the user's lower leg side, and a foot holding portion pivotally attached to the lower end of the strut, and the user's foot dorsiflexion and plantar flexion motion The leg holding part is attached to the support and the support so that the foot holding part swings about the pivoting part, and the leg holding part is attached to a part near the pivoting part according to the dorsiflexion and bottom flexion movements of the user's foot. Using a measurement system comprising a force sensor for detecting the applied force,
Analyzing the sensor output of the force sensor unit when the user performs a plurality of steps of walking motion, and certifying the time when the sensor output is maximized in the plantar flexion direction as the plantar contact period of each step, The output is divided into each step output having one cycle from one foot contact period to the next foot contact period, and data of a specific phase from the start point to the end point of each step output is extracted. This is a method for measuring the recovery of gait function.

  It is preferable to calculate an average value for a plurality of steps for the extracted data of the specific phase. Further, when the period from the start point to the end point of each step output is set to 0 to 100%, the data of the specific phase is preferably data within a range of 55 to 95%.

  According to the measurement system for recovery of walking function of the present invention, a general-purpose short leg brace can be used as a leg brace, and it is not necessary to purchase or manufacture the leg brace specially. Also, the force sensor unit and the data analysis unit can be configured at low cost using a general strain gauge and a personal computer. Therefore, it can be widely spread not only to specific medical institutions such as hospitals and rehabilitation facilities but also to general households.

  Further, according to the measurement system and the measurement method of the present invention, when the sensor output is divided into each step output for each walking cycle and analyzed, the foot ground contact period of each step is set as the starting point. And the swing phase can be accurately identified. Therefore, various data necessary for the evaluation of the walking function recovery status can be easily obtained by automatic computer calculation. For example, if the specific phase is set within the range of 55 to 95% (within the range of the swinging leg phase), the data on the force of dorsiflexion of the foot is extracted with high accuracy and is useful information for evaluating the recovery status of walking function Can be easily obtained.

It is a figure which shows a mode that one Embodiment of the measurement system of the walk function recovery condition of this invention was mounted | worn with the user's left leg. It is a side view (a) which shows the leg orthosis of this embodiment, and is a figure (b) explaining the attachment position of a force sensor part. It is a flowchart which shows one Embodiment of the measuring method of the walk function recovery condition of this invention. It is a time chart which shows the sensor output of a force sensor part. It is a figure explaining the specific phase in 1 cycle of walking. It is a figure explaining the stance phase and the free leg phase in 1 cycle of walking.

  Hereinafter, one embodiment of the measurement system for the walking function recovery status of the present invention will be described with reference to FIGS. 1 and 2. As shown in FIG. 1, the measurement system 10 according to this embodiment includes a leg brace 12 attached to the left leg of the user M, a force sensor unit 14, and a data analysis unit (not shown).

  As shown in FIG. 2, the leg orthosis 12 includes a pair of left and right struts 16 in which the lower leg portion of the user M fits, and a foot holding portion 18 that is a shoe attached to the lower end of the strut 16. Has been. A mounting belt 16a is provided at the upper end of the support column 16, so that the pair of support columns 16 can be fixed to the crus. The foot holding part 18 is pivotally attached at the position of the heel of the user M, and swings around the pivoting part 16b according to the dorsiflexion and bottom flexion motions of the user M's legs. Here, shoes are used as the foot holding portion 18, but for example, a shape such as a sandal in which a foot is placed on a foot-shaped plate and the upper portion is fixed with a belt may be used.

  The force sensor unit 14 includes a strain gauge 14a and a sensor output recording unit 14b. The strain gauge 14a is a sheet-like sensor element that changes its resistance value when it receives a force in a specific direction, and is attached to the front and back side surfaces of the lower ends of the pair of columns 16 as shown in FIG. It is possible to detect an elastic strain that is attached and the support column 16 is bent in the front-rear direction. The sensor output recording unit 14b pulls out the output ends of the four strain gauges 14a with a cable 14c, converts a change in resistance value into an electrical signal using an amplifier circuit such as a bridge circuit, and records the change as a sensor output X on a recording medium. . For example, as shown in FIG. 1, the amplifier circuit and the recording medium are housed in a small housing case and fixed to the waist of the user M with a mounting belt.

  A data analysis unit (not shown) is configured by, for example, a personal computer, reads the sensor output X recorded in the force sensor unit 14 and performs data analysis, and analyzes and evaluates the walking motion of the user M. Details will be described later in the description of the measurement method.

  In the case of the measurement system 10, the sensor output X is recorded in the force sensor unit 14 and then analyzed by the data analysis unit. However, the sensor output X is wirelessly transmitted during walking, and the data analysis unit performs real-time analysis. You may make it the structure which can be analyzed.

  Next, one embodiment of the method for measuring the walking function recovery status of the present invention will be described with reference to FIGS. The inventor has studied a technique for evaluating the recovery of walking function by focusing on the dorsiflexion force of the foot while walking. The measurement method according to this embodiment is a method of performing a walking motion (number of steps = n steps) with the leg brace 12 and measuring the force acting on the support column 16 according to the dorsiflexion and plantar flexion motion of the foot during walking. It is. Specifically, the data analysis unit that has received the sensor output X performs the processing of steps S11 to S14 shown in FIG.

  As shown in FIG. 4, the sensor output X has a repetitive waveform having a substantially sawtooth waveform. Here, the force in the dorsiflexion direction is detected as a positive voltage, and the force in the bottom flexion direction is detected as a negative voltage. The relationship with the walking motion shown in FIG. 6 is that the timing at which the sensor output X is maximum in the plantar flexion direction is the foot ground contact period, and the timing at which the sensor output X is maximum in the dorsiflexion direction is the detached ground period, and then the sensor The timing at which the output X disappears (returns to near zero) is the fingertip separation period, and the timing at which the sensor output X starts to rise in the buckling direction is the saddle contact period. In addition, the stance phase R is a period from the sensor contact X to the dorsiflexion direction after the plantar contact period until the heel-off period, and the swing phase Y is from the fingertip release period. This is the period until the plantar contact period.

  In steps S11 and S12, the data analysis unit performs a process of dividing the sensor output X into each step output X1 to Xn from the first step to the n-th step. The period T1 to Tn of each step from the first step to the n-th step is not greatly different but is not a fixed time. First, in step S11, an average cycle T per step is calculated. The average period T may be obtained, for example, by dividing the total time of n steps by n, or may be strictly calculated by applying an autocorrelation function. Next, in step S12, each step output X1 to Xn for each step is cut out from the sensor output X. At this time, as shown in FIG. 4, the timing at which the sensor output X becomes maximum in the plantar bending direction, that is, the plantar contact period is set as the starting point of each step. The reason for this will be described later. Further, the difference t1 to tn between each step period T1 to Tn and the average period T is set to be equal to or less than the reference value α (α is a value sufficiently smaller than the average period T).

  Next, in step S13, statistical processing is performed on the extracted step outputs X1 to Xn to obtain an average step output X (ave) that is an average of superposition of the step outputs X1 to Xn. When superposing, as shown in FIG. 5, the superposition is performed with reference to the starting point of each step. Since each step period T1 to Tn is different in the range of (T ± α), as shown in FIG. 5, if the range from the start point to the average period T is expressed as 0 to 100%, the average step output X (ave) is 100. Data in the vicinity of% (for example, 95 to 100%) is ignored because the reliability is low.

  Next, in step S14, an average value V is calculated for a range of specific phases d1 to d2 in a period from the start point to the end point of each average step output X (ave). The measurement method of the present embodiment aims to evaluate the recovery of the walking function by focusing on the dorsiflexion force of the foot, so it can be said that it is reasonable to focus on the data of the swing phase Y. The swing phase Y is a period in which the foot is moved in the dorsiflexion direction and a force other than the force of the dorsiflexion of the foot is not generated (a period in which the repulsive force from the ground is not received). This is because the power of can be easily extracted.

  The sensor output X obtained by measuring the walking motion of n steps varies in data from each step from the first step to the nth step, so how to accurately specify the swing phase Y at each step becomes a problem. As a result of the inventor's study, when the sensor output X is divided into the step outputs X1 to Xn, the free leg phase Y is almost uniformly 55 to 95% by setting the start point of each step as the ground contact period. I found out that Therefore, as shown in FIG. 5, the specific phases d1 to d2 are set to 70 to 80% which is the middle period of the swing phase Y, and the period of the phase 70 to 80% of the average step output X (ave) is set. The average value V is calculated. Thus, the average value V of the dorsiflexion force of the foot from the first step to the n-th step can be calculated with high accuracy. The width of the specific phases d1 to d2 can be changed. For example, when the increase / decrease in the data of the average step output X (ave) in the swing phase Y is small, the width of the specific phase may be further narrowed. . On the other hand, when the increase / decrease in data is large, the specific phase should be wide.

  If a force other than the dorsiflexion force of the foot is to be extracted, the specific phase can be set to a range other than 55 to 95%. This is because the phase (range) of the stance phase R and the like can be specified with a certain degree of accuracy by setting the start point of each of the step outputs X1 to Xn as the ground contact period as described above. However, data in a range other than 55 to 95% needs to be analyzed in consideration of the fact that the repulsive force from the ground is added to the force of dorsiflexion or plantar flexion of the foot.

  As described above, according to the measurement system 10 for recovery of walking function, since a general-purpose short leg device can be used as the leg device 12, it is necessary to purchase or manufacture the leg device 12 specially. Absent. Further, the force sensor unit 14 and the data analysis unit can also be configured at low cost by using a general strain gauge 14a and the like and a personal computer. Therefore, it can be widely spread not only to specific medical institutions such as hospitals and rehabilitation facilities but also to general households.

  In addition, according to the measurement system 10 and the measurement method of the present invention, when the sensor output X is divided into the respective step outputs X1 to Xn, since the foot ground contact period of each step is a starting point, It is possible to accurately identify the stance phase and the like. Therefore, various data necessary for the evaluation of the walking function recovery status can be easily obtained by automatic computer calculation. In particular, by setting the specific phase within the range of 55 to 95% (within the range of the swinging leg phase Y), the data on the dorsiflexion force of the foot is extracted with high accuracy, which is effective for evaluating the recovery of walking function Information can be easily obtained.

  In addition, the measurement system and measurement method of the walking function recovery condition of this invention are not limited to the said embodiment. For example, the force sensor unit only needs to be able to detect the force applied to the portion in the vicinity of the shaft attachment part according to the dorsiflexion and plantar flexion movements of the user's foot, and even if the number of strain gauges and the mounting method are changed. Alternatively, a force detection element other than a strain gauge may be used.

  In addition, as described with reference to FIG. 3, the data analysis unit obtains the average step output X (ave) of the superposition of the step outputs X1 to Xn, and calculates the average value V in the specific phases d1 to d2. By doing so, the process of calculating the average value V of a plurality of steps is performed, but this is only an example of a processing method. For example, if the step average values V1 to Vn in the specific phases d1 to d2 are individually calculated for each step output X1 to Xn, then the arithmetic average is obtained and the average from the first step to the nth step is obtained. A value V can be obtained, and changes in the step average values V1 to Vn from the first step to the nth step can be observed. The method of dividing the sensor output X into the step outputs X1 to Xn is also a method different from steps S11 and S12, except that the starting point is the plantar contact period in which the sensor output X is maximum in the plantar flexion direction. May be used.

  Furthermore, in order to facilitate the evaluation or determination of the walking function recovery status, the data analysis unit may compare the user data with the healthy person data, or display the comparison result in a graph or the like.

DESCRIPTION OF SYMBOLS 10 Measuring system 12 for recovery of walking function Leg orthosis 14 Force sensor unit 14a Strain gauge 16 Strut 16b Axis mounting part 18 Foot holding part M User

Claims (5)

It consists of a strut attached to the user's lower leg side, and a foot holding part pivotally attached to the lower end of the strut, and holds the foot according to the dorsiflexion and plantar flexion movements of the user's foot A leg brace that swings about the pivoted portion;
A force sensor unit that is attached to the support column and detects a force applied to a portion in the vicinity of the shaft attachment part according to the dorsiflexion and bottom flexion motions of the user's foot,
A data analysis unit that receives an output of the force sensor unit when a user performs a walking motion of a plurality of steps and analyzes a recovery state of the walking function, and the data analysis unit has a sensor output that is The maximum timing in the direction is recognized as the plantar contact period of each step, and the sensor output is divided into each step output with one cycle from the plantar contact period to the next plantar contact period as one cycle of walking. A system for measuring the recovery of walking function, wherein data of a specific phase from the start point to the end point of each step output is extracted. The support column is made of metal, and is attached to an end of the foot holding unit,
The walking force recovery state measurement system according to claim 1, wherein the force sensor unit is a strain gauge, and detects an elastic strain in which a portion in the vicinity of the shaft attachment portion curves in the front-rear direction. It consists of a strut that is worn on the side of the user's lower leg, and a foot holder that is pivotally attached to the lower end of the strut. A leg brace that swings around the pivot part and a force that is attached to the column and detects the force applied to the part near the pivot part according to the dorsiflexion and bottom flexion movements of the user's foot Using a measuring system with a sensor part,
Analyzing the sensor output of the force sensor unit when the user performs a walking action of multiple steps, certifying the timing at which the sensor output is maximized in the plantar flexion direction as the sole contact period of each step,
The sensor output is divided into each step output having one cycle from one foot contact period to the next foot contact period, and data of a specific phase from the start point to the end point of each step output is obtained. A method for measuring the recovery of gait function, characterized by extracting.   The method for measuring a walking function recovery status according to claim 3, wherein an average value for a plurality of steps is calculated for the extracted data of the specific phase. 5. The walking function recovery status according to claim 3 or 4, wherein the data of the specific phase is data within a range of 55 to 95% when a period from a start point to an end point of each step output is set to 0 to 100%. Measuring method.