Design method for non-circular chain disks that can be applied in rehabilitation and utilize electromyography signals

Abstract

This invention comprises an initial qualitative trial step, a step to modify the first and third radii, a step to modify the second and fourth radii, a step to adjust and determine the remaining radii, and a final design step. The user pedals a left foot pedal and a right foot pedal respectively, rotating a drive chain. A two-myocardial signal detection device obtains raw signals from the user's left and right rectus femoris muscles. These signals are used to modify the design of the first, second, third, and fourth radii of the drive chain, thereby activating the left and right tibialis anterior muscles. By adjusting one of the remaining second or fourth radii to satisfy the initial circular chain's pitch circle length and number of teeth, a non-circular drive chain tooth design is obtained using existing curve connection technology.

Claims

1. A design method for a non-circular chain drive that can be applied in the field of rehabilitation and uses electromyography (EMG) signals, comprising the following steps in sequence: an initial qualitative trial step, which provides a pedaling fitness device, the pedaling fitness device having a frame body, a seat, a handlebar, a drive chain drive, a left pedal, a right pedal, a tachometer, at least two EMG signal detection devices, and a processing device; the seat is fixed to the frame body and is for a user to sit on, the handlebar is fixed to the frame body and is for the user to hold; the drive chain drive is pivotally mounted to the frame body, the left pedal and... The right pedal is angled 180 degrees to the left and right pedals, and is coaxially connected and fixed to both sides of the drive chainring. The left and right pedals are respectively used by the user's left and right feet to pedal, thereby rotating the drive chainring. The tachometer is used to measure the rotational speed signal of the drive chainring. After an initial qualitative test pedaling, at least two electromyography (EMG) signal detection devices are used to obtain a primary signal from the left rectus femoris muscle and a primary signal from the right rectus femoris muscle from the user. The drive chain is circular at this step, and a segment of the circle (R) can be extracted; this segment of the circle (R) has a segment radius (R0); and can be further defined as follows: a first radius (R1), corresponding to the dead point above the right foot when pedaling; a second radius (R2), which lags behind the first radius (R1) and is spaced 90 degrees apart; a third radius (R3), which lags behind the second radius (R2) and is spaced 90 degrees apart; a fourth radius (R4), which lags behind the third radius (R3) and is spaced 90 degrees apart; when the drive chain is circular, (R1)=(R2)=(R3)=(R4)=(R0); a step of modifying the first and third radii is to change the outline of the drive chain to be non-circular; and compare the fluctuation stability of the original signals of the left rectus femoris muscle and the right rectus femoris muscle. If the original signal of the left rectus femoris is relatively unstable, the first radius and the third radius are changed to satisfy (R3) > (R1); (R3) is between (R0) + 5% and (R0) + 15%; (R1) is between (R0) + 0.5% and (R0) + 1.5%; and if the original signal of the right rectus femoris is relatively unstable, the first radius (R1) and the third radius (R3) are changed to satisfy (R1) > (R3); (R1) is between (R0 + 5%) and (R0 + 15%); (R3) is between (R0) + 0.5% and (R0) + 1.5%; In a step of modifying the second radius or the fourth radius, if it is chosen to increase the activation of the left tibialis anterior muscle, the second radius (R2) is changed, and (R2) is between (R0) - 5% and (R0) - 15%; If the desired activation of the right tibialis anterior muscle is desired, the fourth radius (R4) is changed to be between (R0)-5% and (R0)-15%. In the step of adjusting and determining the remaining radius, the radius value of either the remaining second radius (R2) or the fourth radius (R4) satisfies the condition that the pitch circle length and the number of teeth of the circular drive chain disc in the initial qualitative trial step are the same, and is completed according to the existing curve connection technology. In the step of completing the design, a non-circular tooth design of the drive chain disc is obtained, and a solid non-circular drive chain disc can be manufactured.

2. The design method of a non-circular chain disk applicable to rehabilitation and using electromyographic signals as described in claim 1, wherein: In the steps of modifying the first and third radii: one of (R1) and (R3) is 1.01(R0); the other of (R1) and (R3) is 1.09R0; in the steps of modifying the second or fourth radii: one of (R2) and (R4) is 0.89R0; and in the steps of adjusting and determining the remaining radius: the other of (R2) and (R4) is 0.98R0.

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