US-12616625-B2 - Muscle tone assesment device and assesment method thereof

US12616625B2US 12616625 B2US12616625 B2US 12616625B2US-12616625-B2

Abstract

A muscle tone assessment device includes a pedal, a front force sensor and a back force sensor arranged at the pedal, and a controller connected to the sensors. The controller obtains a front force standard deviation, a back force standard deviation, a front force deviation and a back force deviation from the sensing results, and obtains a first and a second threshold value from the front force standard deviation and the back force standard deviation. The front force standard deviation and the back force standard deviation are the standard deviations of the front force signal and the back force signal within a first time interval. The front force deviation and the back force deviation represent the deviation of the front force signal and the back force signal in a second time interval. In addition, the present invention further provides a muscle tone assessment method.

Inventors

Jia-Wei LAI
Che-Wei Chan

Assignees

HIWIN TECHNOLOGIES CORP.

Dates

Publication Date: 20260505
Application Date: 20220526

Claims (5)

1 . A muscle tone assessment device, comprising: a calf support unit to support a lower leg, said calf support unit comprising a pedal, said pedal comprising a pedaling area, said pedaling area being used to carry the foot; an actuating unit adapted for driving said pedal to rotate; a sensing unit comprising at least one front force sensor and at least one back force sensor, said at least one front force sensor being embedded in said pedal and located in a front side relative to said pedaling area for sensing a front pedaling force and correspondingly sending a front force signal, said at least one back force sensor being embedded in said pedal and located in an opposing rear side relative to said pedaling area for sensing a back pedaling force and correspondingly sending a back force signal; and a controller electrically connected to said sensing unit; wherein before said actuating unit drives said pedal, said controller calculates a front force standard deviation and a back force standard deviation respectively according to several force values of said front force signal and said back force signal in a first time interval and also calculates a first threshold value and a second threshold value according to said front force standard deviation and said back force standard deviation; after said actuating unit drives said pedal, said controller respectively calculates a front force deviation and a back force deviation of said front force signal and said back force signals in each second time interval relative to said first time interval where said second time interval is less than said first time interval; when said front force deviation is greater than said first threshold value and said back force deviation is greater than said second threshold value, it means that a state of high tension occurs in the muscles of the lower leg; wherein when said controller determines that said front force signal is greater than said back force signal and said front force deviation is greater than said first threshold value and said back force deviation is greater than said second threshold value, it indicates that the state of high tension occurs in the muscles of the lower leg during dorsiflexion of the foot: when said controller determines that said front force signal is smaller than said back force signal and said front force deviation is greater than said first threshold value and said back force deviation is greater than said second threshold value, it indicates that the state of high tension occurs in the muscles of the lower leg during plantar flexion of the foot; wherein said calf support unit further comprises an upper support and a lower support, said lower support having a top end thereof pivotally connected to a bottom end of said upper support; said pedal is fixed at an opposing bottom of said lower support: said actuating unit comprises a cylinder and a piston rod, said cylinder having a top end thereof pivotally connected to said upper support, said piston rod being linearly displaceable on said cylinder and having a bottom end thereof pivoted on said pedal.
2 . The muscle tone assessment device as claimed in claim 1 , wherein said front force standard deviation is defined as δ front , δ front = 1 N ⁢ ∑ i = 1 N ⁢ ( f fi - μ f ) 2 , said back force standard deviation is defined as δ back , δ back = 1 N ⁢ ∑ i = 1 N ⁢ ( f bi - μ b ) 2 , N is the number of data collected in said first time interval, f fi is the force value of the i th data of said front force signal in said first time interval, μ f is the average value of N numbers of f fi , f bi is the force value of the i th data of said back force signal in said first time interval, μ b is the average value of N numbers of f bi , said front force deviation is defined as δ tf , δ tf = 1 N t ⁢ ∑ i = 1 N t ⁢ ( f tf i - μ f ) 2 , said back force deviation is defined as δ tb , δ tb = 1 N t ⁢ ∑ i = 1 N t ⁢ ( f tb i - μ b ) 2 , N t is the number of data collected in the second time interval, f tfi is the force value of the i th data of said front force signal in said second time interval, f bi is the force value of the i th data of said back force signal in said second time interval.
3 . The muscle tone assessment device as claimed in claim 2 , wherein said first threshold value is defined as δ f , δ f =2*δ front *δ factor , said second threshold value is defined as δ b , δ b =2*δ back *δ factor , δ factor is the sensitivity; when δ factor =1, said first threshold value is 2 times said front force standard deviation, and said second threshold value is 2 times said back force standard deviation.
4 . The muscle tone assessment device as claimed in claim 1 , wherein the pivot angle of said lower support is defined as θ 1 , θ 1 =180°−θ t −θ 2 -θ 3 ,θt is the angle formed between L 1 and L 2 , θ t = cos - 1 ( ( ( L 1 2 + L 2 2 ) - L 3 2 ) 2 × L 1 × L 2 ) , L 1 is the straight-line distance between the pivot axis of said lower support and the pivot axis of said cylinder, L 2 is the straight-line distance between the pivot axis of said lower support and the pivot axis of said piston rod, L 3 is the straight-line distance between the pivot axis of said cylinder and the pivot axis of said piston rod, θ 2 is the angle formed between A 2 and L 2 , A 2 is the axis passing through the pivot axis of said lower support and is perpendicular to said pedal, θ 3 is the angle formed between A 1 and L 1 , A 1 is the axis passing through the fixed axis of said upper support and the pivot axis of said lower support.
5 . The muscle tone assessment device as claimed in claim 1 , wherein said sensing unit comprises two said front force sensors and two said back force sensors, said two front force sensors being located at left and right corners in the front side relative to said pedaling area, said two back force sensors being located at left and right corners in the opposing rear side relative to said pedaling area.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the assessment technology of muscle tension, in particular to a muscle tone assessment device and an assessment method thereof. 2. Description of the Related Art Spasticity is a disorder of muscle movement, usually caused by damage to the brain or spinal cord that controls voluntary movement, such as cerebral palsy, multiple sclerosis, stroke, or amyotrophic lateral sclerosis. These injuries cause changes in the balance of signals between the nervous system and muscles, increasing muscle tone. If the muscle tension is too high, the movement angle of the joint may be limited, which will not achieve a good rehabilitation effect. Therefore, before the patient uses the lower limb training machine for rehabilitation, the physical therapist usually massages the affected limb with bare hands to reduce the muscle tension of the affected limb. However, the above methods completely depend on the experience and subjective feeling of the physical therapist, and it is difficult to accurately assess whether the patient is suitable for rehabilitation and the degree of rehabilitation that can be carried out. On the one hand, the ankle joint rehabilitation device disclosed in TW M311442 uses a rotating plate to fix the foot, and on the other hand, uses a first support member and a second support member to fix the thigh and calf respectively. The torque value of the transmission shaft is sensed by the torque sensor arranged between the rotating plate and the actuator, so as to evaluate the maximum range of motion of the foot joint and whether the muscle tension is too high. However, the aforementioned ankle joint rehabilitation device must keep the patient in a sitting position during use, and the patient needs to be moved when using the lower limb training machine for rehabilitation training, which is inconvenient to use and consumes rehabilitation time. The affected limb training device disclosed in the CN 102614066 B uses a controller to detect the current change of the motor driving unit, then estimates the tension change of the affected limb according to the detected current change, and adjusts the speed of movement and the range of motion at the same time. However, the distance from the ankle joint to the bottom of the foot varies from different patients, so the current change detected by the control unit may be inaccurate. In addition, the aforementioned affected limb training device can only keep the patient in a sitting or lying position when in use. If the lower limb training machine is to be used continuously for rehabilitation training, the patient needs to be moved, which is inconvenient to use and consumes rehabilitation time. SUMMARY OF THE INVENTION The present invention has been accomplished under the circumstances in view. It is the main object of the present invention to provide a muscle tone assessment device, which can accurately determine whether a patient's muscles are in a state of high tension, and can perform subsequent gait training without moving the patient. To achieve this and other objects of the present invention, the muscle tone assessment device of the present invention comprises a calf support unit, an actuating unit, a sensing unit, and a controller. The calf support unit is used to support a lower leg. The calf support unit comprises a pedal. The pedal comprises a pedaling area. The pedaling area is used to carry the foot. The actuating unit is adapted for driving the pedal to rotate. The sensing unit comprises at least one front force sensor and at least one back force sensor. The at least one front force sensor is embedded in the pedal and located in a front side relative to the pedaling area for sensing a front pedaling force and correspondingly sending a front force signal. The at least one back force sensor is embedded in the pedal and located in an opposing rear side relative to the pedaling area for sensing a back pedaling force and correspondingly sending a back force signal. The controller is electrically connected to the sensing unit. Before the actuating unit drives the pedal, the controller calculates a front force standard deviation and a back force standard deviation respectively according to several force values of the front force signal and the back force signal in a first time interval and also calculates a first threshold value and a second threshold value according to the front force standard deviation and the back force standard deviation. After the actuating unit drives the pedal, the controller respectively calculates a front force deviation and a back force deviation of the front force signal and the back force signals in each second time interval relative to the first time interval where the second time interval is less than said first time interval; when said front force deviation is greater than the first threshold value and the back force deviation is greater than the second t