Exoskeleton, control method thereof and tremor simulator device

Abstract

Embodiments of an exoskeleton, a method of controlling the same, and a tremor simulator device are provided. According to one embodiment, an exoskeleton is provided. The exoskeleton comprises: a first support; a second support; the joint structure is rotatably connected with the first supporting piece and the second supporting piece; and a controller. The second support includes: a first anchoring member connected to the joint structure; a second anchoring member; and a sensor coupled to the controller, where the first and second anchoring components are connected by a variable stiffness unit coupled to the controller, and where the variable stiffness unit is configured to provide a variable damping force determined by the controller, to reduce the magnitude of tremor sensed by the sensor.

Description

Technical Field

[0001] The present description relates broadly, but not exclusively, to exoskeletons, methods of controlling the same, and tremor simulator devices. Background Art

[0002] Tremor is a nervous system disorder that causes shaking of one or more parts of the body, most commonly the hands. Tremors can also occur in the arms, legs, head, vocal cords, torso, etc. The rhythmic pattern is caused by unintentional (involuntary) muscle contractions.

[0003] Tremors can occur on their own or as a result of other disorders. Parkinson's disease (PD) is an example of such a disorder. About 80% of people with PD experience tremors. Tremors appear as involuntary shaking of the muscles in the hand or arm, which worsens when at rest or under emotional stress. When tremors occur frequently, people with PD may lose sensation in their hands, which can lead to paralysis. In addition, tremors can cause significant psychological burdens on patients, such as depression, anxiety, impulsivity, and dizziness. Therefore, suppressing tremors is crucial to improving the daily lives of people with PD and reducing their psychological burden.

[0004] As a non-invasive solution, exoskeletons that can suppress tremors have attracted widespread interest. Based on their working mechanisms, these exoskeletons can be divided into three categories: active systems, passive systems, and semi-active systems.

[0005] Active systems actively provide force or torque in the opposite direction of tremor movement to reduce the amplitude of tremor vibration. Typical examples include the Wearable Orthosis for Tremor Assessment and Suppression (WOTAS) developed by Eduardo Rocon et al., the Tremor Suppression Orthosis (TSO) developed by Gil Herrnstadt et al., the Permanent Magnet Linear Motor (PMLM) developed by Amir Hosein-Zamanian et al., and the Wearable Tremor Suppression Glove developed by Zhou Yue et al. These active systems apply effective dynamic forces to the upper limb tremor area and change its biomechanical properties in real time through active control. However, most of these active systems use rigid exoskeletons driven by motors or other actuators. Therefore, their weight is usually measured in kilograms, which adds a heavy burden to patients. In addition, rigid exoskeletons have poor compliance to the human wrist and are less comfortable when actually used.

[0006] Passive systems usually suppress tremors by absorbing or dissipating vibration energy. In 1998, Kotovsky et al. invented the viscous beam, which was the first passive device for vibration suppression. The device limited wrist rotation by applying viscous damping to the flexion and extension of the wrist joint. Nicolas Philip Fromme et al. invented a lightweight passive orthosis that uses air bags to reduce wrist vibration. Compared with active and semi-active systems, these passive systems can be very light (the minimum weight is only 33 grams). However, the damping force or torque provided by the passive system is usually very small, so it is difficult to effectively suppress tremors. Although the mass spring damper system proposed by Sreekanth Rudraraju et al. can reduce tremors by 70% to 80%, this system can only suppress tremors in one direction.

[0007] Semi-active systems typically use embedded sensors to measure vibration amplitude and then adjust the damping force to suppress tremors. In order to generate damping force, semi-active systems generally use magnetorheological fluids, electromagnetic brakes, pneumatic cylinders, etc. Among them, magnetorheological fluids are the most effective solution. The viscosity of magnetorheological fluids can be continuously controlled by the applied magnetic field. It is usually lighter than active systems (about 200 grams to 700 grams) and does not require driving components such as motors, so it is more suitable for human wrists. However, existing magnetic fluid-based flexible wrist exoskeleton mechanisms can usually only provide a damping force of about 10N, so it is difficult to meet actual needs.

[0008] Therefore, there is a need to provide a semi-active exoskeleton system that is designed to overcome or at least minimize the above problems. To this end, the present application provides an exoskeleton and a control method thereof that is not only lightweight but also capable of generating sufficient damping force to effectively suppress tremors in multiple directions simultaneously. In addition, a tremor simulator device is provided that can be used to simulate tremors in different directions, for example, to study the effectiveness of the exoskeleton disclosed herein. Summary of the invention

[0009] According to one embodiment, an exoskeleton is provided. The exoskeleton includes: a first support; a second support; a joint structure that rotatably connects the first support and the second support; and a controller. The second support includes: a first anchoring component connected to the joint structure; a second anchoring component; and a sensor coupled to the controller, wherein the first anchoring component and the second anchoring component are connected by a variable stiffness unit coupled to the controller, and wherein the variable stiffness unit is configured to provide a variable damping force determined by the controller to reduce the amplitude of the tremor sensed by the sensor.

[0010] According to another embodiment, a method of controlling an exoskeleton is provided, the exoskeleton comprising: a first support; a second support; a joint structure that rotatably connects the first support and the second support; and a controller, wherein the second support comprises a first anchoring member connected to the joint structure, a second anchoring member, and a sensor coupled to the controller, and wherein the first anchoring member and the second anchoring member are connected by a variable stiffness unit coupled to the controller. The method comprises: sensing a tremor by the sensor; determining a variable damping force by the controller in response to the sensed tremor; and providing a variable damping force by the variable stiffness unit to reduce the amplitude of the tremor.

[0011] According to another embodiment, a tremor simulator device is provided. The tremor simulator device includes a connecting rod mechanism, a driving motor and a speed controller. The connecting rod mechanism includes a first rod and a second rod configured to rotate relative to each other, and a third rod fixedly connected to the second rod, wherein the third rod is configured to perform linear reciprocating motion relative to the second rod, and wherein the speed controller is configured to control the driving motor to drive the first rod and the second rod to rotate and drive the third rod to perform linear reciprocating motion, thereby causing tremor at the extremity coupled to the tremor simulator device. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The embodiments and implementations of the present invention are provided by way of example only, and may be better understood by those of ordinary skill in the art by reading the following written description in conjunction with the accompanying drawings, in which:

[0013] Figure 1 A schematic diagram of an exoskeleton 100 is shown according to one embodiment.

[0014] Figure 2 A diagram 200 is shown describing another embodiment of an exoskeleton. In this embodiment, the exoskeleton is coupled to the arm and wrist of the wearer. It will be appreciated by those skilled in the art that the exoskeleton can be coupled to other parts of the wearer's body as needed.

[0015] Figure 3 A diagram 300 is shown describing another embodiment of an exoskeleton. In this embodiment, the exoskeleton further includes a vacuum pump that is disposed at the waist of the wearer and is connected to other components of the exoskeleton disposed at the arms and wrists. It will be appreciated by those skilled in the art that the vacuum pump may be disposed at other parts of the wearer's body as desired.

[0016] Figure 4a A diagram 400 showing human wrist motion is shown.

[0017] Figure 4bA diagram 450 illustrating the major muscles and bones involved in wrist tremor is shown.

[0018] Figure 5 Shown are: diagram 500 depicting one embodiment of a chain mail-like structural fabric; diagram 510 depicting the configuration of the chain mail-like structural fabric in an unobstructed, soft state; and diagram 520 depicting the configuration of the chain mail-like structural fabric in an obstructed, hard state.

[0019] Figure 6 is a flow chart illustrating a method 600 of controlling an exoskeleton according to one embodiment.

[0020] Figure 7 A schematic diagram of a control framework 700 for implementing the method 600 of controlling an exoskeleton according to one embodiment is shown.

[0021] Figure 8a A schematic diagram of a three-point bending test apparatus 800 is shown, which can be used to test the damping forces provided by various embodiments of the exoskeleton of the present application in different directions.

[0022] Figure 8b , Figure 8c and Figure 8d The deformation of the variable stiffness unit of various embodiments of the exoskeleton during wrist extension, flexion, and abduction / adduction, respectively, is shown.

[0023] Figure 9a A schematic diagram of a torsion testing system 900 is shown that can be used to test the damping torque provided by various embodiments of the exoskeleton of the present application.

[0024] Figure 9b An embodiment of a torsion testing platform 902 for use in torsion testing system 900 is shown.

[0025] Fig.10a A graph is shown which illustrates experimental results of the damping force in the extension direction versus the rotation angle at different operating negative pressures.

[0026] Fig.10b A graph is shown which illustrates experimental results of the damping force in the flexion direction versus the rotation angle at different working negative pressures.

[0027] Fig.10c A graph is shown which illustrates experimental results of damping force in abduction / adduction direction versus rotation angle at different working negative pressures.

[0028] Fig.10d A graph is shown which illustrates experimental results of the damping force in the pronation / supination direction versus the rotation angle at different negative working pressures.

[0029] Fig.11a A bar graph is shown which illustrates the critical flutter angle in the extension direction at various operating negative pressures.

[0030] Fig.11b A bar graph is shown which illustrates the critical flutter angle at various operating negative pressures in the flexion direction.

[0031] Fig.11c A bar graph is shown illustrating the critical flutter angle at various operating negative pressures in the abduction direction.

[0032] Fig.11d A bar graph is shown illustrating the critical flutter angle at various operating negative pressures in the adduction direction.

[0033] Fig.11e A bar graph is shown illustrating the critical tremor angle at various operating negative pressures in the pronation direction.

[0034] Fig.11f A bar graph depicting the critical tremor angle at various operating negative pressures in the supination direction is shown.

[0035] Fig.12 A diagram 1200 is shown illustrating another embodiment of an exoskeleton in an experimental scenario.

[0036] Fig.13a Graphs showing the amplitude-frequency characteristics of wrist tremor in extension and flexion directions at various operating negative pressures are shown.

[0037] Fig.13b A graph is shown showing the amplitude-frequency characteristics of wrist tremor in abduction and adduction directions at various operating negative pressures.

[0038] Fig.13c Graphs showing the amplitude-frequency characteristics of wrist tremor in the pronation and supination directions at various operating negative pressures are shown.

[0039] Fig.13d Graphs are shown showing electromyographic (EMG) signals during extension and flexion tremors at various operating negative pressures.

[0040] Fig.13e Graphs are shown showing EMG signals during abduction and adduction tremors at various operating negative pressures.

[0041] Fig.13f Graphs showing EMG signals during pronation and supination tremor at various operating negative pressures are shown.

[0042] Fig.14a A schematic diagram of a tremor simulator apparatus according to one embodiment is shown.

[0043] Fig.14b An embodiment of a line sensor and its testing principle is shown.

[0044] Fig.14c An embodiment of a tremor simulator device is shown.

[0045] Fig.15a A graph is shown which illustrates the change in maximum displacement of the wrist at different operating negative pressures in extension and flexion directions at tremor frequencies in the range of 2.2 Hz to 2.7 Hz.

[0046] Fig.15b A graph is shown which illustrates the change in maximum displacement of the wrist at different operating negative pressures in extension and flexion directions at tremor frequencies in the range of 3.4 Hz to 3.7 Hz.

[0047] Skilled technicians will understand that the elements in the figures are shown for simplicity and clarity and are not necessarily drawn to scale. For example, the size of some elements in the schematic diagram, block diagram or flow chart may be exaggerated relative to other elements to help deepen the understanding of the current embodiment. DETAILED DESCRIPTION

[0048] Embodiments will be described by way of example only with reference to the accompanying drawings, in which like reference numerals and characters refer to like elements or equivalents.

[0049] The embodiments of the present application provide an exoskeleton and a control method thereof that is not only light in weight but also capable of generating sufficient damping force to effectively suppress tremors in multiple directions at the same time. A tremor simulator device is also provided, which can be used to simulate tremors in various directions, for example, to study the effectiveness of the exoskeleton disclosed herein.

[0050] Figure 1 1 shows a schematic diagram of an exoskeleton 100 according to one embodiment. In this embodiment, the exoskeleton 100 includes a first support 102, a second support 104, a controller 116, and a joint structure 106 that rotatably connects the first support 102 and the second support 104. The second support 104 includes a first anchoring component 108, a second anchoring component 110, and a sensor 114 coupled to the controller 116. In the second support 104, the first anchoring component 108 is connected to the joint structure 106.

[0051] exist Figure 1In the illustrated embodiment, the joint structure 106 includes two arm members. Each of the two arm members has a first end that is securely engaged with the first support 102 or the second support 104, respectively (i.e., at the first anchoring member 108). Each of the two arm members has a second end that is rotatably interconnected to each other, which in turn provides a rotatable connection between the first support 102 and the second support 104.

[0052] In some embodiments, the rotatable interconnection of the two arm members is achieved by a separate rotatable component. In other embodiments, the rotatable interconnection of the two arm members can be achieved without a separate rotatable component. For example, the rotatable interconnection of the two arm members can be achieved in the following manner: the second ends of the two arm members are coupled to each other to form an integral connection, which allows a certain degree of angular movement around the coupling point. It can be understood by those skilled in the art that the rotatable interconnection of the two arm members and the subsequent rotatable connection between the first support member 102 and the second support member 104 are not limited to the above-mentioned embodiments, but can also be achieved in other ways according to actual needs.

[0053] In an alternative embodiment, instead of two arm members, the joint structure 106 may include a single arm member having a first end securely engaged with the first support 102 and a second end securely engaged with the second support 104 (i.e., at the first anchoring member 108). The arm member needs to have a certain rigidity to withstand vibrations, while also having a certain flexibility to allow the arm member to bend when the user bends their limb in which the exoskeleton is located.

[0054] Those skilled in the art will appreciate that the shape and configuration of the joint structure 106 are not limited to the above embodiments, but may also be implemented in other ways according to actual needs.

[0055] In an embodiment, the secure engagement between the arm member of the joint structure 106 and the first support member 102 and the second support member 104 (particularly the first anchoring member 108) can be a fixed attachment or a removable attachment. The fixed attachment can be achieved by a bolt and nut mechanism, welding, a strong adhesive, or other mechanisms that can be understood by those skilled in the art.

[0056] For removable attachment, Figure 2An embodiment is shown. In this embodiment, the joint structure 106 includes two arm members. Each of the two arm members includes a support structure on the first end. The first anchoring component 108 of the first support member 102 and the second support member 104 can be arranged through the support structure or arranged above the support structure, and the support structure can be fastened to form a secure connection. By loosening the first support member 102 and the second support member 104 (particularly the first anchoring component 108), this secure connection can be removed. In this embodiment and other embodiments of this specification, the first support member 102 and the second support member 104 can be made of various materials, such as elastic bands, or lightweight metals and alloy substitutes, such as aluminum, titanium and magnesium. This removable attachment facilitates providing better portability and easy assembly of the exoskeleton, and allows the position or positioning of the exoskeleton to be adjusted by adjusting the support structure, thereby providing more convenience for the user.

[0057] In the second support member 104, the first anchoring member 108 and the second anchoring member 110 are connected by a variable stiffness unit 112 coupled to a controller 116. The variable stiffness unit 112 is configured to provide a variable damping force determined by the controller 116 to reduce the amplitude of the tremor sensed by the sensor 114. The provision of the variable damping force will be described in the following paragraphs, especially with respect to Figure 6 and Figure 7 Give a description.

[0058] Reference Figure 6 , an exemplary method 600 of controlling the exoskeleton 100 to provide a variable damping force is shown. The method 600 includes at least the following steps.

[0059] In step 602 , tremors are sensed by sensor 114 .

[0060] In step 604 , the controller 116 is configured to determine a variable damping force in response to the sensed tremor.

[0061] Thereafter, in step 606 , a variable damping force is provided by the variable stiffness unit 112 to reduce the amplitude of the vibration.

[0062] In some embodiments, exoskeleton 100 may further include a vacuum pump. In these embodiments, method 600 may further include the following steps.

[0063] - when a tremor is sensed at step 602, detecting a tremor signal received from the sensor 114 by the controller 116; and

[0064] - The vacuum pump is controlled by the controller 116 to activate the variable stiffness unit 112 to provide a variable damping force.

[0065] That is, in response to detection by the controller 116 of a vibration signal received from the sensor 114 when the vibration is sensed, the controller 116 is configured to control the vacuum pump to activate the variable stiffness unit 112 to provide a variable damping force.

[0066] Those skilled in the art will appreciate that, in addition to the vacuum pump, the variable stiffness unit 112 may be activated by other mechanisms to provide a variable damping force. For example, other methods of activating the variable stiffness unit include using a strong electric field or a strong magnetic field, changing the temperature, and the like.

[0067] exist Figure 2 , an embodiment 200 is shown in which the exoskeleton 100 is coupled to the arm and wrist of a user. In this specification, the user is interchangeably referred to as the wearer. As described above, it will be appreciated by those skilled in the art that the exoskeleton 100 can be coupled to other parts of the wearer's body as needed.

[0068] In embodiment 200, the first support can be coupled to the upper arm of the wearer of the exoskeleton 100. The first anchoring member of the second support 204 can be coupled to the forearm of the wearer of the exoskeleton 100. In this case, Figure 1 As shown, the joint structure 106 is an elbow joint 206, which includes two arm members. Each of the two arm members includes a support structure on the first end, i.e., an upper arm support 202 or a wrist support 208. The first anchoring components of the first support member and the second support member 104 can be arranged through the support structure 202, 208 or can be arranged above the support structure 202, 208, and the support structure 202, 208 can be fastened to form a secure connection. By loosening the first support member 102 and the second support member 104 (particularly the first anchoring component 108), this secure connection can be removed. In this embodiment and other embodiments of this specification, the first support member 102 and the second support member 104 can be made of various materials, such as elastic bands, or lightweight metals and alloy substitutes, such as aluminum, titanium and magnesium.

[0069] In embodiment 200, the second anchoring member 214 of the second support 204 can be coupled to the hand of the wearer of the exoskeleton, for example, via the hand support 210. The sensor 214 is configured to be located on or near the hand. For example, the sensor 214 can be an inertial measurement unit (IMU) sensor.

[0070] In the embodiment 200, the variable stiffness unit 212 is located at or near the wrist of the wearer of the exoskeleton, spanning from the first anchoring member 208 to the second anchoring member 214. This arrangement facilitates providing a large coverage area for the variable stiffness unit 212, thereby providing sufficient damping force to reduce the tremor sensed in the user's arm and wrist. It will be appreciated by those skilled in the art that the coverage area of ​​the variable stiffness unit 212 can be modified to a larger or smaller coverage area according to the actual tremor suppression requirements. For example, if the tremor of a particular user is not severe, the configuration of the variable stiffness unit 212 can be modified to occupy only a portion of the area spanning from the first anchoring member 208 to the second anchoring member 214. The variable stiffness unit 212 can include an airtight silicone skin wrapped around two layers of chain mail-like structural fabric (details of which will be described below). It is worth noting that even when the exoskeleton 100 is working, the user may prefer to slightly flex the wrist to perform movements such as grasping. Therefore, the damping force provided by the exoskeleton 100 in flexion must be slightly lower than the forces in other directions. Based on this, an arched structure is invented that matches the back of the arm, which enables bending in the flexion direction.

[0071] Figure 3 An exemplary embodiment 300 is shown in which the exoskeleton 100 further includes a vacuum pump 318 disposed at the waist of the wearer and connected to other components 301 of the exoskeleton 100 disposed at the arms and wrists. In this embodiment, a controller 316 may be provided together with the vacuum pump 318 and auxiliary devices such as a battery 322 and a relay 324 mounted at the waist of the wearer. It will be appreciated by those skilled in the art that the vacuum pump 318 may be disposed at other parts of the wearer's body as required.

[0072] In an alternative embodiment, the vacuum pump may not form part of the exoskeleton 100, but may be provided to the user as an auxiliary device to work in conjunction with the exoskeleton 100 to activate the variable stiffness unit 112 to provide a variable damping force to reduce the amplitude of the tremor.

[0073] Parameters of the embodiment 300 of the exoskeleton 100 are listed in Table 1.

[0074] Table 1 Parameters of the embodiment 300 of the exoskeleton 100

[0075]

[0076] 1*: Model is PENGPU G2BL1288-2.

[0077] 2*: Model number is G1BK1253S.

[0078] 3*: Model number is OOH22H042.

[0079] Tremors may include muscle vibrations / movements in various directions. In some embodiments of the exoskeleton 100, tremors are sensed in one or more of extension and flexion directions, abduction and adduction directions, and pronation and supination directions. In response, the variable stiffness unit 112 may provide a variable damping force in a direction along the direction of the sensed tremor.

[0080] In order to effectively suppress the tremor at the wrist, this specification studies the wrist tremor movement form, that is, the relationship between the tremor amplitude in each direction and the force or torque that causes the corresponding tremor. In this regard, Figure 4a A diagram 400 showing human wrist motion is shown. Figure 4b Diagram 450 is shown to illustrate the major muscles and bones involved in wrist tremor.

[0081] exist Figure 4a , diagram 400 shows the anatomical skeletal structure of the human upper limb, including the hand, wrist joint, forearm, distal radioulnar joint and upper arm. The hand has two degrees of freedom (DoF) relative to the forearm. The first DoF is the rotation (flexion and extension) around the X1 axis in the wrist joint coordinate system O1-X1Y1Z1. The typical range of rotatable angles around the X1 axis is [-71°, 73°]. The rotation (abduction and adduction) around the Z1 axis is the second DoF, where the typical range of rotatable angles is between [-19°, 33°]. In the distal radioulnar joint coordinate system O0-X0Y0Z0, the rotation (pronation and supination) around the Y0 axis has a third DoF relative to the upper arm, where the range of rotatable angles is approximately [-86°, 71°]. Wrist tremor includes combined movements of these three DoFs.

[0082] exist Figure 4b In FIG. 4 , diagram 450 shows the flexor carpi radialis (FCR), flexor carpi ulnaris (FCU), extensor carpi radialis brevis (ECRB), extensor carpi radialis longus (ECRL) and extensor carpi ulnaris (ECU), which are muscles involved in wrist tremor. All five muscles work together to enable free movement of the wrist. The bones mainly include the humerus, radius, ulna and metacarpal bones. Although the origin of wrist tremor in the human body is still unclear, most studies have shown that it is related to the central nervous system oscillation of the human body. In other words, the central nervous system electrically stimulates the relevant muscles to activate the tremor.

[0083] According to the research of Steven et al., the wrist joint can be regarded as a universal joint structure with two non-crossed axes. At the same time, the kinematic coupling between flexion and extension and abduction and adduction of the wrist is very small and can be ignored. When the wrist joint is in its natural state with the palm facing inward, the gravity factor will strengthen the adduction direction. In this way, the dynamic equations including the gravity factor can be obtained, as shown in formula (1).

[0084]

[0085] Among them, α, β, and γ are the rotation angles of the wrist joint in flexion and extension, abduction and adduction, and pronation and supination directions, respectively. α , J β , J γ They are the moments of inertia of the wrist joint in flexion and extension, abduction and adduction, and pronation and supination. α 、T β 、T γ are the active torques of the wrist joint in these three directions, which can be regarded as the external torque generated by the force applied to the center of the palm. Their expressions are shown in formula (2). g is the gravity torque acting on the wrist joint causing the wrist to rotate in the adduction direction, and its calculation formula is shown in formula (3).

[0086]

[0087] Among them, K Pi , B Pi , K 1i , K 2i and K 3i is the joint fixation coefficient in the i direction.

[0088] T g = mgdcosβ (3)

[0089] Where m is the mass of the palm, g is the gravitational constant, and d is the distance from the center of mass of the palm to the wrist joint.

[0090] In this specification, it is assumed that the active moment causing wrist tremor in the flexion and extension, abduction and adduction directions is equal to the external force F applied at the center of the palm. α 、F β The active torque that causes the forearm to tremble in the pronation and supination directions is equivalent to the external torque τ applied at the center of the palm γ Therefore, F α 、F β , τ γ With active torque T α 、T β 、Tγ The relationship between can be expressed as follows:

[0091]

[0092] Refer again Figure 1 , when the exoskeleton 100 is worn on the wrist, the hand (not shown) will rotate toward the forearm only when the wrist has a tremor in the flexion and extension, abduction and adduction directions. In this embodiment, the second support member 104 can be fixed to the joint structure 106 at the forearm point C. The variable stiffness unit can completely cover the wrist. When the variable stiffness unit 112 is soft, the wrist point D can rotate freely relative to the point C. When the variable stiffness unit 112 becomes rigid, the connection between the point C and the point D can be regarded as a rigid link, which makes it difficult to rotate relative to the forearm anchor point C. Therefore, the tremor in the flexion and extension, abduction and adduction directions of the arm can be suppressed. Figure 4a and 4b The analysis in shows that when tremor in the pronation and supination directions occurs, the entire forearm will rotate relative to the distal radioulnar joint. In this embodiment, the first support member 102 can be fixed to the joint structure 106 at point A of the upper arm, and the second support member 104 is fixed to the joint structure 106 at point C of the forearm near the elbow. The joint structure 106 can be a rigid joint, which includes two arm members coupled to each other at point B. In this case, compared with the rigid link AB, the rigid link BC has only one degree of freedom, that is, flexion and extension rotation relative to the joint B. When the variable stiffness unit 112 is soft, the wrist point D can still rotate in the pronation and supination directions relative to point C. When the variable stiffness unit 112 is rigid, BC and CD can be regarded as a rigid link. They can only rotate in the flexion and extension directions relative to point B, but not in the pronation and supination directions. Therefore, the tremor of the forearm in the pronation and supination directions can be limited.

[0093] In order to quantify the damping / resistance range that the exoskeleton 100 needs to provide, and to strike a balance between its light weight and maximum damping force, this specification uses formulas (1) to (4) to simulate the relationship between the equivalent forces in flexion and extension and abduction and adduction directions, the equivalent rotational torque that triggers pronation and supination rotation, and the angle of rotation. For simulation in this specification, the Simulink module in MATLAB 2021 Education Edition software is used. The relevant simulation parameters are shown in Table 2. The simulation results are shown in Figures 10a to 10d The dashed line is shown in the figure to facilitate comparison with experimental data.

[0094] Table 2 Simulation parameters

[0095]

[0096] It is desirable that the exoskeleton 100 be made of a lightweight material. In some embodiments, the variable stiffness unit 112 may be made of a chain mail-like structural fabric. The fabric includes a plurality of interlocking particles that conform to the wearer of the exoskeleton 100 in an unblocked state when no pressure is applied to the fabric. The plurality of interlocking particles are configured to undergo a particle blocking transformation to provide a variable damping force when the controller 116 is activated in response to a tremor sensed by the sensor 114.

[0097] Figure 5 Shown are: diagram 500, which describes an embodiment of such a chain mail-like structural fabric; diagram 510, which describes the shape of the chain mail-like structural fabric in an unobstructed, soft state; and diagram 520, which describes the shape of the chain mail-like structural fabric in an obstructed, hard state.

[0098] In diagram 500, the basic particles (or unit particles) that construct the chain mail-like structural fabric are hollow octahedral frameworks, which are beneficial for reducing the overall density and weight while increasing the contact between particles during blocking. Adjacent particles are interlocked and can rotate 90° with each other, thereby forming a topologically interlocked fabric structure.

[0099] In some embodiments, the unit particles and subsequently the chain mail-like structural fabric can be 3D printed from high-strength and lightweight nylon using a selective laser sintering (SLS) method, thereby making the exoskeleton 100 lighter while meeting strength requirements.

[0100] In order to increase the number of particle contacts during occlusion, the embodiments of the present specification construct a double layer of interlocking particles, the layers being stacked on top of each other. Diagram 510 depicts the shape of the chain mail-like structural fabric in an unoccluded state without negative pressure being applied thereto. The double layer configuration allows the chain mail-like structural fabric to be easily bent and folded, thereby allowing the two layers to slide relative to each other while providing good compliance to the wrist. It will be appreciated by those skilled in the art that the chain mail-like structural fabric is not limited to Figure 5 The double-layer configuration shown. The number of layers or the shape and structure of the unit particles can be modified according to actual needs.

[0101] When negative pressure is applied to the chain mail-like structural fabric, the interlocking particles undergo a particle blocking transformation. In this case, as shown in diagram 520, the interlocking particles in the chain mail-like structural fabric form more contacts with their neighboring particles. When blocked, the bending stiffness of the chain mail-like structural fabric increases significantly within a fraction of a second. As such, the method 600 may further include the following step, in which the controller 116 activates the interlocking particles of the chain mail-like structural fabric to undergo a particle blocking transformation, thereby providing a variable damping force in response to the vibration sensed by the sensor 114.

[0102] Figure 7 A schematic diagram of a control framework 700 for implementing the exemplary method 600 of controlling an exoskeleton 100 described herein is shown. In this embodiment, the exoskeleton 100 includes: an inertial measurement unit (IMU) sensor 702 located on or near the hand of the wearer of the exoskeleton 100; a data processing module 704; a controller 706; a relay 708; a vacuum pump 710; and a variable stiffness unit 712 located on or near the wrist 714 of the wearer of the exoskeleton 100. It will be appreciated by those skilled in the art that in alternative embodiments, the IMU sensor 702, the data processing module 704, the controller 706, the relay 708, and / or the vacuum pump 710 may not be part of the exoskeleton 100, but rather provided as an auxiliary device that works in conjunction with the exoskeleton 100.

[0103] In the control framework 700, the IMU sensor 702 senses and collects data about wrist tremor. Then, the data processing module 704 filters the data using a second-order bandpass Butterworth filter with a passband of 2 Hz to 14 Hz. In order to determine the amplitude and / or frequency of the sensed tremor, the filtered data is subjected to Fourier analysis. The amplitude and / or frequency of the sensed tremor is then transmitted to the controller 706. After detecting such a tremor signal, the controller 706 controls the vacuum pump to start or stop by opening or closing the relay 708 in the following manner according to the amplitude and / or frequency of the sensed tremor.

[0104] When the controller 706 detects a vibration signal, the relay 708 is activated and the vacuum pump 710 is turned on to activate the variable stiffness unit 712. Upon activation, the chain mail-like structural fabric in the variable stiffness unit 712 is blocked into a rigid state, thereby effectively suppressing the sensed vibration.

[0105] When the sensed tremor stops, the controller 706 turns off the relay 708, the vacuum pump 710 turns off, and the variable stiffness unit 712 gradually returns to its normal pressure state (1 atmosphere). The chain mail-like structural fabric within the variable stiffness unit 712 gradually returns to its unobstructed soft state. And the wrist 714 can resume its free movement in all directions.

[0106] Figures 8a to 8d , 9a and 9b, 10a to 10d, 11a to 11f, 12 and 13a to 13f show experimental data demonstrating the effectiveness of the damping force and / or torque provided by the exoskeleton 100 described herein. The experimental data demonstrates that the embodiments described herein produce an exoskeleton 100 that is both lightweight and effective to be able to provide sufficient damping force and / or torque to suppress tremors in all three directions.

[0107] The experiments included bending and torsion tests, which were designed to obtain the quantitative relationship between the damping force / torque and deformation under different working negative pressures. The effective working mode was calculated by comparing the damping force / torque with the damping force / torque obtained from the wrist dynamics model set in equations (1) to (4). Details of the experimental data are as follows.

[0108] In more detail, Figure 8a A schematic diagram of a three-point bending test apparatus 800 is shown, which may be used to test the damping forces provided by various embodiments of the exoskeleton 100 in different directions.

[0109] Figure 8b , 8c 8d and 8d illustrate the deformation of the variable stiffness unit 104 of various embodiments of the exoskeleton 100 during wrist extension, flexion, and abduction / adduction, respectively.

[0110] Experimental setup - bending test

[0111] In the bending test, as shown in Figure a (a), the damping force that the exoskeleton 100 can provide in different directions was tested using a three-point bending test device. The variable stiffness unit 104 was attached to a fixed support at the bottom. The test used a MARK-10F305 mechanical tester, which has a force sensor (range: 0N-250N, resolution: 0.01N) and a stroke sensor (range: 0mm-475mm, resolution: 0.005mm). In the test, a hose connected the variable stiffness unit 104 to a vacuum system. During the test, different pressure levels were applied to the exoskeleton 100 to trigger the blocking transformation. The exoskeleton 100 was then pressed (indent) by the mechanical tester. The pressing position was selected at the position where the variable stiffness unit covered the wrist.

[0112] The exoskeleton 100 can bend in four directions: extension, flexion, abduction and adduction. Since the structure of the variable stiffness units is symmetrically distributed in the abduction and adduction directions, only one bending direction needs to be measured in these two directions. The relationship between force and displacement is tested in three different directions. Figure 8b , 8c 8d and 8d show the deformation of the variable stiffness unit during wrist extension, flexion, and abduction / adduction, respectively. The bending performance of the exoskeleton 100 was measured at negative pressures of 0 kPa, 20 kPa, 40 kPa, 60 kPa, and 80 kPa. To obtain quasi-static bending results, the loading rate was set to 0.05 mm / s. The test was repeated three times for each pressure, and the results and standard deviations were then averaged.

[0113] In the torsion test, a test platform was designed and constructed to study the relationship between torsional torque and rotation angle.

[0114] In further detail, Figure 9a A schematic diagram of a torsion testing system 900 is shown, which may be used to test the damping torque provided by the exoskeleton 100 .

[0115] Figure 9b An embodiment of a torsion testing platform 902 for use in torsion testing system 900 is shown.

[0116] Experimental setup - torsion test

[0117] Figure 9a A schematic diagram of the setup of the torsion test system 900 is shown in FIG. Figure 9b One embodiment is shown. It includes a static torque sensor 904, a first flange 906, a variable stiffness unit 908, an angle sensor support, and a second flange 912. The bottom flange of the static torque sensor 904 is bolted to the workbench, and the top flange 912 is bolted to the fixed first flange 906. The fixed first flange 906 has a spacing hole and is interference fit with the bottom spacing shaft of the variable stiffness unit 908. The interference fit connects the top shaft of the variable stiffness unit 908 to the bottom hole of the angle sensor support. The angle sensor 910 is attached to the support, and its extension shaft is coupled to the top fixed structure by a coupling. The variable stiffness unit 908 is linked to the vacuum system by a hose.

[0118] The variable stiffness unit 908 was tested by applying different negative pressures to the structural fabric to trigger the blocking transformation, and then twisting the structural fabric through the rotation angle sensor 910. During this process, the rotation angle and output torque were recorded. The test was repeated three times for each pressure, the average was taken as the result, and the standard deviation was calculated based on the three tests.

[0119] Results and Discussion of Bending and Torsion Tests

[0120] Figures 10a to 10d The fitted curves and their errors for the bending and torsion test results are shown. The shaded area represents the failure interval of the exoskeleton 100.

[0121] In more detail, Fig.10a Graphs are shown which illustrate bending and torsion test results of the damping force in the extension direction versus the rotation angle at different operating negative pressures. Fig.10b Graphs are shown showing bending and torsion test results of the damping force in the flexion direction versus the rotation angle at different operating negative pressures. Fig.10c Graphs are shown showing bending and torsion test results of damping force in abduction / adduction directions versus rotation angle at different operating negative pressures. Fig.10dGraphs are shown showing bending and torsion test results of damping force in the pronation / supination directions versus rotation angle at different negative working pressures.

[0122] Figures 10a to 10d All dotted lines in the figure are the rotation angle-force / torque simulation results obtained by the mathematical model established using formulas (1) to (4).

[0123] because Figures 10a to 10d The results shown in have similar characteristics, so Fig.10a As a representative of the analysis, it is discussed in detail, while Figures 10b to 10d Can be obtained from Fig.10a Extended.

[0124] exist Fig.10a In the experimental results of the damping force relative to the rotation angle under different working negative pressures, it is shown that the damping force increases with the increase of negative pressure and shows a nonlinear relationship. When the negative pressure increases from 0 kPa to 20 kPa, the damping force increases significantly. However, when the negative pressure increases from 20 kPa to 80 kPa, the damping force increases more slowly. In particular, when the negative pressure increases from 60 kPa to 80 kPa, the damping force hardly changes. This indicates that the performance of the exoskeleton 100 reaches saturation within this pressure range.

[0125] In addition, Fig.10a In Figure 2, the simulation results of the damping force relative to the rotation angle are plotted (dashed line). The simulation curve can be divided into three sections: The slope of section I is very small, indicating that only a small force can cause a large wrist tremor amplitude in the extension direction. Section II is a transition section, in which the slope of the curve gradually increases. When the curve reaches section III, the curve becomes very steep, indicating that a very large equivalent external force is required for a slight increase in the wrist tremor amplitude at this stage. Figures 10b to 10d The results in the other directions shown show similar characteristics and can be extended from this discussion.

[0126] In order to quantitatively evaluate the tremor suppression capability of the exoskeleton 100, a critical tremor angle index is introduced. It is defined as Figures 10a to 10d The intersection of the dashed line in and the damping force test curve under various operating negative pressures. If the vibration amplitude is less than this angle ( Figures 10a to 10d If the pressure is 0, the exoskeleton 100 can provide sufficient damping force to suppress wrist tremor under this pressure. Otherwise, the damping force will be insufficient. Based on this, the critical tremor angle under various negative pressures and directions is calculated, as shown in FIG. Figures 11a to 11f As shown, the dotted line represents the maximum angle that the wrist can reach in that direction.

[0127] In more detail, Fig.11a A bar graph is shown which illustrates the critical flutter angle in the extension direction at various operating negative pressures. Fig.11b A bar graph is shown which illustrates the critical flutter angle at various operating negative pressures in the flexion direction. Fig.11c is a bar graph showing the critical flutter angle at various operating negative pressures in the abduction direction. Fig.11d is a bar graph showing the critical flutter angle at various operating negative pressures in the adduction direction. Fig.11e is a bar graph showing the critical tremor angle at various operating negative pressures in the pronation direction. Fig.11f is a bar graph showing the critical tremor angle at various operating negative pressures in the supination direction.

[0128] according to Figures 11a to 11f , showing that the critical tremor angle generated by the exoskeleton 100 can fully cover the maximum wrist rotation angle when the working pressure in the extension, flexion, abduction and pronation directions is above 20 kPa. When the working pressure reaches 80 kPa, the critical tremor angle achieved by the exoskeleton 100 can reach 85.9%, 77.80%, 81.8% and 94.3% of the maximum rotation angle, respectively. In addition, the percentage of the critical tremor angle in the flexion direction is the lowest, which means that its ability to limit tremor in this direction is weak, which is exactly what the user expects. In addition, when the working pressure in all directions except abduction increases from 0 kPa to 20 kPa, the critical tremor angle covered by the exoskeleton 100 increases significantly (increases by 21.4° to 63.0°). However, when the working negative pressure is increased from 20 kPa to 80 kPa, the increase in the critical tremor angle is only 3.0° to 13.5°. This also shows that the suppression performance of the exoskeleton 100 reaches saturation at a certain pressure level. Since achieving a higher negative pressure requires a significant increase in the size and weight of the vacuum device, working at a lower negative pressure will be beneficial to the portability and miniaturization of the system. Therefore, according to the experiments in this article, it is more cost-effective to choose a working negative pressure limit of 20kPa.

[0129] When determining the working pressure of the exoskeleton 100, the actual needs of the user are considered. If the user's tremor amplitude is small, working at a negative pressure of 20 kPa is conducive to the small and lightweight design of the exoskeleton 100. When selecting a commercial vacuum pump, the rated working pressure should be slightly higher to ensure that the continuous working pressure of the exoskeleton 100 can reach the set pressure. According to the analysis of the commercial pump parameters shown in Table 2, the negative pressure limit of the variable stiffness device 112 is set to 20 kPa, and a vacuum pump with a working negative pressure of 40 kPa can better balance the device performance and lightness. If the user has severe tremor, the working negative pressure can be set to 80 kPa. Although this will increase the overall weight of the exoskeleton 100, the tremor in the adduction and supination directions can be completely eliminated, while greatly suppressing the tremor in other directions.

[0130] Prototype performance evaluation

[0131] Fig.12 A diagram 1200 is shown showing another embodiment of an exoskeleton in an experimental scenario. This embodiment is a prototype exoskeleton.

[0132] After the damping force and torque experiments described above, the prototype was assembled. Two experiments were conducted to evaluate the tremor suppression performance of the prototype. In the first experiment, the ability of the prototype to suppress hand tremors was tested under active tremor conditions, during which the wearer actively shook their hands. During this experiment, the real-time response and signal acquisition capabilities of the prototype were also evaluated. In the second experiment, a tremor simulator device was constructed based on a motor-driven linkage mechanism to test the tremor suppression performance. The tremor simulator device is an important contribution of this specification as it can effectively generate tremors at controllable frequencies and amplitudes to demonstrate the effectiveness of the exoskeleton 100. For the human experiments in this study, all subjects signed informed consent. The experiments conducted at Nanyang Technological University were approved by the Ethics Committee. The experimental procedures were in accordance with the Declaration of Helsinki.

[0133] The first experiment - active tremor experiment and result analysis

[0134] A young male participant was selected for the study to conduct an active tremor experiment. The subject was 32 years old and had a hand length of approximately 18 cm. Wrist flexion and extension, abduction and adduction movements, and rotation of the distal radioulnar joint relative to the forearm were tested (pronation and supination). During the experiment, the participant was asked to swing his wrist or rotate his forearm as much as possible at a frequency of 2 Hz to 6 Hz. The participant shook for 10 seconds in a free state (without wearing the exoskeleton 100). The motion data measured by the IMU sensor was set as the reference group. The subject was then asked to wear the exoskeleton 100 and shake at different negative pressures: 0 kPa, 40 kPa, and 80 kPa. The motion data measured by the IMU sensor was set as the experimental group.

[0135] like Figure 4a and 4b It can be seen that when the wrist is shaken in flexion and extension, abduction and adduction, the radial flexor carpi shows obvious muscle activity. When the forearm is rotated relative to the distal radioulnar joint, the triceps brachii shows obvious muscle activity. In order to minimize the subjective influence of the participants, the electromyography (EMG) sensors were used to collect the EMG signals of these two muscles in real time. The sampling rate was set to 100Hz. Fig.12 Shown is the prototype exoskeleton in an active tremor experiment.

[0136] In this experiment, the IMU sensor collected wrist tremor data at 0 kPa, 40 kPa, and 80 kPa in all directions. In addition, the collected data was Fourier transformed to obtain the relationship between tremor amplitude and frequency, such as Figures 13a to 13c shown. Figures 13d to 13f Shown are the EMG signals of the muscle surface during wrist tremor at different working negative pressures.

[0137] Figures 13d to 13f It is shown that the surface EMG signal amplitude without tremor under different pressures was about 1.55V. During tremor, the surface EMG signal values ​​measured in extension and flexion, abduction and adduction, and pronation and supination directions were 1.4V to 1.7V, 1.5V to 1.7V, and 1.3V to 1.8V, respectively, and there was no significant difference in the EMG signal amplitude. This result shows that the tremor force activation initiated by the participants was similar under different pressure conditions during the experiment, indicating that the participants had less subjective influence.

[0138] according to Figures 13a to 13c Table 3 shows the maximum tremor amplitude of the wrist and forearm under different working negative pressures.

[0139] Table 3 Maximum amplitude of wrist tremor in three directions under different negative pressures

[0140]

[0141] In order to quantify the tremor suppression effect of this experiment, the tremor suppression efficiency η was defined Exp1 , as shown in formula (5):

[0142]

[0143] Among them, i| P represents the experimentally determined flutter angle at pressure P, i| FREE represents the experimentally determined tremor angle in the free state.

[0144] Fig.13a Graphs showing the amplitude-frequency characteristics of wrist tremor in extension and flexion directions at various operating negative pressures are shown. Fig.13b A graph is shown showing the amplitude-frequency characteristics of wrist tremor in abduction and adduction directions at various operating negative pressures. Fig.13c Graphs showing the amplitude-frequency characteristics of wrist tremor in the pronation and supination directions at various operating negative pressures are shown. Fig.13d Graphs are shown showing electromyographic (EMG) signals during extension and flexion tremors at various operating negative pressures. Fig.13e Graphs are shown showing EMG signals during abduction and adduction tremors at various operating negative pressures. Fig.13f Graphs are shown that depict EMG signals during pronation and supination tremors at various operating negative pressures.

[0145] like Figures 13a to 13f As shown in Table 3, when the operating negative pressure of the exoskeleton 100 is set to 0 kPa, the tremor suppression efficiency η in the extension and flexion, abduction and adduction, and pronation and supination directions is Exp1 When the working negative pressure is set to 40 kPa, the η in the above three directions is Exp1 When the working negative pressure is set to 80 kPa, the vibration suppression efficiency η in the three directions is Exp1 The results show that when the exoskeleton 100 is in an inactive state (0 kPa), the tremor suppression effect is minimal in the extension and flexion and pronation and supination directions, and the exoskeleton 100 provides little resistance to wrist movement. When the exoskeleton 100 is activated at a moderate pressure (40 kPa), the tremor can be significantly suppressed. When the exoskeleton 100 is fully activated (80 kPa), the tremor suppression increases to a maximum value, but the difference from 40 kPa is relatively small, indicating that further increasing the negative pressure has little effect on improving the tremor suppression performance.

[0146] The above experiments show that the damping force and torque have a positive but nonlinear relationship with the negative pressure. When the negative pressure exceeds 40 kPa, the increase rate of the damping force and torque is obviously saturated.

[0147] When the exoskeleton 100 was in an inactive state (0 kPa), the vibration in the abduction and adduction directions was reduced by about half compared to when not worn, indicating that the exoskeleton 100 still partially restricted wrist motion even in the soft state. Figures 10a to 10d and Figures 11a to 11f The results are consistent with the critical tremor angle experiments described above. Note that the user's daily activities are not significantly affected by the movement of the wrist in the abduction and adduction directions. When the exoskeleton 100 is fully activated (80 kPa), the tremor attenuation is further increased, and the exoskeleton 100 is shown to effectively suppress wrist tremor in the abduction and adduction directions.

[0148] Second experiment - Tremor simulator and experimental results

[0149] Fig.14a A schematic diagram of a tremor simulator apparatus according to one embodiment is shown. Fig.14b An embodiment of a line sensor and its testing principle is shown. Fig.14c An embodiment of a tremor simulator device is shown.

[0150] exist Fig.14c In the illustrated embodiment, the tremor simulator device includes a linkage mechanism 1402, a drive motor 1404, and a speed controller 1406. The linkage mechanism 1402 includes a first rod and a second rod configured to rotate relative to each other, and a third rod fixedly connected to the second rod. The third rod is configured to perform linear reciprocating motion relative to the second rod. The speed controller 1406 is configured to control the drive motor to drive the first rod and the second rod to rotate and drive the third rod to perform linear reciprocating motion, thereby causing tremors at the end of the limb coupled to the tremor simulator device.

[0151] In some embodiments, the tremor simulator device further comprises a limb holder capable of being coupled to the limb. The linkage mechanism is rotatably connected to an end of the limb holder.

[0152] In some embodiments, the limb may be a forearm of the user. In this case, the limb holder is configured to couple to the forearm of the user. Fig.14c As illustrated in , in this case, the limb holder is an arm support 1408. It can be understood that the limb holder can be coupled to other parts of the user according to actual needs.

[0153] In some embodiments, the tremor simulator device further comprises a sensor configured to be placed on a user's hand. The sensor is configured to measure the displacement of the user's hand relative to the forearm in the extension and flexion directions at a predetermined tremor frequency and a predetermined tremor value. It can be understood that the sensor can also be placed on other parts of the user according to actual needs.

[0154] For example, the predetermined frequency of the tremor may be within a low frequency range of 2.2 Hz to 2.7 Hz or 3.4 Hz to 3.7 Hz. It is understood that the predetermined frequency of the tremor may be within other frequency ranges.

[0155] During the test, the user's forearm is restrained by the arm support 1408. The speed controller controls the motor 1404 and drives the rods l1 and l2 to rotate so that the rod l3 performs linear reciprocating motion. At the same time, when l3 performs linear reciprocating motion, it causes the rod l4 (arm support 1408) to rotate around the rotational substitute 1 (Rotate Sub1), causing the forearm to shake up and down. When the hand is completely relaxed, the hand will swing relative to the forearm due to inertia. Therefore, hand tremor can be simulated.

[0156] In addition, a wire sensor was selected to measure the change in displacement from the back of the hand to the forearm. During the test, one end of the wire sensor was attached to the forearm and the other end was attached to the back of the hand. Fig.14bThe operating principle is shown. If there is no wrist tremor, the relative displacement of the back of the hand relative to the forearm is small, and the signal of the line sensor is also small. If the wrist tremor is severe, the back of the hand will have a larger relative displacement change compared to the forearm, and the line sensor will also output a higher signal.

[0157] In the experiment, the relative displacement of the hand back relative to the forearm in the extension and flexion directions was measured at 0kPa, 40kPa and 80kPa at lower (2.2Hz to 2.7Hz) and higher (3.4Hz to 3.7Hz) tremor frequencies. In addition, the collected data were Fourier transformed to obtain the variation of tremor amplitude with frequency, such as Fig.15a and Fig.15b shown.

[0158] Fig.15a A graph is shown which illustrates the change in maximum displacement of the wrist at different operating negative pressures in extension and flexion directions at tremor frequencies in the range of 2.2 Hz to 2.7 Hz.

[0159] Fig.15b A graph is shown which illustrates the change in maximum displacement of the wrist at different operating negative pressures in extension and flexion directions at tremor frequencies in the range of 3.4 Hz to 3.7 Hz.

[0160] By analyzing Fig.15a and Fig.15b , the maximum displacement changes of the wrist in the extension and flexion directions at lower and higher tremor frequencies and under different operating negative pressures can be obtained, as shown in Table 4.

[0161] Table 4 Maximum tremor amplitude of wrist in extension and flexion direction at different working negative pressures and frequencies

[0162]

[0163] In order to quantify the tremor suppression effect in this experiment, the tremor suppression efficiency η is defined as shown in formula (6): Exp2 :

[0164]

[0165] Among them, L| P Represents the displacement measured by the displacement sensor under pressure P. L| FREE Represents the displacement measured by the displacement sensor in a free state.

[0166] like Fig.15a As shown in Table 4, when the tremor occurs at a low frequency, when the exoskeleton 100 is worn and the negative pressure is 0 kPa, the extension and flexion tremor suppression efficiency η Exp2is about 67.31%. When the negative pressure increases to 40 kPa, η Exp2 When the negative pressure reaches 80 kPa, η Exp2 The experimental results show that wearing the exoskeleton 100 under low-frequency tremor conditions can significantly suppress wrist tremor. Fig.15b As shown in Table 4, when wearing the exoskeleton 100 and experiencing higher frequency tremors, the extension and flexion η Exp2 is about 46.16%, and the negative pressure is 0 kPa. When the negative pressure increases to 40 kPa, η Exp2 Increased to about 68.56%. When the negative pressure reaches 80kPa, η Exp2 The experimental results show that wearing the exoskeleton 100 can significantly suppress wrist tremor under low-frequency tremor conditions, while wearing the inactive exoskeleton 100 has little effect on the movement of the wrist in the extension and flexion directions under high-frequency tremor conditions. When the exoskeleton 100 is fully activated, wrist tremor can be effectively suppressed.

[0167] From the above experiments, it can be seen that the tremor suppression efficiency of the exoskeleton 100 of the present application in all directions is about 52.78% to 78.28%. In terms of tremor suppression freedom, the exoskeleton 100 of the present application can suppress tremors in all three directions. In terms of weight, the wrist portion of the exoskeleton 100 (i.e., the second support member 104 including the variable stiffness unit 112) is only about 277 grams, which is relatively light and portable. In addition, compared with other existing prototypes, the exoskeleton 100 of the present application can achieve a higher damping force. Therefore, the present application realizes an exoskeleton 100 that is compact, lightweight, conformable to the body and comfortable to wear.

[0168] Table 5 Performance parameters of Exoskeleton 100

[0169]

[0170] EFE: elbow flexion / extension; FAA: forearm abduction / adduction; FPS: forearm pronation / supination;

[0171] WFE: wrist flexion / extension; WF: wrist flexion; WE: wrist extension

[0172] WPS: wrist pronation / supination; WAA: wrist abduction / adduction; WAB: wrist adduction, WAD: wrist abduction.

[0173] *: Damping force according to Figures 10a to 10d The analysis in

[0174] Those skilled in the art will appreciate that many changes and / or modifications may be made to the invention shown in the specific embodiments without departing from the spirit or scope of the invention as broadly described. Therefore, the embodiments of the present invention are to be considered in all aspects as illustrative and not restrictive.

Claims

1. An exoskeleton, comprising: a first support member; a second support member; a joint structure, the joint structure rotatably connecting the first support member and the second support member; as well as Controller, The second support member comprises: a first anchoring member connected to the joint structure; a second anchoring member; and a sensor coupled to the controller, wherein the first anchoring member and the second anchoring member are connected via a variable stiffness unit coupled to the controller, and The variable stiffness unit is configured to provide a variable damping force determined by the controller to reduce an amplitude of a tremor sensed by the sensor.

2. The exoskeleton according to claim 1, further comprising: A vacuum pump, wherein, in response to detection of a vibration signal received by the controller from the sensor when vibration is sensed, the controller is configured to control the vacuum pump to activate the variable stiffness unit to provide a variable damping force.

3. An exoskeleton according to claim 1 or 2, in, The first support member is coupleable to an upper arm of a wearer of the exoskeleton, wherein the first anchoring member of the second support is capable of being coupled to a forearm of a wearer of the exoskeleton, wherein the second anchoring member of the second support is coupleable to a hand of a wearer of the exoskeleton, and the sensor is configured to be located on or near the hand, and The variable stiffness unit is located at or near a wrist of a wearer of the exoskeleton, spanning from the first anchoring component to the second anchoring component.

4. An exoskeleton according to any one of the preceding claims, in, The tremor is sensed in one or more of extension and flexion, abduction and adduction, and pronation and supination, and Wherein the variable damping force is provided in a direction along the sensed vibration.

5. The exoskeleton according to claim 2, in, The variable stiffness unit is made of chain mail-like structural fabric. wherein the fabric comprises a plurality of interlocking particles that conform to a wearer of the exoskeleton in an unobstructed state when no pressure is applied to the fabric, and Wherein, upon activation of the controller in response to a tremor sensed by the sensor, the plurality of interlocking particles are configured to undergo a granular blocking transformation to provide the variable damping force.

6. The exoskeleton according to claim 5, in, The chain mail-like structural fabric is 3D printed using a selective laser sintering (SLS) method using high-strength, lightweight nylon.

7. A method for controlling an exoskeleton, the exoskeleton comprising a first support member, a second support member, a joint structure rotatably connecting the first support member and the second support member, and a controller, wherein: The second support member includes: a first anchoring member connected to the joint structure; a second anchoring member; and a sensor coupled to the controller, and wherein the first anchoring member and the second anchoring member are connected by a variable stiffness unit coupled to the controller, The method includes: sensing tremors by means of the sensor; determining, by the controller, a variable damping force in response to the sensed tremor; and The variable damping force is provided by the variable stiffness unit to reduce the amplitude of the vibration.

8. The method according to claim 7, wherein: The exoskeleton further comprises a vacuum pump, and wherein the method further comprises: When sensing tremor, detecting, by the controller, a tremor signal received from the sensor; and The vacuum pump is controlled by the controller to activate the variable stiffness unit to provide the variable damping force.

9. The method according to claim 7 or 8, further comprising: coupling the first support member to an upper arm of a wearer of the exoskeleton; coupling the first anchoring member of the second support member at a forearm of a wearer of the exoskeleton; coupling the second anchoring member of the second support at a hand of a wearer of the exoskeleton such that the sensor is located at or near the hand; as well as The variable stiffness unit is positioned at or near a wrist of a wearer of the exoskeleton, spanning from the first anchoring member to the second anchoring member.

10. The method according to any one of claims 7 to 9, further comprising: In response to tremor sensed by the sensor in one or more of extension and flexion directions, abduction and adduction directions, and pronation and supination directions, the variable damping force is provided by the variable stiffness unit along the direction of the sensed tremor.

11. The method according to claim 8, in, The variable stiffness unit is made of a chain mail-like structural fabric, and wherein the fabric includes a plurality of interlocking particles that conform to a wearer of the exoskeleton in an unobstructed state when no pressure is applied to the fabric, and wherein the method further comprises: In response to a tremor sensed by the sensor, the plurality of interlocking particles are activated by the controller to undergo a particle blocking transition to provide the variable damping force.

12. A tremor simulator device, the tremor simulator device comprising: Connecting rod mechanism; Drive motor; as well as Speed ​​controller, The linkage mechanism comprises a first rod and a second rod configured to rotate relative to each other, and a third rod fixedly connected to the second rod, wherein the third rod is configured to perform linear reciprocating motion relative to the second rod, and The speed controller is configured to control the drive motor to drive the first rod and the second rod to rotate and drive the third rod to perform the linear reciprocating motion, thereby inducing tremor at the end of the limb coupled to the tremor simulator device.

13. A tremor simulator device, the tremor simulator device further comprising: A limb holder is coupleable to a limb, wherein the linkage is rotatably connected to an end of the limb holder.

14. The tremor simulator device according to claim 13, wherein: The limb holder is configured to be coupled to a forearm of a user.

15. The tremor simulator device according to claim 14, further comprising: A sensor is configured to be placed on a user's hand, wherein the sensor is configured to measure the displacement of the user's hand relative to the forearm in extension and flexion directions at a predetermined tremor frequency when the tremor is a predetermined value.

16. The tremor simulator device according to claim 15, wherein: The predetermined vibration frequency is within a low frequency range of 2.2 Hz to 2.7 Hz.

17. The tremor simulator device according to claim 15, wherein: The predetermined vibration frequency is within a low frequency range of 3.4 Hz to 3.7 Hz.

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