WO2024012573A1

WO2024012573A1 - Real-time adjustable kinesthetic and haptic glove apparatus

Info

Publication number: WO2024012573A1
Application number: PCT/CN2023/107493
Authority: WO
Inventors: Chung Wai James CHEUNG; Wai Chi WONG; Pak Hei Bryan SO; Shiu Wang Ethan CHENG; Yiu Chau Andy TAM
Original assignee: The Hong Kong Polytechnic University
Priority date: 2022-07-14
Filing date: 2023-07-14
Publication date: 2024-01-18

Abstract

A haptic glove apparatus wearable by a user for providing tactile and kinesthetic feedback is provided. The haptic glove apparatus includes a glove body and a haptic device coupled to the glove body. The glove body has a finger portion to cover one or more fingers of the user. The haptic device includes one or more anchors positioned at distal ends of the finger portion; one or more feedback modules; and a tendon routing arrangement. The tendon routing arrangement includes one or more tendon wires connecting between the one or more feedback modules and the one or more anchors for exerting a flexion tension and an extension tension on each of the one or more fingers. Each of the one or more feedback modules is configured to adjust the flexion tension and the extension tension to generate a resistive sensation for simulating a contact of a virtual object.

Description

REAL-TIME ADJUSTABLE KINESTHETIC AND HAPTIC GLOVE APPARATUS

Inventor: Chung Wai James CHEUNG; Wai Chi WONG; Pak Hei Bryan SO; Shiu Wang Ethan CHENG; Yiu Chau Andy TAM

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of the US Provisional Patent Application No. 63/368,372, filed on July 14, 2022, which is incorporated by reference herein in its entirety.

FIELD OF THE INVENTION

The present disclosure generally relates to the field of virtual reality (VR) for rehabitation. In particular, the present disclosure relates to the glove apparatus for providing tactile and kinesthetic feedback in VR rehabilitation applications.

BACKGROUND OF THE INVENTION

Virtual reality (VR) technology has made significant advancements in recent years, providing users with increasingly immersive and interactive experiences through a virtual simulation of the real world. VR systems often employ head-mounted displays (HMDs) with tracking functions and controllers, such as joysticks or sensor gloves, to enable users to control avatars within the virtual environments. These environments can be designed for various training and therapeutic purposes, including physical, mental/cognitive, and vocational or life skill training. VR has proven particularly useful in the rehabilitation of motor, cognitive, and sensorial deficiencies, as it allows for constant re-enactment, intuitive capacities, and gamification to facilitate variation and adjustment practices.

The degree of immersion in VR systems is a critical factor in their effectiveness, with immersive systems typically using HMDs and user representation within the virtual environment. Prior work by Hwang et al. [1] demonstrated the benefits of a semi-immersive VR system with a 270-degree touchable screen with locomotor activity, which improved cognitive functions and balance among older adults. VR-based rehabilitation has also been shown to offer feasible, safe, engaging, and enjoyable experiences for patients, particularly those with cognitive decline or impairment, and to produce long-lasting training outcomes when incorporating both physical and cognitive training components.

A crucial aspect of immersive VR systems is the interface devices, which generally include an HMD and a controller. The two main categories of controllers are joysticks and sensor gloves, with the latter offering additional capabilities such as finger tracking, tactile feedback, and kinesthetic feedback. Tactile feedback provides input to the user's skin to recreate different sensations, while kinesthetic feedback offers the impression of movement and resistance through the muscles.

Between 2015 and 2021, 24 commercial sensor gloves were developed [2] , all of which featured hand position and finger motion tracking. However, only 10 of these gloves provided tactile feedback, and a mere 3 of them offered kinesthetic feedback. Previous research demonstrated real-time tactile feedback using internal air pressure generated by an electrostatic force. Another research by Terrile et al. [3] employed a sharp memory alloy (SMA) spring to generate force feedback on a sensor glove. However, the latter system had a pre-set feedback force with only three levels of force generated, making it difficult to recreate the feeling of sketching and squeezing items with changing resistance forces, such as elastic springs or human tissues like an arm.

Given the lack of VR gloves with kinesthetic feedback, especially those with adjustable feedback, the current VR technologies struggle to effectively simulate complex hand activities. As a result, there is a need for an adjustable force feedback and haptic feedback VR glove that can provide users with information about the actual surface shape and hardness of the virtual objects. Such a glove would enhance user immersion experiences and improve virtual training and rehabilitation performance. Furthermore, other desirable features and characteristics will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and this background of the disclosure.

SUMMARY OF THE INVENTION

Provided herein is a glove for providing tactile and kinesthetic feedback in VR rehabilitation applications.

In certain aspects of the present disclosure, a haptic glove apparatus wearable by a user for providing tactile and kinesthetic feedback in virtual reality rehabilitation applications is provided. The haptic glove apparatus includes a glove body and a haptic device coupled to the glove body. The glove body has a finger portion to cover one or more fingers of the user. The haptic device includes one or more anchors positioned at distal ends of the finger portion; one or more feedback modules; and a tendon routing arrangement. The tendon routing arrangement includes one or more tendon wires connecting between the one or more feedback modules and the one or more anchors for exerting a flexion tension and an extension tension on each of the one or more fingers. Each of the one or more feedback modules is configured to adjust the flexion tension and the extension tension to generate a resistive sensation for simulating a contact of a virtual object.

In an embodiment, the haptic glove apparatus further includes one or more finger tracking modules configured to determine a bending angle of each of the one or more fingers in real-time. The bending angle is coupled to a processor for finger position tracking.

In an embodiment, the one or more finger tracking modules each comprises a taut wire and a potentiometer having a torsion spring and a knob. The potentiometer is connected to the one or more anchors via the taut wire to pull the knob to rotate by a flexion motion. The torsion spring retracts to restore the knob by an extension motion.

In an embodiment, the one or more finger tracking modules each includes one or more force sensitive resistors placed on a dorsal side of the one or more fingers. The one or more force sensitive resistors are made of sensing material selected from a semi-conductive tape or a nanomaterial selected from the group consisting carbon nanotube, molybdenum disulfide, and silver nanowire.

In an embodiment, the one or more feedback modules is connected to the one or more tendon wires through a spring. The spring provides a restoring force for simulating different levels of the resistive sensation.

In an embodiment, the spring is made of nylon coated titanium.

In one embodiment, each of the one or more feedback modules includes a linear servo. The linear servo is in driving communication with the one or more tendon wires and the spring to apply a feedback force on the one or more anchors to adjust the flexion tension and the extension tension.

In an alternative embodiment, each of the one or more feedback modules comprises a servo motor and a gearbox connected to the servo motor. The gearbox is in driving communication with the one or more tendon wires and the spring to apply a feedback force on the one or more anchors to adjust the flexion tension and the extension tension.

In an embodiment, each of the one or more tendon wires is arranged at least partially in a Bowden tube for facilitating a transmission of force from the one or more feedback modules to the one or more anchors.

In an embodiment, the Bowden tubes are fixedly fastened by two tube guiders attached to a volar side of the hand and a dorsal side of the hand respectively by a Velcro fastener. Each of the two tube guiders includes a base portion and a plurality of through holes extending across the base portion along a widthwise direction for the Bowden tubes to pass through.

In an embodiment, the haptic device further includes one or more finger thimbles circumscribing the one or more fingers at the distal ends. The one or more anchors are firmly affixed on the one or more finger thimbles. The flexion tension and the extension tension are exerted on two opposite sides of the one or more finger thimbles.

In an embodiment, each of the one or more finger thimbles is a sensor thimble including a sensor-actuator device positioned at an internal location inside the sensor thimble for measuring a grip force and simultaneously providing a haptic feedback by expansions or contractions to simulate the contact of the virtual object in response to the grip force.

In an embodiment, the sensor-actuator device is a piezo buzzer configured to generate an electrical charge proportional to a pressure applied to the piezo buzzer; and covert the electrical charge to a voltage signal for calculating the grip force based on a calibration curve.

In an embodiment, the haptic glove apparatus further includes one or more finger tracking modules configured to determine a bending angle of each of the one or more fingers in real-time. The bending angle and the grip force are coupled to a processor to enable a dynamic control of the one or more feedback modules by adjusting the flexion tension and the extension tension in real-time, thereby enabling accurate finger motions with a desired bending angle and a desired grip force.

This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter. Other aspects and advantages of the present invention are disclosed as illustrated by the embodiments hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

The appended drawings contain figures to further illustrate and clarify the above and other aspects, advantages, and features of the present disclosure. It will be appreciated that these drawings depict only certain embodiments of the present disclosure and are not intended to limit its scope. It will also be appreciated that these drawings are illustrated for simplicity and clarity and have not necessarily been depicted to scale. The present disclosure will now be described and explained with additional specificity and detail through the use of the accompanying drawings in which:

FIG. 1 is a schematic view of the haptic glove apparatus in accordance with one embodiment of the present disclosure.

FIG. 2A is a photo of a potentiometer capable of determining the finger bending angle for finger tracking.

FIG. 2B is a drawing of an integrated device capable of determining the finger bending angle for finger tracking.

FIG. 3A is an exemplary finger thimble with a sensor-actuator device in accordance with one embodiment of the present disclosure.

FIG. 3B is an exemplary finger thimble with a C-ring in accordance with one embodiment of the present disclosure.

FIG. 4A is the tendon routing arrangement for connecting the tendon wires to the finger thimble in accordance with one embodiment of the present disclosure.

FIG. 4B is a photo showing the tendon routing arrangement with two tendon wires for actuating a finger thimber in accordance with one embodiment of the present disclosure.

FIG. 4C is an exemplary tube guider in accordance with one embodiment of the present disclosure.

FIG. 5 is a conceptural drawing of the one or more feedback modules connecting to the one or more tendon wires in accordance with one embodiment of the present disclosure.

FIG. 6A is a computer image of an object in the virtual environments.

FIG. 6B is a computer image of the object when the finger flexed.

FIG. 6C is a computer image showing the bending of the finger.

FIG. 6D is a computer image showing the graspping on the virtual image.

FIG. 7 is a flowchart of the system controlling the feedback module in accordance with one embodiment of the present disclosure.

FIG. 8 is a flowchart of the system integrated with the virtual environment in accordance with one embodiment of the present disclosure.

DETAILED DESCRIPTION OF THE INVENTION

The following detailed description is merely exemplary in nature and is not intended to limit the disclosure or its application and/or uses. It should be appreciated that a vast number of variations exist. The detailed description will enable those of ordinary skilled in the art to implement an exemplary embodiment of the present disclosure without undue experimentation, and it is understood that various changes or modifications may be made in the function and structure described in the exemplary embodiment without departing from the scope of the present disclosure as set forth in the appended claims.

The benefits, advantages, solutions to problems, and any element (s) that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as a critical, required, or essential features or elements of any or all of the claims. The invention is defined solely by the appended claims including any amendments made during the pendency of this application and all equivalents of those claims as issued.

As used herein, the term “virtual reality” or “VR” refers to an artificial environment that is experienced through sensory stimuli generated by a computer and in which a user’s actions partially determine what happens in the artificial environment.

The use of the terms “a” and “an” and “the” and “at least one” and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms “comprising, ” “having, ” and “including” or any other variation thereof, are to be construed as open-ended terms (i.e., meaning “including, but not limited to, ” ) unless otherwise noted. The use of any and all examples, or exemplary language (e.g., “such as” ) provided herein, is intended merely to illuminate the invention better and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.

Unless otherwise defined, all terms (including technical and scientific terms) used in the embodiments of the present invention have the same meaning as commonly understood by an ordinary skilled person in the art to which the present invention belongs.

In light of the background, it is desirable to provide a haptic glove apparatus for providing tactile and kinesthetic feedback in VR rehabilitation applications. The glove and the system thereof can provide users with information about the actual surface shape and hardness of the virtual objects, which can enhance user immersion experiences and improve virtual training and rehabilitation performance.

FIG. 1 is a schematic view of an illustrative haptic glove apparatus in accordance with one embodiment of the present disclosure. The haptic glove apparatus 100 is wearable by a user and may be constructed in the shape of the user’s hand of various sizes. The haptic glove apparatus 100 comprises a glove body with a palm portion 101 and a finger portion 102 for covering one or more fingers of the user. Although it is preferred to have the a finger portion 102 covering all five fingers of the user, it is apparent that the glove body may also be customized for users with finger amputation; or the glove body is designed to cover some fingers of the user only. The glove body may be made from a fabric material or an elastic material. In some embodiments, the glove body may be made from cotton, cloth, leather, polyester, rubber, or any combination thereof. The haptic glove apparatus 100 further comprises The . In particular, the haptic device provides real-time monitor on the fingers and provides the user with tactile and kinesthetic feedback. The system can therefore provide rehabilitation mode for hand strength improvement and grasp-assistant mode for user grasping performance assisting.

In certain embodiments, the haptic device comprises one or more finger tracking modules 200, one or more feedback modules 300 and one or more sensor-actuator devices 400. In the illustrated embodiment, only the structure for the middle finger 104 is shown for clarity and simplicity. The structures for other fingers (if any) are not shown in FIG. 1, which can be duplications of that for the middle finger 104 at the corresponding locations for the other fingers. As an example, if the haptic device is a two-finger haptic device, the haptic device may include two finger tracking modules 200, two feedback modules 300, and two sensor-actuator devices 400. At the distal ends of the finger portion 102, one or more anchors 515 are positioned for enabling the finger tracking and feedback.

The one or more finger tracking modules 200 are configured to determine a bending angle of the one or more fingers in real-time. In one aspect of the invention, finger tracking is achieved by specially designed resistive sensors, which can be built in two different ways.

In the first aspect, the one or more finger tracking modules 200 each comprises a taut wire 215 and a potentiometer 200A having a torsion spring 212 and a knob 211, as shown in FIG. 2A. The torsion spring 212 and the knob 211 are housed within a circular case 213. The resistance reading changes according to the finger bending angle via the potentiometer 200A for finger tracking. The potentiometer 200A is attached on the dorsal side of the hand around the metacarpophalangeal (MP) joint. The potentiometer 200A is connected to the anchor 515 at the dorsal phalanges via the taut wire 215 through one or more guiders 214, which can to pull the knob 211 to rotate by a flexion motion of the finger. The resistance change of the potentiometer 200A can be used for estimating the overall flexion angle of the finger. When the finger relaxes or with an extension motion of the finger, the torsion spring 212 retracts to the original position to restore the knob 211.

In the second aspect, the one or more finger tracking modules 200 each comprises an integrated device 200B having a silicone rubber 222 and one or more force sensitive resistors 221 incorporated into the silicone rubber 222, as shown in FIG. 2B. The integrated device 200B is arranged to be placed on a dorsal side of the one or more fingers. The one or more force sensitive resistors 221 may be a soft sensor using soft materials and nanomaterials, which is integrated with the silicone rubber 222. Preferably, the one or more force sensitive resistors 221 are made of sensing material selected from a semi-conductive tape or a nanomaterial selected from the group consisting carbon nanotube, molybdenum disulfide, and silver nanowire. With the sensitive resistor 221, the bending angle of the MP joint and the proximal interphalangeal (PIP) joint can be accurately measured.

With reference to FIG. 3A, the haptic device further includes one or more finger thimbles 510 circumscribing the one or more fingers at the distal ends of the finger portion 102. Each finger thimble 510 is worn on the fingertip serving multiple purposes. In one embodiment, each of the one or more anchors 515 is an anchor point firmly affixed one of the finger thimble 510 such that the finger thimble 510 can be connected to the finger tracking module 200 and the feedback module 300. The finger tracking module 200 can determine finger bending angle based on the relative position of the anchor 515. The feedback module 300 can also provide haptic and kinesthetic feedback to the user for simulating a contact of a virtual object by generating pull-push force to the one or more anchors 515. The finger thimble 510 may fully cover or partially cover the distal phalange of the user.

In another embodiment, each finger thimber 510 is a sensor thimble comprising a sensor-actuator device 400 positioned at an internal location inside the sensor thimble for measuring a grip force and simultaneously providing a haptic feedback by expansions or contractions to simulate the contact of the virtual object in response to the grip force. In certain embodiments, the sensor-actuator device 400 is a piezo buzzer that can be utilized as a force sensor and as an actuator for providing haptic feedback. The piezo buzzer is configured to generate an electrical charge proportional to a pressure applied to the piezo buzzer; and covert the electrical charge to a voltage signal for calculating the grip force based on a calibration curve. Meanwhile, the piezo buzzer is also configured to provide haptic feedback to the user in virtual environment. With an event happening in the virtual environment, such as touching a virtual object or reaching a target position, a voltage signal is generated and coupled to the piezo buzzer through a haptic driver. By expanding and contracting rapidly in response to the voltage signal, the piezo buzzer produces vibrations that simulate the sensation of touching or grasping of a virtual object. This dual functionality of the sensor-actuator device 400 offers a compact and efficient solution for integrating assistive technology with virtual reality rehabilitation systems.

Referring to FIG. 3B, each finger thimber 510 may further includes a C-ring frame 511 positioned on the intermediate phalange. The C-ring frame 511 may facilitate the transmission of force to the finger thimber 510. From the finger thimber 510, one or more tendon wires 541 are connected via the C-ring frame 511 for guiding the tendon wires to provide haptic and kinesthetic feedback.

With reference to FIG. 4A, the tendon routing arrangement for connecting the tendon wires 541 to the finger thimble 510 is illustrated. The tendon routing arrangement is formed by the one or more tendon wires 541 connecting between the one or more feedback modules 300 and the one or more anchors 515 for exerting a flexion tension and an extension tension on each of the one or more fingers. Therefore, the respective finger is pulled or pushed by the flexion tension and the extension tension. With the tendon routing arrangement, the one or more feedback modules 300 can provide adjustable kinaesthetic feedback, allowing for more realistic force sensations in virtual environments. In one embodiment, the tendon routing arrangement is embedded within the glove body so that the one or more tendon wires 541 are protected.

For facilitating the transmission of force from the one or more feedback modules 300 to the one or more anchors 515, each of the one or more tendon wires 541 is arranged at least partially in a Bowden tube 545. The Bowden tube 545 is preferably light and flexible, but with high rigidity and strength. The tendon wire 541 is inserted into the Bowden tube 545 to enhance the transmission of movement and force from the one or more feedback modules 300 to the finger via the one or more anchors 515. As shown in FIG. 4B, each actuated finger employs two tendon wires (a first tendon wire 541A and a second tendon wire 541B) for connecting the feedback module 300 to the anchors 515. The first tendon wire 541A is arranged on the volar side of the hand such that the the force applied on the first tendon wire 541A can exert a flexion tension on the finger. Similarly, the second tendon wire 541B is arranged on the dorsal side of the hand such that the the force applied on the second tendon wire 541B can exert an extension tension on the finger. Therefore, the flexion tension and the extension tension are exerted on two opposite sides of the one or more finger thimbles 510.

The Bowden tubes 545 are further supported by the tube guiders 530. In the illustrated embodiment, there are two tube guiders 530A, 530B fastened together by a Velcro fastener 536 near the palm area, and another two tube guiders 530C, 530D are fastened together by another Velcro fastener 536 around the wrist area. The two tube guiders 530 are attached to a volar side of the hand and a dorsal side of the hand respectively for securing the Bowden tube 545. In particular, as shown in FIG. 4C, the Velcro fastener 536 is attached to the loops 531 of the tube guider 530. The Bowden tubes 545 are fixedly fastened by the tube guiders 530, wherein each of the two tube guiders 530 comprises a base portion 532 and a plurality of through holes 533 extending across the base portion 532 along a widthwise direction for the Bowden tubes 545 to pass through.

The C-ring frame 511, the finger thimber 510, and the tube guiders 530 may be fabricated using 3D printing technology, utilizing Thermoplastic Polyurethane (TPU) as the material of choice because of its desirable characteristics such as high ductility, excellent biocompatibility, and superior abrasion resistance.

With reference to FIG. 5, another aspect of the present disclosure provides one or more feedback modules 300 configured to adjust the flexion tension and the extension tension to generate a resistive sensation for simulating a contact of a virtual object. The one or more feedback modules 300 is preferably placed on the carpal bones of the user. The one or more feedback modules 300 is connected to the one or more tendon wires 541 through a spring 310. The spring 310 provides a restoring force for simulating different levels of the resistive sensation. In certain embodiments, the spring 310 is made of nylon coated titanium, and wired to the anchor 515 through the tube guiders 530.

Two possible structures of the feedback module 300 is illustrated in FIG. 5. Each of the one or more feedback modules 300 may comprise a linear servo 323, wherein the linear servo 323 is in driving communication with the one or more tendon wires 541 and the spring 310 to apply a feedback force on the one or more anchors 515 to adjust the flexion tension and the extension tension. Alternatively, each of the one or more feedback modules 300 may comprise a servo motor 321 and a gearbox 322 connected to the servo motor 321. In this case, the gearbox 322 is in driving communication with the one or more tendon wires 541 and the spring 310 to apply a feedback force on the one or more anchors 515 to adjust the flexion tension and the extension tension. Based on the required feedback force, the linear servo 323 or the servo motor 321 can pull the tendon wire 541 at different tension by adjusting its position in order to create a restoring force from the spring 310 and produce different levels of resistive sensation.

The second aspect of the present disclosure provides a system having the haptic glove apparatus 100 that can provide users with information about the actual surface shape and hardness of the virtual objects, which can be used for virtual training and rehabilitation applications. The finger tracking module 200 and the sensor-actuator device 400 play a vital role in providing feedback to the system during finger actuation. By streaming real-time data regarding the bending angle and the grip force, the collected information can be used for evaluating the progress of rehabilitation, such as duration, response time, grasp force, etc. In particular, a processor is configured to receive the bending angle as determined by the one or more finger tracking modules 200 and the grip force as determined by the sensor-actuator device 400 in real-time, and control the one or more feedback modules 300 to adjust the flexion tension and the extension tension.

In one example, a table and a cylinder-shaped virtual object are presented in the virtual environment, as shown in FIG. 6A. The object changes its size according to the readings of the one or more finger tracking modules 200 and the sensor-actuator device 400. When the finger flexed, the resistant reading increased, and the size of the object decreased, as shown in FIG. 6B. In one exemplary implementation, the color of the object changes from 240 degrees in hue, saturation, value (HSV) when the finger extended to 0 degrees when the finger flexed. The aim of size and color changes is to enhance the user perception on the resistive change.. Once the bending angle from the one or more finger tracking modules 200 exceeds a certain threshold, the processor would determine that the hand is in contact with the object’s surface (FIG. 6C) . Therefore, the feedback module 300 is activated. The processor controls the linear servo 323 or the servo motor 321 to stretch the spring 310 such that the user feels a feedback force to simulate a grasping motion (FIG. 6D) . In particular, the finger bending movement causes the anchor 515 to a backward position according to the virtual object’s preset physical hardness property, resulting in a feedback force corresponding to the hardness. On the other hand, zero reading in finger bending movement (i.e. finger relaxing state) would automatically drive the linear servo 323 or the servo motor 321 to reset to its original position, eradiating the user from feeling any “pull-back” force.

With reference to the flowchart in FIG. 7, upon pressing the “grasp” button, the feedback module 300 initiates a continuous rotation and wound the tendon wires 541 until both the finger tracking module 200 and the sensor-actuator device 400 obtain readings reached a predetermined threshold for providing sufficient force to stably holding the object. Conversely, pressing the “release” button prompted the feedback module 300 to wind the tendon wires 541 to generate the extension tension, subsequently allowing the finger to relax from its grasping position.

The data from the finger tracking module 200 and the sensor-actuator device 400 also facilitates accurate actuation of the bending angle or grip force. Considering that the user may possess different hand sizes, the required stroke for finger flexion or extension may vary. However, the feedback module 300 alone lacks the capability to adjust the travel distance of the tendon wire 541 to achieve a specific finger angle or grip force. The utilization of the finger tracking module 200 and the sensor-actuator device 400 enables a dynamic control of the one or more feedback modules 300 by adjusting the flexion tension and the extension tension in real-time, thereby enabling accurate finger motions with a desired bending angle and a desired grip force.

The system can also be integrated with VR for the purpose of rehabilitation, particularly for the dementia patients. FIG. 8 shows a flowchart of the system integrated with VR. The system can be remotely controlled by a therapist or a supervisor, who uses the system to help the patient repeatedly performing grasping motions through the one or more feedback modules 300. The bending angle determined by the finger tracking module 200 is used to track the motion of the patient's fingers in real-time, which is then displayed in the virtual environment. In certain embodiments, the environment may include virtual objects other than a model of the patient’s hand. For example, it can be other virtual objects of varying sizes for the patient to grab. To enhance the realism of the virtual environment and the effectiveness of the rehabilitation process, the use of the sensor-actuator device 400 can provide haptic feedback to the fingertips, simulating the sensation of touch when the virtual objects are grasped.

Therefore, the haptic glove apparatus 100 of the present disclosure can provide tactile and kinesthetic feedback in VR rehabilitation applications. This illustrates the fundamental structure of the haptic glove apparatus 100 in accordance with the present disclosure. It will be apparent that variants of the above-disclosed and other features and functions, or alternatives thereof, may be combined into many other different methods or apparatuses. The present embodiment is, therefore, to be considered in all respects as illustrative and not restrictive. The scope of the disclosure is indicated by the appended claims rather than by the preceding description, and all changes that come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

REFERENCES

The following references are cited in the specification. Disclosures of these references are incorporated herein by reference in their entirety.

[1] N. -K. Hwang et al., “Effects of Semi-Immersive Virtual Reality-Based Cognitive Training Combined with Locomotor Activity on Cognitive Function and Gait Ability in Community-Dwelling Older Adults, ” in Healthcare, 2021, vol. 9, no. 7: Multidisciplinary Digital Publishing Institute, p. 814.

[2] M. Caeiro-Rodríguez, I. Otero-González, F. A. Mikic-Fonte, and M. Llamas-Nistal, “A Systematic Review of Commercial Smart Gloves: Current Status and Applications, ” Sensors, vol. 21, no. 8, p. 2667, 2021. [Online] . Available: https: //www. mdpi. com/1424-8220/21/8/2667.

[3] S. Terrile, J. and A. Barrientos, “A Soft Haptic Glove Actuated with Shape Memory Alloy and Flexible Stretch Sensors, ” Sensors, vol. 21, no. 16, p. 5278, 2021. [Online] . Available: https: //www. mdpi. com/1424-8220/21/16/5278.

Claims

A haptic glove apparatus wearable by a user, comprising:

a glove body having a finger portion to cover one or more fingers of the user; and

a haptic device coupled to the glove body for implementing a virtual environment, the haptic device comprising:

one or more anchors positioned at distal ends of the finger portion;

one or more feedback modules; and

a tendon routing arrangement comprising one or more tendon wires connecting between the one or more feedback modules and the one or more anchors for exerting a flexion tension and an extension tension on each of the one or more fingers,

wherein:

each of the one or more feedback modules is configured to adjust the flexion tension and the extension tension to generate a resistive sensation for simulating a contact of a virtual object.
The haptic glove apparatus of claim 1 further comprising one or more finger tracking modules configured to determine a bending angle of each of the one or more fingers in real-time, wherein the bending angle is coupled to a processor for finger position tracking.
The haptic glove apparatus of claim 2, wherein:

the one or more finger tracking modules each comprises a taut wire and a potentiometer having a torsion spring and a knob;

the potentiometer is connected to the one or more anchors via the taut wire to pull the knob to rotate by a flexion motion; and

the torsion spring retracts to restore the knob by an extension motion.
The haptic glove apparatus of claim 2, wherein the one or more finger tracking modules each comprises one or more force sensitive resistors placed on a dorsal side of the one or more fingers; and wherein the one or more force sensitive resistors are made of sensing material selected from a semi-conductive tape or a nanomaterial selected from the group consisting carbon nanotube, molybdenum disulfide, and silver nanowire.
The haptic glove apparatus of claim 1, wherein the one or more feedback modules is connected to the one or more tendon wires through a spring; and wherein the spring provides a restoring force for simulating different levels of the resistive sensation.
The haptic glove apparatus of claim 5, wherein the spring is made of nylon coated titanium.
The haptic glove apparatus of claim 5, wherein each of the one or more feedback modules comprises a linear servo, wherein the linear servo is in driving communication with the one or more tendon wires and the spring to apply a feedback force on the one or more anchors to adjust the flexion tension and the extension tension.
The haptic glove apparatus of claim 5, wherein:

each of the one or more feedback modules comprises a servo motor and a gearbox connected to the servo motor; and

the gearbox is in driving communication with the one or more tendon wires and the spring to apply a feedback force on the one or more anchors to adjust the flexion tension and the extension tension.
The haptic glove apparatus of claim 1, wherein each of the one or more tendon wires is arranged at least partially in a Bowden tube for facilitating a transmission of force from the one or more feedback modules to the one or more anchors.
The haptic glove apparatus of claim 9, wherein the Bowden tubes are fixedly fastened by two tube guiders attached to a volar side of the hand and a dorsal side of the hand respectively by a Velcro fastener, and wherein each of the two tube guiders comprises a base portion and a plurality of through holes extending across the base portion along a widthwise direction for the Bowden tubes to pass through.
The haptic glove apparatus of claim 1, wherein:

the haptic device further comprises one or more finger thimbles circumscribing the one or more fingers at the distal ends;

the one or more anchors are firmly affixed on the one or more finger thimbles; and

the flexion tension and the extension tension are exerted on two opposite sides of the one or more finger thimbles.
The haptic glove apparatus of claim 11, wherein each of the one or more finger thimbles is a sensor thimble comprising a sensor-actuator device positioned at an internal location inside the sensor thimble for measuring a grip force and simultaneously providing a haptic feedback by expansions or contractions to simulate the contact of the virtual object in response to the grip force.
The haptic glove apparatus of claim 12, wherein the sensor-actuator device is a piezo buzzer configured to generate an electrical charge proportional to a pressure applied to the piezo buzzer; and covert the electrical charge to a voltage signal for calculating the grip force based on a calibration curve.
The haptic glove apparatus of claim 12 further comprising one or more finger tracking modules configured to determine a bending angle of each of the one or more fingers in real-time, wherein the bending angle and the grip force are coupled to a processor to enable a dynamic control of the one or more feedback modules by adjusting the flexion tension and the extension tension in real-time, thereby enabling accurate finger motions with a desired bending angle and a desired grip force.