Title of Invention : A wearable robot for rehabilitating the post-stroke people using virtual reality and tele-operating

Technical Field

[0001 ] This product relates to medical rehabilitation of finger disability.

Background Art

[0002] Soft hand exoskeletons often made in gloves configuration. Different devices, such as Rapael Smart Glove, Saebo Glove [4] or Music Glove, have been developed. Although they differ in implementation and the functionalities they offer, their main focus is the recovery of the motor function in the hand. They work also in conjunction with virtual reality.

[0003] The above mentioned devices although are of high quality, have a significantly high cost for the average member of the elderly population.

[0004] The benefits of computer aided therapy through the use of virtual reality have been confirmed by many studies and as such, a variety of devices have been developed for this purpose Virtual reality can be used to create an environment similar to a game, with a series of functional and entertaining tasks, with varying degrees of difficulty which suit the patient’s needs.

[0005] A reward mechanism can be used to keep the individual engaged and offer positive feedback when progress is made in order to boost motivation. Another advantage of computer assistance is the ability to gather accurate real-time data which can be used by the medic to better measure the patient’s evolution.

Summary of Invention

[0006] This project is on designing and manufacturing an active soft wearable robot to rehabilitate the fingers of stroke patients and help them regain their hand’s motor ability. The proposed robot consists of five pieces each for one finger, made from elastomeric materials inspired from PneuNet actuators.

[0007] These pieces are mounted on a palm and form a soft wearable robot for hand.

The robot is active and has a control system. An air pressure mechanism will be used to drive the mechanical system using a miniature diaphragm motor pump and to give the fingers the ability for voluntary flexion movement.

[0008] For the rehabilitation process to be possible, the robot will be mounted on an adjustable mechanical arm to carry the patient’s arm and to compensate the weight of the hand and the mechanical system so that the patient can do the rehabilitation process without tolerating extra force. The rehabilitation process will take place in two hierarchical stages: using virtual reality and using a telerobotics system.

[0009] In the first stage of rehabilitation, the patient performs some simple tasks such as grasping and lifting virtual objects and observes the resultant motions in a virtual environment. Virtual reality tasks help the patients mentally and give them self-confidence.

[0010] In the second stage a master-slave setup will be utilized. The soft robot will be mounted on a setup as a master device. The master is connected to a similar robot as a slave device. The patient wears the soft exoskeleton and tries to manipulate and conduct the slave’s endeffector to do some tasks like taking and throwing a small ball.

Technical Problem

[0011 ] For the majority of stroke survivors, chronic impairment of hand mobility is a major disability. This can hinder activities of daily living and reduce one’s quality of life. The main disability happens in their wrist and fingers, where voluntary motion is essential for the function. The fingers also lose their ability in flexion motion.

[0012] The patients usually recover most of their hand’s function in time, however finer movements can remain permanently limited. For these patients, repetitive task practice therapies can improve hand strength and the range of motion. However, these methods are labor intensive and slow often might result in challenge with patient compliance.

[0013] Alternatively, for hand rehabilitation of these patients as well as other upper motor neuron conditions such as multiple sclerosis (MS) and spinal cord injury, robotic exoskeletons would be more convenient than repetitive task practice therapies by providing strength to accelerate their recovery rate.

[0014] There are two typologies of exoskeletons in the literature: rigid exoskeletons and soft exoskeletons, all showing advantages and drawbacks. There are complementary rather than substitutive approaches, rigid exoskeletons can deliver higher forces but rigidity of their linkages in terms of power requirements and low force/weight ratio make them metabolically nonoptimal in the case of portable devices.

[0015] On the other hand, the compliance of soft devices strongly limits the amount of forces/torques that the device can provide to the human body however this makes soft exosuits suitable for applications requiring a limited magnitude of assistance, and unimpaired biomechanics.

Solution to Problem

[0016] Telerobotics is another concept which is used in rehabilitation. Most robotic rehabilitation systems involve only one robot manipulator interacting with the patient’s limb. A second robot, however, may provide an online role for the therapist to monitor and/or guide the exercise.

[0017] Therefore, a bilateral telerobotic system can provide a cooperative telerehabilitation environment that allows the therapist and the patient to interact with each other during the therapy process.

Advantageous Effects of Invention

[0018] The use of exoskeletons has many advantages rather than therapy treatment in the aspects of performance and patient collaboration. An acceptable exoskeleton is required to meet three major criteria:

(1) being lightweight;

(2) being real time;

(3) ease of use.

[0019] Many wearable robots or hand exoskeletons have been designed for the disabled hand. However, the present idea uses an effective low-weight and user- friendly construct. Unlike several other products that use a cable-driven actuator, the current design uses a PneuNets actuator which allows for better control over actuator behavior and is significantly easier to manufacture. The use of a pneumatic actuator as opposed to a hydraulic one also results in a light and portable overall product which can be mounted on the patient’s body.

[0020] The proposed device uses virtual environments for rehabilitation therapy because of their inherent ability of simulating real-life tasks. Besides helping to engage the patient in life-like activities, virtual environments provide the means to better measure and evaluate the patient's performance. The patients will perform a variety of VR exercises to reduce impairments in their finger range of motion, speed, fractionation and strength.

Brief Description of Drawings

[0021 ] Fig 1 : The soft fingers

[0022] Fig 2: Air pump and air bubbles

[0023] Fig 3: The real time control system in virtual reality

Description of Embodiments

[0024] The soft fingers (fig 1 ) are made of elastomeric materials. In this project Ecoflex 30 (Young’s modulus ~ 0.1 MPa, Shore A hardness 00-30) is used. The overall weight of each finger is about 25 gr. The molds can be manufactured using 3D print technology. The four constructed fingers will be mounted on a glove to form the wearable robot. The total weight of the wearable robot reaches about 150 gr which is considerably low.

[0025] The flexion and extension motions of the fingers are driven by using air pump (1 ). When the air pump pushes the air into the soft fingers, air bubbles are formed in some parts of soft fingers and causes the finger to bend.

[0026] A force-based control strategy is utilized to control the fingers since they should be able to hold objects. The control board will drive the robot using microcontroller system to make the system real time. The control board consists of following elements:

- A miniature diaphragm pump which can provide up to 10 psi pressure - Solenoid valves which can direct the flow of air into the robot

- Pressure sensors which can provide feedback

- A micro-controller (Arduino Mega)

- Switches and MOSFETs

- Power regulators

- A breadbord

[0027] The use of soft robot in the glove structure makes it simple in motion control and comfortable in use compared with the rigid counterparts which have more complex control architecture due to more degrees of freedom of the finger structure.

[0028] A virtual environment containing a table with some objects that the patient will try to touch and grab, a gripper and arm and some other simple effects for decorating are designed. The motor will be connected to the virtual environment by using a microcontroller system. A Bluetooth protocol connects the robot to the computer. The physical parameters of the virtual object such as weight and surface roughness will be defined in the control program.

[0029] The telerobotics system consists of two parts as master section and slave section respectively. The slave part will be guided by a master part which is the wearable soft robot.

Examples

[0030] The robot can work either on the body of a patient by using a miniature air pump or as an established setup in the clinical centers for referral patients services. The virtual reality and telerobotics facilities of the system give it extra capabilities.

[0031 ] Example 1

[0032] The virtual reality environment can be designed as a game with a scoring and rewarding system such that the disable person performs exercises and sees the results. This helps the patient to get faster progress in the rehabilitation process.

[0033] Example 2 [0034] The robot can be utilized as a telerehabilitation tool. A patient can wear the master part of the robot at home and perform some exercises. On the other side the therapist can monitor and/or guide the exercises in his/her office via the slave robot.

Industrial Applicability

[0035] Stroke is one of the leading causes of disability worldwide. Hand rehabilitation using exoskeletons is essential for post stroke people which suffer from fingers motor disability. The exoskeletons are also requested by clinical centers to use them for rehabilitation of referral patients.

[0036] Among the different types of exoskeletons, the soft wearable one with low weight and ease of use is highly on demand. The use of wearable robots in combination with virtual reality and telerobotics makes it suitable for many applications such as telerehabilitation which is applicable in clinical centers.

Reference Signs List

[0037] Walsh, C. Human-in-the-loop development of soft wearable robots. Nat Rev Mater 3, 78-80 (2018)

[0038] Domenico Chiaradia, Michele Xiloyannis, Massimiliano Solazzi, Lorenzo Masia, Antonio Frisoli, Chapter 4 - Rigid Versus Soft Exoskeletons: Interaction Strategies for Upper Limb Assistive Technology, Editor(s): Jacob Rosen, Peter Walker Ferguson, Wearable Robotics, Academic Press, 2020, Pages 67-90

[0039] https://www.neofect.com/us/smart-glove

[0040] https://www.saebo.com/shop/saeboglove/

[0041 ] https://www.activehands.com/product/music-glove/

[0042] Saposnik G, Levin M; Outcome Research Canada (SORCan) Working Group. Virtual reality in stroke rehabilitation: a meta-analysis and implications for clinicians. Stroke. 2011 May;42(5):1380-6.

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[0046] [10] Biggar S, Yao W. Design and Evaluation of a Soft and Wearable Robotic Glove for Hand Rehabilitation. IEEE Trans Neural Syst Rehabil Eng. 2016 Oct;24(10) :1071 -1080. doi: 10.1109/TNSRE.2016.2521544. Epub 2016 Jan 27. PMID: 26829796.

[0047] [11] Y. H. Chan, Z. Tse and H. Ren, "Design evolution and pilot study for a kirigami-inspired flexible and soft anthropomorphic robotic hand," 2017 18th International Conference on Advanced Robotics (ICAR), Hong Kong, 2017, pp. 432-437, doi: 10.1109/ICAR.2017.8023645.

[0048] [12] P. Polygerinos, K. C. Galloway, E. Savage, M. Herman, K. O'Donnell, and C. J. Walsh, “Soft Robotic Glove for Hand Rehabilitation and Task Specific Training,” in IEEE International Conference on Robotics and Automation (ICRA), Seattle, Washington, USA, 2015, pp. 2913-2919