Field of the Invention
This invention relates generally to an arm exoskeleton that attaches to a subject's fore arm through the shoulder, for use in areas such as rehabilitation, and/or easy lifting of the load involving motor function. In particular, the invention relates to an exoskeleton frame structure that provides multiple modes of operation upon getting affixed, attached or worn to the arm, fore arm of the user.
Background and prior art of the Invention
Stroke, physical injury, and disease are causes of impairment of motor function involving one or more limbs. It is often possible to recover some motor function through rehabilitation, and practicing functional multi-joint movements with the impaired limb is an important part of motor recovery. Current therapeutic techniques therefore focus on training with repetitive, frequent functional' movements. Providing patients with the attention they need is a challenge. Each patient requires extensive one-on-one attention, and therapy programs are physically exhausting for the therapist. The use of robotic devices to provide therapy would improve efficiency and effectiveness of the therapy, and this has been at the forefront of recent stroke rehabilitation research.
Over the past several years, arm training devices have been developed to assist in rehabilitating patients who have suffered loss of arm movement, such as due to an injury or stroke. One such device is described in U.S. patent application Ser. No. 12/568,541, titled "UPPER ARM WEARABLE EXOSKELETON," filed Sep. 26, 2009, incorporated herein by reference. Many prior devices, including the device described in the above-referenced patent application, have been limited in their capabilities due to their weight. For example, in one embodiment of the device described in the above-referenced patent application, a plurality of cables are driven by motors mounted to a shoulder cuff worn by the patient. The weight of the motors mounted to the shoulder cuff may add significant weight to a device for use with.a patient who may already be in a somewhat weakened state.

In general, exoskeleton is a suit that can be worn by a person for efficient walking, running that assists with limb movements. They can be used in various fields like medicine, household and military.
Medicine: Patients who are physically challenged in terms of movement of limbs can use exoskeleton as prosthetic device.
Military: Soldiers can use exoskeletons when they need to carry heavy loads (usually weapons) for long distance'in remote areas where it is difficult to bring commercial load carrying machines.
Industries: Workers can carry heavy machine parts with a compact structure and no effort.
Household: In future exoskeletons are going to be used more commonly for lifting weights that we usually handle in home.
Space Exploration: Astronauts exploring other planets with varying gravity can use exoskeletons for locomotion as well as handling tools.
Nicholas Yogan et.al (1890) was the person who concocted an exoskeleton. This exoskeleton enhances the proficiency of the procedure and abatements the exertion prerequisites by people for strolling, running or hopping. This suit is built in a way that the individual can bend the legs with ease. It consists of a compressed fluid accumulator which is fixed to the feet and helps to support and take up the overall load of the body and also a storage reservoir to be carried by the person for storing the compressed gas. Here the fluid is stored under high pressure and it also has a discharge tube with stopcock. So by using all these as the source it helps in efficient walking, running and jumping.
Leslie C. Kelley et.al (1919) built up an exoskeleton called Pedomotors and it is a running gadget which is worked by the power source. This gadget will help in increasing the speed during the running operation with less human exertion. This suit comprises of a set of straps which is utilized to convey the casing at the backside. The casing comprises of a fuel holder alongside the burner. The burner is required to change the

water which is in the evaporator into steam. At that point the steam is helped through the pipe and afterward it can be controlled by an appropriate valve. These valves while being opened enables the pressure to one of the cylinders and after that the pistons in the cylinders tends to move upward and this influences the leg to move. This will tend to propel the body.
Another suit which is called Hardirrian was created by the General Electric Company et.al (1971). They had made examinations on the number of movements required by the people and furthermore discovering the number of joints required to give a man adequate portability. There were such huge numbers of issues identified with this. The load which this suit could convey was 110kgs and it felt as though conveying , 4kgs. This suit was not tried by the people since it had a few downsides. By intuition for all intents and purposes it is important to have isolate masters for controlling the arm and leg movements. To execute this two strategies were required. They are the operators walk and ride. In operators ride mechanism the heaps are carried on a seat and the people will work on the movements. However, these movements are not natural that is not common. In operators walk mechanism the weight, is conveyed by the feet. For being more normal the operators walk mechanism was preferred.
Exoskeleton and orthosis created by Herr et.al (2009) are mechanical gadgets which are worn by the people where the exoskeletons are worn to enhance the execution though orthosis is utilized to help the individual with limb pathology. Tendons which are the elastic elements in the body assume a noteworthy part in the economy and stability of movement. Past examinations demonstrates that the running tracks which follow perfect standards helps in reducing injury and increase the running speed by few percent. The Springbuck shoes which are made out of carbon composite versatile padded sole aides in enhancing the shock absorption and metabolic economy at direct running velocity. By contrasting it and the shoes without versatile padded sole there is just a constrained preferred standpoint. So the elastic exoskeletons have been produced which are utilized in series with human leg will raise the human running rate and economy. In series exoskeletons the loads are borne by the human legs. However, coming to parallel exoskeletons the heaps that are borne by the limbs are decreased

because the loads are transferred to the ground through the exoskeletons and there will not be an increase in limb length.
Pentagon et.al (2016) wants to produce new kind of suit which is created essentially for the soldiers. It is made out of fabric which is light in weight that won't enable the bullets to go through the suit and with the assistance of this suit the muscle power of the soldier is increased. In any case, it was unrealistic to discover this suit. Ray Baughman developed chemically grown nanotubes. They resemble tiny muscles. At the point when electric voltage is applied to these tiny particles these particles tends to contract and gets energy from the fuel cells. These mini muscles than normal muscles are stronger than human muscle tissue. When they are warmed they will contract and gets its original shape when cooled. So Pentagon has offered Ray Baughman to build up an exoskeleton for the US armed force. By manufacturing the suit with the help of this material it will allow the soldiers to jump high above the barriers and the heavy objects can be transported over long distances. There is likewise another nano product which secures the soldiers and it is substantially lighter and stronger than the present bullet proof vests.
HAL invented by Ybshiyuki et.al (2010) is another suit which can be utilized by typical individuals and even physically challenged individuals. This should be possible by utilizing two algorithms which are controlling the movements of the suit. They are cybernic autonomous control and cybernic voluntary control. The voluntary control is the bioelectrical signals which are distinguished from the human brains when they require movement. With the assistance of these signals the Autonomous control is utilized to create the movements in the suit. This enhances people strolling, climbing and so on. At the joints they used DC motors and the gear which they used is the harmonic gears for movements to take place.
Electromyography (EMG) invented by Guiilaume et.al (2016) driven displaying is utilized to anticipate the internal body forces including the joint torque, joint compressive forces, joint stiffness and muscle forces. It is extremely dreary procedure to identify the internal body forces and it needs an invasion methods. So EMG driven modelling is developed and they are broadly utilized. EMG amplifier is connected is connect to the

direct tcp/ip to experimental access in real time to EMG data, experimental recorded joint angles are given as input to (Multidimensional Cubic B spline) MCBS software. It is used to calculate the muscle-tendon length and moment arms from the joint torque. The experimental joint angle and torque data are recorded utilizing the exoskeleton sensors. The H2 is a lower limb exoskeleton having six degree of freedom. These data are send to the system by controller area network (CAN) bus. The joints are produced by electric motor and a harmonic drive that can provide a torque. The GUI provides feedback on the. EMG driven torque, interaction torque,, motor torque and joint angle. EMG were recorded from four muscle groups. The joint angles and joint torques are recorded using H2 exoskeleton The EMG driven has three degree of freedom. The first experiment was primarily done to verify the success of the calibration. The second experiment was to see the calibration on isometric conditions.
The goal of the examination is to identify the functional assistances requirement of potential end users et.ai (2015). To provide better specific mobility, reaching and handling needs of end users and also to provide useful insights in the perspective and needs of end users. The ability of Exo-suit is used to meet the needs of the customer is one of the objective. The end users are divided into three categories within AAL program, primary user who actually use an AAC product (or) service .Secondary users are persons (or) organization directly in contact with primary end user such as formal and informal care person, family members, friends and representation Tertiary end users are institution, private (or) public organization, public sector service organization, social security system, insurance companies. It is dedicated to the engagement of end users throughout the courses of the project and will achieve the establishment of end user and their requirement are listed which is used to formulate the functional specifications. In summary, the present paper provides useful preliminary data on end user requirements, most notably for complex full-body tasks requiring coordinated upper- and lower-body assistance. The main activities for which end users express a desire for assistance may potentially change as the study progresses and the sample broadens, to include older adults with greater functional impairments (and secondary end users reporting on such individuals).. Further questionnaire studies to

determine end user opinions the design and aesthetics of prototype exoskeletons, as well as factors influencing commercialization potential, are planned.
It is used to enhance the tendon therapy exercise et.al (2004) , to permit a user friendly interaction with the device, the control is based on the minimum jerk trajectory generation By this transient and steady state behaviour of the proposed devices are analyzed after designing and fabricating a 2- fingered prototype. The hand exoskeleton works under the mechanism of (RRR) Revolute-Revolute-Revolve. The links are connected by these joints and these joints possess the revolution motion. Hence the RRR mechanism is achieved. In this-exoskeleton forward kinematic model is used to determine the position and orientation of robots end-effectors based on a joint angle. The joint angles are given as the input, the inverse kinematic model providing the joint angles in correspondence with the given position of end- effector The angular position, velocity, and acceleration for determined for each finger joints using (IK) model and jacobian inverse. After identifying the above mentioned parameters there was optimized and the objective was to measure the capabilities and strengths of a human hand in form of its ROM, maximum and average force levels, and these results are compared with the mechanical design The link length of the rehabilitation device has been identified by TRIAL AND ERROR METHOD, by fixing some constraints such as kinematic mapping collision advances as well as advanced workspace concept. And OIF (overall impact factor) is determined by'this method. The control system is based on natural human control strategies The ultimate objective is to create a human circular motion in the rehabilitation device. For smooth moving of hand squared jerk along the trajectory are reduced. To execute the control strategy "Client-Server mode"has been implemented. The realized control system offers the execution of high as well as low level commands .the controller is made up of free scale dsp (56E801). The first prototype is developed by the results from the optimistic procedure and human hand force level is measured.
Yogeswaran et.al 2015) develop a system which enhance the ability of stroked and paralyzed patient or more specified neurological and musculoskeletal disease patient to carry out the daily routines. Exoskeleton limbs therapy is classified into two

types. They are End effectors and Exoskeleton system. Depending upon the issues any one of the therapy are deployed. Generally there are four motions are used in rehabilitation process which are collectively called as semi -exoskeleton with fixed base, mobile exoskeleton, wire based and effector based. The forearm lifting mechanism also another type of rehabilitation exercise whereby it can be done by lifting the arm in the posture of flexion and extension of the elbow. This can be performed by lifting range value of weights depending on the muscular strength. The part of muscle with involve during the rehabilitation exercise for the flexions the biceps brachii muscle meanwhile for the extension of the arm will be controlled using the triceps brachii muscle. However, by examining the conceptual movement of the project's prototype, the dominant muscular and nervous part of the system requires the biceps brachii muscle as to perform the flexion motion rather than the extension of the system will be aided by the elastic mechanism. Rehabilitation has to be carried out to determine the muscular position for two different motions of hand postures. This will ease the detection and placement of the arm. In this process there are two sensors which are used to enhance the detection and placement of the arm namely EMG sensors and IMU sensor. The EMG sensors are used to detect the strength of the forearm whereas IMU sensors are used to detect the position of the forearm. These two sensors are placed in the good arm and the signal from the good arm will be used to move the forearm which is attached to the rehabilitation arm and these results are incorporated with the GUI (Graphical User Interface) for monitoring the position and strength of the arm. In short, the system which had been implemented has no major difference in term of the functionality as the only adaptability of the design is it can be used clinically compare to any other mechanism. Besides, the designation had been done in much low cost mechanism as per compared to existing system.
From this paper we come to realize that Thunyanoot et.al (2011) developed exoskeleton which is controlled by electromyography signals and controllers. The joints at the shoulder and elbow have five degrees of freedom that is the shoulder has three degrees of freedom and elbow has two degrees of freedom. The signals from the amplifiers are sent to the analog to digital converter. Then the simulation is done during the upper limb actuation using the computer interface.

The Hierarchical Cascade Controller developed by Binh Khanh Dinh et.al (2017) is one of the real strategy utilized for controlling the movement of the exoskeleton. Since there are different motions required by the user's significant number of joints are available. The cascade controller has three layers. They are high-level, mid-level and |ow_|eve| controller. The high-level controller is required mainly to obtain the torque required by the user for elbow motion. The mid-level controller is used to provide the desired motion based on the users motion and the low level controller is used to track the motion of the arm. Due to backlash there is some delay and inaccuracy in joint tracking. So when the motion is required by the user the signals are sent to the DC motor to track it precisely.
This exoskeleton arm utilizes the EMD and the myoprocessor which was developed by E.E.Cavaaliaro et.al (2006). The myoprocessor is used to detect the torque required at the joints. The EMD (electro mechanical delay) is the time delay when the neural system activates the muscular system and contracts. The information is gathered based on the EMG signal that is the position and the velocity. Then all these information's are sent to the myoprocessor and then the moments are anticipated. The exoskeleton arm obtains the moments before the muscle contracts. Markus Hessinger et.al (2017) developed the upper limb exoskeleton which guides the user for drilling operation at the required position. This suit provides constant thrust force during drilling operation. All the above operations are done using a force position controller. This suit has seven degrees of freedom. There is a tracking system that is the position sensor is used to detect the accurate position of the end effector. But the position sensor has to be rigid enough or else it will lead to errors. The drilling tool which is carried by the hand has three degrees of freedom and the remaining five degrees of freedom is the drilling path which is controlled with the help of controller.
But none of the prior art documents provide a device for the rehabilitation of the arm and for the ease of lifting the heavy loads of the present invention.

Summary of the Invention
The various aspects of the invention generally comprises an arm and fore arm assistance device and system as well as a method for operating the arm rehabilitation device.
One exemplary embodiment relates to a device for assisting a user to articulate the arm and forearm, the device having an upper section, a lower section, and at least one flexible movable joint between the upper and lower section. In this embodiment, the device comprises an exoskeleton with a top. rectangular hollow frame in one plane adapted to be coupled to the bottom hexagonal hollow frame in a second plane for encompassing around the arm and fore arm section of the device user's shoulder such that the lower hexagonal frame provides a 120 degree of movement to the fore arm in a single axis on a one degree of freedom enabling the lifting of .the predetermined load. The entire weight of the said device is transferred to the shoulder of the user through the backpack holding the said arrangement.
The further exemplary embodiment relates to the device comprising the shafts and pulley operating in the block and tackle mechanism connected through the plurality of. cables. The brushless out runner motor provides a high speed energy controlled by the speed controller which is transmitted to. the said cable through the gear box for the movement of the frame structure. The said device further comprises microcontroller for controlling the operation of the said motor, processing the input from the user, enabling the display of the device.working information and for arresting the operation of the device at emergency, a high powered LiPo battery source discharging at the rate of 2200 mAh for the efficient operation of the load up liftment and plurality of sensors.
Object of the Invention
It is a primary object of the present invention to provide an exoskeleton device for assisting rehabilitation of the arm and for assisting in the ease of lifting heavy loads by the said device user.

It is a secondary object of the present invention to provide an exoskeleton device including a plurality of hollow frame structures operating in multiple planes and affixed around the arm and forearm of the end user.
It is a tertiary object of the present invention to provide an exoskeleton device including at least two frame structures with a lower hexagonal shaped structure encompassing the fore arm and a top rectangular frame structure encompassing the arm with the total weight of the said device is transferred to the shoulder through the top backpack.
It is a fourth object of the present invention to provide an exoskeleton device including a flexible joint separating the two planes of the frame structure providing at least 120 degree of movement in at least one degree of freedom to the said lower hexagonal frame structure.
It is a fifth object of the present invention to provide an exoskeleton device including a plurality of shafts and pulleys attached to the said frame structures and operating on the block and tackle mechanism for transferring the generated torque through the multiple cables.
It is a sixth object of the present invention to provide an exoskeleton device including at least one brushless out runner motor for generating and providing a high speed output.
It is a seventh object of the present invention to provide an exoskeleton device including at least one electronic speed controller to control the output speed from the said brushless motor.
It is an eighth object of the present invention to provide an exoskeleton device including a LiPo battery with at least 2200 mAh power discharging capability for providing heavy current during the load lifting operations.
It is a ninth object of the present invention to provide an exoskeleton device including an user input means preferably a joystick for transmitting the controls by the user to the said device.

It is a tenth object of the present invention to provide an exoskeleton device including with a micro controller for processing the signals from the plurality of devices and for controlling the operations of the multiple devices.
It is an eleventh object of the present invention to provide an exoskeleton device including multiple sensors for detecting the user muscle movement and for detecting the amount of force acting on the user's forearm.
It is a twelfth object of the present invention to provide an exoskeleton device including a OLED for displaying the current mode of operation of the said device, amount of load lifted, position of the arm, battery life.
It is a final object of the present invention to provide a method of operation of the said exoskeleton device in a plurality of operating modes.
Statement of the Invention
1) A device for affixing on the shoulder of the user for enabling rehabilitation of the forearm includes an exoarm skeleton comprising
i) A multiple hinged hollow exoskeleton frame affixed on and for assisting the movement of the arm and forearm region encompassed by the said frame.
ii) A plurality of shaft and pulleys operating on the block and tackle mechanism coupled to the at least one frame for transferring the generated torque to the said frames.
iii) At least one gear box for converting the input mechanical energy into output torque for assisting the movement of the said frames'.
iv) A motor for generating the mechanical force to be applied onto the said shafts and pulleys through the said gearbox for enabling the desired motion of the said exoskeleton frame at the pre-determined rate.

v) A speed controller for monitoring and controlling the operations of the said motor based on the input from the device user. .
vi) A microcontroller for receiving and processing the signals from the user, the speed controller, the motor and the display.
vii) A user controlled input mechanism for providing the instructions on the mode of operation of the said device.
viii)Multiple cables for connecting the said pulleys with the plurality of shafts.
2) A method for operating an user controlled device for the rehabilitation of the forearm and for the lifting of the heavy loads comprises the steps of
i) Inputting the instructions by the end user through the input means such as the joystick for actuating the said motor and for correspondingly controlling the operation of the said device in either of the EMG mode or remote control mode or the automatic mode.
' ii) Detecting the activation of the muscles of the end user by the electromyography sensor for the motor activation.
iii) Tilting the joystick to a pre-determined angle for activating the said motor through the said micro controller.
iv) Prefixing the angle of operation of the device and the time period for the motor activation in the automatic mode.
v) Rotating the output shaft of the gear box in consequence to the actuation of the motor.
vi) Applying the generated torque onto the cables connecting the plurality of pulleys through the shafts.
vii) Enabling the rotational movement to the said corresponding pulley and simultaneously moving the corresponding frame structure for the lifting of the connected load by the said device.

Brief description of the drawings
Fig. 1(A) - 1(G) illustrates the design of the exo skeleton frame structure.
Fig. 2(A) illustrates the orthographic views of the exo -arm and fig. 2(B) illustrates the pictorial view of the fabricated exo arm frame structure.
Fig. 3 illustrates the pictorial view of the brushless out runner motor.
Fig. 4 illustrates the pictorial view of the electronic speed controller.
Fig. 5 illustrates the pictorial view of the LiPo battery.
Fig. 6 illustrates the pictorial view of the frame structure.
Fig. 7 illustrates the pictorial viewof the micro controller.
Fig. 8 illustrates the. pictorial view of the joystick.
Fig. 9 illustrates the pictorial view of the gear box.
Fig. 10 illustrates the pictorial view of the bearings.
Fig. 11 illustrates the pictorial view of the shaft and pulleys.
Fig. 12 (A) - 12(B) illustrates the pictorial view of the sensors.
Fig. 13 illustrates the pictorial view of the OLED.
Fig. 14 illustrates the pictorial view of the electronic circuit arrangement.
Fig. 15 illustrates the flow diagram of the device operation.
Fig. 16 illustrates the pictorial view of the said device on the end user.
Detailed description of the invention
The foregoing summary, as well as the following detailed description of exemplary embodiments of the invention, will be better understood when read in

conjunction with the appended drawings, which are incorporated herein and constitute part of this specification. For the purposes of illustrating the invention, there are shown in the drawings exemplary embodiments of the present invention. It should be understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown. In the drawings, the same reference numerals are employed for designating the same elements throughout the several figures. Although the invention is illustrated and described herein with reference to specific embodiments, the invention is not intended to be limited to the details shown. Rather, various modifications may. be made in the details within the scope and range of equivalents of the disclosure without departing from the invention.
The present inventio.n relates to a cable-driven fore arm exoskeleton. As shown in fig. 1(A) to 1(G), one embodiment of the invention generally includes a frame that defines a space within which the user may insert his/her arm and forearm. Connected to frame and inside the space defined by frame is exoskeleton. The main objective of the invention is to construct a human wearable suit by using combination of various mechanisms that gives mechanical advantage. The invention aims to develop a model that helps in arm movement for patients with traumatic brachial plexus injury. Traumatic brachial plexus injury involves sudden damage of nerves and may cause weakness, loss of feeling or loss of movement in shoulder, arm or hand. This device can be used for their rehabilitation. The mechanism used in the invention is block and tackles along with gear-train mechanism. The block and tackle mechanism is an arrangement of two or more pulleys connected by ropes to lift heavy loads with ease. The gear-train mechanism further amplifies the toque which is used to lift loads.
The device for affixing on the shoulder of the user for enabling rehabilitation of the forearm as illustrated in fig. 16 includes an exoarm skeleton comprises a multiple hinged hollow exoskeleton frame affixed on and for assisting the movement of the arm and forearm region encompassed by the said frame, a plurality of shaft and pulleys operating on the block and tackle mechanism coupled to the at least one frame for transferring the generated torque to the said frames, at least one gear box for converting the input mechanical energy into output torque for assisting the movement of

the said frames, a motor for generating the mechanical force to be applied onto the said shafts and pulleys through the said gearbox for enabling the desired motion of the said exoskeleton frame at the pre-determined rate, a speed controller for monitoring and controlling the operations of the said motor based on the input from the device user, a microcontroller for receiving and processing the signals from the user, the speed controller, the motor and the display, a user controlled input mechanism for providing the instructions on the mode of operation of the said device and multiple cables for connecting the said pulleys with the plurality of shafts.
The frame was designed based on the requirements and considerations of the end user. Before visualizing the frame, we studied the anatomy of human arm, where in a survey conducted among the students it was found that the width of the arm remained within a certain size while the breadth varied from person to person. So we took the maximum dimension for width of frame to fit everyone and provided an adjustable spring loaded link for fitting according to varying sizes in breadth of the bicep. Also the forearm regions frame length was limited so that other mechanisms for wrist movement such as yaw, pitch and roll can be added in future. The other components like gearbox, pulleys, control unit etc., was designed and arranged in way that it does not affect the comfort of the user wearing it. The frame is worn by the user with help of specially made customised belt straps that are used in backpack. The weight of the frame is transmitted to the shoulder, thus reducing effort in the biceps. The straps can be adjusted so it can fit wide range of size and lengths of hands. It also keeps the frame in place without twisting while lifting load.
The device for affixing on the shoulder of the user for enabling rehabilitation of the forearm includes an exoarm skeleton as illustrated in fig. 1(a)-1(g) and 2 wherein the said hollow frame structure for encompassing the arm of the user further comprises a backpack at the top of the said arrangement for holding the exo skeleton frame structure, for surrounding around the user's shoulder and for transferring the weight of the said structure to the shoulders of the device user. The said backpack transfers the entire weight of the device from the arm and forearm to the shoulder of the end user for enabling the ease of operation and for quicker rehabilitation of the arm. Multiple straps

of pre-determined and adjustable length are fitted around the frame structure for manually resizing the width of the said hollow frames to compactly fit around the arms and forearms of the user.
The said hollow frame structure for encompassing the arm of the user further comprises at least one hollow hexagonal bottom end structures and at least one hollow rectangular top end structure at two different planes of the said frame for encompassing around the arm and forearm of the end user as illustrated in fig. 2 wherein the said two different planes are parallel to each other and hinged at the common axis separating the first from the second plane. The hexagonal frame has a length of 68.1 mm with a length of 90 mm frame lying perpendicular to the hexagonal structure for being supported on the forearm. The user inserts the forearm in the cavity formed by the said hexagonal structure with the metallic frame extending along the length of the forearm until the elbow. The bottom hollow frame structure in the second plane encompassing the forearm is movable by around 120 degrees in the forward direction to the said top frame in the first plane for enabling the lifting of the load by the said forearms. The bottom hexagonal frame and the top rectangular frame are flexibly hinged at the central pivot region for enabling the requisite 120 degree movement. The top rectangular frame rests along the length of the arm below the shoulder and is static with respect to the movable bottom, hexagonal metallic frame structure. The said frame structure is made of aluminium for providing a light weight and a good durability for the said device. The first and second planes are separated by an altitude of 60 mm and an horizontal distance of 90 mm and the minimum torque applied on the said frame for the liftment of the pre¬determined load is 30Nm.
The device for affixing on the shoulder of the user for enabling rehabilitation of the forearm includes an exoarm skeleton as illustrated in fig. 1(a)-1(g) and 2 wherein the mechanical linkage between the said plurality of frames on different planes and the multi directional movement of the said frames is executed by the shafts and pulleys interconnected with the cables. The said end threaded shaft including the pulley at its center is fastened to the said hollow frame structure and the said cables connect the

plurality of pulleys transfer the applied torque onto the frames for enabling the lifting and movement operations.

2200mAh, but during loading conditions at least 25 times more current can be drawn at an instant with reduction in battery life. This property is unique to lithium batteries and cannot be found in other batteries such as lead acid battery or in AC power supply. Fig. 6 illustrates the pictorial view of the frame structure. The frame is completely made of aluminium due to its high strength to weight ratio. Since aluminium is a soft metal it is easy to machine by hand powered tools such as hacksaw cutting or bending press.
Fig. 7 illustrates the pictorial view of the micro controller. The Arduino Nano is a microcontroller that is used to control components the Exo-Arm. It obtains input from the user, processes the input and controls the motor accordingly. It also shows the mode of operation on the OLED display mounted. It also has option kill-switch to stop the motor in case of emergency. Fig. 8 illustrates the pictorial view of the joystick. The joystick is used to help the user control the motor during remote control mode. The joystick we used has two potentiometers for each axis, X and Y respectively. We use only X axis since the Degrees of Freedom of Exo-Arm is one. The joystick is calibrated to control the motor in forward, reverse and braking modes. Fig. 9 illustrates the pictorial view of the gear box. The miniature gearbox is used to convert high speed into torque. It contains set of metal gears meshing with each other to form a gear-train. Since the motor which came along with gearbox didn't have sufficient power, we replaced the DC motor with high speed brushless motor. When this motor's speed was reduced around 500 times by the gear-train, the output torque was enough to pull the rope.
Fig. 10 illustrates the pictorial view of the bearings. Bearings are used for reducing friction between two surfaces. Here we used two types of bearings, namely, needle, type thrust bearing and roller bearing. Thrust bearing is used to reduce friction between the upper and lower frames while lifting load. Roller bearings are used between shaft and pulley so that pulleys can rotate freely, without friction. Fig. 11 illustrates the pictorial view of the shaft and pulleys. The set of shaft and pulleys constitute the block and tackle mechanism. The shaft is threaded on both ends to fasten on the frame while the rope slides over the pulley during load lifting. The pulleys are machined from nylon block for their light weight and high strength. Fig. 12 (A) - 12(B) illustrates the pictorial view of the sensors. The electromyography sensor is used to

detect the muscle movement and produce electrical signals accordingly. The electrodes attached to the skin of a muscle group detect the stretching and contraction of skin and produces a voltage. These signals are amplified, filtered and sent to the microprocessor. The microprocessor reads the signal and actuates the motor based on the user need. With this sensor the user can control the exoskeleton hands free without any remote or joystick. The force sensor is used to find the amount of force acting on it by the change in resistance. We use this sensor to know the load carried by the user. The sensor is placed between the arm and the frame so that when the load is lifted the sensor gets compressed hence sending signal to the microprocessor about the force acting on it. Using the average forearm's length we can calculate the weight carried by the user.
Fig. 13 illustrates the pictorial view of the OLED. The 0.96' OLED display is used to tell user about what's happening on the suit. It tells the user about current mode, amount of load lifted, position of the arm, battery life etc. so that the user doesn't get confused about the operating mode. During Automatic mode it displays the timer for the exercise to complete.
OPERATIONS DONE
Several operations were done for fabrication of frame. They are
MACHINING - Using Hacksaw Blade
Since aluminium is a soft material it can be cut using hand powered tools. First the required dimensions or shape is taken from the CAD design and marked on the aluminium bar and was cut using hacksaw blade. After the cutting operation was done, to remove sharp edges filing operation was carried out to get smooth edges.
BENDING
Once all the pieces were cut to required dimensions, then some of them have to be bended to an angle to get the desired shape. From the CAD model the distance and angle to be bent were noted. The line was marked on the aluminium and

placed on the bending press and pressed. The angle was measured using bevel protractor.
WELDING
After bending, welding was done to join aluminium pieces to form the frame. Using Tungsten Inert Gas (TIG) welding was done. After the welding operation was over buffing operation was done to remove the burs created at the welded joints.
DRILLING
Finally the holes to be drilled were marked on the frame from the design. The frame is then clamped on the drill bed and the required hole is drilled on the frame. After drilling, filing was done to remove the burrs around the hole.
LATHE
The drum that winds the rope at the end of gear box was machined using lathe on a nylon block. Also while replacing the motor of the gear box a collar was made from phosphor bronze so that wear doesn't take place at the shaft of the motor.

Fig. 14 illustrates the pictorial view of the electronic circuit arrangement. The connections for the motor, force sensor, battery, speed controller, potentiometer, Arduino Nano, OLED andEMG sensor are given below to run the motor. The said motor is connected to a gearbox for converting the speed of the motor to the requisite torque for operating on the said cables connecting the plurality of pulleys and the said motor is connected to a speed controller for controlling the output torque and directional movement of the said device based on the input from the user operated joy stick. The microcontroller controls the operation of the said motor, processes the input from the user, enables the display of the device working information and arrests the operation of the device at emergency. The user input means including the joystick controls the operation of the said motor in a single degree of freedom and for braking operation and the display visually outputs the mode of operation of the said device, position of the said frame encompassing the arm, battery utilized, total quantity of load lifted and the time consumed for the operation. The high powered LiPo battery source supplies the requisite power to the device and discharges at the rate of 2200 mAh for the efficient operation of the load liftment. The plurality of sensors including the electromyography sensor attached to the skin for detecting the arm and forearm muscle movement and for operating the device in the hands free mode and the force sensor placed between the arm and the frame structure for determining the total load lifted by the said device.
Fig.15 illustrates the flow diagram of the device operation. The method for operating an user controlled device for the rehabilitation of the forearm and for the lifting of the heavy loads comprises the steps of inputting the instructions by the end user

through the input means such as the joystick for actuating the said motor and for correspondingly controlling the operation of the said device in either of the EMG mode or remote control mode or the automatic mode, detecting the activation of the muscles of the end user by the electromyography sensor for the motor activation, tilting the joystick to a pre-determined angle for activating the said motor through the said micro controller, prefixing the angle of operation of the device and the time period for the motor activation in the automatic mode, rotating the output shaft of the gear box in consequence to the actuation of the motor, applying the generated torque onto the cables connecting the plurality of pulleys through the shafts and finally enabling the rotational movement to the said corresponding pulley and simultaneously moving the corresponding frame structure for the lifting of the connected load by the said device. There are three operating modes which are used to actuate the motor. They are the EMG mode, Remote Control mode and the automatic mode. In the EMG mode, the EMG sensor detects the signals when the muscle is flexed. Then the detected signals are used to actuate the motor. Next in the remote control mode, when the joystick is tilted to an angle the signals are sent to the microcontroller and then the signals are processed and motor starts to actuate. In the Automatic mode, the angles and the time period are prefixed for actuating the motor. When the motor actuates the output shaft of the gearbox rotates and the rope attached to the shaft also gets wound over the shaft which in turn lifts the load with ease.
It will be obvious to a person skilled in the art that with the advance of technology, the basic idea of the invention can be implemented in a plurality of ways. The invention and its embodiments are thus not restricted to the above examples but may vary within the scope of the claims.
Further the above-described embodiments of the present invention are intended to be examples only. Alterations, modifications and variations may be effected to the particular embodiments by those of skill in the art without departing from the scope of the invention, which is defined solely by the claims appended hereto.

I Claim
• 1) A device for affixing on the shoulder of the user for enabling rehabilitation of the forearm includes an exoarm skeleton comprising
i) A multiple hinged hollow exoskeleton frame affixed on and for assisting the movement of the arm and forearm region encompassed by the said frame.
ii) A plurality of shaft and pulleys operating on the block and tackle mechanism coupled to the at least one frame for transferring the generated torque to the said frames.
iii) At least one gear box for converting the input mechanical energy into output torque for assisting the movement of the said frames.
iv) A motor for generating the mechanical force to be applied onto the said shafts and pulleys through the said gearbox for enabling the desired motion of the said exoskeleton frame at the pre-determined rate.
v) A speed controller for monitoring and controlling the operations of the said motor based on the input from the device user.
vi) A microcontroller for receiving and processing the signals from the user, the speed controller, the motor and the display.
vii) A user controlled input mechanism for providing the instructions on the mode of operation of the said device.
viii)Multiple cables for connecting the said pulleys with the plurality of shafts.
2) The device for affixing on the shoulder of the user for enabling rehabilitation of the forearm includes an exoarm skeleton as claimed in claim 1 wherein the said hollow frame structure for encompassing the arm of the user further comprises

i) A backpack at the top of the said arrangement for holding the exo skeleton frame structure, for surrounding around the user's shoulder and for transferring the weight of the said structure to the shoulders of the device user.
ii) Multiple straps of pre-determined and adjustable length fitted around the frame structure for manually resizing the width of the said hollow frames to compactly fit around the arms and forearms of the user.
3) The device for affixing on the shoulder of the user for enabling rehabilitation of
the forearm includes an exoarm skeleton as claimed in claim 2 wherein the said
hollow frame structure for encompassing the arm of the user further comprises
i) At least one hollow hexagonal bottom end structures and at least one hollow rectangular top end structure at two different planes of the said frame for encompassing around the arm and forearm of the end user wherein the said two different planes are parallel to each other and hinged at the common axis separating the first from the second plane.
ii) The bottom hollow frame structure in the second plane encompassing the forearm is movable by around 120 degrees in the forward direction to the said top frame in the first plane for enabling the liftment of the load by the said forearms.
4) The device for affixing on the shoulder of the user for enabling rehabilitation of
the forearm includes an exoarm skeleton as claimed in claim 3 wherein the said
hollow frame structure for encompassing the arm of the user including
i) The bottom hexagonal frame and the top rectangular frame are flexibly hinged at the central pivot region for enabling the requisite 120 degree movement.
ii) The said frame structure is made of aluminium.

iii) The first and second planes are separated by ah altitude of 60 mm and an horizontal distance of 90 mm.
iv) The minimum torque applied on the said frame for the liftment of the pre-determined load is 30Nm.
5) The device for affixing on the shoulder of the user for enabling rehabilitation of
the forearm includes an exoarm skeleton as claimed in claim 1 wherein
i) The mechanical linkage between the said plurality of frames on different planes and the multi directional movement of the said frames is executed by the shafts and pulleys interconnected with the cables.
ii) The said end threaded shaft including the pulley at its center is fastened to the said hollow frame structure.
iii) The said cables connecting the plurality of pulleys transfer the applied torque onto the frames for enabling the lifting and movement operations.
6) The device for affixing on the shoulder of the user for enabling rehabilitation of the forearm includes an exoarm skeleton as claimed in claim 1 wherein the said motor is a brushless out runner motor for providing a high pre-determined speed.
7) The device for affixing on the shoulder of the user for enabling rehabilitation of the forearm includes an exoarm skeleton as claimed in claim 1 wherein
i) The said motor is connected to a gearbox for converting the speed of the motor to the requisite torque for operating on the said cables connecting the plurality of pulleys.
ii) The said motor is connected to a speed controller for controlling the output torque and directional movement of the said device based on the input from the user operated joy stick.
8) The device for affixing on the shoulder of the user for enabling rehabilitation of
the forearm includes an exoarm skeleton as claimed in claim 1 wherein the said

i) Microcontroller controls the operation of the said motor, processes the input from the user, enables the display of the device working information and arrests the operation of the device at emergency.
ii) User input means including the joystick controls the operation of the said motor in a single degree of freedom and for braking operation.
iii) Display visually outputs the mode of operation of the said device, position of the said frame encompassing the arm, battery utilized, total quantity of load lifted and the time consumed for the operation.
9) The device for affixing on the shoulder.of the user for enabling rehabilitation of the forearm includes an exoarm skeleton as claimed in claim 1 wherein the said device further includes
i) A high powered LiPo battery source discharging at the rate of 2200 mAh for the efficient operation of the load liftment.
ii) Plurality of sensors including the electromyography sensor attached to the skin for detecting the arm and forearm muscle movement and for operating the device in the hands free mode and the force sensor placed between the arm and the frame structure for determining the total load lifted by the said device.
10)A method for operating an user controlled device for the rehabilitation of the forearm and for the lifting of the heavy loads comprises the steps of
i) Inputting the instructions by the end user through the input means such as the joystick for actuating the said motor and for correspondingly controlling the operation of the said device in either of the EMG mode or remote control mode or the automatic mode.
ii) Detecting the activation of the muscles of the end user by the electromyography sensor for the motor activation.

iii) Tilting the joystick to a predetermined angle for activating the said motor through the said micro controller.
iv) Prefixing the angle of operation of the device and the time period for the motor activation in the automatic mode.
v) Rotating the output shaft of the gear box in consequence to the actuation of the motor.
vi) Applying the generated torque onto the cables connecting the plurality of pulleys through the shafts.
vii) Enabling the rotational movement to the said corresponding pulley and simultaneously moving the corresponding frame structure for the lifting of the connected load by the said device.