Field of the Invention

The present invention relates to physiotherapy apparatus. More specifically the present invention relates to self-trainable physiotherapy apparatus.

Background of the Invention

Due to an injury, dysfunction of a limb and inability to move and perform functional activities of everyday life, which requires physical therapy, may result.

To enable a person who suffered from an injury that causes dysfunction of a limb, to restore, as much as possible, normal functioning of the disabled limb, many hours of physical therapy are necessary. For best results physical therapy should start as soon as possible after injury. However, because of lack of rehabilitation centers, shortage of physical therapists and experts, the average patient begins therapy after the critical period. In many cases, after starting physical therapy, the patient receives only infrequent sessions.

It would therefore be desirable to provide apparatus that facilitates at-home physical therapy in order to undergo rehabilitation for injury victims that increases strength and mobility without having to be dependent upon the availability of physical therapists.

On the other hand, physical therapy conducted at a clinic speeds the rehabilitative process by virtue of the assistance of physical therapists. Each patient responds differently to physical therapy due to different body structures, habits and pain thresholds, and therefore a rehabilitation program has to be individually developed. The patient who is undergoing the physical therapy is generally unaware of his mobility level or pain threshold due to the many activities that he is requested to perform and being unknowledgeable as to the relation between the different rehabilitative activities that are performed. The physical therapist monitors the patient's development and reaction to pain, and instructs when to increase the difficulty level of an activity so that improvement will continue. The assessment made by the physical therapist is generally based on a visual test, and at times on other in-clinic tests using various devices. For example, assessment of a pain sensation is made by observation of a facial grimace or a reluctance to move a specific body region. Personal interaction between the patient and the physical therapist resulting in a suggested intervention therefore promotes improved rehabilitation.

It is an object of the present invention to provide physiotherapy apparatus that will help the patient to perform functional activities in a similar fashion as performed prior to being injured.

It is an additional object of the present invention to reduce the cost of rehabilitation by enabling a patient to train himself and reduce the hours of work with a physical therapist.

It is an additional object of the present invention to provide self-trainable physiotherapy apparatus that facilitates at-home physical therapy while providing an indication when the difficulty level of an activity can be increased. Other objects and advantages of the invention will become apparent as the description proceeds.

Summary of the Invention

Self-trainable physiotherapy apparatus comprises a set of sensors mounted on an injured limb of a user for measuring motion of the injured limb during performance of a user- initiated action; a powered mechanism comprising one or more actuators which is mounted on the injured limb and is configured to controllably cause movement of corresponding bones of the injured limb; and a controller configured with means for recording a synchronized movement of a plurality of bones of the injured limb at each of a plurality of time intervals during performance of the user-initiated action in conjunction with a measurement signal received from each of the sensors, and with means for reproducing the synchronized movement of the plurality of bones at each of the plurality of time intervals by causing the one or more actuators to generate a corresponding controlled force at each of the plurality of time intervals.

Brief Description of the Drawings In the drawings:

Fig. 1 is a schematic illustration of physiotherapy apparatus, according to one embodiment;

Fig. 2 is a schematic illustration of physiotherapy apparatus, according to another embodiment; and - Fig. 3 is a block diagram which shows the main features of a control circuit for use by a controller of the apparatus of Fig. 1.

Detailed Description of the Invention The present invention is related to self-trainable physiotherapy apparatus. Interaction with the physiotherapy apparatus may be carried out at the comfort of one's home without having to be dependent upon the availability of physical therapists.

Sensors are mounted on the injured limb that is in need of rehabilitation in order to measure relative motion at a joint between at least one pair of bones of the injured limb during performance of a desired action. In addition, the apparatus comprises a powered mechanism for controllably moving individual bones on the injured limb, so that the previously performed action can be reproduced by a user-set program. During performance of the desired action, the movement of each bone of the injured limb is measured by the sensors, producing signals transmitted to and processed by a processor, which then commands the powered mechanism to activate corresponding actuators so that each specific bone of the injured limb will move in exactly the same way as during performance of the desired action. The performed action can be reproduced repeatedly to improve a specific rehabilitative process, such as strength and mobility, or may be reproduced once.

Rather than relying on the assessment made by a physical therapist at a health clinic, the user is advantageously able to make a self-assessment of the injured limb during interaction with the apparatus. The user may place more importance on the rehabilitation program that he or she personally chose than on one selected by a physical therapist at a clinic, and therefore may train more seriously. The self-assessment may be made relative to a sensed pain threshold. If at first the performed action is accompanied by pain, and then after repeated or subsequent performance of the action the pain is no longer noticeable, the user realizes that the difficulty level may be increased. The self-assessment may also be made by observation or through a personal experienced determination as to a quality of performance during the selected action. A user whose mobility or motor skills have become impaired, for example due to injury or an accident, is able to compare the current performance to a previous unimpaired performance that is remembered. If the current performance is similar to a previous unimpaired performance, the user realizes that the difficulty level may be increased.

The term limb used in the present invention refers to any one of the jointed appendages of a human, such as an arm, foot, hand and leg, used for locomotion or grasping. Fig. 1 schematically physiotherapy apparatus, generally indicated by numeral 30, according to one embodiment.

Apparatus 30 comprises a plurality of sensors 2, which may be digital or analogical sensors, mounted on injured limb 5, shown to represent an index finger having a distal phalange 3 and an intermediate phalange 4, to track the movement of individual bones of the fingers of a hand. Each sensor 2 is mounted on an anchor element 8 that is secured to a corresponding bone on injured limb 5. Anchor elements 8 may be attached directly to the finger at each side of a joint, e.g. in the form of rings as illustrated.

It will be appreciated that the plurality of sensors 2 may mounted on any other suitable limb, or any other number of appendages.

A customized mounting unit may be provided with all the sensor-mounted anchor elements 8 that are needed to be secured on a corresponding bone of injured limb 5 in order to suitably measure the movement of each bone of the injured limb during performance of the user-initiated action. Adjacent anchor elements 8 may be interconnected by an element of a length that corresponds to the anatomical structure of the limb. Prior to performance of the user-initiated action, each limb is simply inserted within, and secured to, a corresponding anchor element without having to individually size and fixate each anchor element.

When the hand is used, for example to grasp or release an object, adjacent bones in each finger move with respect to one another. The movement of a bone, hereinafter referred to as the "object bone", in relation to one or more other bones, each of which hereinafter referred to as a "reference bone", is detected by the sensors 2. The object bone and the reference bone are connected by a joint that permits relative movement of one with respect to the other. Each sensor 2 transmits a measurement signal H, whether a wireless signal or a wired signal, indicative of a measurement made with respect to a corresponding bone of injured limb 5 to processor-equipped controller 18, which is powered by power supply 20. Controller 18 receives and analyzes all time-dependent signals H from the sensors mounted on limb 5 during performance of a specific motion, such as bending the distal phalange towards the palm or away from the palm, and is able to initiate reproduction of the specific motion through definition of relative motion associated with each phalange of limb 5 following analysis of the received signals H.

A powered mechanism 10 configured to reproduce the specific motion in conjunction with injured limb 5 includes one or more actuators 13 in data communication with controller 18, which are adapted to operate in accordance with a reproducing initiating signal R received from controller 18. One or more transmission elements 28 in kinematic connection with both an actuator and a bone of the injured limb 5 transmit the controlled force F produced by an actuator to a corresponding bone of the injured limb, so that the actuator-controlled movement of all propelled bones will reproduce the previously performed specific motion.

Controller 18 analyzes the received signals H and determines the present range of motion achievable by the injured limb 5. In response to determining the achievable range of motion, controller 18 determines the magnitude and direction of the controlled forces F that have to be generated by each actuator 13, as well as the characteristics of each reproducing initiating signal R to be transmitted to an actuator 13 that is suitable to generate a corresponding controlled force F, in order to reproduce the specific motion by injured limb 5.

Controller 18 is configured with a plurality of user input elements, such as depressable or touch sensitive buttons, including a setting button 7, a record button 9, a stop button 11, and a reproduce button 17. The setting button 7 accesses a menu in which all sensors 2 and actuators 13 associated with apparatus 30 are defined offline by a corresponding identifier and by operational characteristics. Slightly before commencement of the reproducible user-performed action, for example 10 seconds prior to commencement of the reproducible user-performed action, the user presses record button 9, generally with a hand on which the sensors are not mounted. The plurality of sensors 2 and controller 18 are consequently powered by power supply 20, to enable transmission and analysis of signals H during the course of the reproducible user-performed action. During the recording procedure, controller 18 determines, through stored instructions related to analysis of signals H, the synchronized movement of each bone of injured limb 5 at each predetermined time interval, e.g. 20 ms,

The user then presses stop button 11 in real-time to terminate the recording procedure at a selected stage of the action considered by the user to be an end of a treatment session, due to the difficulty encountered by the user to continue the action, such as for example unbearable pain or excessive perceived exertion. At least the plurality of sensors 2 cease to be powered, and signals H are no longer transmitted.

Controller 18 accordingly is able to define the relative location of each bone of injured limb 5 at the start and end of an action, as well as at each predetermined time interval therebetween. At each predetermined time interval following the starting time, a corresponding controlled force F to be applied to each bone is determined that will ensure that the previously defined relative location of each bone will be achieved, when taking into consideration the configuration of each actuator 13 and each transmission element 28. Additionally, characteristics of reproducing initiating signal R to be transmitted to each actuator 13 in order to generate the corresponding controlled force F are also determined.

When reproduce button 17 is subsequently pressed, the plurality of actuators 13 and controller 18 become powered. Controller 18 outputs a corresponding reproducing initiating signal R to each actuator 13 at each predetermined time interval, so that corresponding controlled forces F suitable for reproducing the action will be generated thereby. If at the starting time of the reproduced action controller 18 determines that the relative location of each bone of injured limb 5 is different than at the starting time of the user- initiated action, a correcting signal C is transmitted to each actuator 13, if necessary, that will force movement of each bone to a position that is consistent with the relative location of each bone at the starting time of the user-initiated action.

Fig. 2 illustrates an analog system for reproducing a user-initiated action. For purposes of clarity, the sensors for measuring movements of bones during a user-initiated action are shown to be mounted on limb 25 and the powered mechanism is shown to be mounted on limb 27. It will be appreciated, however, that the sensors and the powered mechanism are generally both mounted on the same limb.

In this embodiment, the sensors mounted on limb 25 are potentiometers 16, which are connected by cables 14a and 140a to corresponding anchor elements 8 that are secured on each finger bone of healthy hand 25. Anchor elements 8 can be attached directly to the finger in the form of a ring, as shown, or can be configured in other ways. It will be appreciated that any other number of sensors and cables may be employed, depending on the anatomy of the limb or on the specific motion that is desired to be reproduced.

A set of flexible cables 140a, 14a is used for each joint of the fingers to measure the relative movement of the object bone relative to the reference bone when the joint is bent. The set of cables comprises an internal cable 140a that passes through the hollow center of an external cable 14a. The external cable, which is essentially a flexible tube, is attached at one of its ends to an anchor element 8 on reference bone 6 and at its other end to a fixed location on the arm of the patient. The internal cable 140a is attached at one of its ends to anchor element 8 on the object bone 3, passes through the hollow center of external cable 14a and is connected at its other end to lever 21. Bending of the joint between object bone 3 and reference bone 6 causes the inner cable 140a to pull on lever 21, which rotates about pivot 9, pulling on linkage 29 and changing the output of potentiometer 16. Not seen in the figure is a spring located on pivot 19. The spring pulls back on the end of the lever to which the inner cable is attached so that, when the joint on the finger is straightened, the tension in the inner cable is maintained and linkage 29 is pushed in the opposite direction changing the output of potentiometer 16. The output of potentiometer 16 is transmitted to controller 18.

In this way, the movements of the object bone 3 in relation to the reference bone 6 are transferred to the related sensor by pull of the cable. As long as the bones move together, the distance between the anchor elements 8 on the object bone 3 and reference bone 6 stays constant, the potentiometer isn’t moved and the system doesn’t react. That is, the wrist is free to move as long as the external and internal cables move together.

The sensors can be either digital or analog, e.g. accelerometer sensors, strain gauges, bend sensors, fiber optic sensors, or Hall Effect sensors. In the case in which digital sensors are used, the sensors are located on the bones at the locations of anchor elements 8. The output signals from each sensor or potentiometer can be transmitted by either a wired or wireless communication link 24 to processor based controller 18. In embodiments of the invention wireless transmitters having a unique IP address are associated with some or all of the sensors and communication link 24 is a wireless network that uses, for example, Wi-Fi or Bluetooth technology.

In controller 18, the output of each of the sensors 16 is analyzed and then signals are transmitted to powered mechanism 10 on limb 27. The transmitted signals are instructions related to the duration and magnitude of the force that should be applied by the components of the powered mechanism 10 to each specific bone on limb 27 in order to cause that bone to move in exactly the same way that the corresponding bone on limb 25 moved.

One example of an actuator that can be used in the powered mechanism 10 is a miniature electric motor 22 that is fixedly attached to the arm of the user and mechanically linked to cables or rods that are connected to anchor elements 12 on the finger bones. Another example is a pneumatic or hydraulic pump and a driving jig connected to the bones in a similar manner. The actuators receive the electric power to activate them from power supply 20 by means of a network of wires 26.

In the embodiment shown in Fig. 2, the small electric motor 22 is activated by instructions received from controller 18. On limb 27, as opposed to limb 25, for each joint the powered mechanism 10 comprises two sets of flexible cables 150a, 15a one on the top of the joint to cause the straightening of the joint and another similar set (not shown in for clarity) on the bottom to cause bending of the joint. Each set of cables comprises an internal cable 150a that passes through the hollow center of an external cable 15a. The external cable, which is essentially a flexible tube is attached at one end to an anchor element 12 on the reference bone and at the other end to a location on the arm above the wrist. The internal cable 150a is attached at one end to an anchor element 12 on the reference bone, passes through the hollow center of external cable 15) and is connected to one end of lever 21. Anchor elements 12 can be attached directly to the finger, e.g. in the form of rings as shown.

The motor 22 is coupled to a screw 23 which, depending on the direction the screw it is rotated by the motor, causes the end of lever 21' it is attached to be pushed forward or pulled backwards. As the end of lever 2G connected to the screw 23 moves, the lever 2G rotates around pivot 19 pulling on the ends of cables 150a causing the object bone to move relative to the reference bone causing the joint between them to bend or be straightened depending on if the top or bottom internal cable is pulled.

According to one embodiment of the invention a feedback sensor system is provided on limb 27. The feedback sensor system is identical to the sensor assembly on limb 25. In the embodiment shown in Fig. 2, the cables and anchor elements of the powered mechanism 10 that are used to move the injured fingers are also utilized for the feedback sensor system. The end of lever 21' of the powered mechanism to which the cables 150a on the top and bottom of a finger are connected is also connected by linkage 29' to potentiometer 16'. As lever 21 moves, linkage 29' is pushed or pulled changing the output signal of potentiometer 16'. The output of potentiometer 16' is transmitted to controller 18. The feedback sensor system on the injured limb provides real time information to controller 18, which uses this information to adjust the magnitude of the force of the actuators on limb 27. This feedback is important in order to match the motion of the bones on limb 27 exactly with that of the corresponding bone on limb 25 and prevent the application of excessive force to the bone which could further injure the hand.

It will be appreciated that any other kinematic system is also in the scope of the invention.

Fig. 3 is a general block diagram presenting an embodiment of a control circuit for use by controller 18. The analog/digital conversion elements connected to the sensor arrays are not necessary when digital sensors are used. The controller may be a dedicated unit attached to or separated from the rest of the apparatus or it can be a general purpose computer, PC, or hand held device. In addition to the processor itself, this module comprises other components including: one or more input/output bus bars to facilitate electrical connection with the components of the apparatus; transmitting and receiving means for wireless and/or wired communication with the sensors; one or more memory units to record the activities and results of the sessions and historical data that show the progress of the patient; input devices, e.g. keyboard, touch pad, or touch screen, to input information about the patient or details of the session and instructions to the apparatus, for example limiting the maximum amount of force that can be applied by the actuators on the injured limb; and output devices, e.g. a display screen or audible signals to allow the progress and results of the session to be monitored. In addition, regardless of the type of processing unit employed, the processor is loaded with dedicated software adapted to receive the signals from the sensors and convert them into instructions to the actuators and also to control the overall operation of the apparatus. The power supply 20 can supply either direct current, e.g. from rechargeable batteries, or low voltage alternating current to the sensors and powered mechanism on the injured limb and to controller 18 by means of electric wires as required.

The apparatus of the invention enables a user to undergo self-training and to reduce the hours of work with a physical therapist. For self-training sessions without the presence of a physical therapist, a patient may receive, together with the apparatus of the invention, a training program with specific instructions of the kind and number of movements to be carried out.

Although embodiments of the invention have been described by way of illustration, it will be understood that the invention may be carried out with many variations, modifications, and adaptations, without exceeding the scope of the claims.