Abstract:
The invention is a wearable mechatronic posture assisting device comprising an upper support ( 10 ) for connecting to the thigh of a person, a lower support ( 20 ) for connecting to the shank of the person and a joint ( 28 ) pivotably connecting both supports ( 10, 20 ), and a damper ( 30 ) with connectors ( 31   a,    32   a ) for pivotably connecting the damper ( 30 ) to the supports ( 10, 20 ). The damper ( 30 ) is designed to linearly damp the pivot of the joint ( 28 ). The damper ( 30 ) comprises a control means allowing a locking and a drive state ( 101, 103 ) of the damper ( 30 ).

Description:
[0001]    This application claims priority from POT application No. PCT/EP2014/067761 filed Aug. 20, 2014 which claims priory from European application No. EP 13004208.8 filed on Aug. 26, 2013, the disclosures of which are incorporated herein by reference. 
     
    
     TECHNICAL FIELD 
       [0002]    The invention is related to a mechatronic posture assisting device. Such a device can be worn engaging a damper and/or brake function in order to assist the user with his body weight, limb weight and/or even objects being carried. The device usually takes the load off the users muscles in any posture. 
       BACKGROUND OF THE INVENTION 
       [0003]    Assisting devices for different purposes and according to different categories are well known. In U.S. Pat. No. 4,138,156 A an apparatus is disclosed supporting the weight of a person&#39;s body comprising a unit for attachment for each leg. Each unit includes a lower bar having an upper section and a lower section which is longitudinally extendable from the upper section. An upper bar is hingeably connected to the upper end of the lower bar. A brace member, pivotable from the upper bar, is selectively positionable between the upper bar and the lower section of the lower bar. The apparatus puts the weight of the person or a part of it onto the ground on which the lower section of the lower part rests. This apparatus has some constraints which to overcome is one aspect of the instant invention. Since the apparatus has no active elements, no brakes and no damper, no automated control is possible. Furthermore, an advantageous apparatus should not necessarily direct the force just to the ground. It is also disadvantageous when only a single very limited number of postures are supported. 
         [0004]    In EP 2 380 529 A1 a knee orthosis and methods of controlling the knee orthosis are disclosed comprising an actuator between the thigh and the shank. The device controls damping based on sensory feedback. The behaviour of the actuator unit depends on measured knee moment and knee angle. However, this knee orthosis has no posture support and is not designed to support the body weight and has no brake. The knee orthosis is designed to be used for the rehabilitation of a knee only. 
         [0005]    In US2009/0184476 A1a orthopaedic knee joint brace is disclosed having an anatomically shaped thigh and shank support. Upper or lower cuff are made of a reinforced plastic with a shape corresponding to thigh and shank region. However, this means has no posture support and is also designed to be used for the rehabilitation of a knee only. A similar device is disclosed in US 2009/182 254 A1. 
         [0006]    In US 2012/259 431 A1 a terrain adaptive power joint orthosis is disclosed which is designed as a powered human augmentation device assisting a person walking on a surface comprising a powered actuator for supplying a linear spring component and a damping component. A controller estimates gait cycle and adjusts to slope and stairs. This device, however, has no posture or active walking support. Additionally, the powered actuator for support applies external forces on the leg and knee in particular. Similar electrical power actuator devices are known. These devices, however, require an external power source which limits the use and implies an additional heavy weight to be carried. 
         [0007]    A device for supporting a human body in various positions is disclosed in US 2009/058151 A1 providing an ergonomic chair which is fixed to the ground or on sliding rails. The device, however, is not wearable and walking with the device not possible. 
         [0008]    Trousers associated with a ground engaging improved support for seat engagement by wearer are disclosed in U.S. Pat. No. 3,538,512 A. These trousers are designed as a combination of garment including trousers for a wearer having a pair of legs joining with the waist, each of the legs having a means there along for receiving an elongated rod means extending. The rod is dislocated from the bottom half during walking, whereas the rod slides into the lower half to create a rigid vertical structure when seating. Again, these trousers redirect force to ground thereby providing limited possibilities for posture support and no damping at all. 
       SUMMARY OF THE INVENTION 
       [0009]    The invention has the object to provide a posture assisting device with extended possibilities for posture support, which device should be wearable also during walking. Additionally, the device should include at least dampers and the device should be controlled to support the predetermined posture of the possible postures. Furthermore, a device should be provided without any extended electrical power consumption or like, at least to remove the need for actively powered actuators and use a natural force, gravity, to drive the system for actuation. A holding force that will remain engaged passively using only gravity and the body mass for activation will reduce the energy consumption. The user shall be the driver of the device and not be assisted in movement or actions except only when having to maintain a posture for some desired period of time. 
         [0010]    The object of the invention is solved by the posture assisting device. The posture assisting device comprises an upper support for connecting to the thigh of a person and a lower support for connecting to the shank of said person. A joint, which joint is preferably designed as an articulated joint, connects the upper support and the lower support, and a damping means with two ends an upper end and a lower end—and an upper connector for pivotably connecting the upper end to the upper support, preferably at or adjacent to the joint or at the location were the joint is connected to the upper support with a lower connector for pivotably connecting the lower end to the lower support, preferably at the middle third of the lower support, or at the third quarter—of the top. The damping means are designed to linearly damp the drive between its two ends, thereby damping the pivot of said joint. The damping means comprise a control means, said control means at least having a locking state locking the drive of the damper and a drive state which may be designed as an “open” state of a valve, allowing the drive of the damper which is a strong but light damping unit which is able to passively engage large holding forces. The properties of the damping unit can be controlled either manually or with an electric motor. 
         [0011]    The support structure is optimized for weight and size and can ultimately be implemented into the wearer&#39;s clothes. The cost effective design allows providing devices which are affordable to a broader target group than current exoskeletons and other posture supports. 
         [0012]    The invention as a wearable mechatronic posture assisting device that, when worn, can engage a damper and brake function, assists the user with his body weight, limb weight or even objects being carried. The device takes the load off the users muscles in any posture. The device herein called “Chairless Chair” is one example of such a posture support for the lower limbs. It consists of a support structure and a damper. The support structure itself consists of an upper part which is strapped to the upper leg and a lower part which is strapped to the heel of the shoes of the user. One essential advantage of this mechanism over most of the currently available solutions is the low energy consumption. The locking and damping can be done passively. Together with the very high force to weight ratio this allows decreasing the overall weight of the device and therefore the movability of the user wearing this device. The cost effective design allows providing devices which are affordable to a broader target group than current exoskeletons and other posture supports. 
         [0013]    With this device being widely available the risk of musculoskeletal disorders (MSD) and therefore the loss of productivity due to sick days of the employees can be reduced. The mechanism can also be used in other fields like for exercising in rehabilitation or for home trainers. 
         [0014]    In an advantageous embodiment of the invention a connecting rod at the lower support connects the lower connector of the damper to the lower support so that a force conducted from the upper support onto the upper end of said damper and from the damper onto the lower support is essentially directed onto the lower support to the forward direction of the person. 
         [0015]    It is also advantageous when the lower support comprises additional connecting means for connecting the lower part of said lower support to the heel of the person or the heel of the shoe of the person, redirecting the force conducted from the upper support onto the upper end of said damper and from the damper onto the lower support is redirected forward onto the heel of the person or the heel of the shoe of the person. 
         [0016]    According to one aspect of the invention, the damping means comprise a liquid-type damper or a viscous type damper. The control means include a valve. Preferably, the control means additionally allow one or more states with a lower movement, corresponding to a higher drag, than the drive state (open state). The control means could allow to continuously control the movement between said locking state and said drive state (open state). 
         [0017]    According to a basic configuration of the invention, the control means comprise a manually driven lever to control the valve. In a more advanced configuration the said control means comprise an electrical driven valve. The skilled person will note that the electrical power necessary to change the state of the valve cannot be compared with the power necessary to drive an actuator to change the posture as provided by some device according to the above-discussed prior art. 
         [0018]    The posture assisting device can have laces for connecting the upper support to the thigh of the person and/or for connecting the lower support to the shank of the person, preferably by means of hook-and-loop fasteners. It should be noted that the upper support as well as the lower support can be formed so that the back part of the thigh or the shank comfortably fit to the respective support. In an advantageous embodiment of the invention the upper support and/or the lower support are adjustable in respect of the length as to fit comfortably to persons with different length of the thigh and the shank, respectively. 
         [0019]    The aforementioned elements as well as those claimed and described in the following exemplary embodiments, to be used according to the invention, are not subject to any particular conditions by way of exclusion in terms of their size, shape, use of material and technical design, with the result that the selection criteria known in the respective field of application can be used without restrictions. It should be noted that all means used to implement the invention are not limited to a particular design. The mechanism of the invention is not limited to the lower limbs but can also be used for arms, shoulders and back support. 
         [0020]    The skilled person will note that the usage of the posture assisting device according to the present invention is not limited to the usage for workers and for other persons to be assisted during their work, i.e. at a band-conveyor. Moreover, the posture assisting device can be used supporting the rehabilitation of injured persons or even for assistance of persons having disseminated sclerosis. One main usage can be the assistance for recreational activities, i.e. fishing and hunting. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0021]    Examples of the posture assisting device will hence forth be described in more de ail by reference to the drawings, wherein are shown: 
           [0022]      FIG. 1  a side view of a preferred embodiment of the invention worn by a person, 
           [0023]      FIG. 2 a    a perspective view of the embodiment according to  FIG. 1 , 
           [0024]      FIG. 2 b    a perspective view according to  FIG. 2 a    from another angle, 
           [0025]      FIG. 3 a    a view onto the main elements of the damping means substructure according to  FIGS. 1 and 2   a ,  213 ; 
           [0026]      FIG. 3 b    a view onto the damping means according to  FIG. 3   a;    
           [0027]      FIG. 4  a view onto the valve according to a preferred embodiment in different positions with the functions closed, damped and open, 
           [0028]      FIG. 5  a side view according to  FIG. 4  with the functions closed and open. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0029]    The embodiment described hereby is one preferred embodiment of the invention called “Chairless Chair”. 
         [0030]    The “Chairless Chair” comprises a support structure with an upper support  10  for connecting to the thigh of a person, a lower support  20  for connecting to the shank of the person and damping means  30 . A joint  28  connects the upper support  10  and the lower support  20 . The support structure with the upper support  10  and the lower support  20  is ergonomically shaped to provide a good fit to the legs and is designed to ensure a comfortable feeling. The strapping is not shown in  FIG. 1 . The strapping comprises soft padding which allows a firm fit of the support structure to the leg with a well-distributed pressure. 
         [0031]    The joint  28  is—according to the described embodiment—designed as an articulated joint connecting the upper support and the lower support. It is a normal pin hole joint or—alternatively—an auto-adjustable joint that follows the natural movement of the center of rotation of the knee joint. In this example the force of the body weight gets absorbed by the support structure and the damper and then redirected to the heel connector. 
         [0032]    The damping means  30  comprise a hydraulic variable damper. It can vary the resistance from very low damping up to very high damping and ultimately brake. The damper has two ends—an upper end  31  and a lower end  32 —and an upper connector  31   a  for pivotably connecting the upper end  31  to the upper support  10 , preferably at or adjacent to the joint or at the location were the joint  28  is connected to the upper support  10  with a lower connector  32   a  for pivotably connecting the lower end  32  to the lower support  20 , preferably at the middle third of the lower support  20 , or at the third quarter—from the top. The damping means  30  are designed to linearly damp the drive between its two ends  31  and  32 , thereby damping the pivot of said joint  28 . The damping means  30  comprise a control means, said control means at least having a locking state locking the drive of the damper  30  and a drive state which may be designed as an “open” state of two disc valve, allowing the drive of the damping means  30 . The manual handle  33  of the damper is used to control the relative angle between the discs of the rotary two disc valve. II can be replaced by a motor, i.e. an electrical motor. An inner shaft  34  is connected to the disc at the end of the piston with opening  37  and to the manual handle. The inner shaft  34  translates the movement of the handle to the disc  41 . A cover nut  35  secures the guider and the tube sealing  40  on the hydraulic tube  39 . The linear guider assembly  36  restricts the movement of the piston to the axial direction and seals of the top end of the hydraulic tube  39 . The piston with opening is considered as the core element of the rotary two disc valve. It absorbs the damping and braking force, respectively from the host device. The disc  41  with opening is the second element of the rotary two disc valves. Its relative turning angle to the piston defines the amount of damping and, when the disc  41  closes the flow of the hydraulic fluid, the brake function, respectively. A release valve  38  is installed to allow emergency push open of the brake when locked. The hydraulic tube  39  contains the hydraulic fluid and restricts the piston to a linear movement. The tube sealing  40  seals the bottom part of the hydraulic tube  39 . 
         [0033]    The force redirection according to the embodiment called “Chairless Chair” is shown by the arrows  104  and  106  in  FIG. 1 . The body weight  104  gets absorbed by the upper support  10 , the damping means  30  when in the operation mode as a brake with the valve closed, the lower support  20  and then gets redirected to the heel of the person or the person&#39;s shoe according to the arrow  106 . Because of the shape of the support structure and the position of the straps the direction of the force changes from the vertical direction (down) to mainly horizontal direction (forward). The mechanization of the redirection is supported by the connecting means  22  at the lower support  20  connecting the lower end of the damper  30  to the lower support  20 . The connecting means  22  are arranged on the lower support such that a component of the stress is redirected from the support to a part of the body or equipment, e.g. the heel of the shoes. Means  23  for connecting the lower part of said lower support  20  to the heel of the person or the heel of the shoe of the person are provided therefore. 
       Valve Operation Principle 
       [0034]    The operation principle of the two disc valve is illustrated in  FIG. 4  and described here thereafter. 
         [0035]    When the two discs of the valve are perfectly overlapped—situation  101 —then the valve is closed and the damper acts as a brake. If the holes in the two discs are perfectly aligned then the valve is open—situation  103 . The amount of resistance to the flow of the working fluid depends and the effective opening area of the orifice. The effective orifice area can be changed by rotating one disc relative to the other —situation  102 . The damping can therefore be continuously changed from very low damping  103  to very high damping and brake  101 . 
       Safety Mechanism 
       [0036]    To ensure possibility to unlock the damper even when the brake is engaged a safety mechanism was included into the valve. The working principle of the safety mechanism is shown in  FIG. 5 . The rotatable disc  41  is in lock position, the brake is engaged. When needed the piston can be pushed in the opposite direction (extension of damper). The spring  42  acts as compliance and allows the disc  41  to travel away from the piston due to the fluid stream pressing against disc  41 . This leads to a small gap between the two discs and therefore the valve is no longer closed. A small catch  43  ensures that the disc is still aligned in its relative rotation. So when the pressure from extending the damper drops the disc  41  is pushed back onto the piston disc by spring  42 . 
       LIST OF REFERENCE SIGNS 
       [0000]    
       
           10  upper support 
           20  lower support 
           22  connecting means 
           23  means for connecting the lower part of said lower support to the heel 
           28  joint 
           30  damping means 
           31  upper end of the damper 
           31   a  upper connector 
           32  lower end of the damper 
           32   a  lower connector 
           33  manual handle 
           34  inner shaft 
           35  cover nut 
           36  linear guider assembly 
           37  piston with opening 
           38  release valve 
           39  hydraulic tube 
           40  tube sealing 
           41  disc with opening 
           42  spring 
           43  small catch 
           101  situation of closed valve 
           102  situation of partly opened valve 
           103  situation of fully opened valve 
           104  gravitational force/body weight 
           106  redirected force