Patent Publication Number: US-9895277-B2

Title: Transfer assistance device

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application is based upon and claims the benefit of priority from Japanese patent application No. 2015-200578, filed on Oct. 8, 2015, the disclosure of which is incorporated herein in its entirety by reference. 
     BACKGROUND 
     1. Field 
     The present disclosure relates to a transfer assistance device. 
     2. Description of Related Art 
     Japanese Unexamined Patent Application Publication No. 2014-61448 discloses a walking assistance device that that assists a person requiring assistance to walk. The walking assistance device includes a lower extremity frame, an upper extremity frame that is rotatably supported by the lower extremity frame, and a holding part that is supported by the upper extremity frame. The holding part includes a central part on which a central air bag is disposed, a left wing part on which a left air bag is disposed, and a right wing part on which a right air bag is disposed. The central part, the left wing part, and the right wing part are connected to form a C shape as a whole. The central part is disposed to face a front surface of a torso of the person requiring assistance. Likewise, the right wing part is disposed to face a right flank of the torso of the person requiring assistance, and the left wing part is disposed to face a left flank of the torso of the person requiring assistance. 
     The walking assistance device further includes a central air compressor that adjusts air pressure of the central air bag, a left air compressor that adjusts air pressure of the left air bag, and a right air compressor that adjusts air pressure of the right air bag. Thus, the air pressure of the central air bag, the air pressure of the left air bag, and the air pressure of the right air bag can be independently adjusted, and the air pressure can be differentiated among the central air bag, the left air bag, and the right air bag. 
     However, with the configuration disclosed in Japanese Unexamined Patent Application Publication No. 2014-61448, although the air pressure of the whole central air bag can be adjusted, the air pressure of different regions in the central air bag cannot be independently adjusted. This is also applicable to the lateral (right and left) air bags. There is thus a need for an improved technique that can reduce a burden on the person requiring assistance. 
     An object of the present disclosure is to provide a technique that adjusts pressure on different parts of one surface (a front surface, lateral surfaces, and a back surface) of a torso of a person being assisted so that the pressure on the above different parts of the one surface relatively differs so as to reduce a burden on the person being assisted at the time of assisting transfer of the person being assisted. 
     SUMMARY 
     An exemplary aspect of the present disclosure is a transfer assistance device that includes: a bogie; an arm tiltably supported by the bogie; a holding part that is supported by the arm and includes at least one of a front surface holding part configured to hold a front surface of a torso of a person being assisted, a lateral surface holding part configured to hold a lateral surface of a torso of a person being assisted, and a back surface holding part configured to hold a back surface of the torso of the person being assisted. The holding part includes at least a first bag and a second bag configured to respectively face different parts of at least one of the front surface, the lateral surface, and the back surface of the torso of the person being assisted. The transfer assistance device further includes an air pressure adjuster to individually adjust air pressure of the first bag and air pressure of the second bag. With such a configuration, when the transfer assistance device assists transfer of the person being assisted, it is possible to adjust pressure on different parts of at least one of the front surface, the lateral surface, and the back surface of the torso of the person being assisted so that the pressure will relatively differ on the different pans of the one of the front surface, the lateral surface, and the back surface of the torso of the person being assisted to thereby reduce a burden on the person being assisted. 
     The first bag is configured to face a solar plexus of the front surface of the torso of the person being assisted, the second bag is configured to face some or all parts other than the solar plexus of the front surface of the torso of the person being assisted, and the air pressure adjuster is configured to adjust the air pressure of the first bag to be lower than the air pressure of the second bag when the holding part holds the person being assisted. With such a configuration, it is possible to effectively reduce a burden on the solar plexus of the torso of the person being assisted when the transfer assistance device assists transfer of the person being assisted. 
     According to the present disclosure, it is possible to reduce a burden on a person being assisted. 
     The above and other objects, features and advantages of the present disclosure will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not to be considered as limiting the present disclosure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective diagram of a transfer assistance device; 
         FIG. 2  is a plan view of a holding part; 
         FIG. 3  is a perspective diagram of a left flank holding part; 
         FIG. 4  is a developed view of the holding part; 
         FIG. 5  is a block diagram of an air pressure adjusting mechanism; 
         FIG. 6  is a functional block diagram of a transfer assistance device; 
         FIG. 7  is a flowchart for explaining transfer of a person being assisted; 
         FIG. 8  is a drawing showing a pressure distribution of air pressure of the holding part; 
         FIG. 9  is a drawing showing a pressure distribution of the air pressure of the holding part; and 
         FIG. 10  is a drawing showing a pressure distribution of the air pressure of the holding part. 
     
    
    
     DESCRIPTION OF THE EXEMPLARY EMBODIMENTS 
       FIG. 1  is a perspective diagram of a transfer assistance device  1 . The transfer assistance device  1  is a device for transferring a person being assisted P who is sitting on a bed or the like to a wheel chair or the like. The transfer assistance device  1  includes a bogie  2 , an arm  3 , and a holding part  4 . 
     The bogie  2  includes a bogie body  5 , two driving wheels  6 , two trailing wheels  7 , a footrest plate  8 , and a bogie motor  9 . The two driving wheels  6  are rotationally driven by the bogie motor  9 . The footrest plate  8  is a plate on which soles of feet of the person being assisted P are placed. 
     The arm  3  is tiltably supported by the bogie  2 . The arm  3  includes a lower arm  10  that is fixed to the bogie body  5  and is vertically extended, an upper arm  11  that is tiltably supported by an upper end of the lower arm  10 , and an arm motor  12  that tilts and drives the upper arm  11 . 
     The holding part  4  is supported by the arm  3  and holds a torso Q of the person being assisted P. The holding part  4  includes a front surface holding part  20 , a left flank holding part  21  (a lateral surface holding part), a right flank holding part  22  (a lateral surface holding part), and two back surface holding parts  23 . 
       FIG. 2  is a plan view of the holding part  4 . The front surface holding part  20  faces a front surface Q 1  of the torso Q of the person being assisted P and is attached to a leading end of the upper arm  11  of the arm  3 . The left flank holding part  21  faces a left flank Q 2  (a lateral surface) of the torso Q of the person being assisted P. The right flank holding part  22  faces a right flank Q 3  (a lateral surface) of the torso Q of the person being assisted P. The left flank holding part  21  and the right flank holding part  22  are supported by the front surface holding part  20 . A distance between the left flank holding part  21  and the right flank holding part  22  is configured to be adjustable as appropriate according to a build of the person being assisted P. The two back surface holding parts  23  face a back surface Q 4  of the torso Q of the person being assisted P. One of the two back surface holding parts  23  is supported by the left flank holding part  21  in such a way that the one of the two back surface holding parts  23  can be freely opened and closed, and the other one of the two back surface holding parts  23  is supported by the right flank holding part  22  in such a way that the other one of the two back surface holding parts  23  can be freely opened and closed. 
       FIG. 3  is a perspective diagram of the left flank holding part  21 . As shown in  FIG. 3 , the left flank holding part  21  is configured to include a base plate  30 , a cushion  31 , a plurality of air cells  32 , and an outer skin  33  (see  FIG. 2 ). The base plate  30  is formed of resin, carbon fiber, a metal plate, or other hard materials. The cushion  31  is pasted onto the base plate  30  and is formed of urethane foam or other soft materials. The plurality of air cells  32  (small bags) are pasted onto the cushion  31  and are boxes formed of sheet-like polyurethane, polyvinyl chloride, or rubber material. Each of the air cells  32  inflates or deflates according to an amount of air pressure inside. As shown in  FIG. 2 , the outer skin  33  is disposed to cover over the plurality of air cells  32 . The outer skin  33  is formed of an elastic material so that the outer skin  33  will not inhibit the inflation and deflation of the air cells  32 . As shown in  FIG. 3 , the plurality of air cells  32  are connected to each other by airflow path parts  34  to enable air to flow among the air cells  32 . 
     As the right flank holding part  22  and the two back surface holding parts  23  have the same configuration as that of the left flank holding part  21 , descriptions thereof will be omitted. 
       FIG. 4  is a developed view of the holding part  4 . As shown in  FIG. 4 , as with the left flank holding part  21 , the front surface holding part  20  also includes the base plate  30 , the cushion  31 , the plurality of air cells  32 , and the outer skin  33  (see  FIG. 2 ). However, in the front surface holding part  20 , the plurality of air cells  32  are divided into a low pressure cell group  35  and a high pressure cell group  36 . The plurality of air cells  32  belonging to the low pressure cell group  35  face a solar plexus of the torso Q of the person being assisted P when the holding part  4  holds the torso Q of the person being assisted P. On the other hand, the plurality of air cells  32  belonging to the high pressure cell group  36  face parts other than the solar plexus of the torso Q of the person being assisted P when the holding part  4  holds the torso Q of the person being assisted P. The plurality of air cells  32  belonging to the low pressure cell group  35  are connected to one another by the airflow path parts  34  so that air can flow through the plurality of air cells  32  belonging to the low pressure cell group  35 . Likewise, the plurality of air cells  32  belonging to the high pressure cell group  36  are connected to one another by the airflow path parts  34  so that air can flow through the plurality of air cells  32  belonging to the high pressure cell group  36 . On the other hand, as the plurality of air cells  32  belonging to the low pressure cell group  35  and the plurality of air cells  32  belonging to the high pressure cell group  36  are not connected, air cannot flow between the plurality of air cells  32  belonging to the low pressure cell group  35  and the plurality of air cells  32  belonging to the high pressure cell group  36 . With such a configuration, the air pressure of the respective air cells  32  belonging to the low pressure cell group  35  and the air pressure of the respective air cells  32  belonging to the high pressure cell group  36  can be differentiated. 
     Next, an air pressure adjusting mechanism R that adjusts the air pressure of the respective air cells  32  belonging to the front surface holding part  20 , the left flank holding part  21 , the right flank holding part  22 , and two back surface holding parts  23  will be described with reference to  FIG. 5 . 
     The air pressure adjusting mechanism R includes a compressor  40 , a positive pressure tank  41 , a vacuum pump  42 , and a negative pressure tank  43 . The compressor  40  adjusts air pressure inside the positive pressure tank  41  to a predetermined air pressure that is higher than atmospheric pressure, which is positive pressure. The vacuum pump  42  adjusts air pressure inside the negative pressure tank  43  to a predetermined air pressure that is lower than the atmospheric pressure, which is negative pressure. The air pressure adjusting mechanism R includes six positive pressure side solenoid valves  50 , six electro-pneumatic regulators  51 , six pressure gauges  52 , and six negative pressure side solenoid valves  53 . 
     (Low Pressure Cell Group  35 ) 
     Any one of the air cells  32  belonging to the low pressure cell group  35  is connected to the positive pressure tank  41  with one of the positive pressure side solenoid valves  50  and one of the electro-pneumatic regulators  51  interposed therebetween. The positive pressure side solenoid valve  50  and the electro-pneumatic regulator  51  are disposed in parallel between the above air cells  32  belonging to the low pressure cell group  35  and the positive pressure tank  41 . The positive pressure side solenoid valves  50  control the valves to be fully opened or closed according to input signals. The electro-pneumatic regulators  51  adjust air pressure to be output by feedback control according to the input signals. Thus, although the electro-pneumatic regulators  51  can adjust the air pressure in the respective air cells  32  belonging to the low pressure cell group  35  highly accurately, responsiveness of the electro-pneumatic regulators  51  is poor. The air cells  32  belonging to the low pressure cell group  35  are connected to the negative pressure tank  43  with one of the negative pressure side solenoid valves  53  interposed therebetween. One of the pressure gauges  52  measures the air pressure of the respective air cells  32  belonging to the low pressure cell group  35 . 
     (High Pressure Cell Group  36 ) 
     Likewise, any one of the air cells  32  belonging to the high pressure cell group  36  is connected to the positive pressure tank  41  with one of the positive pressure side solenoid valves  50  and one of the electro-pneumatic regulators  51  interposed therebetween. The positive pressure side solenoid valve  50  and the electro-pneumatic regulator  51  are disposed in parallel between the above air cells  32  belonging to the high pressure cell group  36  and the positive pressure tank  41 . The air cells  32  belonging to the high pressure cell group  36  are connected to the negative pressure tank  43  with one of the negative pressure side solenoid valves  53  interposed therebetween. One of the pressure gauges  52  measures the air pressure of the respective air cells  32  belonging to the high pressure cell group  36 . 
     (Left Flank Holding Part  21 , Etc.) 
     As the structure that adjusts the air pressure of the plurality of air cells  32  of the left flank holding part  21 , the right flank holding part  22 , and two back surface holding parts  23  is the same as the one described above, a description thereof will be omitted. 
     With the above configuration, the air pressure adjusting mechanism R can individually adjust: the air pressure that is common to the plurality of air cells  32  belonging to the low pressure cell group  35 , the air pressure that is common to the plurality of air cells  32  belonging to the high pressure cell group  36 , the air pressure that is common to the plurality of air cells  32  of the left flank holding part  21 , the air pressure that is common to the plurality of air cells  32  of the right flank holding part  22 , the air pressure that is common to the plurality of air cells  32  of one of the back surface holding parts  23 , and the air pressure that is common to the plurality of air cells  32  of the other one of the back surface holding parts  23 . 
       FIG. 6  is a functional block diagram of the transfer assistance device  1 . As shown in  FIG. 6 , the transfer assistance device  1  further includes a control unit  60  and an input unit  61 . The input unit  61  is for an assisting person to operate the transfer assistance device  1 . The control unit  60  includes a CPU  62  (Central Processing Unit) that is a central processing unit, a RAM  63  (Random Access Memory) that is readable and writable, and a ROM  64  (Read Only Memory) that is read only. When the CPU  62  reads a control program stored in the ROM  64  and executes the control program, the control program enables hardware such as the CPU  62  to function as a bogie control unit  65 , an arm control unit  66 , and an air pressure control unit  67 . 
     The bogie control unit  65  drives the bogie motor  9  according to a signal from the input unit  61  in order to control the bogie  2 . 
     The arm control unit  66  drives the arm motor  12  according to a signal from the input unit  61  in order to control tilting of the arm  3 . 
     The air pressure control unit  67  controls the six positive pressure side solenoid valves  50 , the six electro-pneumatic regulators  51 , and the six negative pressure side solenoid valves  53  according to signals from the input unit  61  and signals from the six pressure gauges  52 . When the air pressure control unit  67  outputs HIGH to the positive pressure side solenoid valves  50 , the positive pressure side solenoid valves  50  are opened, while when the air pressure control unit  67  outputs LOW to the positive pressure side solenoid valves  50 , the positive pressure side solenoid valves  50  are closed. The electro-pneumatic regulators  51  perform feedback control on the air pressure to be output according to a voltage value output from the air pressure control unit  67  to the electro-pneumatic regulators  51 . When the air pressure control unit  67  outputs HIGH to the negative pressure side solenoid valves  53 , the negative pressure side solenoid valves  53  are opened, while when the air pressure control unit  67  outputs LOW to the negative pressure side solenoid valves  53 , the negative pressure side solenoid valves  53  are closed. 
     Next, transfer of the person being assisted P using the transfer assistance device  1  will be described with reference to  FIGS. 7 to 10 . 
     Firstly, the assisting person opens the two back surface holding parts  23  outward (S 300 ). Next, the assisting person operates the input unit  61 , as shown in  FIG. 8 , to supply negative pressure to all the air cells  32  so that the air cells  32  will deflate (S 310 ). Next, the assisting person operates the input unit  61  to run the transfer assistance device  1  and move the transfer assistance device  1  in front of the person being assisted P (S 320 ). Next, the assisting person closes the two back surface holding parts  23  inward (S 330 ). At this time, the assisting person places the soles of the feet of the person being assisted P on the footrest plate  8 . 
     Next, the assisting person presses a raise button (not shown) of the input unit  61  (S 340 ). Then, as shown in  FIG. 9 , firstly the air pressure control unit  67  supplies positive pressure to the respective air cells  32  so that the air pressure of the respective air cells  32  will be a first air pressure (S 350 ). The first air pressure is, as shown in  FIG. 9 , 20 kPa for the air pressure of the low pressure cell group  35 , 40 kPa for the air pressure of the high pressure cell group  36 , 60 kPa for the air pressure of the left flank holding part  21  and the right flank holding part  22 , and 80 kPa for the air pressure of the two back surface holding parts  23 . Thus, the holding part  4  temporarily holds the torso Q of the person being assisted P. 
     Next, as shown in  FIG. 10 , the air pressure control unit  67  supplies positive pressure to the respective air cells  32  so that the air pressure of the respective air cells  32  will be a 1 second air pressure (S 360 ). The second air pressure is, as shown in  FIG. 10 , 30 kPa for the air pressure of the low pressure cell group  35 , 70 kPa for the air pressure of the high pressure cell group  36 , 80 kPa for the air pressure of the left flank holding part  21  and the right flank holding part  22 , and 100 kPa for the air pressure of the two back surface holding parts  23 . Thus, the holding part  4  firmly holds the torso Q of the person being assisted P. 
     Next, the arm control unit  66  controls tilting of the arm  3  to thereby raise the person being assisted P while holding the person being assisted (S 370 ). Then, the air pressure control unit  67  returns the air pressure of the respective air cells  32  to the first air pressure (S 380 ). 
     Next, the assisting person operates the input unit  61  to move the transfer assistance device  1  that is holding the person being assisted P to a desired location (S 390 ). 
     Next, the assisting person presses a lower button (not shown) of the input unit  61  (S 400 ). Then, firstly, the air pressure control unit  67  increases the air pressure of the respective air cells  32  to the second air pressure again (S 410 ). Next, the arm control unit  66  controls the tilting of the arm  3  to lower the person being assisted P while holding the person being assisted P (S 420 ) and seats the person being assisted P on a bed or the like. Next, the air pressure control unit  67  supplies negative pressure to the respective air cells  32  so that the respective air cells  32  will deflate (S 430 ). 
     Next, the assisting person opens the two back surface holding parts  23  outward (S 440 ), and operates the input unit  61  to move the transfer assistance device  1  away from the person being assisted P (S 450 ). In this manner, transfer of the person being assisted P is completed. 
     In this exemplary embodiment, air pressure adjuster corresponds to the air pressure adjusting mechanism R and the air pressure control unit  67 . 
     The preferable exemplary embodiment has been explained so far. The above exemplary embodiment has the following features. 
     The transfer assistance device  1  includes the bogie  2 , the arm  3  that is tiltably supported by the bogie  2 , and the holding part  4  that is supported by the arm  3  and holds the torso Q of the person being assisted P. The holding part  4  includes at least the low pressure cell group  35  (a first bag) and the high pressure cell group  36  (a second bag) that are disposed to face different parts of the front surface Q 1  of the torso Q of the person being assisted P. The transfer assistance device  1  further includes the air pressure adjuster (the air pressure adjusting mechanism R and the air pressure control unit  67 ) that can individually adjust the air pressure of the low pressure cell group  35  and the air pressure of the high pressure cell group  36 . With such a configuration, when the transfer assistance device  1  assists transfer of the person being assisted P, it is possible to adjust pressure on different parts of the front surface of the torso of the person being assisted so that the pressure will relatively differ on the different parts to of the front surface of the torso of the person being assisted thereby reduce a burden on the person being assisted P. 
     The low pressure cell group  35  is disposed to face the solar plexus of the front surface Q 1  of the torso Q of the person being assisted P. The high pressure cell group  36  is disposed to face some or all of the parts other than the solar plexus of the front surface Q 1  of the torso Q of the person being assisted P. The air pressure adjuster adjusts the air pressure of the low pressure cell group  35  to be lower than that of the high pressure cell group  36  when the holding part  4  holds the person being assisted P. With such a configuration, it is possible to effectively reduce a burden on the solar plexus of the torso Q of the person being assisted P when the transfer assistance device  1  assists transfer of the person being assisted P. 
     The low pressure cell group  35  and the high pressure cell group  36  include the plurality of air cells  32  (small bags) that project toward the torso Q of the person being assisted P and the airflow path parts  34  that are connected between the plurality of air cells  32  to enable air to flow among the plurality of air cells  32 . With such a configuration, when the plurality of air cells  32  are individually deformed, the low pressure cell group  35  or the high pressure cell group  36  can be in contact with the torso Q of the person being assisted P with uniform surface pressure. 
     The air pressure adjuster includes positive pressure supply means (the compressor  40  and the positive pressure tank  41 ) that supplies positive pressure to the low pressure cell group  35  and the high pressure cell group  36  and negative pressure supply means (the vacuum pump  42  and the negative pressure tank  43 ) that supplies negative pressure to the low pressure cell group  35  and the high pressure cell group  36 . With such a configuration, it is possible to adjust the air pressure of the low pressure cell group  35  and the high pressure cell group  36  more quickly than when the air pressure adjuster does not include the negative pressure supply means (the vacuum pump  42  and the negative pressure tank  43 ). 
     The exemplary embodiment that has been explained above can be modified in the following manner. 
     For example, in the above exemplary embodiment, the holding part  4  includes at least the low pressure cell group  35  (the first bag) and the high pressure cell group  36  (the second bag) that are disposed to respectively face the different parts of the front surface Q 1  of the torso Q of the person being assisted P. However, in place of the above configuration or in addition to the above configuration, the holding part  4  may include at least the low pressure cell group (the first bag) and the high pressure cell group (the second bag) that are disposed to respectively face different parts of the back surface Q 4  of the torso Q of the person being assisted P. More specifically, for example, the low pressure cell group is disposed to face parts not protected by ribs of the back surface Q 4  of the torso Q of the person being assisted P. The high pressure cell group is disposed to face some or all of parts protected by the ribs of the back surface Q 4  of the torso Q of the person being assisted P. The air pressure adjuster adjusts the air pressure of the low pressure cell group  35  to be lower than that of the high pressure cell group when the holding part  4  holds the person being assisted P. With such a configuration, it is possible to effectively reduce a burden on the parts not protected by the ribs of the back surface Q 4  of the torso Q of the person being assisted P when the transfer assistance device  1  assists transfer of the person being assisted P. 
     Likewise, the holding part  4  may include at least the low pressure cell group (the first bag) and the high pressure cell group (the second bag) that are disposed to respectively face different parts of the left flank Q 2  (the lateral surface) of the torso Q of the person being assisted P. Likewise, the holding part  4  may include at least the low pressure cell group (the first bag) and the high pressure cell group (the second bag) that are disposed to respectively face different parts of the right flank Q 3  (the lateral surface) of the torso Q of the person being assisted P. More specifically, for example, the low pressure cell group is disposed to face parts not protected by ribs of the lateral surfaces (the left flank Q 2  and the right flank Q 3 ) of the torso Q of the person being assisted P. The high pressure cell group is disposed to face some or all parts protected by the ribs of the lateral surfaces (the left flank Q 2  and the right flank Q 3 ) of the torso Q of the person being assisted P. The air pressure adjuster adjusts the air pressure of the low pressure cell group  35  to be lower than that of the high pressure cell group when the holding part  4  holds the person being assisted P. With such a configuration, it is possible to effectively reduce a burden on the parts not protected by the ribs of the lateral surfaces (the left flank Q 2  and the right flank Q 3 ) of the torso Q of the person being assisted P when the transfer assistance device  1  assists transfer of the person being assisted P. 
     According to the above modified example, when the transfer assistance device  1  assists transfer of the person being assisted P, it is possible to adjust pressure on different parts of any one of the front surface, the lateral surfaces (the right flank and the left flank), and the back surface of the torso of the person being assisted so that the pressure will relatively differ on the different parts of any one of the front surface, the lateral surfaces (the right flank and the left flank), and the back surface of the torso of the person being assisted to thereby reduce a burden on the person being assisted P. 
     From the invention thus described, it will be obvious that the embodiments of the invention may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended for inclusion within the scope of the following claims.