Abstract:
A self-assisting robot for assisting a paraplegic user is disclosed which comprises a platform having a plurality of wheels, a robotic arm, an inclination sensor, operable to measure the inclination angle formed between said platform and a road in front thereof, a saddle configured to be adjusted up and down to fit the height of a user, a controller panel connected to said saddle, a processor operable to control the operations of the self-assisting robot, and a kneeling seat connected to and move with the robotic arm.

Description:
FIELD OF THE INVENTION 
     The present invention relates generally to the field of medical device. More specifically, the present invention relates to a robot that assists a user to transfer from a wheel chair to another location and vice versa. 
     BACKGROUND ART 
     There are three different types of devices that assist a user from a wheel chair. The first type is the simple mechanical type without any automatic mechanism to assist the transferring of the user to and from the wheel chair that needs the assistance of a nurse to transfer the user from a wheel chair. The second type is the semi-automatic device that still needs some human assistance. The third type is the fully automatic device that does not need the assistance of a nurse. 
     It is easy to understand that the first type of user transfer device is inconvenient for both the user and a nurse because the user needs complete assistance from the nurse. Furthermore, to reduce the human assistance in the first type of user transfer device, either a specially designed toilet (self-rotating toilet seat) or a user lift hanging from the ceiling needs to be deployed. These types of devices increase costs and still require full assistance from a nurse. 
     In the semi-automatic user transfer devices, a special cart is provided just to move a user to and from a toilet seat. At the toilet seat or the wheel chair, a nurse needs to present in order to move the user onto the toilet seat or back to the wheel chair. These devices cost money and still require human labor. 
     Finally, in the conventional automatic user transfer devices such as the self-transfer aid robotics by Yoshihiko Takahashi. Even though the robotic eliminates assistance from a nurse, it is still not preferred by users for the reasons discussed below. 
     Now referring to  FIG. 1 , a prior-art Y. Takahashi self-transfer aid robotics  100  (hereinafter referred to as robotics  100 ) is illustrated. Robotics  100  includes a platform  110  with wheels  103 - 104  connected on the lower side, a robotic arm  120  connected to the upper side of the platform  110 . A saddle  130  is placed on top of robotic arm  120 . A control panel  140  is originated from robotic arm  120  so that a user can control robotics  100 . In robotics  100 , a worm gear  162  and  163  are used to incline or decline robotic arm  120 . A worm gear motor  161  is used to control worm gear  162 - 163 . 
     In use, when arriving at the user&#39;s location, robotic arm  120  and saddle  130  leans forward toward the user. Next, the user puts all of his or her weight onto saddle  130  in order to move away from the wheel chair. Then, the conventional self-transfer robotics  100  re-erects robotic arm  120  to the vertical position. Finally, robotic  100  rotates the user (while the user is hanging on saddle  130 ) and moves the user to another location, i.e., a toilet. 
     Continuing with  FIG. 1 , in self-transfer aid robotics  100 , the user puts all his or her weight onto saddle  130 . This causes great discomfort to the user. This is especially true when the user does not have any lower body strength. In addition, robotics  100  lacks safety in that it does not have inclination detector to detect the inclination between itself and the ground. When moving through steep ramps, robotics  100  can lose balance and topple, causing great danger to the user. 
     Another problem of robotics  100  is that it lacks adaptability. In other words, robotics  100  cannot measure the height of the location where the user sits. For example, if the user sits on a high chair or a high level bed, or a high table surface, robotics  100  cannot adjust itself to help the user. 
     Still referring to the discussion of  FIG. 1 , yet another problem of robotics  100  is that when the user is home alone and when robotics  100  is far away from the user, it is stressful for the user to move toward robotics  100 . 
     Therefore what is needed is a user lift that can overcome the above described problems. 
     SUMMARY OF THE INVENTION 
     Accordingly, an objective of the present invention is to provide a self-assisting robot for assisting a paraplegic user is disclosed which comprises a platform having a plurality of wheels, a robotic arm, an inclination sensor, operable to measure the inclination angle formed between said platform and a road in front thereof, a saddle configured to be adjusted up and down to fit the height of a user, a controller panel connected to the saddle, a processor operable to control the operations of the self-assisting robot, and a kneeling seat connected to and move with the robotic arm. 
     These and other advantages of the present invention will no doubt become obvious to those of ordinary skill in the art after having read the following detailed description of the preferred embodiments, which are illustrated in the various drawing Figures. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. 
         FIG. 1  is a diagram illustrating an example of one of the prior art devices (Takahashi self-transfer aid robotics) designed to assist transferring a user from a wheel chair to a toilet and vice versa; 
         FIG. 2  is a diagram illustrating a self-assisting robot for transferring a user from a wheel chair to another location and vice versa in accordance with an embodiment of the present invention; 
         FIG. 3  is a diagram illustrating a worm gear in connection with a robotic arm used in the self-assisting robot in accordance with an embodiment of the present invention; 
         FIG. 4  is a diagram illustrating a platform, a worm gear, and the base of the robotic arm in accordance with an embodiment of the present invention; 
         FIG. 5 . is a diagram illustrating all the wheels located on the bottom side of the platform of the self-assisting robot in accordance with an embodiment of the present invention; 
         FIG. 6  illustrates the control panel of the self-assisting robot in accordance with an embodiment of the present invention; 
         FIG. 7  illustrates a system level diagram inside the processor of the self-assisting robot is accordance with an embodiment of the present invention; 
         FIG. 8  is a flow chart illustrating method of using the self-assisting robot in accordance with an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Reference will now be made in detail to the preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. While the invention will be described in conjunction with the preferred embodiments, it will be understood that they are not intended to limit the invention to these embodiments. On the contrary, the invention is intended to cover alternatives, modifications and equivalents, which may be included within the spirit and scope of the invention as defined by the appended claims. Furthermore, in the following detailed description of the present invention, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be obvious to one of ordinary skill in the art that the present invention may be practiced without these specific details. In other instances, well-known methods, procedures, components, and circuits have not been described in detail so as not to unnecessarily obscure aspects of the present invention. 
     One embodiment of the invention is now described with reference to  FIGS. 2 to 6 .  FIG. 2  shows an embodiment of a self-assisting robot  200  of the present invention. Self-assisting robot  200  includes a platform  210  having a top side  210 U and a bottom side  210 B. A first caster wheel  201 , a second wheel  202 , a third wheel  203 , a fourth caster wheel  204 , and a fifth caster wheel  205  are all mechanically connected to the bottom side  210 B of platform  210 . In one embodiment of the present invention, second wheel  202  and third wheel  203  are not caster wheels. A first motor  207  and a second motor  208  (not seen in  FIG. 1 , please refer to  FIG. 6 ) are connected to second wheel  202  and third wheel  203  respectively. First motor  207  and second motor  208  are independently operated so that self-assisting robot  200  is capable of moving forward, backward, turning left, or turning right. 
     Continuing with  FIG. 2 , on top side  210 U of platform  210 , a robotic arm  220  is connected to a worm gear assembly  260 . A kneeling seat  280  coupled to two bendable legs  281  and  282  is also connected and move with robotic arm  220 . In one embodiment of the present invention, a fourth motor  270  (not shown in  FIG. 2 , please refer to  FIG. 3 ) is connected to extend or withdraw robotic arm  220  vertically to bring the top surface of saddle  230  to the height level of the user&#39;s seat. Finally, a processor box  250  is connected first motor  207 , second motor  208 , third motor  261 , and fourth motor  270 . Third motor  261  is dedicated to drive worm gear assembly  260 . 
     Continuing with  FIG. 2 , robotic arm  220  further includes a fixed part  221  containing a moving part  222 . In other words, moving part  222  is inserted to move freely inside fixed part  221 . The bottom section of moving part  222  is connected to fourth motor  270 . The top of moving part  222  is connected to a saddle  230  and a control panel  240 . More specifically, control panel  240  is positioned on an arm  241  extended outward from moving part  222 . In one embodiment, extending arm  241  is adjustable up or down in order to provide complete assistance to the user without the help of a nurse. 
     Still continuing with  FIG. 2 , in one embodiment, a remote controller  290  is used to control self-assisting robotic  220 . Remote controller  290  controls self-assisting robot  200  which includes a moving forward button  290 - 1 , a moving backward  290 - 2 , a turning left button  290 - 3 , a turning right button  290 - 4 , an extending button  290 - 5 , a withdrawing button  290 - 6 , a restoring button  290 - 7 , and an inclining button  290 - 8 . 
     Now referring next to  FIG. 3  and  FIG. 4 , worm gear assembly  260  operative to cause robotic arm  220  to incline forward or backward is illustrated.  FIG. 3  shows the front side of worm gear assembly  260  while  FIG. 4  shows the back side. Worm gear assembly  260  further includes third motor  261  for driving a worm screw contained in box  262  and a worm wheel  263 . Worm wheel assembly  260  is well known in the art; therefore, the detailed description of worm gear assembly  260  is not discussed here. In one embodiment, third motor  261  is a 24 VDC linear motor which has a reduction ratio of 1/150 and a rated torque of 98 kgf-cm. 
     Next,  FIG. 5  illustrates bottom side  210 B of platform  210  where wheels  201 - 205 , first motor  207 , and second motor  208  are located. First motor  207  and second motor  208  are operated independently so that self-assisting robot  200  can turn left, right, forward, and backward. In one embodiment of the present invention, first motor  207  and second motor  208  are 24 VDC motor with a rated moment of 100 kgf-cm and gear reduction ratio of 1/546. First motor  207  and second motor are controlled by control panel  240  and remote controller  290 . 
     Now referring to  FIG. 6 , the layout of control panel  240  is illustrated. Control panel  240  includes a power switch  242  where the user can turn on and turn of all motors  207 ,  208 ,  261 , and  270 . A display unit  244  is used to inform a user whether a battery is low, the power is on or off, or any problem with the motors  207 ,  208 ,  261 , and  270 . A stop button  243  is used to manually stop self-assisting motor  200  when the user either changes his/her mind or when a buzzer alarms the user of steep inclination ahead. Section  245  is dedicated to the controls of second wheel  202  and third wheel  203  via first motor  207  and second motor  208  respectively. Section  245  includes a forward button  245 U, a backward button  245 D, turning left button  245 L, and turning right button  245 R. Varying the power to first motor  207  with respect to second motor  208  causes self-assisting robot  200  to turn either left or right. 
     Continuing with  FIG. 6 , section  246  is dedicated to control robotic arm  220 . Section  246  includes an inclining forward (toward the user) button  246 R, an restoring (back to the initial position) button  246 L, an extending button  246 U for rising robotic arm  220  higher, a withdrawing button  246 D for withdrawing robotic arm  220  toward platform  210 , a turning left button  246 F for turning robotic arm  220 . 
     Referring next to  FIG. 7 ,  FIG. 7  illustrates a schematic diagram  700  of the hardware implementation of control panel  240 . A central processing unit (CPU)  701  is connected to provide control of self-assertive robot  200  via control panel  240 . In addition, CPU  701  communicates to a motor controller circuit  702 . As its name suggests, motor controller circuit  702  controls all four motors  207 ,  208 ,  261 , and  270 . A first potentiometer  704  senses how far robotic arm  220  needs to incline in order to accommodate to the user. Then, first potentiometer  704  sends the distance information to CPU  701 . A second potentiometer  705  senses the height of the user&#39;s seat and sends this information to CPU  701 . An inclination sensor  703  senses the angle between platform  210  and the ground surface whereupon self-assisting robot  200  is moving. As mentioned above, if this angle is too steep, CPU  701  sends a signal to sound a buzzer  710 . Buzzer  710  emits a loud audio signal in order to warn the user. In the automatic mode, CPU  701  also automatically stops self-assisting robot  200 . A power supply  707  provides the necessary voltages to CPU  701 . 
     Continuing with  FIG. 7 , in one embodiment of the present invention, self-assisting robot  200  is capable of operating in either manual mode via control panel  240  or remote controller  290  as discussed in  FIG. 2 . A data receiver  706  receives wireless signals from remote controller  706  which, in turn, sends them to CPU  701 . In the manual mode, the user controls the inclination degree and the extension of robotic arm  220 . The user also stops self-assisting robot  200  when buzzer  710  sounds the alarming signals. In addition, the user moves and rotate self-assisting robot  200  by using either remote controller  290  or control panel  240 . 
     Still continuing to  FIG. 7 , alternatively, self-assisting robot  200  can be operated by an automatic mode. In the automatic mode, CPU  701  automatically extends and inclines robotic arm  200 . CPU  701  also retrieves robotic arms  220  and kneeling seat  280  after the user has transferred from the wheel chair (not shown) to kneeling seat  280 . In the final phase, CPU  701  rotates self-assisting robot  200  to orient the user in a correct direction. After the structure of self-assisting robot  200  is described, the operation of self-assisting robot  200  is fully explained in  FIG. 8 . 
     Now referring to  FIG. 8 , a method  800  for operating self-assisting robot  200  described above is illustrated. In operation, self-assisting robot  200  is caused to move toward a user on a wheel chair by remote controller  290 . When reaching the user, self-assisting robot  200  stops. Kneeling chair  280  and robotic arm  220  learn forward toward the user. The user then moves onto kneeling chair  280  by leaning on saddle  230 . After a predetermined time, kneeling chair  280  and robotic arm  220  withdraw back to the initial position, pulling the user out of the wheel chair. At this moment, the user sits completely comfortable on kneeling chair  280 . Next, self-robotic arm  280  rotates to orient the back of user toward the destination. Finally, self-assisting robot  200  moves forward the destination. 
     First, at step  802 , moving self-assisting robot  200  toward a user and his/her wheel chair. In practice, step  802  is realized by first wheel  201 , second wheel  202 , third wheel  203 , fourth wheel  204 , fifth wheel  205 , first motor  207 , and second motor  208 . 
     At step  804 , the inclination angle of self-assisting robot is measured. Step  804  is realized by inclination sensor  703  and CPU  701 . 
     Next at step  806 , the measured inclination angle is compared with a threshold angle to determine whether the inclination angle is less than or equals to the threshold angle. 
     At step  808 , if the inclination angle is less than or equals to the threshold angle, continue to move forward until reaching the user. Upon reaching the user, causing robotic arm  220  and kneeling chair  280  to learn forward the user. In practice, step  808  is realized by third motor  261  and first potentiometer  704 . As mentioned above, first potentiometer  704  senses how far robotic arm  220  and kneeling seat  280  need to incline. Without first potentiometer  704 , robotic arm  220  could either fail to incline forward far enough to reach the user, which is a defect of self-assisting robot  200 . On the other hand, robotic arm  220  could incline too far, which could potentially cause harm to the user. 
     At step  810 , the user is transferred onto a kneeling seat. More specifically, the user grasps and leans onto saddle  230  while transfers his or her weight onto kneeling seat  280 . Without kneeling seat  280 , all the pressure is put heavily on the user&#39;s chest. As a consequence, worm gear  260  is worn out quickly. Thus, adding and coupling kneeling seat  280  onto robotic arm  220  of the present invention provide great comforts to the user. 
     Following is step  812 , after completely transferring the user to kneeling seat  280 , robotic arm  220  is restored to its initial position, which is perpendicular to platform  210 . As a result, the user is now sitting straight up in the normal sitting position. 
     At step  814 , move self-assisting robot  200  and the user to a new destination. Within the scope of the present invention, new destination can be a toilet, another seat, a bed, a car, etc. 
     During moving to the next destination, step  816  constantly measures the inclination angle in order to present self-assisting robot  200  from being overturned due to steep surface such as staircase, a vertical step, or a cliff. At step  816 , steps  804 - 808  are repeated and then step  816  jumps to step  818 . 
     At step  818 , upon reaching the destination, self-assisting robot  200  rotates by means of first motor  207  and second motor  208 . Self-assisting robot  200  rotates until the user is oriented to the desired position relative to the new destination. In one embodiment, the new destination is a toilet seat, self-assisting robot  200  rotates so that the user&#39;s back faces the front of the toilet seat. 
     At step  820 , robotic arm  220  and kneeling seat  280  are again inclined forward. Within the scope of step  820 , second potentiometer  705  constantly measures and feedbacks how far robotic arm  220  and kneeling seat  280  need to incline forward. 
     At step  822 , the user is transferred to the new destination. 
     Finally, at step  824 , in case the inclination angle is greater than the safe threshold angle, CPU  701  causes buzzer  710  to alarm the user. The user either presses the stop button  243  or self-assisting robot  200  automatically stops for the user. The user then uses section  245  of control panel  240  to move self-assisting robot  200  away from steep inclination angle. 
     The foregoing description details certain embodiments of the invention. It will be appreciated, however, that no matter how detailed the foregoing appears in text, the invention can be practiced in many ways. As is also stated above, it should be noted that the use of particular terminology when describing certain features or aspects of the invention should not be taken to imply that the terminology is being re-defined herein to be restricted to including any specific characteristics of the features or aspects of the invention with which that terminology is associated. The scope of the invention should therefore be construed in accordance with the appended claims and any equivalents thereof.