WO1996011658A1

WO1996011658A1 - Posture change system and posture change method

Info

Publication number: WO1996011658A1
Application number: PCT/JP1995/002088
Authority: WO
Inventors: Misako Funaki
Original assignee: Ikedamohando Co., Ltd.
Priority date: 1994-10-14
Filing date: 1995-10-12
Publication date: 1996-04-25
Also published as: AU3673295A

Abstract

The object of the present invention is to provide a posture change system and a posture change method which are capable of being applied to a wide range of patients. The posture change system (A) according to the present invention includes a frame (2) with casters (14). The frame (2) comprises an arm (20) rocked by a screw driven mechanism (80), a pair of knee pads (40) and a level-adjustable foot rest plate (42). The arm (20) is composed of upper and lower rods (24, 26) extending parallel to each other. These rods (24, 26) cooperate with each other to form a parallelogram link. Rocking centers (24a, 26a) of the arm (20) are positioned at the level of the abdominal portion of the patient (B) in a sitting posture. To the arm (20) is attached a slide means (27) which is slidably movable in the direction which the arm (20) extends. A hook (118) is provided on a slider (116) which defines a part of the slide means (27). In addition, a hook (34) is provided on a bent forward chest pad (28) attached to the tip end of the arm (20). A sling (100) mounted on the patient (B) is attached to the system (A) by engaging its upper arm portions (102) with the hook (34) of the chest pad (28) and engaging its lower arm portions (103) with the hook (118) of the slider (116), whereby the patient (B) is united with the system (A).

Description

SPECIFICATION

TITLE OF THE INVENTION

POSTURE CHANGE SYSTEM AND POSTURE CHANGE METHOD

Technical Field

The present invention relates to a posture change system and a posture change method for the disabled, in particular, patients who find it difficult to stand up by themselves, or who are unable to do so, and more particularly, to a posture change system and a posture change method for changing the posture of the patients from a sitting one to a standing one and vice versa.

BACKGROUND OF THE INVENTION

Among recent problems concerning medical treatment for old people, the importance of enabling old people who are obliged to be confined to their beds for a long time to stand up has begun to be acknowledged. This also applys to disabled patients who have damaged their backbones, etc. because of traffic accidents and the like. The pleasure for a formerly bedridden person of being able, even if an auxiliary device is involved, to stand up, move to a toilet, or move from their bed to a wheel chair-all of which can be accomplished without greatly bothering their attendant-is beyond the imagination of healthy people.

Patient Mover ( brand name) produced by Ergo Aid Denmark Co.Ltd in Denmark has been known as a system for meeting such a requirement. Thi Patient Mover includes an arm which is attached to a frame with caster and pivots in a vertical plane about a horizontal axis, drive means fo driving the arm and knee pads attached to the frame. In addition, th free end of the arm has a sling member attached thereto which circle both armpits of the patients to support his/her back portion. Accordingly, by this mechanism, the patient in a sitting posture i enabled to stand up by operating a cylinder to lift up the arm after th sling is mounted on the patient in the sitting posture.

This system enables the patient who is normally unable to stand u by himself/herself to assume the standing posture. Furthermore, due t this system, the attendent is able to move the patient, while th patient is thereon, to a toilet, etc. where he is enabled to move fro the standing posture to the sitting one on a toilet. For these reasons, it is not an exaggeration to say that this is a long-awaited system which is a boon to bedridden patients and that the standing up function of this system also defines a rehabilitaion function for preventing a malfunction of the patients's legs.

Based on the observation of the standing up motion of the patient resulting from the use of the prior art system, it appears that the prior art system was designed based on the idea that the patient is suspended by a support member circling his/her back. In other words, the prior art system enables the patient to stand up by pulling up the upper half of his/her body while supporting his/her knees with the knee pads. Therefore, the patient is obliged to lean against the support member which supports his/her back, thereby standing up while his/her center of gravity still remains to the back. However, such standing up motion is extremely unnatural so that the patient never fails to have a feeling of physical disorder or uneasiness during the changing process from the sitting posture to the final standing posture. In other words, during this changing process the patient is forced to bend rearward with his/her face upward, which is an extremely unnatural posture for a person. For this reason, the application of the prior art system is mainly restricted to a patient having a lower half of his/her body which is considerably sturdy. Consequently, the prior art system can not be applied to a patient, for instance, who has stiffened knee joints.

SUMMARY OF THE INVENTION

The object of the present invention is to provide a posture change system and a posture change method which are capable of being applied to a wider variety of patients than is possible in the case of the prior art.

Another object of the present invention is to provide a posture change system and a posture change method by which the patient is enabled to stand up in a way which is as natural as possible without a feeling of physical disorder.

Yet another object of the present invention is to provide a posture change system and a posture change method by which the patient is enabled to assume a standing posture suitable for his/her physical condition. Judging from the natural standing up motion of people, it has been recognized that a person assumes the standing up motion by moving his/her knees slightly forwardly and horizontally while keeping the upper half of his/her body bent slightly forward. After the present applicant studied closely what is required for accomplishing such a natural standing up motion, it was found that since the prior art system adopts the mechanism by which the back of the patient is supported so that the patient is forced to bend rearward to lean against the support member, it is basically impossible for patients so supported to assume a bending forward posture. On the contrary, if a posture change system enables the chest portion of the patient to be supported, the patient who leans against the system necessarily assumes a bending forward posture.

Based on such an understanding, in order to solve the above- mentioned technical problems, it is the intention of a posture change system of the present invention to enable a patient to stand up by supporting his/her chest and his/her knees. More concretely, the present posture change system for changing a posture of a patient from a sitting one to a standing one comprises an arm which swings in a vertical plane about a horizontal axis, a support member for supporting the patient which extends underneath both his/her armpits to his/her back and is attached to the tip end of the arm, and knee pads for supporting his/her knees, characterized in that a chest pad for supporting his/her chest which is provided on the tip end of the arm, and means for adjusting the effective length of the support member which is provided on the support member, whereby his/her posture is changed by swinging the arm after his/her chest is made to lean against the chest pad by adjusting the effective length of the support member.

According to the present posture change system, since the chest pad is adapted to support the chest of the patient, the patient leans against the chest pad and thus necessarily assumes the bending forward posture. If the accomplishment of this bending forward posture is to be further assured, the bent forward chest pad may be attached to the arm. In addition, forward and horizontal movement of his/her knees involved when the patient stands up may be absorbed by the resiliency of the knee pads. However, the knee pads may be swung about a horizontal axis to absorb more positively such movement. In this case, it is important that the pivot points of his/her knees be positioned slightly above the level of the swing center of the knee pads. Therefore, in order to adjust the level of his/her knees, a level adjustable foot rest plate for resting his/her feet thereon is preferably provided. This enables the forward and horizontal movement of his/her knees due to the standing up motion of the patient to be absorbed by the swinging movement of the knee pads.

In addition, the horizontal axis of the arm may be positioned at the level of the chest of the patient in a sitting posture, and it is preferable that it be positioned below that level so that his/her chest may be pushed up from below from the time when the initial standing up motion of the arm takes place. This provides the system with an advantage in that the patient is assured of keeping his/her bending forward posture at the initial motion stage. With regard to the concrete level of the swing center of the arm, it may either be at the level of the abdomen of the patient in a sitting posture or at the level of his/her knees. In addition, if the arm is attached to a pole provided on a frame, for instance, this pole may be arranged to be adjustable in height so as to adjust the level of the swing center of the arm according to the patient's height.

A method for enabling the patient to stand up may be either performed in one step, that is he is enabled to stand up by supporting and pushing up his/her chest while supporting his/her knees while at the same time forward and horizontal movement thereof is allowed, or in two steps, one step for stretching the lower half of his/her body by supporting both his/her knees and chest and another step for raising the upper half of his/her body by pushing up his/her chest. These two steps may be effected either step by step or simultaneously.

The posture change system and the posture change method according to the present invention are capable of not only changing the posture of the patient between a sitting one and a standing one and vice versa without a feeling of physical disorder, but also allowing the patient to assume the standing posture with his/her chest leaning against the chest pad. In addition, since his/her chest leans against the chest pad, the system can be stopped before the patient has completely stood up so that it can be applied to patients who can not be applied to the prior art system. Accordingly, the present posture change system and the posture change method can provide bedridden patients not only with the pleasure of standing up and the like, even if they are not able to accomplish a perfect standing posture, but instead one which matches their respective physical abilities, but also a significant rehabilitation tool which enables them to maintain and recover the function of the lower halves of their bodies.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects and advantages of the present invention will become apparent from the following description when read in conjuction with the accompanying drawings wherein: Figure 1 is a perspective view of a posture change system A of a first embodiment of the present invention, as seen diagonally from its forward side.

Figure 2 is a side view of the posture change system A in Figure 1. Figure 3 is a plan view of a sling used along with the posture change system A.

Figure 4 is a diagram showing the steps for mounting the sling in Figure 3 on a patient, wherein 4(A) shows the first step in which the sling is applied to the back and the waist of the patient, 4(B) shows the second step in which upper and lower arm portions of the sling applied to the patient are drawn to the front of the patient, 4(C) shows the third step in which the upper and lower arm portions drawn forward in the second step are drawn completely forward, whereby the sling is secured to the patient and 4(D) shows the fourth step in which the sling is engaged by the posture change system A.

Figure 5 is a partially perspective detailed view for clarifying the relation between the hooks provided on the chest pad and the slide, respectively, and the sling engaged by these hooks.

Figure 6 is a perspective view of an alternative sling mounted on the posture change system A.

Figures 7 to 9 show a series of motions of the posture change system A and the corresponding changes of the posture of the patient, wherein:

Figure 7 is a diagram showing the patient in a sitting posture.

Figure 8 is a diagram showing the patient in a half-sitting posture.

Figure 9 is a diagram showing the patient in a standing posture. *

Figure 10 is a partially perspective enlarged view showing th posture change system A to which an alternative safety means fo stopping it compulsorily is attached.

Figure 11 is a sectional view taken along the line Xll-Xll o Figure 10.

Figure 12 is a perspecive view of a posture change system E of second embodiment, as seen diagonally from its forward side.

Figure 13 is a side view of the posture change system E of th second embodiment showing a condition in which the patient is enabled t assume a standing posture.

Figure 14 is a side view of a posture change system F of a thir embodiment.

Figure 15 is a front view of the posture change system F of th third embodiment.

Figure 16 is a partially perspective view showing a chest pad and patient support member incorporated into the posture change system F o the third embodiment.

Figure 17 is a side view of a posture change system G of a fourt embodiment showing the step for stretching the lower half of the bod of the patient in a sitting posture.

Figure 18 is a side view of the posture change system G of th fourth embodiment showing the step for raising the upper half of th body of the patient.

Figure 19 is a plan view of the posture change system G of the fourth embodiment.

Figure 20 is a partially enlarged plan view of a table, a chest pad and armpit pads of the fourth embodiment. Figure 21 is a diagram for illustrating the motion of the posture change system G of the fourth embodiment, in particular, the first step in which the lower half of the patient's body in a sitting posture is stretched.

Figure 22 is a diagram for illustrating the motion of the posture change system G of the fourth embodiment, in particular, the second step in which the upper half of the patient's body is raised after the first step in Figure 21.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The preferred embodiments will be hereinafter described with reference to the accompanying drawings.

First Embodiment(Figures 1 to 11)

Figure 1 is a perspective view of a posture change system A, as seen diagonally from its forward side. Figure 2 is a side view of a posture change system A. The posture change system A is typically applied to the disabled, especially a patient who is not able to stand up by himself/herself. For instance, it is utilized to allow patients who sit on a bed, a portable chamber pot, a wheel chair and the like, or who sit on a side edge portion of a bed to assume a standing posture, and vice versa.

The posture change system A has a frame 2 which comprises a pair of right and left base portions 4 extending in the forward and backward( longitudinal) direction, a lower lateral member 6 which connects the forward portion of one of the base portions 4 to that of the other one, a base plate 8 which connects the middle portion of one of the base portions 4 to that of the other one, the base plate 8 being in contact with just a portion of each of the base portions 4, a pair of right and left poles 10, each of which extends upwardly from the middle portion of the lower lateral member 6, and an upper lateral member 12 which connects the upper portion of one of the poles 10 to that of the other one. The system A includes casters 14 at the front end and the rear end of the respective base portions 4 to enable a patient to be moved in all directions, and a grip 16 for a patient which extends forwardly and upwardly from the middle portion of the upper lateral member 12. Each of the casters 14 at the front end of the respective base portions 4, in other words, at the side where an attendant for the patient stands, is preferably equipped with a stopper so that the attendant can lock the system A by manipulating it, for instance, by foot after the system A is displaced to an appropriate position.

Each pole 10 has such a length that its upper end corresponds to the height of the abdomen of the patient in a sitting posture. A first bracket 18 protrudes upwardly from the middle portion of the upper surface of the upper lateral member 12. One base end of an arm 20 is pivotably attached to the first bracket 18, while the other free end of the arm 20 has a second bracket 22. Describing this point in more detail, as shown in Figure 2, the arm 20 comprises a pair of upper and lower rods 24,26 which are spaced apart vertically in the vertical plane and extend parallel with each other. The base ends of these rods, the upper rod 24 and the lower rod 26, are attached to the first bracket 18 through a first horizontal axes 24a, 26a, respectively, while the free ends are attached to the second bracket 22 through a second horizontal axes 24b,26b,respectively, to form a parallelogram link. A slide mechanism 27, which will be described in detail later, is mounted on the arm 20.

On the second bracket 22 is provided a chest pad 28 which tilts forwardly about 10 degrees to 15 degrees with respect to the vertical line. The chest pad 28 may be vertically attached to the second bracket 22, and it may preferably be fixed to the second bracket 22 while being bent forward, and in the most preferred form, its tilting angle may be adjustable.

The chest pad 28 comprises a support plate 30 fixed to the second bracket 22 by means of fastening means such as a bolt and a resilient member 32 which is attached thereto to define a pad for a chest. The support plate 30 includes a pair of right and left hooks 34 which protrude forwardly, each of which is firmly attached to a respective side portion thereof. The role of the pair of right and left first hooks 34 will be described later, however, there may be just one hook 34, and it may be positioned selectively at the second bracket 22 or the arm 20.

A table 36 which extends horizontally above and adjacent to the upper rod 24 and a grip 38 for a patient which is positioned in front of the pad 28 and stands vertically are fixed to the second bracket 22. The arm 20, which forms a parallelogram link, can always keep the table 36 and the grip 38 for a patient at a constant tilting angle, irrespective of the motion of the arm 20.

The posture change system A has a pair of knee pads 40, which pads are provided at the level corresponding to that of a knee portion of a patient and a foot rest means 42 on which a patient rests his/her feet. The knee pads 40 includes a pair of vertically extending right and left flat support plates 44 and a pair of right and left resilient members 46 ,respectively, resilient members 46 being attached to respective support plates 44 to define pads for knees. Each of the support plates 44 is pivotably attached to the rear end of a corresponding rod 48 for a knee pad which extends in the frontward and backward direction through corresponding horizontal axis 50. The front portions of the pair of right and left rods 48 are fitted respectively into a pair of right and left outer tubes 52 which extend in the frontward and backward direction, each outer tube 52 being fixed to a respective outer surface of the pair of right and left poles 10.

For persons having a height very different from the average height, the level of the knee pad 40 may be adjustable, more concretely, each outer tube 52 may be attached to a respective one of the poles 10 in such a manner that it can move vertically in parallel relationship with the plate 8.

Each of the knee pad rods 48 may be preferably adjustable in length in a continous manner or in stages. The concrete construction for adjusting the length of the rod 48 by stages is as follows. A plurality of recesses 48a, which are formed to be spaced apart from one another in the frontward and backward direction, are provided in the side surface of the rod 48. A single hole( not shown ) is formed in the outer tube 52 and a stopper 53 is removably inserted thereinto. The stopper 53 may be, for instance, a pin with a head or a bolt which cooperates with the plurality of recesses 48a to define means for adjusting a substantial length in the frontward and backward direction, the longitudinal position of the knee pad 40 being adjusted by selecting one of the recesses 48a which engages the stopper 53. The foot rest means 42 includes a horizontally extending foot rest plate 54 whose opposite side portions are connected to the base plate 8 through a pair of right and left cross links 56,respectively. Each cross link 56 has a first link 58 and a second link 60 which are disposed in a crossed relation to each other and a pivot 62 connects one intersecting portion to the other one. The first link 58 extending forwardly and diagonally from the base plate 8 is attached to the base plate 8 at its lower end via an axis 58a and is attached at its upper end to the front portion of the foot rest plate 54 via an axis 58b. On the other hand, a lower end 60a and an upper end 60b of the second link 60 which extends rearwardly and diagonally are movably attached in the frontward and backward direction to the base plate 8 and the foot rest plate 54, respectively.

Now describing this point in detail, a first guide member 64 and a second guide member 66 are fixed to the base plate 8 and the rear end of the foot rest plate 54, respectively. Horizontally extending first and second slots 64a, 66a are formed in the first and second guide members 64,66, respectively. An axis 60a attached to the lower end of the second link 60 and an axis 60b attached to the upper end of the second link 60 are slidably fitted into the first slot 64a at the side of the base plate 8 and the second slot 66a at the side of the foot rest plate 54, respectively. In addition,the lower end of the second link 60 is biased backwardly by means of a tension spring 70. In other words, the tension spring 70 is interposed between the lower end of the second link 60 and the rear part of the base plate 8 to bias the second link 60 toward its rising direction.

The axis 60a attached to respective lower ends of the pair of second links 60, in this embodiment, is composed of a common axis 68 whic extends laterally, its intermediate portion being connected to the rea end of a manipulating rod 71 which extends forwardly. The manipulatin rod 71 is composed of a screw rod, and a nut 72 threaded thereinto i attached to the front end of the middle portion in the lateral directio of the base plate 8.

The manipulating rod 71 includes a circular handle 74 at its fron end, the level of the foot rest plate 54 being adjusted by rotating th handle in the clockwise or counterclockwise direction. The manipulatin force required for rotating the handle 74 to raise the level of th foot rest plate 54 can be decreased due to the biasing force by th spring 70. In addition, since the lower end and the upper end of th second link 60 which extends backwardly and diagonally from the bas plate 8 are adapted to be guided by the guide members 64,66 to be moved along the first and second slots 64a, 66a, respectively, the foot rest plate 54 moves backward in the longitudinal direction as it is raised.

A screw driven unit 80 is provided in the area sandwiched between the pair of right and left poles 10. The unit 80 includes a screw driven mechanism 82 and a controlling mechanism 83. Since this type of unit has been well known, the description in more detail will be omitted.

The system A may be supplied with electric power from an outlet of a domestic power supply or from a battery equipped therewith (not shown).

The base end of the screw driven mechanism 82 is pivotably attached to the frame 2 and the tip end of an operating rod 82a which extends upwardly from the mechanism 82 is attached to a third bracket 84 through a horizontal axis 86. When the operating rod 82a expands due to the actuation of the screw driven mechanism, the arm 20 turns upwardly about the axes 24a, 26a, while on the other hand, when the rod 82a contracts, the arm 20 turns downwardly about the axes 24a, 26a.

The actuation of the screw driven mechanism 82 is controlled by pressing a raising button and a lowering button in a portable swich 90 selectively. This portable swtich 90 is movable so that the attendant may manipulate its buttons or the patient himself/herself may manipulate the buttons while resting the switch 90 on the table 36.

The lowering motion of the arm 20 is stopped by a rocking switch 92 attached to its rear end, apart from the portable switch 90. The rocking switch 92 comprises a lever member 94 attached pivotably to the second bracket 22 of the arm 20 and a switch ( not shown ) which is actuated to interlock the rocking motion of the lever member 94 with such actuation. The lever 94 protrudes downwardly from the lower rod 26 due to its own weight. The switch associated with the lever member 94 is turned off when the lever 94 rocks slightly in the direction of the arrow C from the position indicated by a solid line in Figure 2 . The lever member 94 is set up so as to rock substantially in the direction of the arrow C even after the switch is turned off.

The posture change system A changes the posture of the patient by using a sling 100 shown in Figure 3 which is comprised of a support member for supporting the upper half of the body and the hip portion of the patient. The sling 100 includes a support portion 101 for supporting the waist portion and the back portion of the patient, a pair of right and left upper arm portions 102 which extend upwardly and diagonally from the right and left upper corners of the support portion 101,respectively, and a pair of right and left lower arm portions 103 which extend downwardly and diagonally from the right and left lower corners of the support portion 101,respectively, to support the hip portion of the patient. A plurality of holes 102a, 103a are formed in the arm portions 102,103, respectively. Sets of the holes 102a are aligned with each other in the longitudinal direction, as are sets of the holes 103a.

The sling 100 is mounted according to Figures 4(A) to 4(D). As can be clearly seen from Figure 4(A) showing a first process, after the support portion 102 is applied to the waist and the hip portions of a patient B, the pair of upper arm portions 102 are drawn forward through his/her respective armpits, while at the same time the pair of lower arm portions 103 are drawn forward through inner portions of his/her respective thighs in accordance with processes (B) to (D). As described later in detail, the pair of right and left upper arms 102 engage the first right and left hooks 34 of the chest pad 28, respectively. The right and left lower arm portions 103 engage the slide mechanism 27. In this connection, in Figures 4(A) and 4(B), the sling 100 is shown being mounted on the patient B who is in a half-sitting posture. However.these Figures are used to clearly show the mounting process of the sling 100. It is thus needless to say that the sling 100 may be also mounted on the patients B sitting on a chair and the like.

The slide mechanism 27 will now be described with reference to Figures 1 and 2. The slide mechanism 27 includes a guiderod 110 disposed above the front half portion of the upper rod 24 of the arm 20. The guide rod 110 extends parallel to the upper rod 24 in the same vertical plane as that containing the upper rod 24 while being disposed upwardly therefrom to be slightly spaced apart from the rod 24. The front end and the rear end of the guide rod 110 are fixed to the upper rod 24 by fasteners 112, 114, respectively. The slide mechanism 27 also includes a slide 116 which is movably guided by the guide rod 110 and the upper rod 24. The fasteners 112,114, and in particular, the fastener 114 at the rear end of the rod 110, serve as a stopper stopping movement of the slide 116. A hook(second hook)118 is fixed to the slider 116, which hook protrudes upwardly so as to be utilized for mounting the sling 100 on the arm 20.

Figure 5 is a partial perspective view showing mounting of the sling 100 on the system A. The mounting of the sling 100 applied to the patient B is effected by engaging the pair of upper arms 102 extending forwardly from his/her right and left armpits with the right and left first hooks 34 of the chest pad 28, respectively, and engaging the pair of lower arms 103 extending forwardly from the inner portions of his/her right and left thighs with the second hook 118 of the slider 116. This engagemnt of the sling 100 with the first hooks 34 and the second hook 118 enables the patient B to be united with the system A.

Various configurations of the sling 100 can be devised according to the functions possessed by the patient. For instance, the sling 100 may be divided into a portion for supporting his/her back portion and a portion for supporting his/her hip portion so that either of them can be selectively used according to the progress in the rehabilitaion of the patient.

For instance, in a case where the patient can stand up only by having the upper half of his/her body supported, the sling extending from the back of the patient B underneath his/her respective armpits may be provided by which his/her chest portion may be fixed to the chest pad 28. One example of this configuration is shown in Figure 6. The sling 104 in Figure 6 comprises a belt 105 and an air cushion 106 removably attached to the inner surface of the belt 105. In addition, a valve( not shown) is provided in the air cushion 106 to control the inner air pressure.

A loop tape 107 extending in the longitudinal direction is sewed to the outer surface of the air cushion 106. The loop tape 107 defines a simple fastener which is well-known as Velcro or Magic Tape( registered trademark). Further, corresponding hook tape 108 is attached to the inner surface of the belt 105. The air cushion 106 may be contained in the belt 105. In this case, the belt 105 may be formed into a bag to house the air cushion 106 therein.

A plurality of holes 105a aligned with one another in the longitudinal direction are formed at the opposite ends of the belt 105. In the case where the patient B is united with the chest pad 28, one of the holes 105a is appropriately selected to engage one of the first hooks 34 in order to prevent the extreme play (overly free movement) between the patient B and the chest pad 28 .

Figures 7 to 9 show a series of the motions of the posture change system A and the corresponding changes of the posture of the patient B. Figures 7 to 9 show a sitting posture, a hal -sitting posture and a standing posture, respectively. Referring to these Figures, a series of the motions of the posture change system A from the initial setup thereof will be described hereinafter.

First, the posture change system A is mounted on the patient B sitting on a chair 120 and the like. The mounting of the posture change system A first involves positioning of the posture change system A relative to patient B. The attendant holds the grip 16 to move the system A to apply the chest pad 28 to his/her chest portion, thus completing the positioning of the posture change system A. In this initial condition, the arm 20 remains in the horizontal position, as can be seen from Figure 7. Then, after the attendant allows the patient B to rest his/her feet on the foot rest plate 54, the level of the foot rest plate 54 and the frontward and backward position of each knee pad 40 are adjusted. The adjustment of the frontward and backward position of each knee pad 40 comprises a step for adjusting the effective length of corresponding rods 48 in such a manner that each knee pad 40 lightly contacts a corresponding knee of the patient B in the sitting posture. In addition, the level of the foot rest plate 54 is adjusted so as to match the adjustment of each knee pad 40.

The attendant rotates the handle 74 to adjust the level of the foot rest plate 54. However, it is to be noted that each knee joint of the patient B should be positioned slightly above the level of the rocking center point of the corresponding knee pad 40, that is, the corresponding horizontal axis 50. Since the patient who is short has short legs, the foot rest plate 54 has to be lifted up. However, the required force for rotating the handle is decreased due to the biasing force of the above-described spring 70, which lightens the burden of the attendant.

In order to effect the easy adjustment of the level of the knee joint of the patient B, a height indication pin designated by reference 130 in Figure 2 may be provided on the foot rest plate 54 and a scale facing the pin 130 (not shown ) may be provided on one of the poles 10, for instance. The scale is adapted to be set to such an extent that the knee joint of the patient is positioned slightly above the horizontal axis 50 of the knee pad 40, taking into account the average level of th knee joint in order to adjust it to the various heights. This enable the level of the knee joint of the patient B who is, for instance 150cm tall, to be automatically positioned slightly above the horizonta axis 50 of the knee pad 40 by only adjusting the level of the foot res plate 54 so that the height indicating pin 130 may conform to the scal indicating (150cm) on the pole 10.

In addition, since a short patient has a shorter thigh portion tha a tall patient, the rod 48 of the knee pad 40 needs to be drawn mor closely towards the patient B. However, both feet rested on the foo rest plate 54 move rearwardly automatically in accordance with the rise of the plate 54, since the foot rest plate 54 moves rearwardly upon its being raised. This rearward movement of both feet causes each knee of the patient B supported by corresponding knee pad 40 to be bent appropriately, thereby positioning each under thigh portion slightly rearward from the corresponding knee portion. This definitely prevents the patient from extending his/her knee excessively to damage the knee joint. Without this rearward movement, the patient B would be forced to stand up with his/her thigh portion protruding forwardly( an angle formed around his/her knee joint is more than 90 degrees) due to the fact that the attendant fails to notice this.

The sling 100 is mounted on the patient B as the above-described adjustment of the posture change system A is performed. The attendant, as described above, engages the upper arm portions 102 of the sling 100 mounted on the patient B with the corresponding first hooks 34 of the chest pad 28 and the lower arm portions 103 with the second hook 118 of the slider 116 to unite the patient B with the system A. At this time, it is important to assure of being free of the extreme play between the chest of the patient B and the chest pad 28 so that they do not move toward each other too freely. The selection of one of the holes 102a of each of the upper arm portions 102 engaged by the corresponding first hooks 34 can accomplish this adjustment.

On the other hand, when one of the lower arm portions 103 is engaged by the second hook 118 of the slider 116, it is preferable that the slider 116 be drawn toward the rear side stopper{fastener) 114 to engage the second hook 118 so as to loosen the state of the lower arm portion 103. If on the contrary, the lower arm portion 103 is engaged by the second hook 118 while being in a state of tension, the knee of the patient B may strongly contact the knee pad 40 during the lifting up process. A height indication is applied to each hole 103a of the lower arm portion 103 in a preferred configuration. When the attendant observes that the patient B is, for instance, 160cm tall, an appropriate looseness can be easily given to the lower arm portion 103 upon mounting it by engaging one of the holes 103a to which the indication 160cm is applied with the second hook 118. It is sufficient that such indications indicate by stages, such as 160cm, 165cm, 170cm. This allows the knee of the patient B to be supported appropriately by the knee pad 40 and facilitates the appropriate mounting process of the sling 100 while the patient B is being lifted up.

After completion of such an initial mounting, the patient B grips the grip 38 by hand and then the attendant or the patient himself/herself operates the portable switch 90 to expand the screw driven mechanism 82. The lifting up motion of the arm 20 in accordance with the expansion of the mechanism 82 enables the patient B to change his/her posture from a half-sitting posture shown in Figure 8 to a complete standing posture shown in Figure 9 through the same natural movement as that done by a healthy person to stand up by himself/herself.

Describing this point in more detail, a person naturally stands up by bending the upper half of his/her body forward while at the same time displacing his/her knee a little forwardly and horizontally. In contrast, since the chest pad 28, as described above, is attached to the arm 20 forming a parallelogram link while at the same time it is bent a little forward, the pad 28 keeps its predetermined tilting condition, irrespective of the motion of the arm 20. Since the patient B is united with the chest pad 28 by the sling 100 while leaning against the chest pad 28, the upper half of his/her body is kept bent a little forward. In addition, in this embodiment, since the level of the center of pivot of the arm 20( the horizontal axes 24a, 26a) is set lower than that of the chest of the patient B in a sitting posture, the lifting up motion of the arm 20 causes the patient B to stand up in such a way that the upper half of his/her body is lifted up from below, thereby assuring the maintaining of his/her bending forward posture.

The forward movement of the knees due to the stand up motion of the patient B is absorbed in the rocking motion of the knee pad 20 interlocked with the movement of his/her knees. In other words, as described above, with respect to the patient B in a sitting posture, since his/her knees are adapted to be disposed substantially higher than those of the pivot point( the horizontal axis 50) by the adjustment of the level of the foot rest plate 54, the knee pads 40 are bent forward by following the forward movement of his/her knee when the patient stands up, and as a result, the pad 40 absorbs that movement.

When the patient B stands up by resting his/her feet on the foot rest plate 54 and by being supported by the knee pad 40 and the chest pad 28, his/her hip portion is lifted up by means of the lower arm portion 103 of the sling 100, which assures the patient B is prevented from standing up in a state in which his/her back is bent.

With regard to the support of the hip portion of the patient B by the sling 100, since the slide mechanism 27 which supports the lower arm portion 103 of the sling 100 is interlocked with the movement of the arm 20, the lower arm portion 103 of the sling 100 is adapted to continue to support his/her hip portion so as to follow the change of posture of the patient B in accordance with the motion of the arm 20. In short, as can be seen from Figures 7 to 9, the hip portion is raised gradually to a higher level and closer to the pole 10 of the frame 2 in accordance with the stand up motion of the patient B. Further, the effective length of the lower arm portion 103 contacting the patient B becomes longer as the lifting up motion of the patient B proceeds. Accordingly, as the process advances from a sitting posture through a half-sitting posture to a standing posture, the effective length of the lower arm portion 103 extending from patient B becomes shorter.

Further, the lifting up motion of the arm 20 causes the slider 116 to which the lower arm portion 103 of the sling 100 is attached to develop a component force to move the slider 116 toward the front side. In fact, the slider 116 begins to move forward by this component force. In addition, the slider 116 moves forwardly upon the lifting up motion of the arm 20. By such motion of the slider 116 interlocked with the motion of the arm 20, the motion of the lower arm portion 103( sling 100) occurs in accordance with the change of the posture of the patien B caused by the motion of the arm 20.

When the patient B assumes the standing posture as shown in Figur 9, the portable switch 90 is actuated to stop the operation of th screw-driven mechanism 82. After the stop of the operation of the screw- driven mechanism 82, the patient B assumes a posture in which he bends slightly forward, resting his/her feet on the foot rest plate 54 and supported by the chest pad 28, the knee pad 40 and the sling 100. Since the hip portion of the patient B is supported by the sling 100 even in the slightly bending forward posture, the patient B is assured of assuming the standing posture without his/her hip portion protruding downwardly.

For instance, in a case where the patient has a stiff knee joint or a deformed ankle, the patient may only be able to stand up appropriately in accordance with the condition of his/her leg. In other words, for a patient who is not able to bend and expand his/her knee joint, for instance, more than 45 degrees, the operation of the screw-driven mechanism 82 may be stopped when he partially stands up. As can be seen from the half-sitting posture shown in Figure 8, any posture before completely standing up ( Figure 9) is an extremely natural half-sitting posture. Therefore, even if the operation of the rod 82a is stopped at this stage, there is no fear that the patient B will fall backward. Thus, he can complete the process for standing up in line with his/her physical condition without a feeling of physical disorder.

In this connection, whereas the prior art system is not capable of being applied to a patient who cannot assume the standing posture due to the physical condition of his/her legs, the present system according to the present invention can enable the patient to undergo an extremely natural motion during the process that occurs between sitting and standing up so that it does not matter at all even if the operation is stopped during the process. Accordingly, the system A of the present invention can be applied to the patient who was previously obliged to stay in bed permanently, the prior art not being applicable to such a patient.

After the patient B has assumed the standing up posture in line with his/her physical condition, the attendant grips the grip portion 16 and transfers the system A together with the patient B from the bed to a desired place, for instance, to a wheel chair or to a toilet. By way of example, after the patient B is transfered to the toilet, the system A is positioned in front of the toilet and then actuated in the reverse way ( the rod 82a of the screw-driven mechanism 82 is contracted) to return the patient B from the standing posture to the sitting posture. When the patient B sits on the toilet, the portable switch 90 is turned off at the appropriate time to stop the movement of the screw-driven mechanism 82. Even if the turning off of the switch 90 should be delayed, the contracting movement of the screw-driven mechanism 82 is stopped by the rocking switch 92 at the moment when the lever member 94 of the rocking switch 92 provided on the arm 20 comes into contact with the femoral region of the patient B. After or immediately before the patient B sits on the toilet, the lower arm portion 103 of the sling 100 may be disengaged from the second hook 118. This facilitates the removal of his/her underwear from the patient B.

In this connection, as described above, since the large play of the lever member 94 is secured after the switch is turned off, even if the arm 20 is lowered due to its inertia, the lever member 94 never fail to continue rocking due to its contact with the femoral region of th patient B. Thus, it is assured that the patient B will not be hurt b the presence of the lever member 94 protruding downwardly from the ar 20. In addition, when the system A is only moved enough to be remove from the patient after the patient B has sat down, it is also assure that the patient B will not be hurt by the rocking motion of the leve member 94 even if the lever member 94 should touch his/her body.

Instead of the lever member 92, as shown in Figures 10 and 11, a rubber cushion 96 may be attached to the lower surface of the table 36 and a pressure sensitive sensor(not shown) may be mounted in the rubber cushion 96 to stop the motion of the system A when the femoral region of the patient B touches the cushion 96. The rubber cushion 96 containing the pressure sensitive sensor may be attached to the lower end surface of the chest pad 28. In addition to the contact type device such as the rocking switch 92 or the pressure sensitive sensor which stops the operation of the system A when it touches the body of the patient, a non-contact type device, for instance, an infrared radiation sensor, can be utlilized. This device stops the operation of the system A when the arm 20 goes down to a position lower than the predetermined one by detecting such a position of the arm 20 in a non-contact manner.

The patient B having certain shapes can supposedly cause a situation where the lever member 94 is actuated inappropriately so that the system A stops, thus leaving the patient B in a sling. In order to overcome such a problem, it is preferred that a manual switch (not shown) be provided for cancelling the operation of an operation stop mechanism such as the lever member 94 to compulsorily stop the system A. Judging from the shape of the patient, the attendant, if necessary, may operate this manual switch to cancel the operation stop mechanism such as the lever member 94 compulsorily to stop the motion of the system A by actuating the portable switch 90.

The features of the alternative embodiments will be hereinafter described, however, the description as to elements the same as those of the first embodiment is omitted, such elements being given the same reference numbers as those in the first embodiment.

Second Embodiment(Figures 12 and 13)

In a posture change system E in this embodiment, a pair of driving wheels 150 and a simple seat 152 are added to the system A in the first embodiment. This self-propelled posture change system E allows a patient B sitting on the simple seat 152 or in a standing posture to move freely to a destination without the help of an attendant. The features of this self-propelled posture change system E will now be described in detail.

A base portion 2 of the system E comprises a pair of right and left front foot members 156 and a pair of right and left rear foot members 158, both of which extend in the frontward and backward direction. The front members 156 are disposed on respective ends of the lower lateral member 6 and pivotably mounted at their longituidinal intermediate portions on the lateral member 6 via respective pins 159. A caster 14 and a driving wheel 150 are attached to each front end and rear end of the front foot members 156, respectively. The driving wheel 150 has a larger diameter(22.5 mm) than that of the caster 14 and is composed of a wheel containing an electric motor with a reduction unit. The preferred position of the driving wheel 150 will be described later. Since the wheel containing the electric motor with the reduction unit has been known, its detailed description will be omitted.

Each of the right and left rear foot members 158 comprises a main foot member 160 made of a hollow tube which extends backward from the lower lateral member 6 and has a generally rectangular section and an extended foot member 162 inserted into the rear end opening of the main foot member 160. Each extended foot member 162 includes two of the casters 14 attached to its rear end portion. These two casters 14 are disposed to be spaced apart from each other in the frontward and backward direction and the simple seat 152 is removaly attached to each extended foot member 162 at the intermediate portion between these casters 14.

The simple seat 152 comprises an elongated seat plate portion 164, a pair of right and left legs 166 which extend downwardly from the right and left end of the seat plate portion 164, respectivelty, and a pair of right and left attachments 168 mounted at the lower end of the right and left legs 166, repectively. By engaging and locking each attachment 168 with the corresponding extended foot member 162, the simple seat 152 is securely fixed thereto. On the contrary, by releasing the lock of each attachment 168 and disengaging it from the corresponding extended foot member 162, the simple seat 152 can be removed from the extended foot members 162, i.e. the system E.

Since the height of the simple seat 152 is preferably ajustable when it is in practical use, as can be seen from Figure 13, each of the pair of right and left legs 166 is composed of inner and outer tubes so that by inserting the inner tube into the outer tube or by removing the former from the latter, its effective length is made adjustable. In this case, by forming a plurality of holes disposed spaced apart from one another in the longitudinal direction in the inner tube and inserting a threaded lock pin disposed in the upper end of the outer tube into the selected hole, the effective length of the leg 166 may be fixed. Reference numeral 170 in Figure 13 shows the operation knob of the threaded lock pin.

A controller 172 for controlling the movement of the system E is provided at the right side of the table 36 and the operation of the drive wheel 150 is controlled by manipulating manually a handling stick 172a which extends upwardly from the body of the controller 172. More concretely, when the handling stick 172a is moved forward from the neutral position where it stands erect, the system E begins to move straight and forward. The system E accelerates forward when the stick 172a is moved greatly forward. On the contrary, when the stick 172a is moved rearward, the system E starts moving straight and backward, it accelerates backward when the stick 172a is moved greatly rearward. In addition, when the stick 172a is moved sideways to the right, the right one of the pair of drive wheels 150 decelerates so that the system E turns right. The right drive wheel decelerates so much that the system E makes a small turn to the right when the stick 172a is moved greatly sideways to the right. On the contrary, when the stick 172a is moved sideways to the left, the left one of the pair of drive wheels 150 decelerates so that the system E turns left, and it decelerates so much that the system E makes a small turn to the left when the stick 172a is moved greatly sideways to the left.

The support plate 44 of each knee pad 40 provided in the system E is curved in a concave manner toward the patient B, as can be seen from Figure 12. This curved shape of each support plate 44 of each knee pad 40 prevents the lateral movement of the corresponding knee of the patient B to ensure his/her knee is supported.

As to the position of the driving wheel 150, as shown in Figure 13, the driving wheel 150 is preferably positioned immediately below his/her center of gravity G. This position of the driving wheel 150 enables the patient B to get rid of any feeling of physical disorder when he gets on the system E and enables the system E to make a smaller turn to be rendered suitable for domestic use.

There is a difference between the center of gravity of the patient B when he assumes the standing posture and the one when he sits on the simple seat 152, the latter, in particular, being situated relatively rearward. In order to maintain the system E in a stable condition even when the center of gravity of the patient B changes, a mechanism for adjusting effective length of each of the extended foot members 162 is preferably provided. More concretely, each of the extended foot members 162 may be contracted to be interlocked with the lifting up motion of the arm 20.

In addition, according to the system E, since each front foot member 156 to which the respective casters 14 and the respective large driving wheel 150 are attached is adapted to rock about the pin 159, the system E can smoothly pass over a floor even if the level of the floor is somewhat uneven.

Third Embodiment( Figures 14 to 16)

In a posture change system F of a third embodiment, as can be seen from Figure 15, the pole 10 extends from the lower lateral member 6 and the first bracket 18 is attached directly to the upper end of the pole 10. Each knee pad 40 is fixed to the rear end of the corresponding rod 48,the resilient member contained in each knee pad 40 being made up of a plastic foam.

The posture change system F is provided with a pair of armpit pads 200 at the right and left sides of the chest pad 28, respectively, each armpit pad 200 being pivotably attached to a corresponding side surface of the chest pad 28 about an associated vertical axis 201. A buckle 202 is attached to the rear end of one of the armpit pads 200, and a belt 203 is attached to the rear end of the other armpit pad 200. A reference number 204 in Figure 16 shows an air cushion on which a valve( not shown) is mounted, inner air pressure being adjusted by operating the valve. The air cushion 204 has an elongated shape which is long enough to encircle the chest portion of the patient B. Three loop tapes 205 spaced apart from one another in the longitudinal direction are sewed to the outside surface of the air cushion 204. The corresponding hook tapes 206 are attached to the inner surfaces of the chest pad 28 and the pair of armpit pads 200, respectively.

In use, first, the air cushion 204 is mounted around the chest of the patient B sitting on a chair and the like. Then, after disengaging the belt 203 from the buckle 202 and holding both armpit pads 200 outwardly open, the patient B grips the grip portion 16 to move the posture change system F and abut the chest pad 28 against his/her chest. Then, after both hands of the patient B are raised and both armpit pads 200 are inwardly opened to be positioned below the armpits of patient B, the armpid pads 200 are tightened by the belt 203 and the buckle 202. This allows the patient B to be united with the posture change system F. The motion of the posture change system F thereafter is identical to that of the posture change system A in the first embodiment so that the patient B can stand up naturally with his/her chest leaning against the chest pad 28, guided by the motion of the system F.

Fourth Embodiment( Figures 17 to 22)

In the above-mentioned first to third embodiments, the patient B in a sitting posture is guided into the standing posture through a series of natural motions. On the contrary, as to the posture change system G in a fourth embodiment, the patient in a sitting posture is guided into the standing posture through a series of motions involving two stages. These two stage type motions will be described schematically. Figures 21 and 22 show the first and second motions of the posture change system G, respectively. As can be seen from these Figures, only the lower half of the patient's body is extended by the first motion of the posture change system G( See Figure 21), and then the upper half of his/her body is raised by the second motion thereof( See Figure 22). Thus, this two stage type motion enables the patient B to assume a standing posture.

Describing the posture change system G in detail, the system G includes a main screw driven mechanism 300 disposed at the side of the pole 10. The main screw driven mechanism 300 is fixed to a side portion of the base plate 8 and extends upwardly from the base plate 8 while being bent slightly forward. An arm 306 is attached to the tip end portion of an operating rod 302 of the main screw driven mechanism 300 via a horizontal axis 304. This main screw driven mechanism 300 forms an extension means for expanding the effective length of the arm 306, as will be explained later. A second screw driven mechanism 310 is attached to the upper end of the main screw driven mechanism 300 via a bracket 308.

The second screw driven mechanism 310 extends parallel to the main screw driven mechanism 300 and an link 316 is pivotably attached to a piston rod 312 extending upwardly from the mechanism 310 via a pin 314. The link 316 is united with the arm 306 via the above-described horizontal axis 304. When the second screw driven mechanism 310 expands and contracts, either motion is transmitted to the arm 306 via the link 316, and as a result, the arm 306 rocks in the direction of an arrow a shown in Figure 17 about the horizontal axis 304.

A table 322 is attached to the tip end of the arm 306 via the second horizontal axis 320 and a chest pad 324 and a pair of armpit pads 326 are fixed thereto, as shown in Figure 20. The chest pad 324 and the armpit pads 326 are substantially identical to those described in Figure 16, however, the chest pad 324 has a downward extending portion in this embodiment, as can be seen from Figures 17 and 18. When the posture change system G is being used, the patient B is united with the posture change system G by utilizing the air cushion 328 and the belt 330 in a manner similer to that shown in Figure 16. In addition, his/her chest and abdominal region are totally supported by the chest pad 324 extending downwardly.

A third screw driven mechanism 340 is pivotably attached to the tip end portion of the arm 306 via a pin 342 and a piston rod 34 of the third mechanism 340 is pivotably connected to the table 322 via a pin 346. The pin 346 is positioned more forward than the attachment position of the above-mentioned arm 306, that is the second horizontal axis 320. This causes the table 322 and the chest pad 324 to rock in the direction of an arrow β shown in Figure 18 when the third mechanism 340 expands and contracts.

The posture change system G includes a controller ( not shown) comprising, for instance, a micro computer, and the three screw driven mechanisms 300,310 and 340 are controlled according to the operational programme incorporated into this controller. When the posture change system G is being used, the attendant inputs data on the patient B to the controller by an input means( not shown). Based on the data on the patient B, the controller controls the patient B according to the kind of shape the patient has.

The motion of the system G when the posture of the patient B is changed from a sitting one to a standing one will now be described. First, the operational rod 312 of the second screw driven mechanism 310 is contracted. This causes the arm 306 to move from the position designated by a solid line in Figure 17 to that designated by a phantom line, thereby causing the patient B to be guided, while being supported by the knee pad 40, into the posture in which the lower half of his/her body is stretched. ( See Figure 21). The degree of stretching of the patient B, that is the contracting stroke of the operational rod 312 of the second screw driven mechanism 310 may be adjusted in accordance with the patient's physical condition( especially, the lower half of his/her body), as has already been described in the first embodiment. Therefore, the lower half of his/her body is moderately and appropriately stretched by this first stage motion.

Then, the main screw driven mechanism 300 and the second screw driven mechanism 310 are both expanded( this stroke is designated by symbol u in Figure 18). In addition to this, the third screw driven mechanism 340 is expanded to raise the chest pad 324 from the horizontal position( See Figure 17) to the vertical position ( See Figure 18). These three screw driven mechanisms cooperate with one another to raise the upper half of the patient's body. This two stage type motion causes the patient B to change his/her posture from the sitting one to the standing one in Figure 18, and vice versa. As mentioned above, the process for raising the upper half of his/her body takes place after th process for stretching the lower half of his/her body, however, thes two processes may take place simultaneously.

In addition to the embodiments according to the present invention described already, components contained in these embodiments can be combined in various manners to form the posture change system. In addition, which of the above-described systems can be suitably used can be determined according to the physical condition of the patient or the progress of his/her rehabilitation. Moreover, the system F shown in Figure 14, for instance, can serve as a tool for training the patient B to walk by gripping the grip 38. Besides, in a case where the posture change system is intended to be designed only for those who are comparatively strong, such as those who can train themselves to walk, the foot rest plate 54 can be eliminated, thereby enabling the space between the right and left base portions 4 to be widened as large as possible, whereby the patient can freely walk without any hinderance. In such a case, means for varying the length of the pole 10 may be provided as means for, in turn, adjusting the level of the knee pads 40.

Claims

1. In a posture change system for changing a posture of a patient from a sitting one to a standing one comprising: an arm which swings in a vertical plane about a horizontal axis; a support member for supporting the patient which extends underneath both of his/her armpits to his/her back and is attached to the tip end of the arm;and, knee pads for supporting his/her knees; characterized in that said system includes a chest pad for supporting the patient's chest which is provided on the tip end of said arm; and, means for adjusting the effective length of said support member which is provided on said support member; whereby his/her posture is changed by swinging said arm after his/her chest is made to lean against said chest pad by adjusting said effective length of said support member.

2. The posture change system in accordance with claim 1, further including an air cushion which is attached to said support member and filled with air.

3. The posture change system in accordance with claim 1, wherein each said knee pad swings about a horizontal axis.

4. The posture change system in accordance with claim 3, further including positioning means for positioning the pivot center of each knee of the patient above the swing center of each said knee pad .

5. The posture change system in accordance with claim 1, further including a driving wheel disposed close to a position just under the patient in a standing posture.

6. The posture change system in accordance with claim 1, wherein each said knee pad has a cross section curved in a concave manner so as to receive the patient's knee.

7. The posture change system in accordance with claim 1, further including driving means for driving said arm and a switch means attached to the tip end portion of said arm for compeling the lowering motion of said arm to stop by stopping said driving means when it contacts the patient.

8. The posture change system in accordance with claim 1, further including driving means for driving said arm and a pressure sesitive sensor attached to the tip end portion of said arm for compeling the lowering motion of said arm to stop by stopping said driving means when it contacts the patient.

9. The posture change system in accordance with claim 4, wherein said positioning means comprises level-adjustable foot rest means upon which the patient rests his/her;and, further including means for adjusting each said knee pad in the frontward and backward direction.

10.The posture change system in accordance with claim 9, wherein said foot rest means includes a foot rest plate upon which the patient's feet are received and means for displacing said foot rest plate toward a position closer to the patient's side as said foot rest plate is raised higher upon the level thereof being changed.

11.The posture change system in accordance with claim 10, further including a patient height indication pin provided on said foot rest plate.

12.A posture change system for changing a posture of a patient who finds it difficult to stand up by himself/herself from a sitting posture to a standing one comprising: a frame with casters which includes a vertically extending pole; an arm which is swingably attached to the upper end of the pole via a horizontal axis and comprises upper and lower rods disposed vertically spaced apart in a vertical plane to define a parallelogram link; drive means for swinging the arm; a chest pad for supporting the patient's chest which is attached to the tip end of the arm; a support member which is removably attached to the tip end of the arm and extends underneath both of the patient's armpits to his/her back to cooperate with the chest pad to encircle his/her chest portion;and, knee pads for supporting the patient's knees which are provided on the pole.

13.A posture change system in accordance with claim 12, wherein said chest pad is attached to said arm while being bent forward.

14.A posture change system in accordance with claim 12, wherein said upper end of said pole is positioned below the level of the chest portion of the patient in a sitting posture.

15.A posture change system in accordance with claim 14, wherein the height of said pole is adjustable so as to adjust the level of the pivot center of said arm in accordance with the height of the patient .

16.A posture change system in accordance with claim 12, further including a slider which is attached to said arm and is slidably guided by said arm and a first engaging member provided on said slider, and said support member including a pair of right and left lower arm portions each of which extends downwardly; whereby the tip end of each of said lower arm portions is engaged by said first engaging member of said slider by passing said corresponding lower arm portion underneath an inner portion of the patient's thigh and drawing it to the front of the patient.

17.A posture change system in accordance with claim 16, wherein a plurality of holes aligned with one another are formed in each of said pair of right and left lower arm portions.

18.A posture change system in accordance with claim 17, further includes a second engaging member provided on said chest pad, said support member includes a pair of right and left upper arm portions each of which extends upwardly; whereby the tip end of each of said upper arm portions is engaged by said second engaging member of said chest pad by passing said corressponding upper arm portion underneath the patient's armpits to his/her back and drawing it to the front of the patient.

19.A posture change system in accordance with claim 12, further including a pair of right and left driving wheels at the middle portion of said frame in the frontward and backward direction.

20.A posture change system in accordance with claim 19, further including a seat removably attached to the rear end portion of said frame .

21.A posture change system for changing a posture of a patient who finds it difficult to stand up by himself/herself from a sitting posture to a standing one through two steps comprising: a frame with casters; first drive means which is attached to said frame and expands and contracts in the vertical direction; an arm which is swingably attached to the upper end of said first drive means via a horizontal axis; second drive means for swinging said arm; a chest pad for supporting the patient's chest which is pivotably attached to the tip end of the arm via a horizontal axis; a support member which extends from said chest pad underneath both the patient's armpits to his/her back to cooperate with said chest pad to encircle his/her chest portion; third drive means for pivoting said chest pad which is attached to the tip portion of said arm; and, knee pads for supporting the patient's knees; whereby the lower half of the patient's body is stretched while said knee pads support his/her knees by actuating said second drive means to raise said arm and then the upper half of his/her body is raised by actuating said first drive means and said third drive means to expand said first drive means and at the same time move the chest pad to a vertical position.

22.A posture change system in accordance with claim 21, wherein said chest pad has such a size that it extends from the chest of the patient to his/her abdominal portion.

23.A posture change method for changing a posture of a patient who finds it difficult to stand up by himself/herself from a sitting posture to a standing one comprising: a step for enabling the patient in a sitting posture to stand up by his/her chest being pushed up and at the same time being supported while his/her knees being allowed to move longitudinally and at the same time being supported.

24.A posture change method in accordance with claim 23, further including a step for fastening the patient's chest.

25.A posture change method for changing a posture of a patient who finds it difficult to stand up by himself/herself from a sitting posture to a standing one comprising: a step for stretching the lower half of the patient's body by supporting his/her knee and at the same time supporting his/her chest; and a step for raising the upper half of his/her body by pushing up his/her chest.