Patent Description:
Society is facing an aging crisis in which there are not enough caretakers to take care of the elderly. One of the biggest challenges for elderly is mobility. While there are electric wheelchairs to take care of many of the mobility issues, transferring from the bed to the wheelchair or a shower chair often still requires a lot of external help.

Thus, in a society where a caretaker may not be readily available, simplifying or automating the patient transfer process is a huge priority.

In the prior art there exists many examples of cranes or transfer mechanisms such as the conveyor belt system in <CIT>. In this example, they use a complicated conveyor belt that can pivot upward to support the back and be slowly used to transport the user down the bed. Not only will this method cause unacceptable and dangerous chafing of the skin due to rubbing and friction, it is likely to be expensive, and require a fair bit of outside intervention. For example, if the bed could dump the user onto the ground. Moreover, this prior art would require a lot of space (lengthwise and vertically) and would dump the contents of a bed all over the place. In short, it would be unpractical and potentially dangerous.

A more typical transfer mechanism is the patient lift or hoist used in <CIT> and which requires outside help to put on the harness and seep under the person to be hoisted. After hoisting the user, a helper or caretaker would need to move the crane or hoist to the intended location or device before lowering the patient again and pulling the hoist out from underneath. This solution, while it alleviates the burden of lifting from the user, still requires a lot of outside intervention and is relatively expensive and space hogging.

The system in <CIT> introduces another type of bed to wheelchair system, which uses an interleaf system to detach a frame from the bed using a series of lifting apparatus. The shortcoming of this system is that the lifting apparatus must be large and strong, to support lifting the user and a large frame up and out of the bed and rearward over the bedframe before carefully lowering the user and frame onto a separate. The size of this humongous lifting apparatus makes the device impractical from a space-usage perspective and the design expensive to implement. Moreover, the potential for misuse is large and thus would likely require external help and adjustment to operate the lifting apparatus to ensure alignment is perfect.

Besides, there is also a desire for the wheelchair or shower chair to be practical for regular, normal use. For example, a wheelchair should not be too bulky and a shower chair or commode should have a seat opening for the toilet. It is known from prior art <CIT> which discloses a nursing system enables a bedridden patient or handicapped person to move unattended from his bed or wheelchair to a toilet, bathtub, or other nursing aid, wherein same members are part of the preamble of claim <NUM>. Furthermore, <CIT> and <CIT> are mentioned as reference in the present disclosure.

Thus, the motivations for this disclosure include: minimizing or removing the need for external assistance during the transfer process; providing a solution that prevents chafing of the skin during transfer, is not bulky, so as to hinder manoeuvrability, and is reasonably inexpensive to manufacture.

It is also the intention of this invention, which is set out in the appended set of claims, to introduce a system for patient transfers that can be done automatically, safely and with little or no caretaker assistance.

In order to achieve the above-mentioned motivations, embodiments of the present disclosure provide a patient transfer system for transferring a user between a bed and a purposefully designed mobile sitting device that is aligned and berthed alongside the bed, wherein, the bed is adaptable to a seated arrangement and includes an interleaf structure of cushions and platforms, the platform including: a padding, a rail, restricted path or track, and means for transferring the padding in a direction parallel to the ground away or towards the bed; the bed further includes means to raise or lower the top of the cushions or the padding; and the mobile sitting device includes a receiving rail, restricted path or track to receive the padding.

According to the above-mentioned patient transfer system, in a first state, an interleaf structure is arranged to create a relatively uniform or level top surface between the cushions and the top of the padding which together form a mattress for the bed. A second state involves creating a gap in elevation such that the top of the padding is above the top of the cushions. The top of the padding supports the weight of the user above the cushions allowing him/her to be transferred sideways while minimizing any friction against the cushions.

The user along with the padding are then pushed or moved along a pre-defined track (or restricted path) to the mobile sitting device before being locked or secured in place. Preferably this pushing or pulling is done automatically and the pushing / pulling means is retracted afterwards.

It should be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure.

The current disclosure involves a patient transfer system for transferring between a bed <NUM> and a purposefully designed mobile sitting device <NUM> such as a wheelchair, mobile shower chair or commode. Preferably the bed <NUM> is adaptable into a sitting position for ease of alignment and includes an interleaf structure of cushions <NUM> and platforms <NUM>, the platform <NUM> further including a detachable padding at its top <NUM>, a rail, restricted path or track <NUM>, and means <NUM> for transferring the padding and user in a direction parallel to the ground along the track. The wheelchair also contains a matching rail, restricted path or track <NUM> and alignment features for correct berthing with the bed.

Preferably the bed <NUM> includes an upper portion 100c for supporting the upper body of the user, a middle portion 100b for supporting the middle portion or buttocks section of the user and a lower portion 100a for supporting the legs and feet. The mobile sitting device <NUM> similarly includes an upper portion 200c for supporting the upper body of the user, a middle portion 200b for supporting the middle portion or buttocks section of the user and a lower portion 200a for supporting the legs and feet.

In <FIG> the interleafing structure has platforms <NUM> and cushions <NUM> arranged side-by-side in a fully reclined position such that the top of its cushions <NUM> are fully level with the top of the platforms <NUM>/ paddings <NUM>.

In <FIG>, the bed <NUM> is arranged in a regular upright sitting surface with the top of its cushions <NUM> maintaining a relative uniform top level with that of the platforms <NUM>/ paddings <NUM> in a shape that reflects a regular chair or couch. In this figure, the lower portion 100a bends downward and the upper portion 100c bends upwards.

In <FIG> the bed <NUM> is arranged in an upright sitting position with the top of the padding <NUM> raised relative to the top of the cushions.

In <FIG>, the embodiment shows the cushion structures <NUM> contracting or lowering relative to the platforms <NUM>/ paddings <NUM>. In <FIG>, an alternative embodiment shows the paddings <NUM> raised or expanding relative to the cushions <NUM>.

Optionally the cushion <NUM> or padding <NUM> includes an air cushion <NUM>. The air cushion <NUM> is expanded in <FIG> and contracted in <FIG>, which can be used to raise and lower the top surface of the cushions <NUM> or paddings <NUM> respectively. The air cushions <NUM> in <FIG> are preferably embedded in a layer of foam or other soft filling <NUM>. Alternatively, the cushions <NUM> or paddings <NUM> can be raised or lowered through the use of a motor or piston (not shown).

Prior to attempting a transfer, the mobile sitting device <NUM> is aligned or berthed alongside the reclining bed <NUM> as in <FIG>. An alignment mechanism <NUM> is used to ensure that the mobile sitting device <NUM> is berthed properly beside the reclining bed within a certain range of tolerance.

As depicted in <FIG>, the alignment mechanism <NUM> includes male section 110a and female section 110b found on the mobile sitting device <NUM> and bed <NUM> respectively. Preferably the female section 110b of an alignment mechanism has a tapered design such that the male section 110a can be inserted snuggly in so as to ensure a consistent position. When the male section 110a is snuggly berthed with the female section 110b, indicating that the mobile sitting device is properly positioned beside the bed <NUM>, it preferably sets off or pushes the sensor <NUM>.

<FIG> and <FIG> illustrate a potential alignment mechanism for the back of the bed <NUM>. In 8a, a bed is depicted with a sensor 112a mounted on a side of the upper portion of the bed 100c. When the upper portion of the bed 100c rotates upward from a reclined position into a sitting position, it comes into contact with a part of the upper portion of the mobile sitting device 200c. This activates the sensor or button 112a indicating that the bed <NUM> is properly aligned and that the raising of the upper portion 100c can stop.

For example, in one embodiment if the shape of the bed is not configured or arranged in a manner that is aligned to the mobile sitting device, it is adjusted until it hits the limiter or the sensor indicates the alignment is correct. For safety purposes preferably the transfer can only begin when the sensors indicate alignment is correct.

Subsequently, after berthing and alignment are indicated to be complete, the mobile sitting device <NUM> is preferably locked in place or locked to the bed <NUM>. The transfer process then begins with the gap in elevation created between the platforms <NUM>/ paddings <NUM> and cushions <NUM> as in <FIG>. As in <FIG>, the user can then be transferred horizontally (or parallel to the ground), carried by the paddings <NUM>, or a portion of it, along the tracks <NUM> of the bed <NUM> to the mobile sitting device <NUM> (which also has tracks <NUM>).

An example or more detailed depiction of the platform <NUM> and means for transfer <NUM> are depicted in <FIG> and <FIG>. A platform <NUM> consists of padding <NUM>, a track <NUM> and a means <NUM> for transferring the padding <NUM> to the tracks <NUM> of the mobile sitting device <NUM>. Preferably the platform includes wheels <NUM>.

In the embodiment of the platform <NUM> in <FIG>, the means for transfer <NUM> consists of an actuator pad 152a mounted on a rack and pinion system <NUM>. This actuator pad 152a is interlocked or secured to the detachable padding <NUM> by an interlock <NUM> such that as the rack moves horizontally, the actuator pad 152a pushes the padding <NUM> and the user over to the mobile sitting device <NUM>.

After the padding <NUM> has reached its intended destination, the interlock <NUM> is disengaged from the padding and the means for transfer <NUM> retracted. The interlock <NUM> is engaged in <FIG> and disengaged in 10e to 10f. Preferably the mobile sitting device <NUM> contains means for securing the padding <NUM> in place once the padding and user has been transferred over. This means for securing may include a side panel or latch <NUM> which blocks the motion of the padding <NUM> in <FIG>, lowered in <FIG> but raised again in 10f.

To transfer the user or the padding <NUM> back to the bed, the process is largely reversed. After successful alignment and berthing, the side panel or latch <NUM> of the mobile sitting device is release or lowered. As in <FIG>, the means for transfer <NUM> extends outward and the interlock <NUM> engages with the padding <NUM>. The padding <NUM> is then pulled along the tracks <NUM>, <NUM> back to the bed. The top of the cushions <NUM> and padding <NUM> can then be aligned once again for the comfort of the user to rest upon.

<FIG> depict an alternative embodiment of the platform <NUM> and transfer mechanism <NUM> in 10a to <NUM>. In this embodiment, the transfer mechanism <NUM> includes a linear piston with an interlock <NUM> for latching onto a bottom part of the padding <NUM>. The padding is once again mounted on wheels <NUM> and the process for transferring is generally similar to the previous embodiment except that the transfer mechanism <NUM> has been changed.

<FIG> depicts the embodiment with the padding <NUM> firmly on the bed. In <FIG>, the side panel or latch <NUM> of the mobile sitting device is lowered so that the padding <NUM> can begin to be moved over. In <FIG> the linear actuator <NUM> pushes the padding <NUM> and the user over to the mobile sitting device <NUM>. In <FIG>, the interlock <NUM> is disengaged from the bottom of the padding, the linear piston or transfer mechanism <NUM> is retracted and the side panel <NUM> of the mobile sitting device is raised.

To transfer the user and padding <NUM> back to the bed, the side panel <NUM> is lowered, the linear piston or actuator <NUM> is extended, the interlock <NUM> secures onto the padding <NUM> and the padding <NUM> is pulled along the tracks <NUM>/<NUM> back to the bed <NUM>.

<FIG> depict yet another embodiment of the patient transfer system similar to the ones in <FIG>, but where there is an additional "variant" type of platform or holder 150a.

When transferring from a bed <NUM> to a chair <NUM>, the foot or leg section 100a of the bed often cannot be lowered sufficiently to match the angle of the foot or leg section 200a of the mobile sitting device <NUM> (due to the length of the bed). Thus, rather than let the legs fall sharply down after reaching the edge of the bed <NUM>, a "variant" platform or holder 150a is used to support the legs of the user. Similarly, when transferring from the mobile sitting device <NUM> back to the bed <NUM>, the legs may need to be lifted.

In <FIG>, a user is shown being transferred between a bed <NUM> and a mobile sitting device <NUM>. When the means for transfer <NUM> is retracted, the padding 152b for the variant platform 150a is also retracted (unlike the other paddings <NUM> which stay with the user). Moreover, the padding 152b is not only retracted, but its angle, size or position may be altered. An example of the change is better illustrated in <FIG>.

When the user is transferred over to the mobile sitting device <NUM>, the legs of the user are generally elevated. Thus, the variant padding 152b/ holder 150a is either expanded or adopts a position where the foot is elevated in <FIG>. The user's feet are then lowered through the contraction or movement of the variant padding 152b/ platform 150a in <FIG>. The whole variant padding 152b/ holder 150a is then retracted from behind the lowered legs in <FIG>. When the user is to be transferred back, the variant padding 152b is inserted behind the user's legs, expanded or moved upwards, and then pulled back along with the user.

In another aspect of the invention, preferably the padding <NUM> is perforated to contain holes connecting its front and back surfaces, such that water can pass through the holes and people can bathe on the mobile sitting device <NUM>. Further, in some exemplary embodiments, when the padding <NUM> is used to lay on the bed <NUM>, the holes are filled such that the laying surface is level and comfortable for people to lay on. This can be done through either physically removing the inlays <NUM> by hand or through the expansion or contraction of an air bag. It can also be accomplished by lowering the inlays <NUM> similarly to the cushions in <FIG>. The process of lowering the inlays is depicted in <FIG>. The padding <NUM> can then be transferred horizontally without interference. In addition, the holes can also be opened through the relative elevation of the padding above the lower cushions or the contraction of an air bag. Moreover, the padding <NUM> may include a waterproof material.

Claim 1:
Abed (<NUM>), adaptable to a seated arrangement and comprising an interleaf structure of cushions (<NUM>) and platforms, each platform (<NUM>) comprising:
- a padding (<NUM>),
- a rail, restricted path, or track, and
- means for transferring the padding (<NUM>) in a direction parallel to the ground away or towards the bed;
and the bed further comprising means to raise or lower the top of the cushions (<NUM>) or the padding (<NUM>), characterized in that the bed (<NUM>) further comprises a male section (110a) or a female section (110b), such that the male section (110a) or female section (110b) can be inserted snuggly in the female section (110b) or male section (110a) found on a mobile sitting device (<NUM>) to be berthed alongside the bed, for alignment.