Patent Description:
The present invention is an improvement to a previously filed and granted invention to the same inventor having a Patent No. <CIT>.

It is well known that patients who are confined to a bed or chair for extended periods of time are at risk of developing decubitus ulcers, i.e., pressure sores, or bed sores as they are more commonly known. These ulcers are often seen to develop within soft tissue that is compressed between a bed or chair surface and a patient's weight-bearing bony prominences, the compressed tissue being at least partially deprived of oxygenated blood flow. A continued lack of blood flow, and resultant lack of oxygen, can result in cell death which may be evidenced in the form of pressure sores. Pressure sores do not develop immediately, but rather form over time, with the development speed depending on a number of factors including the firmness and friction of the supporting surface against the patient's skin, the patient/ambient temperature, the amount of moisture in contact with the skin, and the health and susceptibility of the skin due to age or illness.

One venerable and generally accepted means of reducing the risk of decubitus ulcer development in bedfast patients is to turn them regularly, usually at approximately two hour intervals. For example, a patient in a back rest position might be periodically rolled to one side or the other, such motion helping to maintain blood to flow to soft tissue that is under compression. Similar strategies are employed for patients that are confined to a chair for long periods of time. Obviously, an assisted-movement strategy relies to a large extent on the vigilance of the attending staff to insure that the patient is properly relocated. Further, it is far too easy for the busy care giver to let the time for turning the patient slip by in the press of other daily emergencies. To the extent that the caregiver is too busy or forgets to perform this service, this method can fail to achieve its purpose. Further, this sort of strategy can be counterproductive for use with the patient that has some capacity for self-movement.

More particularly, the process of moving a patient to another position is admittedly disruptive to the patient and this is especially true at night, since the patient - if he or she were sleeping - will be awakened for the purpose of relocation. The typical two-hour movement interval must be observed around the clock if the method is to be effective, so it is necessary to rouse the patient - who might be sleeping soundly at the time to make the required adjustment in position. Further, this adjustment might not have even been necessary if the patient had recently moved of his or her own volition. Thus, in many situations it would be advantageous for the caregiver to know if and when the patient last moved his or herself. Then, if the last movement were within a prescribed period of time, it might be possible to spare the patient an unnecessary interruption in his or her healing sleep. The caregiver would then relocate the sleeping patient, only if that relocation were actually required. Further, knowing which patients do not need to be moved could result in a substantial savings in labor costs, as the time that would otherwise be devoted to moving the patient that did not actually need to be moved could be productively applied elsewhere. That being said, as useful as this sort of information might be to the health care provider, however, the present state-of-the-art in patient management does not provide this sort information.

<CIT> issued to the same inventor disclosed an apparatus for reducing the risk of developing decubitus ulcers on bedfast or immobile patients and adjunct to the treatment thereof. Said apparatus comprises a bed frame, a plurality of spaced apart pusher assemblies transversely disposed on said bed frame, each said pusher assemblies being defined by a hollow shaft being rotatably secured to said bed frame and pusher members securely held by said shaft. The pusher assemblies are rotated either manually or by a drive motor to rotate the pusher members, wherein said pusher members are arranged alternately such that a mattress placed above the apparatus where immobile patients rest is repetitively reconfigured with the rotation of the pusher members. This approach actually prevents the development of decubitus ulcers or bedsores at the back of the patient or may help in the treatment of such if the patient has already said decubitus ulcers or bedsores.

However, further studies have proven that formation of bedsores is different from patient to patient. For example, bigger or heavier patients are more likely to contract bedsores faster that smaller and lighter patients as the weight adds pressure to the back or other body parts of the patient that are constantly in contact with the bed. Another parameter that may affect the quick formation of decubitus ulcers or bedsores is the temperature and humidity of the environment. Considerable temperature will cause the body to sweat which will hasten the formation of bedsores if not attended to. Since the apparatus of <NUM>-<NUM>-<NUM> is activated or rotated manually or by using a preset timer, one patient may have to wait until the set time has elapsed, usually between <NUM> and <NUM> hours, before the body is flipped by the movement of the pusher members, although movement should have been completed way before the elapsed time. In addition, manual operation of the apparatus involves human intervention that an attending doctor or nurse must be in constant reminder to activate the rotational movement of the pusher members. With this practice, it is not hard to imagine that said attending doctor or nurse may forget or may unintentionally delay the required operation of the apparatus.

<CIT> discloses a bed assembly (<FIG>) for the prevention and the treatment of decubitus ulcers or bedsores on immobile patients, comprising a plurality of pusher assemblies arranged in alternating manner, such that, every area of the mattress is moved in alternating pattern for every simultaneous rotation of the pusher assemblies.

Accordingly, it is the primary object of the present invention to provide an apparatus for the prevention and the treatment of decubitus ulcers or bedsores on immobile patients that aims to solve the drawbacks of the prior art. The present invention is defined by the appended claims, and proposes a mechanized bed assembly wherein the rotational movement of the pusher assemblies is initiated by a drive motor which is activated by a programmable controller. The programmable controller obtains input parameters from temperature and moisture sensors provided with the mechanized bed so that activation of the drive motor may be initiated at a faster rate than the pre-set time.

Another object of the present invention is to provide a mechanized bed for the prevention and the treatment of decubitus ulcers or bedsores on immobile patients that is provided with a weight monitoring device which is also in communication with the programmable controller, such that the measured weight may be used as a parameter for determining the pre-set time required to activate the drive motor.

Another object of the present invention is to provide a mechanized bed for the prevention and the treatment of decubitus ulcers or bedsores on immobile patients wherein the mattress is provided with spaced holes to permit ventilation of the patient's body from below the mattress.

Another object of the present invention is to provide a mechanized bed for the prevention and the treatment of decubitus ulcers or bedsores on immobile patients that is provided with a blower fan that provides ventilation to the body of the patient through the holes of the mattress. The blower fan is in communication with the programmable controller so that automatic operation thereof is dictated by the input parameters being inputted by the different sensors.

Another object of the present invention is to provide a mechanized bed for the prevention and the treatment of decubitus ulcers or bedsores on immobile patients that is provided with tiltable support frame structure to facilitate tilting or inclining and reclining of the pusher assemblies and the mattress that complies with the regulations of hospitals to permit the patient in inclined position without getting up from the mattress.

These and other object and advantages of said invention will come to light upon a reading of the following description when taken in conjunction with the appended drawings.

Referring now to the several views of the drawing wherein like reference numerals designate same parts throughout, shown is the invention for a mechanized bed assembly for the prevention and the treatment of decubitus ulcers or bedsores on immobile patients, the bed assembly generally designated as reference numeral <NUM>.

The bed assembly <NUM> comprises a rectangular bed frame <NUM> defined by a pair of side frame members <NUM> and a pair of end frame members <NUM>, corner footings <NUM> provided at the bottom of the bed frame proximate the corners thereof, a head guard rail <NUM> on top of one of the end frame members <NUM> of said rectangular bed frame <NUM>, a foot guard rail <NUM> on top of the opposite end frame member, and a pair of side guard rails <NUM> on top of the side frame members <NUM>. As is conventional in hospital beds or beds for patients, the guard rails <NUM>, <NUM> and <NUM> can be made removable or foldable as they can be hindrances in facilitating transfer of immobile patients. The corner footings <NUM> are provided with caster wheels <NUM> to facilitate easy movement of the bed assembly <NUM> when necessary, and adjustable foot base <NUM> when it is necessary to avoid movement of the bed assembly <NUM> as well as to provide stability when set on uneven floor surface. The rectangular bed frame <NUM> can also be provided with a meter stick <NUM> fixed at the side frame member <NUM>.

A plurality of spaced pusher assemblies <NUM> is arranged transversely within said bed frame <NUM> and a mattress <NUM> is provided on top of said plurality of pusher assemblies <NUM>. As shown in <FIG>, each pusher assembly <NUM> is defined by a square shaft <NUM>, a plurality of pusher members <NUM> fixed along the length of said square shaft <NUM> in a spaced manner, and a pair of pillow blocks <NUM> supporting the ends of said square shaft. Each pusher member <NUM> is defined by a generally triangular pusher body <NUM> having a square hole <NUM> at the vertex thereof. The square hole <NUM> is adapted to fit into the square shaft <NUM> of the pusher assembly <NUM>. Preferably, the triangular pusher body <NUM> includes an inner body <NUM> being made of metal and an edge <NUM> being made of engineering plastic material. Preferably, the inner body <NUM> is made of light metal such as aluminum.

As best shown in <FIG>, the spaced pusher assemblies <NUM> are adapted to be simultaneously rotated by a drive motor <NUM> through a gear box <NUM>, a drive shaft <NUM> and a chain link assembly <NUM> (shown in dotted lines) that connects the drive shaft <NUM> with the spaced pusher assemblies <NUM>. In the embodiment shown in <FIG>, chain link assembly <NUM> can be defined by pulleys and belt, but it can also be defined by toothed gears or sprockets <NUM>, as shown in <FIG> and <FIG>. As shown, the spaced pusher assemblies <NUM> are arranged in alternating manner, such that, a first row of spaced pusher members <NUM> is aligned with the spaced pusher members <NUM> of the third, fifth, seventh rows, etc. and a second row of spaced pusher members <NUM> is aligned with the spaced pusher members <NUM> of the fourth, sixth, eighth rows, etc. The triangular shape of each pusher member <NUM> will provide a different elevation as they rotate, and the alternate arrangement will ensure that every area of the mattress <NUM> will have altered or moved in alternating pattern for every simultaneous rotation of the pusher assemblies <NUM> through the drive motor <NUM>.

The spacing of the pusher members <NUM> can be adjusted to ensure that engagement of the pusher members with the back of the patient is optimized.

The chain link assembly <NUM> is provided with cover plates <NUM>, and the drive motor <NUM> is provided with a motor cover <NUM>. The cover plates <NUM> can be made of any suitable material such as stainless steel or rigid plastic.

In accordance with the advantages of the present invention, the drive motor <NUM> is activated by a programmable controller <NUM>. Unlike the manual rotation of the pusher assemblies of the prior art, or the fixed and preset time activation of the drive motor, the controller <NUM> of the present invention can be programmed to activate the drive motor through different parameters. As shown in <FIG>, <FIG> and <FIG>, the bed assembly <NUM> of the subject invention further includes weight detectors <NUM> and a temperature sensor <NUM>. In addition, the bed assembly <NUM> can also include a moisture detector <NUM> arranged within the bed frame <NUM> and proximate the mattress <NUM>. The weight detectors <NUM>, temperature sensor <NUM>, and moisture detector <NUM> are all in electrical communication with the controller <NUM> and serve to provide input parameters for the activation of the drive motor <NUM>. For example, when the immobile patient is heavier than average, the controller <NUM> can be programmed to activate the drive motor <NUM> at a faster rate than ordinary as a bigger individual may be more prone to bedsores than smaller and lighter patients. If the temperature in the room is hotter, the controller <NUM> can be programmed to activate the drive motor <NUM> at a faster rate since the patient may sweat faster and sweat may cause faster formation of bedsores. And in case the moisture detector <NUM> senses moisture or wetness, the controller <NUM> can be programmed to instantly activate the drive motor <NUM> to rotate the spaced pusher assemblies <NUM>.

In accordance with another advantage of the present invention, the bed assembly <NUM> can be further provided with at least one blower fan <NUM>, preferably arranged below the mattress <NUM> and the mattress <NUM> is provided with a plurality of spaced ventilating holes <NUM>. Similarly, the at least one blower fan <NUM> can be activated by the controller <NUM> using the input parameters from the temperature sensor <NUM> and the moisture detector <NUM>. When heat and moisture are detected, the controller <NUM> will activate the blower fan <NUM> to deliver ventilating air through the spaced ventilating holes <NUM> of the mattress <NUM>, as shown by the dashed arrows in <FIG>, thus preventing or reducing formation of bedsores caused by heat and sweat of patients.

Claim 1:
A bed assembly (<NUM>) for the prevention and the treatment of decubitus ulcers or bedsores on immobile patients, the bed assembly (<NUM>) comprising a rectangular bed frame (<NUM>) defined by a pair of side frame members (<NUM>) and a pair of end frame members (<NUM>), corner footings (<NUM>) provided at the bottom of the bed frame (<NUM>) proximate the corners thereof, a drive motor (<NUM>) with a gear box (<NUM>), a drive shaft (<NUM>), a chain link assembly (<NUM>), a plurality of spaced pusher assemblies (<NUM>) arranged transversely within said bed frame (<NUM>), and a mattress (<NUM>) provided on top of said plurality of pusher assemblies (<NUM>), each pusher assembly (<NUM>) being defined by a square shaft (<NUM>), a plurality of pusher members (<NUM>) fixed along the length of said square shaft (<NUM>) in a spaced manner, and a pair of pillow blocks (<NUM>) supporting the ends of said square shaft (<NUM>), the spaced pusher assemblies (<NUM>) adapted to be simultaneously rotated by the drive motor (<NUM>) through the gear box (<NUM>), the drive shaft (<NUM>) and the chain link assembly (<NUM>), the spaced pusher assemblies (<NUM>) arranged in alternating manner, such that, every area of the mattress (<NUM>) is moved in alternating pattern for every simultaneous rotation of the pusher assemblies (<NUM>) through the drive motor (<NUM>), characterized in that, a programmable controller (<NUM>) controls the activation of said drive motor (<NUM>) through different parameters, the bed assembly (<NUM>) further comprising weight detectors (<NUM>), a temperature sensor (<NUM>) and a moisture detector (<NUM>) arranged within the bed frame (<NUM>) and proximate the mattress (<NUM>), wherein the weight detectors (<NUM>), temperature sensor (<NUM>), and moisture detector (<NUM>) are all in electrical communication with the controller (<NUM>) and serve to provide input parameters for the activation of the drive motor (<NUM>).