Mattress with cushion layer for treating bedsores by restoring arterial blood supply

Abstract

The present invention relates to a medical device that allows a small portion of the epidermis to be simultaneously affected by micro-suspension and inflow of a large amount of arterial blood through an alternately pressurized tubing system. The arterial blood cannot pass through the capillaries [(7) in Figure 6] again due to the action of the pressurized conduit, as they bear greater pressure than without the device, forced through the capillaries [(8) in Figure 6], as if they are suspended in the air, as they no longer come into contact with the support surface. The device works periodically, which means that no matter where the lesion is located, the amount of arterial blood flowing through the lesion is larger than that of arterial blood flowing through the lesion in the prior art.

Description

Technical Field

[0001] This invention is applicable to the medical field, and more specifically, to the research and treatment of pressure ulcers or bedsores.

[0002] As is well known, pressure ulcers are injuries to the skin and subcutaneous tissues caused by prolonged pressure between bony protrusions above and external supporting surfaces below on soft tissues (skin, subcutaneous tissue, and muscles).

[0003] This pressure hinders the normal flow of blood, making these tissues prone to necrosis due to insufficient nutrition.

[0004] Therefore, bedsores mostly form on bony prominences (sacrum, ischium, heel, neck and back, spine), where the soft tissues are compressed by the hard supporting surface. Background Technology

[0005] At the beginning of the last century, an Italian doctor advised that patients should not maintain the same posture for more than two hours.

[0006] At the time, it was known that prolonged static postures could lead to bedsores, so it was recommended that patients move around, for example, starting from a supine position and tilting to one side first, then to the other, raising their legs, torso, etc. The purpose of this method was to prevent bony prominences from compressing the corresponding soft tissues for more than 2 hours, so that the compressed soft tissues could regain arterial blood supply before the next compression.

[0007] In 1930, Dr. Randy measured the average local arterial pressure in the skin to be about 32 mmHg. Therefore, pressure greater than 32 mmHg applied to a part of the skin for a sufficient period of time can lead to bedsores.

[0008] Currently, all guidelines, from the U.S. Department of Health Care and Rehabilitation (AHCPR) to Norton D., McLaren R., and Exten Smith in the 1962 Survey of Geriatric Care in Hospitals, to Policlinico S. Orsola Malpighi of the Bologna Hospital Group, AISLe.C. in the 1995 Guidelines on Posture Change, and Patterson JA and Bennet RG in the 1995 Guidelines on Prevention and Treatment of Pressure Ulcers, all recommend against applying pressure to the skin exceeding 32 mmHg for more than 2 hours, as this can lead to pressure ulcer formation.

[0009] In her 1995 books, *The Pathophysiology of Pressure Ulcers* and *Key Aspects of Geriatric Care*, Dr. Cucinotta D. suggested that pressure time should be significantly shortened because pressure ulcer formation is not solely dependent on pressure. In fact, pressure ulcer formation also depends on local skin thickness (which depends on the patient's age and health status), various hemodynamic factors, blood viscosity, hematocrit, obesity, urinary incontinence, malnutrition, and more.

[0010] In summary, the most advanced technology currently available is that there are many anti-decubitus mattresses and / or mattress pads that work by applying pressure and releasing air alternately, thereby distributing the patient's weight evenly on the same body surface and changing their position every 2 hours.

[0011] The “alternating pressure device” consists of a set of interconnected pipes (or buffers) that prevent continuous pressure from the body from acting on the same skin area by alternating inflation and deflation. By alternating the range of influence of the pipes, the pressure in the same area is kept to a minimum for 2 hours.

[0012] These devices attempt to deliver arterial blood flow to pressure ulcers by using pressures typically above 32 mmHg within the tubing, thereby healing the ulcers by providing nutrition. However, as we will demonstrate later, the pressure used is below the pressure required to combat pressure ulcers, and therefore they fail to achieve the benefits they hope to attain.

[0013] The "ventilation device" also consists of a set of interconnected tubes (or buffers) made of porous fabric, which allow air to flow from the outside to the patient, in addition to allowing pressure changes caused by the patient's weight. This airflow helps control humidity and prevent damage from skin maceration.

[0014] There is also something called a "fluidized air device," where the airflow is dynamic. This device consists of a bed containing silicified microspheres, which are encased in a breathable liner and kept fluidized by a flow of hot air, thus maintaining continuous movement.

[0015] Therefore, suspending the body not only effectively distributes weight but also ensures the patient can continue to move, thus preventing bedsores.

[0016] Among the countless systems for preventing pressure ulcers, we must consider the patent "US5010608" granted to Dr. Barnett Richard on April 30, 1991, entitled "Support System for Reducing Pressure Ulcer Formation." This patent claims to have invented a device consisting of "N" groups of soft, flexible tubes. By inflating all but one tube, and alternately inflating and deflating these tubes, the pressure on the body can be altered to allow patient movement, thereby minimizing the time of pressure on bony prominences and the soft tissue between the underlying mattress.

[0017] In 2018, Dr. Chapin William Lawrence of the United States was granted patent number US160821 on June 14, 2018, entitled "Moving Wave Air Mattress and Method and Apparatus for Generating Moving Waves Thereon". The patent claims to have invented a device consisting of tubes that are sequentially inflated and deflated to generate wave-like motion, with the aim of preventing bedsores. It also states that "the wave pattern can simulate water ripples and / or the swaying of a boat, thereby providing a relaxing effect for the patient".

[0018] Dr. Chapin actually invented a system that automatically schedules the continuity of inflation and deflation (like all devices that utilize alternating pressure in the tubes that make up a mattress), attempting to simulate calm ocean waves to help patients relax and provide a comfortable environment. Because the maximum pressure in the tubes that create the waves is only 25 mmHg, there is a risk of the patient's nervous system experiencing effects similar to seasickness.

[0019] In recent years, in addition to traditional and advanced dressings, new treatments for numb ulcers and slow-healing wounds have emerged, encompassing biological therapies, physical therapies, and new surgical techniques. Among these, the field of "biological therapies" has developed particularly rapidly and is now a mature clinical practice in some specialized centers in Italy. This includes "maggot therapy," which utilizes fly larvae that feed on necrotic or infected tissue without damaging healthy tissue; furthermore, they release antibacterial substances that promote wound healing.

[0020] All the devices described above attempt to distribute the patient’s weight evenly across the body surface in various ways, thereby reducing pressure between bony prominences and corresponding soft tissues, and by applying pressure alternately, they attempt to optimize the recommendations made by an Italian physician more than a century ago.

[0021] Therefore, the idea today (and for over a century) is (and always has been) not to apply continuous pressure to certain parts of a patient's body for extended periods.

[0022] Significant progress has been made in the treatment of pressure ulcers, thereby improving patients' quality of life.

[0023] Unfortunately, little has changed to date. In fact, the Healthcare Policy and Research Agency (AHCPR), after reviewing more than 300 texts, 45,000 reports, and 1,700 documents, concluded that the scientific evidence has not substantially changed since the guidelines were published in 1992.

[0024] In fact, to date, there is no device, or even any scientific method, that can prevent bedsores or cure them by reversing them until they disappear.

[0025] Problems to be solved

[0026] Pressure ulcers are caused by the pressure of a patient's own weight on the capillaries when the patient is lying in bed. The surface the patient lies on compresses the capillaries in the soft tissue between bony prominences and the supporting surface, thus hindering the normal flow of arterial blood, preventing cells from receiving enough nutrients, and ultimately leading to pressure ulcers.

[0027] Therefore, to avoid injury, the patient should be suspended in the air with no solid support below, so that the patient's own weight would not block the capillaries... but this is simply impossible. Attached Figure Description

[0028] These accompanying figures and diagrams schematically illustrate the following:

[0029] Figure 1 The device on the mattress consists of pipe 2, fluid distribution manifold 3, both placed on the mattress 1, and box 4 containing all control elements. The orthogonal cross-section of the device is indicated by the symbol ZZ.

[0030] Figure 2 The various pipes are arranged in an alternating pattern, belonging to different groups. The first number 2 indicates a general-purpose pipe. Figure 1 The second number 1 (or 2, or 3) indicates the group to which they belong, and the third number 1 (followed by 2-3-4-5) indicates the incremental number of the pipes belonging to the same group.

[0031] The accompanying drawing schematically illustrates the arrangement of the collector pipes (31-32-33) for distributing fluid within the pipes that make up the mattress.

[0032] Figure 3 The first stage of the cycle [the case of a device consisting of 3 sets of pipes, cross-sectional view ZZ ( Figure 1[ ], where 1a and 2a represent the first and second groups of pressurized pipelines respectively, 3a represents the third group of depressurized pipelines; a represents the pressurized pipeline, b represents the depressurized pipeline; g represents the sheath containing the pipeline.

[0033] Figure 4 The second phase of the cycle, in which group 1a is depressurized, while groups 2a and 3a are pressurized;

[0034] Figure 5 The third phase of the cycle, in which groups 1a and 3a are pressurized, while group 2a is depressurized;

[0035] Figure 6 The diagram illustrates the states of two capillaries 7: one type is "compressed" due to the combined effects of body pressure 5 and the pressure 6 of the pressurized pipe a; the other type is "free" due to body pressure 5 alone. The diagram also shows the distance d between the mattress and the surface c, and the distance e between the two unconnected pressurized pipes a. It should be noted that the dimensions of the capillaries in the diagram are not proportional to the dimensions of other components.

[0036] Figure 7 , Figure 8 , Figure 9 The "heel" is located at a diameter of 16mm. Figure 7 [a'], 20mm Figure 8 [a''] and 40mm [ Figure 9 The state when above the pipe in [a'''].

[0037] The reference numerals used in this specification

[0038] In the following text, we will use the following method to represent:

[0039] •BS: Bedsores (Italian version: LdD);

[0040] •1:[ Figure 1 ]Mattress;

[0041] •2:[ Figure 1 A mattress made of pipes;

[0042] • n: The number of tubing groups that make up the mattress;

[0043] •Φ: Diameter of the pipe [ Figure 6 ];

[0044] •a:[ Figure 6 Pressurized pipeline;

[0045] •b:[ Figure 6 Zero internal pressure piping;

[0046] •c:[ Figure 6 The boundary line of the epidermis;

[0047] •d:[ Figure 6 The distance between the skin c and the mattress 1;

[0048] •e:[ Figure 6 The distance between two discontinuous pressurized pipes a;

[0049] •σ P :[exist Figure 6 The pressure, represented as 5, is evenly distributed on the patient and originates from the patient's own body weight.

[0050] •τ:[in Figure 6 The pressure value of the pipeline is represented as shown in Figure 6.

[0051] •7:[ Figure 6 [Under pressure σ] P The location of capillaries that work in conjunction with pressure τ is defined as "compressed capillaries".

[0052] •8:[ Figure 6 [Only affected by the pressure σ of the patient's own body weight] P The location of the capillaries that act is defined as "free".

[0053] •ψ=σ P +τ: Pressure on capillaries [pressure σ] P The sum of pressure τ is due to the combined effect of the patient's own body weight and the pressure caused by the device.

[0054] •ψ R =kψ: The value is passed from ψ to the free capillaries at position 8, which are only subjected to pressure σ. P Its function;

[0055] •k: Reduction factor;

[0056] •t ψ The time for applying pressure ψ is equal to the time for applying pressure τ t. τ [Same], in one phase of the cycle;

[0057] •T cycle The duration of the entire operation cycle;

[0058] •β: Under normal conditions, i.e. when the device is not in use, the pressure of the compressed capillaries between the bony prominence and the underlying mattress.

[0059] •β R =70%β: When the patient is under the influence of this device, they are in position 8 [ Figure 6The residual blockage pressure on the "free" capillaries;

[0060] •ta:[ Figure 7 Average width of the heel;

[0061] •λ=[(n-1) xt ψ [ ]: The total pressurization time of a single set of pipelines within a complete operating cycle of the device.

[0062] The "principles" behind the invention

[0063] Unfortunately, "no other preventive and therapeutic measures are useful without eliminating local pressure" [Beltracchi V., Calosso A., Marieschi M., AISLe.C., 1996]: Therefore, patients should be elevated to cure or prevent pressure sores.

[0064] To solve this problem, imagine a river branching into three directions, distributing the water flow in those three directions. If you imagine closing two of the branches, then the total flow of the river will inevitably flow through the remaining, unclosed branch.

[0065] If you further consider the presence of an obstacle in the only open branch, then the water flow can only overcome the obstacle if it has sufficient force; otherwise, the water flow will also be obstructed in the only open branch.

[0066] Returning to the issue of pressure ulcers, if by applying various techniques we can obstruct arterial blood flow in certain capillaries (defined as "compressed"), thereby forcing the same amount of blood flow (obstructed in the compressed capillaries) to the pressure ulcer at location 8 [ Figure 6 [Blood is supplied to it at the same time, so the capillaries are "free"... as long as the arterial blood flow has enough thrust to overcome the residual obstruction pressure β] R We have solved the problem by addressing the obstacles that they represent.

[0067] The practical effects of the invention

[0068] To achieve positive results, we envisioned a mattress [ Figure 1 It consists of a set of soft, flexible tubes that can periodically pressurize and depressurize, thus stimulating bedsores on the patient's skin that come into contact with the device.

[0069] Therefore, it is necessary to determine the pressurization pressure τ of the pipeline, which is related to the body pressure σ. P Together they constitute the pressure ψ=(τ+σ) PThis pressure is sufficient to block blood flow in some capillaries, forcing the blocked blood flow to flow into capillaries that are not affected by pressure ψ but only by body pressure σ. P The capillaries that act. Since the device operates periodically, it is clear that when the pressure ulcer is in position 8 […]. Figure 6 During the process, the affected capillaries will receive more arterial blood flow, and this arterial blood and the nutrients it contains will be able to overcome the obstructive effect of bedsores.

[0070] Next, we examine different values ​​and find that:

[0071] 1. The pressure ψ applied to the capillary to be compressed at location 7 must be assessed to avoid triggering new pressure sores due to excessive pressure ψ;

[0072] 2. The application time t of the aforementioned pressure ψ must be evaluated. ψ The emergence of new bedsores also depends on the duration of pressure application;

[0073] 3. Because the conduits constituting the device follow pressurization and depressurization cycles, capillaries flowing into pressure ulcers in contact with the device will periodically appear at positions 7 and 8, which are... Figure 6 All of them have been highlighted in the text;

[0074] 4. Pressure ulcers are caused by obstructive pressure β, which is assessed in the range of 120 to 170 mmHg [Redfern S. et al., "Ten Types of Local Pressure in Patient Support Systems," *The Lancet*, 1973] and [Molinelli S., "Pressure Ulcers," 2007]. We use β... R This indicates that when these blocked capillaries (present in bedsores) are opened from position 7 due to the action of our device... Figure 6 Arrival at location 8 Figure 6 At the same time, the residual obstructive pressure generated in the same blocked capillaries, that is, when they are only subjected to body pressure σ P When there is no contact with the mattress underneath;

[0075] 5. Similarly, the residual value ψ of the pressure ψ must be evaluated. R The residual value ψ R From the capillaries that were intentionally blocked by the device [in Figure 6 [Location 7] transmits blood to the arterial blood flow, when the capillaries are located Figure 6 At position 8, arterial blood flow will pass through the blocked (but "free") capillaries inside the bedsore;

[0076] 6. Once β is obtained R and ψ R The values ​​need to be verified to be:

[0077] ψ R >β R

[0078] Otherwise, the function of the pressurization pipeline would be completely irrelevant.

[0079] Based on these premises, we consider transforming the above theoretical reasoning into a medical device.

[0080] Testing a historical hypothesis and its effects

[0081] The assumptions discussed here are as follows:

[0082] "Pressure sores can be caused by applying 32 mmHg of pressure to the same body part for more than 2 hours." [Landy, 1930]

[0083] We know that the blood pressure in capillaries is 32 mmHg. Therefore, it is understandable that even if the external pressure is only 32 mmHg, it will still have a negative impact on blood flow in capillaries after a period of time (because tissue hypoperfusion can only be tolerated for a short period of time (AISLe.C. 1996)).

[0084] Therefore, when the threshold determined by the product of pressure and duration is exceeded, we call it the "total pressure Q". pt When the value of “” equals the following formula, bedsores will inevitably occur.

[0085]

[0086] in:

[0087] •P is the reference pressure, set to 32 mmHg;

[0088] •T is the expected maximum application time of the pressure P.

[0089] Equals 2 hours, expressed in minutes;

[0090] •Q pt It is the total pressure P that the skin experiences throughout the entire period during which the pressure P is applied;

[0091] • 3,840 mmHg is the total pressure transmitted in one minute;

[0092] Exceeding the specified value means that the appearance of new bedsores can be confirmed and will be approved.

[0093] The above formula is strictly empirical, and therefore is declared "not applicable": in reality, a pressure of 3840 mmHg is unbearable for humans, and it is unrealistic to say that capillaries will develop new bedsores after one minute of malnutrition. However, this equation is crucial for subsequent development.

[0094] The following inequality serves as a theoretical upper limit, thereby preventing the development of new bedsores.

[0095]

[0096] in

[0097] •τ is the pressure in the pressurized pipeline;

[0098] •σ p The pressure is determined by the patient's own body weight and is evenly distributed across the body area affected by bedsores;

[0099] •λ is the pressure ψ=(τ+σ) applied by a set of pressurized pipes during a complete operating cycle of the device. P The duration of action of )

[0100] This applies pressure ψ=(τ+σ) P The relationship between the pressure and its duration λ indicates the maximum pressure that each individual pressurized pipeline group must not exceed during each complete operating cycle. Summary of the Invention

[0101] In order to achieve the expected results described in the chapter "The Principles Behind the Invention," we created a mattress [ Figure 1 It consists of “n” groups of soft, flexible tubes arranged adjacent to each other along the length of the mattress, thus forming a single, continuous surface that completely covers the underlying mattress.

[0102] The pipes are then inserted into a fireproof sleeve, which is washable and sterilized at 90°C to ensure hygiene. The pipe diameter ranges from 20mm to 40mm (we will explain the reasons for these measures later), but all pipes in the same installation are the same size.

[0103] In addition to the mattress itself, there is a padding layer made of tubing with the same diameter as the mattress tubing, arranged along the width of the mattress and thus at a 90° angle to the direction of the tubing that makes up the mattress. This padding tubing will also be encased in a sheath for hygiene and connected to the fluid distribution system via small silicone tubes connected by necessary connectors.

[0104] The periodic pressurization of the pipelines will be achieved by a compressor that pushes the fluid (liquid or gas) into a distribution system that connects all the pipelines. Figure 2 ] .

[0105] The system will be managed by an electronic board that controls various pressurization and depressurization actions through special solenoid valves; the maximum pressure value τ of the pipeline will be controlled by a pressure switch (which will check whether the pressure exceeds the preset value) and visually monitored by a pressure gauge.

[0106] All pipelines will be divided into several groups, so that at any given time, only one group is under depressurization, while all other groups are under pressurization.

[0107] Figure 3 , Figure 4 and Figure 5 The pressurization phase of a cycle process is highlighted:

[0108] 1) In Figure 3 In the stages shown, the first and second groups are pressurized, while the third group is depressurized;

[0109] 2) Similarly, in Figure 4 In the experiment, the second and third groups were pressurized, while the first group was depressurized;

[0110] 3) Finally, in Figure 5 In the experiment, the first and third groups were pressurized, while the second group was depressurized;

[0111] Therefore, it can be inferred that the duration of pressure ψ within a cycle (consisting of 3 stages, corresponding to the number of pipe groups) is equal to twice the duration of each stage.

[0112] Use t ψ If we define the duration of a certain stage in the cycle, then the duration of the complete operating cycle of the device formed by n sets of pipes is:

[0113]

[0114] The actual duration of the pressure exerted by ψ on the capillaries [located at positions corresponding to a set of channels] throughout the entire operating cycle is...

[0115]

[0116] To assess the patient's physical stress σ P We must use the BSA (Body Surface Area) formula [Dubois D., Dubois EF, Arch. Intern. Med. 1916], which calculates the patient's body surface area based on the patient's height and weight. The specific formula is as follows.

[0117]

[0118] in:

[0119] 1. "h" represents height, measured in centimeters;

[0120] 2. “p” represents weight, measured in kilograms;

[0121] 3. Results are expressed in square meters.

[0122] Therefore, by knowing the body surface area and dividing it by 2, we can obtain the dorsal surface area of ​​the patient when supine on the mattress, and thus determine the uniformly distributed σ that the affected capillaries (when the patient is supine) will experience. P pressure:

[0123]

[0124] [ Figure 6 The number 5 in the middle represents pressure.

[0125] The above content aims to emphasize that not only a patient's weight, but also their height, can affect the even distribution of pressure caused by their own weight.

[0126] However, it is noteworthy that the average pressure on the compressed tissue (and capillaries) between the bony prominence and the underlying supporting surface is between 120 and 170 mmHg [Redfern S. et al., The Lancet, 1973, “Ten Local Pressures in Patient Support Systems”]; while other literature [Molinelli S., Bedsores, 2007] indicates that the maximum pressure on the sacrum in the supine position is 150 mmHg.

[0127] The average value reported by “Redfern” is not significantly different from the value indicated by “Molinelli”, so we will use the latter value as the basis and reference for future development.

[0128] Let's now look at how our device should work when treating bedsores on the pelvis.

[0129] First, we determined the occlusion pressure of the capillaries in the pelvic cavity to be β = 150 mmHg.

[0130] Now let's continue evaluating the other values ​​we need, namely σ. P , τ, ψ, β R ψ R , tψ, and the diameter Φ of the pipe to be used.

[0131] To assess σ, which is uniformly distributed across the pelvis PWe must apply the "Rule of 9" (proposed by Wallace in The Lancet in 1951), which is used for burn patients, to determine the burn area. As can be seen from the table, the pelvis accounts for 18% of the total body surface area (half anteriorly and half posteriorly), while the pelvis itself accounts for only 1%.

[0132] Therefore, 9% of the body surface area represents the entire posterior pelvic region. However, within this complete body surface area, a portion (equivalent to the area of ​​the buttocks, which accounts for 2.5%) directly contacts the mattress. Therefore, the actual surface area of ​​contact between the pelvis and the mattress is...

[0133] The pelvis accounts for 5% of the body surface area.

[0134] Similarly, the "rule of 9" is also used to assess the "weight" of various parts of the body. Specifically, the pelvis accounts for 18% of a patient's total weight, therefore the pressure σ evenly distributed on the pelvis is... P Determined by the patient's predicted value, as follows:

[0135]

[0136] σ can be easily obtained from this. P The value is the local pressure exerted by the patient's body weight on the contact surface between the pelvis and the mattress.

[0137] Now we need to find out when the patient is lying on the device and the pressure ulcer is located in "two pressure tubes [ Figure 6 The residual blocking pressure β generated in the region e between but not adjacent to each other [a] R The value of [value missing]. Clearly, in this position, since there is no pressure difference with the mattress below, the obstructive pressure will be lower than the pressure of a pressure ulcer when the patient's own weight is compressed between the pressure difference and the mattress. Theoretically, since we are in a suspended state, the pressure should disappear. But in reality, this is impossible.

[0138] At the same time, it's important to consider the fact that the diameter of the tubing (which will never exceed 40mm, the reason for which we'll explain later) helps prevent contact with the mattress underneath due to its small size. However, on the other hand, the two discontinuous pressurized tubing acts like a group of people pulling a sheet tight to support another person falling from a height, thus the surface will take on a shape similar to the letter C. Figure 6 ] .

[0139] It is known that a pressure of 750 mmHg must be applied to dilate the aorta by 30 mm [E. Piaggio Interdisciplinary Research Center, Faculty of Engineering, University of Pisa].

[0140] In this case, the part of the skin located between two unconnected pressurization pipes and not in contact with the mattress below is:

[0141] 1- Only subject to physical stress; on average, this stress will never exceed 10 mmHg.

[0142] 2- The skin's deformability is much greater than that of the aorta. Considering that the empirical ratio between the stiffness of the aorta and the skin is 1:5, we should apply a pressure of 150 mmHg [=750 mmHg divided by 5] to the skin surface to obtain the same deviation as the 30 mm recorded for the aorta. This deviation will cause the patient to come into contact with the mattress underneath.

[0143] 3- To obtain a uniformly distributed pressure of 150 mmHg, we would need a patient weighing 225 kg but with a body surface area of ​​less than 1.50 square meters, which is clearly outside the normal range!

[0144] The patient's skin portion located between two pressurized but unconnected tubes is in a state of "temporary micro-suspension" because this portion never comes into contact with the mattress underneath. However, on the other hand, due to the action of the two lateral pressurized tubes, the skin is in a state of tension, which is similar to (albeit dynamically, but always) contact with the mattress underneath.

[0145] Therefore, the residual blocking pressure β R It cannot be zero as it would be in actual suspension, but it will certainly be lower than the value of the blocking pressure β.

[0146] Since the pressure drop caused by the development of pressure ulcers cannot be assessed, we consider pressure β R It is equal to 60%~70% of the initial value β of the blocking pressure, therefore we choose the following equation:

[0147]

[0148] In reality, this value will fluctuate between 90 and 105 mmHg, and we choose to use the following values:

[0149]

[0150] Now we must discover what can counteract the residual blocking pressure β. R The combined pressure ψ value enables arterial blood flow to provide the necessary nutrition to the capillaries present in the pressure ulcer, thereby overcoming the pressure ulcer.

[0151] Figure 6 The capillaries at the location indicated by reference numeral 7 in the attached diagram will be subjected to a combined pressure ψ under the action of the device. This will hinder the normal flow of arterial blood. Therefore, this obstructed flow must find another path, and this path can only be... Figure 6The region e, indicated by reference numeral 8 in the attached figure, is occupied by capillaries at a location we define as "free" capillaries [i.e., unaffected by pressure τ and contact with the mattress, and therefore only subject to pressure σ under quasi-suspension conditions]. P [The role of]

[0152] Therefore, the flow direction is located at position 8 [ Figure 6 Arterial blood flow in the capillaries will be lower at a pressure lower than that at location 7 due to the natural pressure drop. Figure 6 The pressure in the capillaries.

[0153] We will use the residual pressure ψ R The evaluation is equal to:

[0154]

[0155] Here, we use "k" to represent the reduction factor, which we estimate to be equal to

[0156]

[0157] Where Φ represents the diameter of the pipe, in mm.

[0158] Since we consider the occlusion pressure in the capillaries (which are part of the previously "pressurized" but now "free" bedsores) to be equal to β R = 100mmHg, pressure ψ R The value must be greater than this for nutrients to return to the bedsores [let's recall the example of a river: even if there's an obstacle in the only open tributary and the water pressure is insurmountable, the river must find other paths to reach all the tributaries]. To ensure the device functions effectively, we assess this increase as 50%, thus we obtain the following inequality.

[0159]

[0160] From this, the value of the pressurization pressure τ of the pipeline can be obtained.

[0161]

[0162] Now we need to assess the pipe dimensions. We'll use an average heel size of 45mm as a reference. This reference value is very important; in fact, observing... Figure 7 and Figure 8 It can be seen that a pipe with a diameter of 20mm can effectively separate the foot and foot, thus enabling the device to operate efficiently. And... Figure 9 The display showed that a 40mm diameter pipe almost completely occupied the space at the heel, causing the device to malfunction. Therefore, we concluded that the maximum pipe diameter suitable for our device should not exceed 40mm.

[0163] Similarly, the minimum diameter of the pipe must not be less than 20mm; otherwise, both sizes d and e... Figure 6 The size will be very small, thus limiting the expansion of the "free" capillaries 8, which contradicts the function of the device.

[0164] Of course, the device can function even when using pipes with a diameter greater than 40mm, but it cannot intervene in lesions of the heel and elbow.

[0165] For daily use, it is recommended to use pipes with an outer diameter of 30mm.

[0166] Now evaluate the time of a certain phase of the combined pressure application period ψ [time equal to the pressure τ], see expression (1) on page 11.

[0167] Q pt = P x T = 3,840mmHg x 1'.

[0168] Let's consider a device consisting of "n" sets of pipes, which are always pressurized at all times, with only one set (not always the same set) at zero pressure. Figure 3 , Figure 4 , Figure 5 ] .

[0169] Therefore, it is necessary to evaluate the pressure delivered to the patient by the device through its pressurization tubing and compare it with the maximum permissible pressure Q. pt Compare them.

[0170] During one operating cycle, the pressure value that each individual set of pipes in this device will withstand will be:

[0171]

[0172] Where ψ = τ + σ P ,

[0173] Period T cycle = nxt τ ,

[0174] Where n = the number of pipe groups that make up the device.

[0175] Where t = the duration of the pressurization phase,

[0176] Based on the above description, it must be

[0177]

[0178] Therefore, it is easy to obtain the duration value t of each stage of pressurizing the pipeline.τ (with t) ψ (The values ​​are the same).

[0179]

[0180] Given that Dr. Cucinotta D. suggested in her 1995 publications, "The Pathophysiology of Pressure Ulcers" and "Key Aspects of Geriatric Care," that the formation of pressure ulcers depends not only on pressure but also on the combined effects of other factors, we consider making necessary modifications to the above expression (1), reducing its maximum value, and relating it to the clinical condition of the patient as described below:

[0181] -For body surface area >1.50m² 2 The number of patients decreased by 70%.

[0182] Q 0 pt = 30% Q pt ≤ (0.3 x 3,840) = 1,152mmHg x 1';

[0183] -For body surface area ≤1.50m² 2 For patients who are extremely weak, it is necessary to further reduce total stress, by up to 80%, which will result in:

[0184] Q 0 pt = 20% Q pt ≤ (0.2 x 3,840) = 768mmHg x 1'

[0185] Therefore, in summary, these potential inequalities must be considered in practical applications:

[0186] (17) Has a body surface area > 1.50 m² 2 → Q 0 pt ≤ 1,150 mmHg x 1 minute

[0187] (18) Has a body surface area > 1.50 m² 2 → Q 00 pt ≤ 770mmHg x 1 minute

[0188] It should be noted that as the number of pipe groups increases, under the same pressure ψ and the same cycle time (T), cycleUnder pressure, and after deducting the natural pressure drop, more arterial blood will flow through the area containing the capillaries (the area corresponding to the unpressurized tubing). In fact, when the number of tubing groups is 3, the ratio of arterial blood flowing through the area containing the unpressurized tubing is 2:1, because the "blocked" arterial blood (i.e., the blood flowing through this area) comes from twice the surface area; when the number of tubing groups is 4, this ratio becomes 3:1, and so on, increasing with the number of groups. The advantage of increasing the number of tubing groups is obvious, because by increasing the amount of arterial blood forced to flow through the capillaries of the pressure ulcer, more nutrients can be provided, thus accelerating the healing process; however, this does not preclude the possibility of using the device with only 2 tubing groups. The device can still function even if only one component is pressurized and the other is not.

[0189] Finally, it must be remembered that “prolonged application of low pressure is more harmful than short-term application of high pressure,” a finding confirmed by Dr. Zanetti [Zanetti E. Pathophysiology of Pressure Ulcers, 1996].

[0190] The last point must be carefully considered, because formulas (17) and (18) provide us with two interrelated data points, namely pressure and duration of action, so the operator can assess whether to increase pressure and sacrifice duration of action based on the patient’s general condition, or vice versa, always adhering to the maximum values ​​indicated by inequalities (17) and (18).

[0191] Now let's look at the minimum pressure required for the pipe to function properly.

[0192] As can be seen from [Redfern S. et al., “Local pressures in ten patient support systems,” The Lancet, 1973, p. 10], the Δ value of blood pressure is between 120 and 170 mmHg.

[0193] Therefore, without our device, when the minimum occlusion pressure acting on the compressed capillaries between the bony prominence and the underlying mattress is 120 mmHg, the device is in position 8 [ Figure 6 The situation will then become:

[0194] β R =70% × 120mmHg = 84mmHg

[0195] Therefore, the pressure ψ that can overcome this obstacle R It must have the following values:

[0196] ψ R = (84mmHg x 1.5) = 126mmHg.

[0197] This value demonstrates the undeniable fact that, due to the microsuspension effect, the pressure applied to the tubing is far lower (and therefore more acceptable to patients) than the pressure required to overcome pressure ulcers without using our device.

[0198] This is pressure ψ R This is a minimum pressure level that must be reached before the device can begin delivering nutrients to less invasive lesions. Below this level, no effective results can be obtained; lower pressure is completely meaningless for the eventual healing of pressure ulcers.

[0199] Therefore, in summary, we can write down the pressure value ψ that the device must provide. R Relative to residual blocking pressure β R The following inequality must always be satisfied:

[0200]

[0201] This is the residual composite pressure ψ R The necessary conditions must be met to ensure that the blocked capillaries in the bedsores can receive the necessary nutrients, thereby eradicating the bedsores; lower pressure will be completely irrelevant.

[0202] In summary, based on the patient's weight and height, and the expression above, we are confident that arterial blood can counteract the obstructive pressure β by providing all the nutrients to the pressure ulcer. R This allows the bedsores to regress until they disappear completely.

[0203] To achieve this goal, the device must simultaneously meet the following four conditions:

[0204] First condition:

[0205] The values ​​indicated by the following two inequalities must be obeyed.

[0206] (17) Has a body surface area > 1.50 m² 2 → Q 0 pt ≤ 1,150 mmHg x 1 minute

[0207] (18) Has a body surface area > 1.50 m² 2 → Q 00 pt ≤ 770mmHg x 1 minute

[0208] The second condition:

[0209] This inequality must be verified.

[0210]

[0211] The third condition:

[0212] The pipes constituting this device must have a diameter Φ between

[0213] (20) 20 mm ≤ Φ ≤ 20 mm

[0214] The fourth condition:

[0215] The piping constituting this device preferably consists of a group of no fewer than three pipes, therefore

[0216] (21) Quantity ≥ 3 groups

[0217] In fact:

[0218] -As long as the "first condition" is met, we can be certain that no new bedsores will appear;

[0219] -As long as the "second condition" is met, we can ensure that the device can deliver arterial blood at the correct pressure, thereby overcoming the residual pressure β maintained on the pressure ulcer. R ;

[0220] -As long as the "third condition" is met, we can ensure that the device functions properly because:

[0221] 1) When the diameter is greater than 40mm, the epidermis (especially in the elderly and frail) will come into contact with the mattress, thereby counteracting the microsuspension effect and failing to affect bedsores present on the heels and elbows;

[0222] 2) When the diameter is less than 20mm, the two dimensions d and e [ Figure 6 Too small for "free" capillaries to be visible. Figure 6 It is difficult to expand, thus affecting the function of the device;

[0223] -As long as the "fourth condition" is met, we can ensure that the device can deliver a sufficient amount of arterial blood to provide the necessary adequate nutrition for pressure ulcers.

[0224] Of course, the device must always be supported by all care and clinical measures aimed at keeping pressure ulcers clean and free from suppuration. Detailed Implementation

[0225] In one exemplary embodiment of the invention, regarding the device on the mattress, it is assumed that a pipe with an outer diameter of 30 mm is used.

[0226] Therefore, 30-gauge tubing is needed to cover the entire width of the mattress; each tubing must be 180 cm long, thus allowing collector 3 [ Figure 1 There is space to place it under the padding layer.

[0227] First, the type of fluid to be used for pressurizing the pipeline needs to be determined. Air is preferable to liquid fluids because it offers the following advantages:

[0228] a) In a hospital rehabilitation department, it is impossible to use liquids through tubing;

[0229] b) It is lighter than a liquid (and therefore easier to handle);

[0230] c) No container is needed to receive the fluid during the decompression phase; air can be released into the environment.

[0231] d) Air can be heated like a liquid.

[0232] All equipment required for the operation of the unit, such as the compressor, pressure switch, pressure gauge (visible from the outside of the container), electronic control panel for all operations, electrical safety switch, and all other components required for the normal operation of the unit, will be placed in container 4 located at the end of the bed. Figure 1 ]Inside.

[0233] To heat the fluid, a cylindrical heater must be inserted into each set of pipes while keeping the heater temperature below 20°C; excessively high temperatures can cause oozing, which can lead to skin maceration.

[0234] However, if the device is used in the intensive care unit and the patient also has hypothermia, the heater must be able to reach a temperature of 40°C; the combined effect of the warming blanket and the heating device will help overcome this problem.

[0235] The piping assemblies on the mattress pad will connect to the piping on the mattress via standard quick-connect fittings; these piping assemblies will also be controlled by a device located in a container at the foot of the bed.

[0236] Based on the above and the current situation, there should be no major obstacles for those skilled in the art to manufacture this device (including the command and control system).

[0237] How to calculate the value attributed to the device based on the patient's characteristics?

[0238] 1) On the mattress

[0239] Let us consider a patient who is 165cm tall, weighs 62kg, and has 3 sets of tubes with a diameter of Φ30mm: Therefore, using formula (5), we can calculate his body surface area as 1.68m². 2 .

[0240] Therefore, we will use expressions

[0241] (17) Q 0 pt ≤ 1,150 mmHg x 1 minute

[0242] Assuming the pressure ulcer is located in the pelvic region, then, according to the "Nine" formula, the pressure σ evenly distributed on the pelvis... P for:

[0243]

[0244] The coefficient k of expression (10)

[0245] k = (1 - 0.2%Φ) = 0.94

[0246] And it was decided to assume that the bedsore was in position 8 [ Figure 6 At that time, the residual pressure on the pelvis is equal to

[0247] β R When = 100mmHg, we will have

[0248] ψ R = 0.94 ψ = 1.5β R =150 mmHg, from which we obtain

[0249] ψ = 159.57 mmHg

[0250] Therefore, we can calculate the pressure increase τ in the pipeline:

[0251] Τ = ψ - σ P =(159.57 - 9.78)=149.79mmHg

[0252] It needs to be applied for a period of time [using expressions (15) and (16)].

[0253]

[0254] From expression (3), we can obtain:

[0255]

[0256] Therefore, we have derived the pressure increase value that should be applied to the pipeline.

[0257] τ = 150mmHg

[0258] and its application time

[0259] t τ =3'36" (3 minutes and 36 seconds).

[0260] Therefore, we have derived all the elements required for the device to function properly.

[0261] 2) Subbase

[0262] Based on the same "rule of 9," we know that the surface area of ​​the head and neck accounts for 9% of the human body's surface area. Therefore, we assume that the head surface area in contact with the padding accounts for 3% of the human body's surface area (calculated using the body surface area method). In this case, the head surface area in contact with our device will be:

[0263] ;

[0264] Similarly, the head and neck account for 9% of body weight, that is:

[0265] ;

[0266] Therefore, due to the patient's own body weight, the local pressure acting on the capillaries affected by the head is evenly distributed as follows:

[0267]

[0268] This value is not significantly different from the value found on the hip, so a single previously calculated pressure τ value is applied to the device, and the tubing on the pad will work in the same way as the tubing on the mattress.

[0269] From the calculations highlighted above, we can derive the pressure value τ and its duration t applied to the mattress and padding for any patient. τ They are actually the same.

[0270] As can be seen from the above description, the device is easily adaptable to any type of patient and any type of lesion: the micro-suspension of small parts of the body is continuous and can substantially affect the entire body surface in contact with the tube that replaces the mattress; in fact, continuous micro-suspension means that arterial blood flow will not stop periodically supplying the entire body surface affected by the device.

[0271] Industrialization of the device

[0272] The industrialization of the device involved in this patent application is objectively necessary because, to date, there is no treatment for pressure ulcers that can reverse them and prevent their recurrence. It is well known that due to advancements in medical technology, the world's population is living longer, but this has led to an increasing number of people suffering from pressure ulcers. In reality, pressure ulcers typically only occur in the elderly, with only a small number of young people unable to move independently due to trauma. Therefore, the number of pressure ulcer sufferers worldwide is enormous, and we currently cannot imagine the industrial production of a single device capable of reversing pressure ulcers and preventing their recurrence.

[0273] In Italy alone, according to statistics from the 2010s, approximately 2 million people suffer from bedsores, and that number is increasing by about 8% every year.

[0274] The industrialization of this device can be achieved through the following methods:

[0275] - Molds can provide all the tubing needed for mattresses and padding in one go;

[0276] - A mold will also be used to integrally shape the fluid distribution manifold;

[0277] - All other components are readily available on the market and are in continuous production, so there are no obstacles to manufacturing a container box containing all the components needed for the device to operate.

[0278] The difference between our device and other devices

[0279] Currently, all anti-bedsore products on the market determine their "ratios" based on the following three basic principles:

[0280] 1. Distribute the patient's weight across as many body surfaces as possible, avoiding key stress points such as the shoulder blades and hips;

[0281] 2. Avoid keeping one part of the patient's body in the same position for more than two hours;

[0282] 3. Massage, which involves applying alternating pressure, aims to increase blood flow to the patient, thereby providing blood supply to pressure ulcers.

[0283] However, due to the component dimensions of existing devices (pipe or fan-shaped devices) being much larger than the 40mm limitation, the patient remains in constant contact with the support surface. Furthermore, since the pressure that existing devices can apply is almost always below the value shown in expression (19), these systems are ineffective in preventing and treating pressure ulcers. Taking a river with two closed tributaries and one open tributary as an example, we argue that, in order to achieve a positive therapeutic effect, the only open tributary (which is still blocked) must be subjected to pressure ψ R Not lower than the blocking pressure β R A water flow 1.5 times greater: To date, no one has assessed this "necessary condition," so a positive therapeutic effect will never be achieved.

[0284] Furthermore (as stated on page 5), the Agency for Health Care Policy and Research (AHCPR), after reviewing more than 300 texts, 45,000 reports, and 1,700 documents, concluded that "the scientific evidence to date has not changed substantially since the guidelines were published in 1992."

[0285] The "principle" in this study differs from all other results for the following reasons:

[0286] - The devices currently known do not take into account our "inequalities (17) and (18)" (used to estimate pressure and delivery time), which may lead to the creation of additional pressure ulcers instead of treating existing ones;

[0287] - None of the currently known devices mention a "body surface area" value, which is crucial for characterizing patient features (other devices assume all patients have the same body size). Therefore, research must use this as a basis to calculate individualized values ​​applicable to each patient: In fact, a patient weighing 40kg, 150cm tall, and with a body surface area of ​​1.29m²... 2 For patients with a body weight of 100kg, height of 180cm, and a body surface area of ​​2.23m², the buttocks will experience a uniformly distributed pressure of 8.16mmHg; while for patients with a body weight of 100kg, height of 180cm, and a body surface area of ​​2.23m², the buttocks will experience a uniformly distributed pressure of 8.16mmHg; 2 For a patient with a body surface area of ​​1 square meter, the buttocks will be subjected to a pressure of 11.67 mmHg. Therefore, the tubing pressure value will vary, but more importantly, according to our formulas (17) and (18), the “maximum pressure value” assigned to the device tubing group will vary according to the patient’s body surface area;

[0288] Most devices are unable to intervene in pressure sores in the heel and elbow areas because they can never separate these sores; and some devices that currently have tubes or fan-shaped areas that can separate the heel and elbow areas are also unable to intervene actively due to the low pressure efficiency they use.

[0289] Finally, a substantial difference is that there is currently no known device capable of operating at position 7 [ Figure 6 The capillaries are subjected to "deliberately applied pressure" [calculated based on the patient's own body surface area]. Under the pressure of the patient's own weight and the compression of the pressure tubes, which are designed to obstruct normal arterial blood flow, the same obstructed blood flow is forced to supply the pressure ulcer. In fact, in order for arterial blood flow to be able to... R Through the letter e [ Figure 6 The space shown in the figure thus counteracts the residual blocking pressure β. R (Residual pressure due to micro-suspension) requires finding the value of the pressure τ applied to the pipe, which can be done using our expression (13);

[0290] -Because the pressure changes are periodic, the pressure ulcer will be transported by arterial blood flow as long as it is in contact with the device, regardless of its location;

[0291] - No known device has anticipated reducing obstructive pressure to promote arterial blood supply to pressure ulcers, while our invention achieves this by using local "micro-suspension" that extends to the entire body surface in contact with the device during the operating cycle;

[0292] - No known device takes into account that pressure ulcers caused by "minimum" occlusion pressure (estimated and generally accepted effective value of 120 mmHg) must receive arterial blood flow at pressures much higher than 120 mmHg to be treated, and almost no device can achieve this value.

[0293] - Currently known devices treat patients in a standardized manner, and any differences are inferred from the operator's experience. Our device, however, provides "precise instructions that must be taken into account each patient's physical and clinical condition": these instructions enable cure, prevention, and relapse prevention by respecting and assessing the characteristic clinical condition of the patient receiving treatment.

[0294] Having tested and confirmed that multiple treatment and prevention options for bedsores are unrelated to our “discovery,” we are convinced that our “discovery” is unique and will certainly contribute to further scientific research to eradicate bedsores.

[0295] Advantages of this device

[0296] As stated above, this discovery undoubtedly helps improve patients' quality of life because it eliminates persistent (24-hour) pain caused by necrosis by reversing necrotic and regenerating tissue; in addition, continuous massage can improve blood circulation, benefiting patients as a whole.

[0297] To more carefully evaluate the advantages of this device, this article reports data presented at the CORTE National Congress (the Italian Conference on Ulcers, Sores, Wounds and Tissue Repair Research held in Rome in 2014), which highlights what the appearance of pressure ulcers means:

[0298] a) It increased the number of patients in the hospital tenfold;

[0299] b) It increases the risk of death fourfold;

[0300] c) The recurrence rate is not less than 70%;

[0301] d) It causes permanent disability in 30% of cases.

[0302] In summary, the advantages of this device can be summarized as follows:

[0303] • Reduce nursing care services;

[0304] • Reduce medication dosage;

[0305] With continued use of the device, recurrence will be impossible.

[0306] • Eliminate pain and improve quality of life;

[0307] • Reduce hospitalizations.

[0308] Considering that bedsore treatment accounts for more than 4% of Italy's national healthcare expenditure, its advantages cannot be ignored from both an economic and quality-of-life perspective.

[0309] in conclusion

[0310] The device does not claim to solve pressure ulcer problems, but it does help remove necrotic tissue, prevent recurrence, and significantly improve the quality of life for patients with pressure ulcers.

[0311] The methods described above are sufficient to enable an expert to manufacture the device. Therefore, in practical applications—for an expert in the art—it is obvious that countless variations and modifications can be made to the description (e.g., involving shape, size, arrangement, and components with equivalent functions) without departing from the scope of protection of the invention, as shown in the claims that form part of this specification.

[0312] It is understood that while the invention described herein is fully capable of achieving the intended purpose and providing the listed advantages, the embodiments and features of the invention are purely exemplary.

[0313] Therefore, we do not intend to limit the scope of our proprietary rights and privileges to the details of the described embodiments.

[0314] Therefore, we wish to include equivalents, adaptations, and modifications of the invention (which can be reasonably inferred from the description contained herein) within the scope of the invention as defined by the appended tables and claims.

Claims

1. A medical device for treating pressure ulcers [Figure 1], comprising: a) A mattress consisting of n sets of soft, flexible tubes [2 in Figure 1], which are interconnected to form a single, continuous and uninterrupted surface. These surfaces are arranged above the mattress according to the length of the underlying mattress and are traversed by fluids, liquids or gases. b) All pipes in the same device have the same diameter as described in section a); c) Fire-resistant sleeves that can be cleaned and disinfected at 90°C, including all pipes described in paragraph a); d) A mattress layer, the shape of which is similar to that described in items a), b), and c); e) A manifold [3 in Figure 1] located under the padding connects a set of pipes and distributes a filling fluid, i.e., liquid or gas, driven by a compressor, such that all pipes except one set of pipes [pipe (b) in Figure 6] are at maximum pressure [pipe (a) in Figure 6], and are pressurized in a cyclic mode, so that each set of pipes has its maximum pressure and zero pressure cycles [Figures 3, 4 and 5]; f) A container [4 in Figure 1] located on the endplate, which contains all the tools required for the operation of the device; and, Its features are, Pressureψ=(τ+σ P ) -where τ [(6) in Figure 6] represents the pressure applied to the pressurized pipeline. -where "σ" P "[Refer to formula (6) on page 14 and formula (7) on page 15] represents the uniformly distributed local pressure generated by the patient's own body weight in the body area where the pressure ulcer is located; Multiply by time (λ) -and {[represents the total pressurization time of one of the n groups of pipelines in a complete operating cycle[Refer to expression (4)]}; The following inequality based on the BSA [body surface area, formula (5)] value must be satisfied, namely: a) For bodies with a surface area greater than 1.50 m² 2 The patient must be (ψ x λ) ≤ 1,150 mmHg x 1 minute b) For bodies with a surface area less than or equal to 1.50 m² 2 The patient must be (ψ x λ) ≤ 770 mmHg x 1 minute.

2. The apparatus according to claim 1, Its features are, When a pressure ulcer is located at position (8) in [Figure 6], the pressure (ψ) that must be applied to the capillaries flowing into the pressure ulcer must be... R The value must satisfy the following inequality: (ψ) R )≥ 1.5(β R ) -wherein ψ R =kψ[Refer to expression(10)] -where k is a reduction factor [refer to expression (11)] -where β R =70%β[Refer to expression(8)] -Where β = according to Redfern S.'s variable [Lancet 1973 (page 14)] → 120 mmHg ≤ β ≤ 170 mmHg.

3. The apparatus according to claim 1 or 2, Its features are, The diameter (Φ) of the pipe for this device must be between the following dimensions. 20mm ≤ Φ ≤ 40mm.

4. The apparatus according to claim 1, 2, or 3, Its features are, It must consist of a group of n pipes, with at least 3 of them, such that: Quantity ≥ 3 sets of pipes.

5. The apparatus according to claim 1, 2, 3, or 4, Its features are: All four conditions must be met simultaneously.

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