A skeleton support type local wave anti-bedsore air cushion and a method for using the same

Abstract

This invention discloses a skeleton-supported, locally fluctuating anti-decubitus air mattress and its usage method, relating to the field of nursing equipment. This skeleton-supported, locally fluctuating anti-decubitus air mattress achieves significant performance benefits by completely decoupling overall support and localized pressure relief at the structural level. The rigid support skeleton forms a gravity transmission path independent of the pressure regulation unit's movement, maintaining its shape under all operating conditions and providing a constant reference support surface for the human body. This fundamentally eliminates the posture disturbance caused by overall center of gravity fluctuations during the alternating inflation and deflation of traditional airbags. Each pressure regulation unit is independently zoned according to high-risk areas for decubitus ulcers, such as the sacrum and coccyx, and employs a time-coordinated inflation and deflation strategy to provide periodic stress release to the target contact areas. The built-in ventilation channels in the skeleton, combined with a low back pressure exhaust design, create a passive heat and moisture diffusion path. A silent fan and a non-direct airflow organization scheme keep operating noise at a low level.

Description

Technical Field

[0001] This invention relates to nursing equipment technology, specifically to a skeletal support type local fluctuation anti-decubitus air cushion and its method of use. Background Technology

[0002] Existing pressure ulcer prevention air mattresses are mainly divided into two categories: full-bag alternating inflation type and static pressure relief mattress. The full-bag alternating inflation type is currently the mainstream solution on the market. It uses two sets of airbags to alternately inflate and deflate, causing the pressure points on the body to rotate periodically. However, the fatal flaw of this solution is that the overall support function and the local pressure alternation function are both provided by the same set of airbags. During inflation and deflation, these two functions physically conflict—when the airbags inflate, the body is lifted up; when the airbags deflate, the body falls down, resulting in continuous up-and-down swaying of the entire body. For patients who need to maintain strict positional stability after fracture surgery, spinal injuries, or other conditions, this overall swaying not only causes severe discomfort but may even lead to secondary injuries. Some patients refuse to use it because they cannot tolerate the swaying, leading to interruptions in pressure ulcer prevention. Furthermore, this solution requires the air pump to operate continuously, generating considerable noise, which affects the sleep of patients and roommates at night; some products have their exhaust vents directly facing the patient's body, causing direct airflow and discomfort. While static pressure-reducing pads such as memory foam and gel pads do not have a wobbling problem, they can only reduce the peak pressure and cannot achieve the core mechanism of pressure ulcer prevention: "allowing the compressed tissue to rest periodically." For patients who have already developed erythema or superficial pressure ulcers, the preventive effect is even far less than that of alternating air-filled bags.

[0003] To address the aforementioned shortcomings, there is an urgent need for an anti-bedsore air cushion that can achieve both localized pressure alternation and overall support stability, thereby enabling effective rotation and rest of compressed tissues while ensuring body position stability. Summary of the Invention

[0004] The purpose of this invention is to provide a skeleton-supported local fluctuation anti-bedsore air mattress and its usage method, so as to solve the problem that the existing anti-bedsore air mattresses cannot achieve effective rotation and rest of the pressure tissues while ensuring the stability of the body position.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a skeletal-supported, locally fluctuating anti-bedsore air cushion, comprising:

[0006] A rigid support frame, wherein multiple unit slots are provided on the rigid support frame;

[0007] Multiple pressure regulating units are provided and are respectively arranged in each of the unit slots. When the pressure regulating unit is in the unfolded state, the height of the top surface of the pressure regulating unit is greater than the height of the reference surface of the upper surface of the rigid support frame. When the pressure regulating unit is in the retracted state, the height of the top surface of the pressure regulating unit is less than or equal to the height of the reference surface of the upper surface of the rigid support frame.

[0008] A fluid drive unit is installed in the rigid support frame and is used to drive each of the pressure regulating units to work alternately according to a preset time sequence;

[0009] Each pressure regulating unit is provided with a fluid interface and connected to the fluid drive unit through an independent pipeline. The connection between the independent pipeline and the fluid interface of the pressure regulating unit is provided with an asymmetrical snap or a foolproof interface to ensure that the pipeline and the pressure regulating unit are assembled in a one-to-one correspondence, and to avoid timing disorder caused by incorrect assembly.

[0010] The rigid support frame forms a gravity transmission path independent of the movement of the pressure regulating unit. A portion of the human body's weight is directly transmitted to the base support surface via the rigid support frame. The rigid support frame maintains its shape during the operation of the pressure regulating unit.

[0011] Preferably, the pressure regulating unit includes a bottom shell that is snapped into the unit slot and an airbag mounted on the bottom shell. A retaining plate is connected to the inner wall of the unit slot. The upper surface of the retaining plate is inclined downward. The unit slot is connected to the stepped structure between the bottom shell and the airbag by the retaining plate. A 0.5mm to 1mm movable gap is left between the retaining plate and the bottom shell. A gap is left between the outer wall of the pressure regulating unit and the inner wall of the unit slot.

[0012] Preferably, the unit slot includes at least six unit slots corresponding to the sacrum, left and right buttocks, left and right scapulae, and heel, and each pressure adjustment unit is respectively disposed in the unit slot at the corresponding position.

[0013] Preferably, the fluid drive unit includes a micro air pump, a fluid control component, a control unit, and a power supply. The power supply provides power to the micro air pump, the fluid control component, and the control unit. The control unit is connected to the micro air pump and the fluid control component. The fluid control component includes a multi-way solenoid valve. The output end of the micro air pump is connected to the input end of each solenoid valve. The output end of each solenoid valve is connected to a pressure regulating unit at a different location via an independent pipeline. This allows the output of the micro air pump to be transmitted to different pressure regulating units according to the control command of the control unit. The control unit drives the output ends of each solenoid valve to open and close sequentially according to a preset spatial sequence.

[0014] Preferably, the rigid support frame is a high-density EVA foam board, PP honeycomb board, or medical-grade injection molded part with a thickness of 10-25mm; the depth of the unit groove is 8-20mm; the top surface of the pressure adjustment unit after unfolding is 5-15mm higher than the reference surface of the upper surface of the frame; the 5-15mm parameter range is the critical range that simultaneously satisfies the two indicators of effective decompression and body position stability: when it is below 5mm, the decompression effect decreases significantly, and when it is above 15mm, the body position stability decreases significantly.

[0015] Preferably, the rigid support frame is also provided with several through-holes with a diameter of 3-6 mm and a spacing of 20-40 mm, which connect the upper and lower spaces to form a passive dehumidification channel.

[0016] Preferably, a silent fan is also installed on the side of the rigid support frame to deliver air to the space below the rigid support frame, forming a micro-airflow circulation through the vent holes.

[0017] Preferably, a thin-film pressure sensor is provided on the top of the pressure regulating unit to provide real-time feedback of the contact pressure to the fluid drive unit, thereby achieving closed-loop pressure regulation.

[0018] Preferably, the rigid support frame and pressure adjustment unit are covered with a contact surface layer, which is made of medical-grade breathable mesh or microporous membrane fabric.

[0019] Preferably, each of the pressure regulating units is equipped with a mechanical pressure relief valve in its pipeline, with an opening pressure of 40-60 mmHg.

[0020] A method for using a skeletal support type localized fluctuation anti-decubitus air cushion includes the following steps:

[0021] Real-time data collection of contact pressure, internal air pressure, back temperature and humidity, continuous pressure duration, and frame tilt angle for each airbag;

[0022] Calculate the global pressure distribution, pressure center, and left-right symmetry index; combine inertial data to determine the supine, lateral, or rolling position; and calibrate the lateral tilt angle.

[0023] For each region, a pressure risk score is calculated by considering the overall pressure level, duration of pressure exposure, rate of pressure change, and temperature and humidity correction factors.

[0024] When a certain area is subjected to pressure for an extended period, pressure overload, severe lateral tilt, or excessively high temperature and humidity, the corresponding posture change command (inflation / deflation / frequency adjustment) is triggered; if spontaneous turning over is detected, intervention is paused.

[0025] The corresponding airbag is driven to move at a preset rate, and the pressure is adjusted to the target value in real time through PID to ensure a smooth transition;

[0026] The timer resets after a posture change, records historical events, dynamically adjusts the risk weights of each area, and achieves personalized parameter optimization.

[0027] The system monitors air pressure and pressure consistency throughout the process. It will release pressure and sound an alarm in case of exceeding limits or sensor malfunction. It will notify nursing staff in case of serious loss of control.

[0028] Compared with existing technologies, the present invention provides a skeletal support-type localized undulating anti-decubitus air mattress, which achieves significant performance benefits by completely decoupling overall support and localized pressure relief at the structural level. The rigid support skeleton forms a gravity transmission path independent of the pressure regulation unit's movement, maintaining its geometric shape under all operating conditions and providing a constant reference support surface for the human body. This fundamentally eliminates the postural disturbances caused by overall center of gravity fluctuations during the alternating inflation and deflation of traditional airbags. Each pressure regulation unit is independently zoned according to high-risk areas for pressure ulcers, such as the sacrum, coccyx, and scapula, employing a time-coordinated inflation and deflation strategy to ensure periodic stress release at the target contact areas, precisely implementing intervention mechanisms for pressure injuries. The built-in ventilation channels in the skeleton, combined with a low back pressure exhaust design, create a passive heat and moisture diffusion path. A silent fan and non-direct airflow organization scheme keep operating noise at a low level, effectively improving the nighttime usage environment. The peristaltic wave mode, achieved through the physical allocation of the pipeline topology, simulates natural turning movements, further enhancing the user experience for long-term bedridden individuals. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0030] Figure 1 This is a schematic diagram of the overall structure provided for an embodiment of the present invention;

[0031] Figure 2 This is a schematic diagram of the upper structure of the rigid support skeleton provided in an embodiment of the present invention;

[0032] Figure 3 This is a schematic diagram of the lower structure of the rigid support skeleton provided in an embodiment of the present invention;

[0033] Figure 4 This is a schematic diagram of the pressure regulating unit structure provided in an embodiment of the present invention;

[0034] Figure 5 This is a diagram illustrating the working mode of the pressure regulating unit provided in an embodiment of the present invention.

[0035] Figure 6 This is a system block diagram of a fluid drive unit provided in an embodiment of the present invention;

[0036] Figure 7 This is a schematic diagram illustrating the airbag's expansion and contraction process as provided in an embodiment of the present invention.

[0037] Explanation of reference numerals in the attached figures:

[0038] 1. Rigid support frame; 11. Unit slot; 12. Ventilation hole; 13. Card plate; 2. Pressure regulation unit; 21. Bottom shell; 22. Airbag; 23. Thin film pressure sensor; 3. Fluid drive unit; 4. Silent fan; 5. Contact surface layer. Detailed Implementation

[0039] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0040] As attached Figure 1 To be continued Figure 7 As shown:

[0041] Example:

[0042] This invention provides a skeleton-supported, locally fluctuating anti-bedsore air cushion, comprising:

[0043] A rigid support frame 1, wherein a plurality of unit slots 11 are provided on the rigid support frame 1;

[0044] Multiple pressure regulating units 2 are provided and are respectively arranged in each of the unit slots 11. When the pressure regulating unit 2 is in the unfolded state, the height of the top surface is greater than the height of the reference surface of the upper surface of the rigid support frame 1. When the pressure regulating unit 2 is in the retracted state, the height of the top surface of the pressure regulating unit 2 is less than or equal to the height of the reference surface of the upper surface of the rigid support frame 1.

[0045] The fluid drive unit 3 is installed in the rigid support frame 1 and is used to drive each of the pressure regulating units 2 to work alternately according to a preset time sequence;

[0046] Each pressure regulating unit 2 is provided with a fluid interface and connected to the fluid drive unit 3 through an independent pipeline. The connection between the independent pipeline and the fluid interface of the pressure regulating unit 2 is provided with an asymmetrical snap or a foolproof interface to ensure that the pipeline and the pressure regulating unit 2 are assembled in a one-to-one correspondence, and to avoid timing disorder caused by incorrect assembly.

[0047] The rigid support frame 1 forms a gravity transmission path independent of the movement of the pressure regulating unit 2. A portion of the human body's weight is directly transmitted to the base support surface via the rigid support frame 1. The rigid support frame 1 maintains its shape during the operation of the pressure regulating unit 2.

[0048] A silent fan 4 is also installed on the side of the rigid support frame 1 to deliver air to the space below the rigid support frame 1. The airflow is circulated through the vents 12 to further dehumidify and cool down the space.

[0049] As can be seen from the above, the complete decoupling of overall support and local pressure relief at the structural level brings about significant performance benefits. The rigid support frame 1 forms a gravity transmission path independent of the movement of the pressure regulation unit 2, maintaining its geometric shape under all working conditions and providing a constant reference support surface for the human body. This fundamentally eliminates the posture disturbances caused by the fluctuation of the overall center of gravity during the alternating inflation and deflation of traditional airbags. Each pressure regulation unit 2 is independently zoned according to high-risk areas for pressure sores such as the sacrum, coccyx, and scapula, and adopts a time-coordinated inflation and deflation strategy to ensure periodic stress release at the target contact points, precisely executing the intervention mechanism for pressure injuries. The built-in ventilation holes 12 of the rigid support frame 1, combined with the low back pressure exhaust design, construct a passive heat and moisture diffusion path. The silent fan 4 and the non-direct airflow organization scheme keep the operating noise at a low level, effectively improving the nighttime usage environment. The peristaltic wave mode is achieved through the physical allocation of the pipeline topology, which can simulate natural turning movements, further enhancing the user experience for long-term bedridden users.

[0050] The pressure regulating unit 2 includes a bottom shell 21 that is snapped into the unit groove 11 and an airbag 22 mounted on the bottom shell 21. A retaining plate 13 is connected to the inner wall of the unit groove 11. The upper surface of the retaining plate 13 is inclined downwards, and the retaining plate 13 is a downwardly inclined strip. The unit groove 11 uses the retaining plate 13 to snap the stepped structure between the bottom shell 21 and the airbag 22. The cross-section of the retaining plate 13 can be trapezoidal or dovetail-shaped, with the inclined surface facing the middle of the unit groove 11. This facilitates the bottom shell 21 sliding down the inclined surface of the retaining plate 13 and also allows the lower end of the retaining plate 13 to engage the bottom shell 21. The retaining plate 13 can change shape during the engagement of the bottom shell 21. After deformation and repositioning, the pressure regulating unit 2 is inverted and placed on the stepped structure between the bottom shell 21 and the airbag 22 to prevent the pressure regulating unit 2 from detaching from the unit slot 11. To accommodate the thermal expansion and contraction and elastic deformation of the material during the operation of the pressure regulating unit 2, and to prevent jamming or loosening due to temperature changes or long-term use, a 0.5mm to 1mm gap is left between the clamping plate 13 and the bottom shell 21. A gap is left between the outer wall of the pressure regulating unit 2 and the inner wall of the unit slot 11 to prevent the airbag 22 from rubbing against the inner wall of the unit slot 11 during contraction and expansion, which would generate noise or wear. The pipes of the bottom shell 21 pass through the wiring holes at the bottom or side wall of the unit slot 11.

[0051] When the user places the pressure regulating unit 2 into the unit slot 11, the bottom shell 21 can force the clamping plate 13 to deform. The bottom shell 21 slides down along the deformed clamping plate 13. When the bottom shell 21 slides past the clamping plate 13, the clamping plate 13 returns to its original shape and locks the bottom shell 21, preventing the bottom shell 21 from falling out of the unit slot 11.

[0052] To improve the effectiveness of the device, the pressure adjustment unit 2 needs to be positioned at the location on the patient's torso that is prone to pressure. The unit slot 11 includes at least six unit slots 11 corresponding to the sacrum, left and right buttocks, left and right scapulae, and heel. Each pressure adjustment unit 2 is respectively positioned in the corresponding unit slot 11.

[0053] The fluid drive unit 3 includes a micro air pump, a fluid control component, a control unit, and a power supply. The power supply provides power to the micro air pump, the fluid control component, and the control unit. The control unit is connected to the micro air pump and the fluid control component. The fluid control component includes a multi-way solenoid valve. The output end of the micro air pump is connected to the input end of each solenoid valve. The output end of each solenoid valve is connected to a pressure regulating unit 2 at a different location via an independent pipeline. This allows the micro air pump's output to be transmitted to different pressure regulating units 2 according to the control command of the control unit. The control unit drives the output ends of each solenoid valve to open and close sequentially according to a preset spatial sequence.

[0054] The miniature air pump is preferably a 3-5V silent brushless pump with a noise level of ≤30dB. The fluid control component is preset with multiple working modes, including a standard alternating mode and a peristaltic wave mode. Users can switch working modes via physical buttons or a remote control. The power supply uses a rechargeable lithium battery or an external USB power supply, which can meet the requirements of more than 24 hours of battery life.

[0055] When the control unit issues control commands according to the standard alternating mode, each pressure regulating unit 2 operates alternately in the following manner: Stage 1: The sacral and coccygeal pressure regulating unit 2 is working and supported, while the scapular pressure regulating unit 2 is released; Stage 2: All pressure regulating units 2 are in the intermediate state, and the overall pressure is balanced; Stage 3: The sacral and coccygeal pressure regulating unit 2 is released, while the scapular pressure regulating unit 2 is working and supported; Stage 4: Same as Stage 2; The cycle period is preferably 5 to 15 minutes; Since the pressure regulating unit 2 in the unit slot 11 only performs local work, the human body is always supported by the constant support surface of the rigid support frame 1 and the unfolded top surface of each pressure regulating unit 2. The rigid support frame 1 does not deform due to changes in the state of the pressure regulating unit 2, and the overall posture of the human body remains stable.

[0056] In addition to the standard alternating mode, a peristaltic wave mode can also be used, specifically including: sequentially turning pressure regulating units 2 on and off from the head side to the foot side to form a peristaltic wave from head to toe; or sequentially turning pressure regulating units 2 on and off from the midline of the spine to the left and right sides to form a spreading wave from the center to the outside. This mode is achieved through the physical tubing distribution of the fluid control component, which differs from the simple two-set alternation in existing technologies. The peristaltic wave mode simulates the natural turning movement of the human body, further reducing the pressure sensation caused by prolonged bed rest.

[0057] The rigid support frame 1 is a high-density EVA foam board, PP honeycomb board, or medical-grade injection molded part with a thickness of 10-25mm. The overall structure is a flat plate or slightly curved surface that is adapted to the human lying posture. The depth of the unit groove 11 is 8-20mm. After the pressure adjustment unit 2 is unfolded, its top surface is 5-15mm higher than the reference surface of the upper surface of the frame. The 5-15mm parameter range is the critical range that simultaneously satisfies the two indicators of effective pressure reduction and postural stability: when it is below 5mm, the pressure reduction effect decreases significantly, and when it is above 15mm, the postural stability decreases significantly.

[0058] The rigid support frame 1 is also provided with several through-hole ventilation holes 12, with a hole diameter of 3 to 6 mm and a hole spacing of 20 to 40 mm, which connect the upper and lower spaces to form a passive dehumidification channel, reducing the accumulation of moisture and heat on the user's back.

[0059] The pressure regulating unit 2 is equipped with a thin-film pressure sensor 23 on its top, which is used to provide real-time feedback of the contact pressure to the fluid drive unit 3 to achieve closed-loop pressure regulation.

[0060] The rigid support frame 1 and the pressure adjustment unit 2 are covered with a contact surface layer 5. The contact surface layer 5 is made of medical-grade breathable mesh or microporous membrane fabric and has the characteristics of low friction, moisture permeability and removability for cleaning.

[0061] Each of the pressure regulating units 2 is equipped with a mechanical pressure relief valve in its pipeline, with an opening pressure of 40-60 mmHg, to prevent excessive pressure from causing local compression.

[0062] To improve the effectiveness of this skeletal support-type localized fluctuation anti-decubitus air mattress, a method for using the skeletal support-type localized fluctuation anti-decubitus air mattress is provided, the method comprising:

[0063] Real-time data collection of contact pressure, internal air pressure, back temperature and humidity, continuous pressure duration, and frame tilt angle for each airbag;

[0064] Calculate the global pressure distribution, pressure center, and left-right symmetry index; combine inertial data to determine the supine, lateral, or rolling position; and calibrate the lateral tilt angle.

[0065] For each region, a pressure risk score is calculated by considering the overall pressure level, duration of pressure exposure, rate of pressure change, and temperature and humidity correction factors.

[0066] When a certain area is subjected to pressure for an extended period, pressure overload, severe lateral tilt, or excessively high temperature and humidity, the corresponding posture change command (inflation / deflation / frequency adjustment) is triggered; if spontaneous turning over is detected, intervention is paused.

[0067] The corresponding airbag is driven to move at a preset rate, and the pressure is adjusted to the target value in real time through PID to ensure a smooth transition;

[0068] The timer resets after a posture change, records historical events, dynamically adjusts the risk weights of each area, and achieves personalized parameter optimization.

[0069] The system monitors air pressure and pressure consistency throughout the process. It will release pressure and sound an alarm in case of exceeding limits or sensor malfunction. It will notify nursing staff in case of serious loss of control.

[0070] The specific sensors include:

[0071] Thin-film pressure sensor 23 is used to collect pressure value Pi; temperature and humidity sensor, located in the gap of unit slot 11, is used to collect back temperature Tk and relative humidity Hk; airbag pressure sensor, located in each pressure regulating unit 2, is used to collect airbag inflation pressure Qi; timing sensor, located in fluid drive unit 3, is used to collect the current continuous pressure bearing time t of each airbag. i c Total usage time; a three-axis accelerometer-gyroscope, positioned at the geometric center of the rigid support frame 1, is used to measure the tilt angle θ of the rigid support frame 1. x and θ y .

[0072] Define variables: i∈{1,2,…,n} represents the i-th pressure regulation unit (airbag), n≥6, corresponding to the sacrococcygeal region, left buttock, right buttock, left scapula, right scapula, heel, etc. respectively; P i (t): Measured contact pressure (in mmHg) at time t on the top of the i-th airbag; Q i (t): The air pressure inside the i-th airbag at time t (unit: mmHg); T k (t),H k (t): Temperature (°C) and relative humidity (%) at time t of the k-th temperature and humidity measuring point; t i c (t): The current continuous pressure duration of the i-th airbag at time t (in minutes); θ x (t),θ y (t): The tilt angle of the skeleton around the left-right axis (X-axis) and front-back axis (Y-axis) of the human body (unit: °).

[0073] A posture recognition algorithm is used to process sensor data and identify the patient's posture. Specific steps include:

[0074] Extracting pressure distribution characteristics:

[0075] Define the global pressure distribution vector at time t:

[0076]

[0077] Define the normalized pressure distribution weight:

[0078]

[0079] Where ε=10 −6 To prevent small quantities with a denominator of zero. α i (t) represents the weight-bearing percentage of the i-th contact area at the current moment.

[0080] Define the coordinates of the Center of Pressure (CoP):

[0081]

[0082] Among them, (x i ,y i (x) represents the geometric center coordinates (in mm) of the i-th airbag on the skeletal plane. CoP ,y CoP This refers to the projection position of the pressure center of the human torso on the air cushion plane.

[0083] Define the pressure distribution asymmetry index:

[0084]

[0085] Where: P left (t) = P_left hip(t) + P_left scapula(t), P right (t) = P right hip (t) + P right scapula (t), A sym (t)∈[0,1], the closer to 0, the more symmetrical the left and right pressure, and the closer to 1, the more obvious the tilt.

[0086] Establish a body position classification decision tree:

[0087] Obtain P(t) and x at time t CoP (t), y CoP (t), A sym (t), θ x (t), θ y (t) and inertial measurement data;

[0088] Coarse-grained body position recognition – based on pressure distribution template matching.

[0089] Define a standard body position template library M = {Supine, Left lateral decubitus, Right lateral decubitus, Sitting (semi-recumbent), Head-up-feet-down, Head-down-feet-up}. For each template, define the theoretical pressure center range Ωm and the theoretical pressure distribution weight vector. Pre-calibrated using clinical samples.

[0090] Calculate the weighted Euclidean distance between the current pressure distribution and each template:

[0091]

[0092] in: ω represents the standardized pressure ratio of the i-th region under template m; i λ represents the weighting coefficient for each region (the sacrococcygeal region and buttocks have higher weights due to their greater pressure); λ is the balance coefficient (empirical value is 0.3 to 0.5). Let m be the standard pressure center coordinates of template m.

[0093] Determining coarse-grained body position : .

[0094] Fine-grained attitude calibration based on the fusion of inertial measurement and pressure asymmetry index:

[0095] When A sym When (t)>0.35 and lasts for more than 30 seconds, combined with θ y (t) (roll angle about the front and rear axles) is used to estimate the lateral angle: .

[0096] Where η is an empirical calibration coefficient (usually taken as 0.8 to 1.0), ϕ lateral (t) represents the estimated lateral decubitus angle (unit: °), with a value range of 0° to 90°.

[0097] Simultaneously, the actual skeleton tilt angle θ is calculated using accelerometer data. y (t), when When a sensor consistency check warning is triggered, a Kalman filter is used to fuse the two results:

[0098]

[0099] in: To observe the fusion value, K t The Kalman gain is calculated recursively.

[0100] Establish a pressure risk assessment model:

[0101] Define the instantaneous risk index for the body surface area corresponding to the i-th airbag:

[0102] Among them, P thr,i : The safe pressure threshold for the i-th region (40 mmHg for the sacrococcygeal region, 45 mmHg for the buttocks, 35 mmHg for the scapula, and 30 mmHg for the heel, empirical values); t thr Continuous pressure bearing safety time threshold (generally taken as 20 minutes); : Rate of change of contact pressure over time (unit: mmHg / min), calculated by numerical differentiation; β1, β2, β3: weighting coefficients, β1=0.5, β2=0.35, β3=0.15, satisfying ∑β=1.

[0103] Define the microenvironment correction factor:

[0104]

[0105] Wherein, T0=32℃ is the comfortable temperature threshold; H0=60% is the comfortable humidity threshold; γT=0.2, γH=0.15 are environmental sensitivity coefficients (empirical calibration).

[0106] The revised overall pressure risk score is as follows:

[0107]

[0108] Define the global risk field:

[0109]

[0110] or

[0111]

[0112] Where ω i risk Risk weights for each region (highest for the sacrococcygeal region, followed by the heel region, and then the scapular region), when Ψ i (t)>Ψ warn When the warning threshold (empirically taken as 0.65) is reached, the corresponding area triggers an "intervention required" state; when Ψ i (t)>Ψ crit An emergency posture change command is triggered when the danger threshold (empirically taken as 0.85) is reached.

[0113] Generate body position change instructions:

[0114] Define the target body position S at the current time t. target With current body position S pose The deviation function between (t):

[0115]

[0116] in, It is a weighted distance metric based on pressure distribution differences and pressure center offset.

[0117] Timed active posture change command:

[0118] When the continuous pressure time in any region meets the following:

[0119]

[0120] Among them, t max =30min (maximum allowable continuous pressure bearing time), δ i =min(5min,0.15) t max As a lead time, the control center generates a "preventive posture change instruction":

[0121]

[0122] Where: U represents the set of all executable posture-changing movements (including standard alternation, creeping wave, local release, and other patterns); H high (t)={i∣Ψ i (t)>Ψ warn} represents a set of high-risk areas; As an indicator function, the control center prioritizes posture-changing modes that can reduce pressure on high-risk areas.

[0123] Event-driven posture change commands:

[0124] Pressure overload event: When P i (t)>1.2 P thr,i If the inflator continues for more than 2 minutes, the airbag will immediately deflate and decompression command will be triggered: C release (i) = {When the i-th airbag switches to the contracted state, the adjacent airbags in the corresponding area switch to the deployed support state};

[0125] Asymmetric load event: When A sym (t)>0.5 and |θ y (t)∣>5 lasts for more than 3 minutes, triggering the "contralateral pressure replenishment + ipsilateral slow release" coordinated adjustment command, causing the pressure center to return to the midline;

[0126] Excessive humidity and heat: When any measuring point T k (t)>35℃ or H k If (t)>75% persists for more than 5 minutes, a combined control command of "increase the speed of the silent fan by 4 and increase the frequency of airbag fluctuation in this area" will be triggered to enhance the local micro-airflow circulation and accelerate the periodic release of the pressure point in this area.

[0127] Autonomous turning over detection event: When detected A rapid increase (>5mm / s) accompanied by significant fluctuations in the accelerometer readings indicates that the patient is turning over voluntarily. At this point, the control center automatically pauses the preset posture change command for 60 seconds and automatically recalibrates the posture template after detecting that the posture is stable, so as to avoid conflict with the patient's voluntary movements.

[0128] Comprehensive optimization decision-making:

[0129] Define the overall control objective function (minimize risk and energy consumption):

[0130]

[0131] Among them: Q max The maximum safe operating pressure for the airbag (taken as 60 mmHg); Δt i switch (t) represents the number of times the i-th airbag was switched within 2 hours prior to the current moment (to prevent frequent switching from causing patient discomfort and increased energy consumption); , , Weighting coefficients ( =0.6, =0.2, =0.2).

[0132] The control center aims to minimize J(t) while satisfying the following constraints:

[0133]

[0134] (N) max Given the premise of 12 times / 2 hours, generate the optimal body position change instruction sequence C. opt (t).

[0135] Closed-loop execution and adaptive strategies:

[0136] The control center will C opt (t) is converted into specific solenoid valve switching timing and micro air pump speed control signals, which drive each pressure regulating unit 2 to perform inflation or deflation actions according to the target instructions through independent pipelines.

[0137] During execution, the internal air pressure Qi(t) and contact pressure Pi(t) of each airbag are monitored in real time at a frequency of 1Hz to construct a closed-loop feedback control:

[0138] Define pressure tracking error:

[0139]

[0140] Among them, P i target (t) represents the target contact pressure (preset based on target body position and patient weight). The air pump output is dynamically adjusted using a PID control law.

[0141]

[0142] in, , , These are the proportional, integral, and differential coefficients (fixed after empirical calibration), ui (t) represents the PWM drive duty cycle of the i-th solenoid valve.

[0143] When a mechanical pressure relief valve in any pipeline is activated (opening pressure 40-60 mmHg), the control center records the event and lowers the target pressure limit for that pipeline.

[0144] After each posture change, the control center recalculates the current posture classification Spose(t) and the global risk field Ψ. global (t), Update the patient position history database:

[0145]

[0146] Where ΔT = 120 min is the historical backtesting window. The risk weights ω for each region are dynamically adjusted based on historical data. i risk Airbag switching frequency threshold N max This enables personalized adaptive care.

[0147] Anomaly detection and security protection:

[0148] Contact pressure and air pressure consistency verification. Define deviation index:

[0149]

[0150] Where C i Let ξ be the conversion factor between the effective contact area and air pressure of the i-th airbag. i If (t)>0.25 for more than 10 seconds, it is judged as a sensor malfunction or airbag leakage, triggering a system self-test alarm.

[0151] All raw sensor data and control commands are written to local storage at a frequency of 0.5 Hz and uploaded to the nursing terminal via Bluetooth or Wi-Fi, supporting remote viewing and historical review.

[0152] When any airbag pressure Q is detected i (t)>Q max +5 mmHg or contact pressure P i If the pressure (t) is greater than 80 mmHg for more than 5 seconds, the control center will immediately cut off the gas supply and activate the emergency pressure relief valve.

[0153] When the comprehensive risk score Ψ global (t)>Ψ crit If the condition persists for more than 2 minutes and automatic repositioning fails to effectively reduce the score, the control center sends an "emergency manual intervention" alarm to the caregiver via a buzzer in the fluid drive unit and wireless communication, and uploads a package of historical data from all current sensors so that the caregiver can quickly assess the patient's condition.

[0154] The following are specific embodiments of the above method:

[0155] The patient is a 70kg male who has been bedridden for a long time, mainly in a supine position.

[0156] Initially, the pressure regulating unit 2 is installed into six unit slots 11 located in the sacrum, coccyx, left and right buttocks, left and right scapulae, and heels. Each airbag's independent tubing is connected to the corresponding port of the fluid drive unit 3 via asymmetrical snap-fit ​​connections. After the system powers on and performs a self-test, the control unit automatically performs a baseline inflation test on the six airbags, recording the top height and contact pressure of each airbag at 30 mmHg, thus completing the sensor zero-point calibration.

[0157] The control center continuously collects the contact pressure values ​​Pi(t) of each thin-film pressure sensor 23 at a frequency of 10Hz, and collects temperature and humidity data at a frequency of 1Hz. After 8 minutes of operation, the algorithm calculates that the patient is in a "supine position," and the pressure center (x) is... CoP ,y CoP Located approximately 15 mm from the foot side of the geometric center of the skeleton, the pressure distribution of each region is as follows: sacrococcygeal region 32%, left buttock 19%, right buttock 18%, left scapula 13%, right scapula 12%, and heel 6%. The continuous pressure time (t) for each region is as follows. i c The duration was approximately 8 minutes, and the pressure risk index Ψi was less than 0.5.

[0158] At the 18th minute of operation, the contact pressure P of the sacral and coccygeal airbags... 骶尾 =42mmHg, continuous pressure bearing time t 骶尾 c =18min, calculated to obtain Ψ 骶尾 =0.58 (close to the warning threshold of 0.65), and the microenvironment temperature T=34.2℃, humidity H=68%, microenvironment correction coefficient Γ=1.09, comprehensive risk score Ψ 骶尾 修正 =0.63. The control center determined that a preventative posture change was necessary and generated the target instruction: the sacrococcygeal airbag was slowly deflated to the contracted state at a rate of 5 mmHg / s, while the left and right hip airbags were simultaneously inflated to the deployed height at a rate of 3 mmHg / s, realizing the posture shift from "main pressure on the sacrococcygeal region" to "main pressure on the hips", simulating the standard alternating support pattern.

[0159] During execution, the PID controller adjusts the air pump speed and solenoid valve opening in real time to ensure that the actual contact pressure deviation from the target value does not exceed ±2 mmHg. The entire posture change takes about 12 seconds. Because the rigid support frame 1 maintains its shape throughout, the patient's overall center of gravity fluctuates by less than 3 mm, and the posture remains stable.

[0160] After the position change was completed, the control center recalculated the position classification, confirmed that the patient had smoothly transitioned to a "hip-support-dominant" position, and set the continuous pressure timer for the sacral and coccygeal airbags to t. 骶尾 c Reset to zero and begin a new round of monitoring.

[0161] If the patient is detected turning over spontaneously at any time during the operation (x CoP If the movement speed is greater than 5 mm / s, the control center will pause the execution of new posture change commands, wait 60 seconds to re-identify the body position, and adjust the subsequent control strategy according to the new body position.

[0162] The foregoing has only described certain exemplary embodiments of the present invention by way of illustration. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the foregoing drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A skeleton supported local wave anti-bedsore air cushion, characterized in that, include: A rigid support frame (1) is provided with multiple unit slots (11). Multiple pressure regulating units (2) are provided and are respectively installed in each of the unit slots (11). The top surface height of the pressure regulating unit (2) in the unfolded state is greater than the height of the reference surface of the upper surface of the rigid support frame (1). In the contracted state, the top surface height of the pressure regulating unit (2) is less than or equal to the height of the reference surface of the upper surface of the rigid support frame (1). A fluid drive unit (3) is installed in the rigid support frame (1) to drive each pressure regulating unit (2) to work alternately according to a preset time sequence; Each of the pressure regulating units (2) is provided with a fluid interface and is connected to the fluid drive unit (3) through an independent pipeline; The rigid support frame (1) forms a gravity transmission path that is independent of the movement of the pressure regulating unit (2). A portion of the human body's weight is directly transmitted to the base support surface through the rigid support frame (1). The rigid support frame (1) maintains its shape during the operation of the pressure regulating unit (2).

2. The skeletonized, partial wave anti-bedsore air mattress according to claim 1, wherein, The pressure regulating unit (2) includes a bottom shell (21) that is snapped into the unit groove (11) and an airbag (22) installed on the bottom shell (21). The inner wall of the unit groove (11) is connected to a retaining plate (13). The upper surface of the retaining plate (13) is inclined downward. The unit groove (11) is snapped into the stepped structure between the bottom shell (21) and the airbag (22) by the retaining plate (13). There is a 0.5mm to 1mm gap between the retaining plate (13) and the bottom shell (21). There is a gap between the outer wall of the pressure regulating unit (2) and the inner wall of the unit groove (11).

3. The skeletonized, partial wave anti-bedsore air mattress according to claim 1, wherein, The unit slot (11) includes at least six unit slots (11) corresponding to the sacrum, left and right buttocks, left and right scapulae and heel, and each pressure adjustment unit (2) is respectively set in the unit slot (11) at the corresponding position.

4. The skeleton-supported localized undulating anti-decubitus air cushion according to claim 1, characterized in that, The fluid drive unit (3) includes a micro air pump, a fluid control component, a control unit, and a power supply. The power supply is used to power the micro air pump, the fluid control component, and the control unit. The control unit is connected to the micro air pump and the fluid control component. The fluid control component includes a multi-way solenoid valve. The output end of the micro air pump is connected to the input end of each solenoid valve. The output end of each solenoid valve is connected to a pressure regulating unit (2) at a different location through an independent pipeline. This is used to transmit the output of the micro air pump to different pressure regulating units (2) according to the control command of the control unit. An asymmetric snap or a foolproof interface is provided at the connection between the independent pipeline and the fluid interface of the pressure regulating unit (2). The control unit drives the output end of each solenoid valve to open and close sequentially according to a preset spatial sequence.

5. The skeleton-supported localized undulating anti-decubitus air cushion according to claim 1, characterized in that, The rigid support frame (1) is a high-density EVA foam board, PP honeycomb board or medical-grade injection molded part with a thickness of 10-25mm; the unit groove (11) has a depth of 8-20mm; the top surface of the pressure adjustment unit (2) is 5-15mm higher than the reference surface of the upper surface of the frame after unfolding.

6. The skeleton-supported localized undulating anti-decubitus air cushion according to claim 1, characterized in that, The rigid support frame (1) is also provided with several through-holes (12), with a hole diameter of 3-6 mm and a hole spacing of 20-40 mm, which connect the upper and lower spaces to form a passive dehumidification channel. The rigid support frame (1) is also equipped with a silent fan (4) on its side, which is used to send air to the space below the rigid support frame (1) and form a micro airflow circulation through the air holes (12).

7. The skeleton-supported localized undulating anti-decubitus air cushion according to claim 1, characterized in that, The pressure regulating unit (2) is equipped with a thin-film pressure sensor (23) on top, which is used to provide real-time feedback of the contact pressure to the fluid drive unit (3) to achieve closed-loop pressure regulation.

8. The skeleton-supported localized undulating anti-decubitus air cushion according to claim 1, characterized in that, The rigid support frame (1) and the pressure regulating unit (2) are covered with a contact surface layer (5), which is made of medical-grade breathable mesh or microporous membrane fabric.

9. A skeleton-supported, locally fluctuating anti-decubitus air cushion according to claim 1, characterized in that, Each pressure regulating unit (2) is equipped with a mechanical pressure relief valve in its pipeline, with an opening pressure of 40-60 mmHg.

10. A method of using a skeletal-supported, locally fluctuating anti-decubitus air cushion, characterized in that the steps include... include: Real-time data collection of contact pressure, internal air pressure, back temperature and humidity, continuous pressure duration, and frame tilt angle for each airbag; Calculate the global pressure distribution, pressure center, and left-right symmetry index; combine inertial data to determine the supine, lateral, or rolling position; and calibrate the lateral tilt angle. For each region, a pressure risk score is calculated by considering the overall pressure level, duration of pressure exposure, rate of pressure change, and temperature and humidity correction factors. When a certain area is subjected to pressure for an extended period, pressure overload, severe lateral tilt, or excessively high temperature and humidity, the corresponding posture change command (inflation / deflation / frequency adjustment) is triggered; if spontaneous turning over is detected, intervention is paused. The corresponding airbag is driven to move at a preset rate, and the pressure is adjusted to the target value in real time through PID to ensure a smooth transition; The timer resets after a posture change, records historical events, dynamically adjusts the risk weights of each area, and achieves personalized parameter optimization. The system monitors air pressure and pressure consistency throughout the process. It will release pressure and sound an alarm in case of exceeding limits or sensor malfunction. It will notify nursing staff in case of serious loss of control.

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