System and method for a pressure controlled inflatable mattress and a pressure controlled inflatable mattress

Abstract

The invention relates to a system for a pressure controlled inflatable mattress, the system comprising a first sensor pad (2), an inflatable base pad (3) and an air source (4) A first fluid path (5) is arranged enters the first sensor pad (2) via a first inlet (6) and exit the first sensor pad (2) via a first outlet (7). The first outlet (7) is arranged with a first pressure sensor (8). The inflatable base pad (3) comprising a base pad inlet (9), a base pad outlet (10). The air source (4) is in fluid connection with the first sensor pad (2) and the inflatable base pad (3). Between the air source (4) and the first sensor pad (2) a first non-return valve (11) is arranged, between the air source (4) and the inflatable base pad (3), a base pad non-return valve (12) is arranged. The base pad outlet (10) is arranged with a base pad pressure sensor (13) and a solenoid valve (14).

Description

[0001] SYSTEM AND METHOD FOR A PRESSURE CONTROLLED INFLATABLE MATTRESS AND A PRESSURE CONTROLLED INFLATABLE MATTRESS

[0002] TECHNICAL FIELD

[0003] The present application generally relates to a system and method for a pressure controlled inflatable mattress, and more particularly to the technical field of medical devices.

[0004] BACKGROUND ART

[0005] Pressure controlled inflatable beds, also known as hospital beds, have been marked by developments since the 1980s. The beds have evolved from simple, manually adjustable models to sophisticated, technologically advanced systems designed to enhance patient comfort and safety. The 1980s marked a shift in focus towards the development of mattresses used in hospital beds. Therapeutic mattresses were developed during this period leading to beds using various types of pressure to inflate the beds. The concept of smart hospital beds emerged out of the necessity to upgrade traditional, manual hospital beds. These new beds integrated advanced technology to provide a more comprehensive care experience. They encompassed features such as different monitoring systems, partly automated adjustments, communication capabilities, and integrated scales. One of the challenges faced by these beds was monitoring patient movements to determine a patient possible movement activity with respect to the bed. Some traditional methods and systems were often such they included heart rate and respiratory monitors, embedded pressure sensors for preventing pressure ulcers. However, such systems were not without their problems. For instance, sometimes a mobility monitor in-bed sensor system did not significantly manage to monitor and determine with enough accuracy to be able to determine a patient activity if the patient would be in the bed or would not be in the bed. An example of an inflatable mattress may be disclosed in patent document number EP2465480A1 . The disclosed mattress has been developed over the years as explained above. A problem with that mattress, and other mattresses, are that they are not able to accurately monitor when a patient is about to leave the bed. With a sensor you may be able to monitor if a person is in the bed or not anymore in the bed. However, in a devastating situation that a patient would fall out from a bed, the falling may result in severe damages for the patient. There have been many attempts to try to overcome this problem by arranging different systems to monitor the patients activity while in bed. However, the problem has been, and still appears to be, to be able have a system which would be able to provide an alert before the patient actually is about to leave the bed, or in wors case, fall of from the bed down and on the floor.

[0006] SUMMARY OF THE INVENTION

[0007] An object of the present invention is to provide a system and a method for a pressure controlled inflatable mattress, as well as a pressure controlled inflatable mattress where the addressed problem of monitoring and detecting a patient activity on a pressure controlled inflatable mattress is overcome. This object, and other objects, are achieved to accurately detect when a patient leaves the mattress and generating an alert signal to ensure their safety and well-being in accordance with claims 1 , 7 and 10.

[0008] There is disclosed a system for a pressure controlled inflatable mattress. The system comprising a first sensor pad, an inflatable base pad and an air source.

[0009] The first sensor pad comprises a first fluid path which enters the first sensor pad via a first inlet and exit the first sensor pad via a first outlet, the first outlet is arranged with a first pressure sensor.

[0010] The inflatable base pad comprising a base pad inlet, a base pad outlet.

[0011] The air source is in fluid connection with the first sensor pad and the inflatable base pad, between the air source and the first sensor pad a first non-return valve is arranged, between the air source and the inflatable base pad, a base pad non-return valve is arranged.

[0012] The base pad outlet is arranged with a base pad pressure sensor and a solenoid valve. The inclusion of a first pressure sensor at the first outlet of the first sensor pad allows for real-time monitoring of pressure within the sensor pad, enabling the system to dynamically adjust the air pressure for optimal comfort and support.

[0013] The arrangement of a non-return valve between the air source and the first sensor pad prevents backflow of air, ensuring consistent inflation levels and enhancing the reliability of the system.

[0014] The presence of a base pad pressure sensor and a solenoid valve at the base pad outlet facilitates precise control of the deflation process, allowing for quick adjustments to the firmness of the mattress and improving user experience.

[0015] The system for a pressure controlled inflatable mattress provides the advantage of accurately monitoring the pressure levels in the mattress through the use of multiple sensor pads and pressure sensors.

[0016] The inclusion of non-return valves in the system ensures efficient airflow and prevents backflow, enhancing the overall performance and functionality of the mattress.

[0017] The addition of a solenoid valve and restrictor valve in the system allows for precise control of the air pressure in the inflatable base pad, resulting in optimal comfort and support for the patient.

[0018] The incorporation of a second sensor pad in the system further enhances the monitoring capabilities, providing additional data for analysis and improving the accuracy of detecting patient activity.

[0019] The method for detecting a patient leaving the mattress offers a reliable and efficient way to track patient movements, allowing for timely alerts and appropriate actions to be taken.

[0020] There is disclosed a system wherein the solenoid valve is arranged with a restrictor valve.

[0021] The integration of a restrictor valve with the solenoid valve allows for fine- tuning of the air flow, which can be used to adjust the rate of inflation or deflation of the mattress for more precise comfort settings.

[0022] The restrictor valve can help in maintaining a desired pressure level within the inflatable base pad by modulating the air flow, contributing to the longevity of the mattress material by preventing overinflation.

[0023] There is disclosed a system wherein the system comprises a second sensor pad. The addition of a second sensor pad increases the system's sensitivity to pressure changes, allowing for more accurate adjustments to the user's body weight distribution and movements, thereby enhancing the therapeutic benefits of the mattress.

[0024] The system's capability to monitor two separate points of pressure independently can be used to provide customized support to different areas of the body, which is particularly beneficial for individuals with specific pressure relief needs.

[0025] With a second sensor pad, it enables the system to take into account the differences in weight and movements from the patient body with respect to the patient upper body and lower body.

[0026] There is disclosed a system wherein the second sensor pad comprises a second fluid path which enters the second sensor pad via a second inlet and exit the second sensor pad via a second outlet, the second outlet is arranged with a second pressure sensor.

[0027] The second fluid path with its own inlet, outlet, and second pressure sensor enables independent monitoring and adjustment of pressure in different zones of the mattress, which can improve comfort and support for users with varying pressure point sensitivities.

[0028] The configuration of the second sensor pad with its dedicated pressure sensor allows for the system to detect and respond to asymmetric loads or movements, ensuring a balanced sleeping surface and reducing the risk of discomfort or pressure sores.

[0029] There is disclosed a system wherein the air source is in fluid connection with the second sensor pad.

[0030] The fluid connection between the air source and the second sensor pad ensures real-time monitoring of pressure changes, enabling rapid adjustments to the patient's support conditions.

[0031] This configuration minimizes the complexity of the system by reducing the need for additional conduits or control mechanisms, thereby enhancing the reliability and ease of maintenance of the system.

[0032] There is disclosed a system wherein between the air source and the second sensor pad a second non-return valve is arranged. The inclusion of a second non-return valve prevents the backflow of air, ensuring that the desired pressure is maintained within the second sensor pad for accurate monitoring.

[0033] The second non-return valve contributes to the overall system safety by providing a fail-safe mechanism that protects against sudden deflation, which could compromise patient support and comfort.

[0034] There is disclosed a pressure controlled inflatable mattress for supporting and monitoring a patient activity while being arranged on the pressure controlled inflatable mattress, the pressure controlled inflatable mattress comprises a head part, a feet part, a first long side and a second long side, a top cover, an air cell layer, a sensor layer, and a base cover, the air cell layer is arranged with air cells which collaborate with an air source arranged to provide pressurized air to the air cells, the air source is in communication with a processor which regulates amount of pressurized air from the air source to the air cells. Further, the pressure controlled inflatable mattress is arranged with an inflatable base pad neighboring the sensor layer and which inflatable base pad is part of system as described above.

[0035] The integration of an inflatable base pad adjacent to the sensor layer allows for enhanced pressure distribution and patient comfort by providing an additional layer of adjustability to the mattress's firmness.

[0036] The communication between the air source and the processor facilitates automated regulation of air pressure, which can adapt to the patient's movements and weight changes, thereby preventing pressure ulcers and improving patient outcomes.

[0037] There is disclosed a pressure controlled inflatable mattress wherein the inflatable base pad is arranged between a bladder and the sensor layer in the pressure controlled inflatable mattress.

[0038] Positioning the inflatable base pad between the bladder and the sensor layer offers a protective cushioning that shields the sensors from direct pressure and potential damage, thereby increasing the durability and lifespan of the sensors.

[0039] This arrangement allows for more accurate data collection from the sensor layer as the inflatable base pad can evenly distribute the patient's weight across the sensors, leading to improved monitoring and patient care management.

[0040] There is disclosed a pressure controlled inflatable mattress wherein the inflatable base pad is arranged above and next to the first sensor pad. The arrangement of the inflatable base pad above and next to the first sensor pad provides a more accurate detection of pressure changes due to the patient's movements, enhancing the sensitivity and reliability of the system.

[0041] This configuration allows for a compact design of the mattress system, potentially reducing the overall size and making it more suitable for various healthcare settings.

[0042] There is disclosed a method to detect a patient leaving a pressure controlled inflatable mattress comprising a system as described above. Further, the method comprising the following steps:

[0043] - performing a change of pressure on the pressure controlled inflatable mattress by the patient as the patient arranged on the pressure controlled inflatable mattress transitioning from a laying position to a sitting position on the pressure controlled inflatable mattress,

[0044] - sampling values from the change of pressure by the inflatable base pad and the first sensor pad as digital signals in the inflatable base pad and the first sensor pad,

[0045] - communicating the signals from the inflatable base pad and the first sensor pad to a processor,

[0046] - calculating the signals in the processor into a first value, a second value, and a third value,

[0047] - processing and comparing the first value, the second value, and the third value in the processor with a preset threshold value,

[0048] - if at least one of the first value, second value, or third value deviates from the preset threshold value, the processor generates a first digital output signal to a receiving unit which indicates the patient is present on the pressure controlled inflatable mattress,

[0049] - if the first value, the second value, and the third value meet the preset threshold value, the processor generates a second digital output signal to the receiving unit which indicates the patient has moved away from the pressure controlled inflatable mattress.

[0050] The method enables real-time monitoring of a patient's movements, allowing for immediate response by healthcare providers in case the patient requires assistance, thereby improving patient safety. By processing and comparing multiple values against a preset threshold, the system minimizes false alarms, ensuring that alerts are only generated when significant movement is detected.

[0051] The use of digital signals for communication between the sensor pads and the processor ensures high accuracy and reduces the likelihood of signal degradation, leading to more reliable monitoring.

[0052] There is disclosed a method wherein the method comprises the step of sampling the pressure change obtained from the second sensor pad.

[0053] Sampling pressure changes from the second sensor pad provides an additional data point for detecting patient movement, which can improve the accuracy of the system in determining whether a patient is still present on the mattress.

[0054] The inclusion of a second sensor pad allows for cross-verification of data, which can help in reducing false positives and negatives, thereby enhancing the overall reliability of the patient monitoring system.

[0055] There is disclosed a method wherein the method comprises the step of sampling values from the pressure change obtained from the second sensor pad into the processor.

[0056] Directly sampling values from the pressure change obtained from the second sensor pad into the processor allows for faster data processing, leading to quicker response times in the event of a patient leaving the mattress.

[0057] This method simplifies the data acquisition process by eliminating the need for intermediate data handling steps, potentially reducing the complexity of the system and improving its robustness.

[0058] There is disclosed a method wherein the method comprises the step of calculating sum of the values from the second sensor pad together with the values from the inflatable base pad and the first sensor pad.

[0059] The integration of values from multiple sensor pads, including the second sensor pad, the inflatable base pad, and the first sensor pad, provides a comprehensive data set that enhances the accuracy of the monitoring system by considering various pressure points or contact areas.

[0060] By calculating the sum of values from different sensor pads, the method allows for a more robust detection of anomalies or changes in the monitored environment or subject, which can lead to improved responsiveness in applications such as medical monitoring or security systems.

[0061] The aggregation of data from multiple sources can compensate for potential deficiencies or inaccuracies in individual sensors, leading to a more reliable overall measurement that can be critical in safety-critical applications.

[0062] There is disclosed a method wherein the method comprises the step that the comparing of the values is performed during a time period between 1 to 5 seconds.

[0063] Performing the comparison of values within a specific time period of 1 to 5 seconds ensures timely processing of data, which is essential for real-time applications where immediate decision-making is required, such as in medical devices or emergency response systems.

[0064] The defined time period for comparison allows for the system to filter out transient noise or temporary fluctuations that may not be relevant to the analysis, thereby reducing false positives and improving the precision of the system.

[0065] By standardizing the time period for comparison, the method can be optimized for power efficiency, as the processing unit can enter a low-power state when not actively comparing values, which is beneficial for battery-operated devices.

[0066] There is disclosed a method wherein the method comprises the step that the comparing of the values is performed during a time period of at least 3 seconds.

[0067] A minimum comparison time period of at least 3 seconds ensures that the system accounts for sustained trends in the data, which can be indicative of significant events or conditions, thus enhancing the reliability of the monitoring process.

[0068] The extended duration for data comparison reduces the likelihood of premature alerts based on short-term fluctuations, leading to fewer interruptions for users and a more user-friendly experience.

[0069] By setting a threshold duration for comparison, the method can be tailored to detect conditions that manifest over a longer time scale, which is particularly advantageous in applications such as sleep monitoring or long-term environmental sensing.

[0070] There is disclosed a method wherein the method comprises the step of generating an alert signal by the receiving unit when the receiving unit receives the second signal from the processor. The generation of an alert signal by the receiving unit upon receipt of the second signal from the processor enables immediate notification of critical events, allowing for swift intervention or corrective action, which is crucial in emergency or health monitoring scenarios.

[0071] This feature facilitates a decentralized alert system where the receiving unit can act independently to notify users or connected systems without the need for continuous communication with the processor, thereby enhancing the system's efficiency and reliability.

[0072] The ability to generate an alert signal based on processed data ensures that users are informed based on a comprehensive analysis rather than raw data, which can help prevent unnecessary alarms and focus attention on genuine issues.

[0073] BRIEF DESCRIPTION OF DRAWINGS

[0074] The present disclosure is illustrated by way of example and not limited in the accompanying Figureures in which like reference numerals indicate similar elements. Embodiments of the application will now be described with reference to the attached drawings:

[0075] Figure 1 shows an exploded view of a pressure controlled inflatable mattress;

[0076] Figure 2 shows a pressure controlled inflatable mattress system with a first sensor pad;

[0077] Figure 3 shows a pressure controlled inflatable mattress system with a second sensor pad;

[0078] Figure 4 shows a flowchart of a method for detecting a patient leaving a pressure controlled inflatable mattress.

[0079] DETAILED DESCRIPTION OF PREFERRED EMBODIMENT OF THE INVENTION

[0080] Figure 1 illustrates a pressure controlled inflatable mattress (1 ) in an exploded view format showing the head part (22), feet part (23), the first long side (24), and the second long side (25), along with other internal components such as the air cell layer (27), the sensor layer (28), the inflatable base pad (3), and the first and second sensor pads (2, 16). The image depicts an exploded view of the components making up the pressure controlled inflatable mattress (1). At the top, there is a representation of the top cover (26) which spans the head part (22) to the feet part (23) with the first long side (24) and the second long side (25). Below that, the air cell layer (27) is equipped with multiple air cells (30) distributed across the layer to provide adjustable support. Below the air cell layer (27), a bladder (31 ) is positioned to presumably offer structural integrity or additional pressure distribution. The bladder (31 ), also called turning bladder (31), may comprise a first and second turning bladder. The turning bladders are arranged to inflate and help a patient on the pressure controlled inflatable mattress (1 ) to change their position on the pressure controlled inflatable mattress (1). The first turning bladder is arranged along the first long side (24) of the pressure controlled inflatable mattress (1 ). The second turning bladder is arranged along the second long side (25) of the pressure controlled inflatable mattress (1 ). The first and the second turning bladder may be arranged on a part of the pressure controlled inflatable mattress (1 ) which is arranged to mainly receive a patient upper body when the patient is lying on the pressure controlled inflatable mattress (1). During use, the first or the second turning bladder is inflated with air whereby its volume increases whereby the patient is pushed, or partly lifted, by the turning bladder (31 ) for facilitating the patient to change their position on the pressure controlled inflatable mattress (1). The turning bladders are arranged to be in communication with the air source (4). The inflatable base pad (3) is shown with a patterned surface suggesting its inflatable nature and is designed to be adjacent to the sensor layer (28). The sensor layer (28) is situated above the second sensor pad (16) which contains multiple components and circuitry for monitoring pressure changes. The base cover (29) forms the bottom-most layer, and the first sensor pad (2) is depicted immediately above the base cover (29) and may also be loaded with various sensor and control elements. The components are disassembled to clearly show the arrangement and relationship between each part within the pressure controlled inflatable mattress system. This detailed breakdown aids in understanding the construction and functionality of this complex device.

[0081] Figure 2 depicts a schematic representation of a pressure controlled inflatable mattress system, showing an air source (4) connected to a first sensor pad (2) and an inflatable base pad (3) with associated valves, sensors, and a restrictor valve. The Figure 2 illustrates the components and their connections within a pressure controlled inflatable mattress system. - An air source (4) is shown, which is connected and provides air flow to both a first sensor pad (2) and an inflatable base pad (3).

[0082] - The first sensor pad (2) includes a first fluid path (5) entering via a first inlet (6) and exiting via a first outlet (7). At the first outlet (7), a first pressure sensor (8) is located to measure the pressure inside the first sensor pad (2).

[0083] - The inflatable base pad (3) is communicating to the air source (4) via a base pad inlet (9) and features a base pad outlet (10). A base pad pressure sensor (13) and a solenoid valve (14) are associated with the base pad outlet (10).

[0084] - Two non-return valves are visible in the system as illustrated in Figure 2: one is a first non-return valve (11 ) placed between the air source (4) and the first sensor pad (2), and the other is a base pad non-return valve (12) situated between the air source (4) and the inflatable base pad (3). These valves ensure unidirectional flow from the air source (4) to the respective components.

[0085] - Additionally, the solenoid valve (14) is equipped with a restrictor valve (15) to regulate the flow and pressure exiting the inflatable base pad (3) through the base pad outlet (10).

[0086] - An air feed sensor (32) is also depicted and in communication with the air source (4). The air feed sensor (32) may be outside the direct flow path of the pressurized air, likely used for monitoring or controlling the air supply. This system, as claimed, is designed to control the pressure within the inflatable mattress to support patient needs and monitor their activity.

[0087] Figure 3 depicts a schematic representation, configuration, of a pressure- controlled inflatable mattress system with various components such as the air source (4), sensor pads, non-return valves, a solenoid valve, and pressure sensors. The schematic representation illustrates an air source (4) connected to two distinct pathways through non-return valves (11 , 17). One path leads to a first sensor pad (2) regulated by a first non-return valve (11 ), entering through a first inlet (6) and exiting through a first outlet (7), where a first pressure sensor (8) is located. The second path leads to a second sensor pad (16) through a second non-return valve (17), with a second inlet (19), a second outlet (20), and a second pressure sensor (21 ). The first sensor pad (2) and the second sensor pad (16) are depicted with their respective fluid paths (5, 18). Additionally, an inflatable base pad (3) is connected to the air source (4) via a non-return valve (12) and features a base pad inlet (9) and a base pad outlet (10). A base pad pressure sensor (13) and a solenoid valve (14) equipped with a restrictor valve (15) are situated at the base pad outlet (10). Also visible is an air feed sensor (32) that likely monitors the air flow or pressure leaving the air source (4). The diagram outlines the flow of air from the air source (4) to both the sensor pads and the base pad, the regulation of this flow by various non-return valves, and the monitoring of pressure by the pressure sensors (8, 13, 21 ), the solenoid valve (14), and the restrictor valve (15) within the system. The respective pressure sensor (8, 13, 21 ) may be communicating with a processor. In the processor information, e.g. signals, from the sensors are processed whereby activity of the air source (4) may be regulated. Further in the processor, the processed signals may also regulate, or control, respective valve how much fluid they may allow to pass through.

[0088] Figure 4 illustrates a flowchart that sequences steps involved in detecting a patient leaving a pressure controlled inflatable mattress through sampling of pressure sensor values, calculating several conditions based on these values, comparing them against threshold values, and potentially activating an alarm if the conditions are met.

[0089] The flowchart starts with the initial step A (101 ) "Starting system". From there, it proceeds to step B (102) "Sampling values from pressure sensors" where the system samples the pressure values obtained from the sensors. Following this, steps C to E (103 - 105) involve processing the sampled values being:

[0090] - step C (103) "Calculating first sum of values from the sensor pad pressure sensors";

[0091] - step D (104) "Adding the calculated first sum to an automat short moving average and an automat long moving average", and;

[0092] - step (105) "Calculating second sum from each individual sensor pad pressure sensor minus base pad pressure".

[0093] The subsequent steps F to I (106 - 109) involve further data analysis being:

[0094] - step F (106) "Adding the calculated second sum to a differential short moving average and a differential long moving average";

[0095] - step G (107) "Calculating condition A = (differential short moving average) I (differential long moving average)";

[0096] - step H (108) "Calculating condition B = differential long moving average", and; - step I (109) "Calculating condition C = (automat long moving average) - (automat short moving average)".

[0097] The decision-making process involves checking these calculated conditions against thresholds in steps J to Q (110 - 117). For each condition, if it does not meet its respective threshold value at step L (112), step 0 (115), or step R (118), there is a loop back to an earlier step with the assistance of either the "Resetting counter" at step W (123) or "Initiating delay - Period for sampling values from the pressure sensors" at step X (124), allowing the process to re-sample and re-evaluate.

[0098] The decision steps are as follows:

[0099] - step J (110) "Condition A < Percentage Threshold Value";

[0100] - step M (113) "Condition B > Min differential pressure Threshold Value";

[0101] - step P (116) "Condition C > Min automat pressure Threshold Value".

[0102] If all conditions meet their respective threshold values, the flowchart moves to step S (119) "Incrementing counter" and step T (120) "Counter = Patient exit determination patient count". If the counter equals the patient exit determination patient count, step II (121) leads to step Y (125) "Activating of alarm" indicating that the patient has potentially left the mattress. If not, step V (122), the process loops back to the initiating delay step X (124). After step X (124), the process may be entered in again after the initial step A (101 ) "Starting system", but before step B (102) "Sampling values from pressure sensors".

[0103] Hereinbefore it has been described that the pressure controlled inflatable mattress may be arranged for patients for monitoring the patient activity to be able for a patient care taker to be alerted if the movements of the patient would risk the patient to fall of the pressure controlled inflatable mattress. It will be appreciated that the principles in regards of the system, the method and the mattress described above may be applied to other systems, methods and mattresses or other types of arrangements for monitoring a patient activity. REFERENCE NUMERAL LIST

[0104] 1 pressure controlled inflatable mattress

[0105] 2 first sensor pad

[0106] 3 inflatable base pad

[0107] 4 air source

[0108] 5 first fluid path

[0109] 6 first inlet

[0110] 7 first outlet

[0111] 8 first pressure sensor

[0112] 9 base pad inlet

[0113] 10 base pad outlet

[0114] 11 first non-return valve

[0115] 12 base pad non-return valve

[0116] 13 base pad pressure sensor

[0117] 14 solenoid valve

[0118] 15 restrictor valve

[0119] 16 second sensor pad

[0120] 17 second non-return valve

[0121] 18 second fluid path

[0122] 19 second inlet

[0123] 20 second outlet

[0124] 21 second pressure sensor

[0125] 22 head part

[0126] 23 feet part

[0127] 24 first long side

[0128] 25 second long side

[0129] 26 top cover

[0130] 27 air cell layer

[0131] 28 sensor layer

[0132] 29 base cover

[0133] 30 air cells

[0134] 31 bladder

[0135] 32 air feed sensor cell holding element Step A StepB StepC StepD StepE StepF StepG StepH Step I Step J Step K StepL StepM Step N StepO StepP StepQ step R StepS StepT Step U StepV StepW StepX StepY

Claims

CLAIMS1 . A system for a pressure controlled inflatable mattress (1), the system comprising a first sensor pad (2), an inflatable base pad (3) and an air source (4), the first sensor pad (2) comprises a first fluid path (5) which enters the first sensor pad (2) via a first inlet (6) and exit the first sensor pad (2) via a first outlet (7), the first outlet (7) is arranged with a first pressure sensor (8), the inflatable base pad (3) comprising a base pad inlet (9), a base pad outlet (10), the air source (4) is in fluid connection with the first sensor pad (2) and the inflatable base pad (3), between the air source (4) and the first sensor pad (2) a first non-return valve (11 ) is arranged, between the air source (4) and the inflatable base pad (3), a base pad non-return valve (12) is arranged, characterized in that, the base pad outlet (10) is arranged with a base pad pressure sensor (13) and a solenoid valve (14).

2. A system according to claim 1 , wherein the solenoid valve (14) is arranged with a restrictor valve (15).

3. A system according to claim 1 , wherein the system comprises a second sensor pad (16).

4. A system according to claim 3, wherein the second sensor pad (16) comprises a second fluid path (18) which enters the second sensor pad (16) via a second inlet (19) and exit the second sensor pad (16) via a second outlet (20), the second outlet (20) is arranged with a second pressure sensor (21).

5. A system according to claim 4, wherein the air source (4) is in fluid connection with the second sensor pad (16).

6. A system according to claim 5, wherein between the air source (4) and the second sensor pad (16) a second non-return valve (17) is arranged.

7. A pressure controlled inflatable mattress (1) for supporting and monitoring a patient activity while being arranged on the pressure controlled inflatable mattress (1 ), the pressure controlled inflatable mattress (1 ) comprises a head part (22), a feet part (23), a first long side (24) and a second long side (25), a top cover (26), an air cell layer (27), a sensor layer (28), and a base cover (29), the air cell layer (27) is arranged with air cells (30) which collaborate with an air source (4) arranged to provide pressurized air to the air cells (30), the air source (4) is in communication with a processor which regulates amount of pressurized air from the air source (4) to the air cells (30), characterized in that, the pressure controlled inflatable mattress (1) is arranged with an inflatable base pad (3) neighboring the sensor layer (28) and which inflatable base pad (3) is part of system according to claim 1 to 6.

8. A pressure controlled inflatable mattress (1) according to claim 7, wherein the inflatable base pad (3) is arranged between a bladder (31 ) and the sensor layer (28) in the pressure controlled inflatable mattress (1).

9. A pressure controlled inflatable mattress (1) according to claim 7, wherein the inflatable base pad (3) is arranged above and next to the first sensor pad (2).

10. A method to detect a patient leaving a pressure controlled inflatable mattress (1) comprising a system according to claims 1 to 6, the method comprising the following steps: - performing a change of pressure on the pressure controlled inflatable mattress (1) by the patient as the patient arranged on the pressure controlled inflatable mattress (1 ) transitioning from a laying position to a sitting position on the pressure controlled inflatable mattress (1),- sampling values from the change of pressure by the inflatable base pad (3) and the first sensor pad (2) as digital signals in the inflatable base pad (3) and the first sensor pad (2),- communicating the signals from the inflatable base pad (3) and the first sensor pad (2) to a processor,- calculating the signals in the processor into a first value, a second value, and a third value,- processing and comparing the first value, the second value, and the third value in the processor with a preset threshold value,- if at least one of the first value, second value, or third value deviates from the preset threshold value, the processor generates a first digital output signal to a receiving unit which indicates the patient is present on the pressure controlled inflatable mattress (1),- if the first value, the second value, and the third value meet the preset threshold value, the processor generates a second digital output signal to the receiving unit which indicates the patient has moved away from the pressure controlled inflatable mattress (1 ).11 . A method according to claim 10, wherein the method comprises the step of sampling the pressure change obtained from the second sensor pad (16).

12. A method according to claim 10, wherein the method comprises the step of sampling values from the pressure change obtained from the second sensor pad (16) into the processor.

13. A method according to claim 10, wherein the method comprises the step of calculating sum of the values from the second sensor pad (16) together with the values from the inflatable base pad (3) and the first sensor pad (2).

14. A method according to claim 10, wherein the method comprises the step that the comparing of the values is performed during a time period between 1 to 5 seconds.

15. A method according to claim 10, wherein the method comprises the step that the comparing of the values is performed during a time period of at least 3 seconds.

16. A method according to claim 10, wherein the method comprises the step of generating an alert signal by the receiving unit when the receiving unit receives the second signal from the processor.

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