Security system for detecting errors in medical station

Abstract

A system for detecting errors of sensors in a surgical table and / or errors in determining a load or a load center, the system comprising: a surgical table having an adjustable patient support surface for supporting a patient; a sensor device having a plurality of sensors that output sensor values; a determination unit that determines, from the sensor value, at least one of the following first variables: a load, a center of the load, a speed of the center of the load, and an acceleration of the center of the load, where the load is a load acting on the sensor device or a load acting on the operating table or a total load of the operating table; a calculation unit that predicts or calculates at least one expected second variable; and an error detection unit which compares the sensor value or the at least one first variable with at least one expected second variable and detects an error and / or a possible error if the deviation exceeds a predetermined value.

Description

[0001] This application claims the priority of German Patent Application No. 10 2022 110888.0 filed with the German Patent and Trademark Office on May 3, 2022. The disclosure content of German Patent Application No. 102022110888.0 is hereby incorporated into the disclosure content of the present application. Technical Field

[0002] The present disclosure relates to medical and operating tables, in which the table top and / or sections of the table top are movable. In particular, it relates to a system that can detect errors that may occur in the medical table. These errors can be, for example, malfunctions of sensors integrated into the table or errors that occur when determining the load or load center. Background Art

[0003] Operating tables are used, for example, to support patients during surgical operations. Currently, nurses and doctors have to consider many important aspects in order to be able to use the operating table correctly, due to the flexibility during the setting up of the operating table, the number of accessories and the different possibilities for patient positioning provided by the operating table. Some of these aspects are listed below:

[0004] - The accessories used should be adapted to the patient's weight.

[0005] - The configuration of accessories should also be matched to the patient's weight.

[0006] - The patient support surface on which the patient is positioned should only move within the permitted limits.

[0007] - If there are movement restrictions, then care should be taken not to exceed the permitted limits at any time.

[0008] When adjusting the operating table, care must be taken that it does not collide with external objects, such as a C-arm.

[0009] - In addition, when adjusting the operating table, care should be taken that the patient is properly secured and does not fall or slip off the operating table.

[0010] Important information about the above points is listed in the operating table's instructions for use. If the user ignores the instructions for use or does not pay enough attention to collisions and patients, the following dangerous events may occur:

[0011] - Operating table tip-over: The patient falls, which can result in permanent injury or even death.

[0012] - Overloading of accessories and structural components of the operating table: This may cause permanent bending or breaking of structural components and result in permanent injury or even death to the patient.

[0013] - Overloading of the motor-driven joints: This results in limited mobility because the operating table cannot move.

[0014] - Collisions of the operating table with external objects: During movement, the operating table may collide with and damage expensive equipment, such as a C-arm.

[0015] - Patient falls: When the patient is not adequately secured, the patient may start to slide in case of table movement, which in the worst case may cause the patient to fall to the floor.

[0016] The patient support surface of the operating table can have replaceable, detachably connected sections. Usually, some or all replaceable sections are movable. By using different replaceable sections, a unique operating table can be reconfigured in different ways for different patients and medical methods. In addition, each section or the entire patient support surface can be adjusted in different ways. For example, each section or the entire patient support surface can be tilted or flipped or moved in the longitudinal or vertical direction. However, this means that the size, shape, size, weight and firmness of each operating table are different at different times. In order to prevent the operating table from tipping over or the individual structural parts of the operating table or the entire operating table from being overloaded, it should be known that the patient support surface and its sections are located in which position and how much load is applied to the patient support surface or the entire operating table and where the center of the load is located. For this purpose, the operating table can have different sensors, which for example measure or determine the load applied to the operating table, at what angle the patient support surface is tilted or flipped or how far the patient support surface moves out. Such sensors must be fail-safe, otherwise the safety of the patient cannot be ensured. When a sensor fails and provides bad information, the system should take note of this. In addition, the user should be warned that a particular system is unreliable and the operating table is in a safety-critical state. In addition, certain functionality of the operating table may be blocked and the movement of the operating table may be slowed or completely stopped.

[0017] The solution to the described problem is to use a second set of redundant sensors. If one of the sensors fails, this will be noticed by the second redundant sensor. However, redundant sensors are cost-intensive and are usually not available due to insufficient installation space in the operating table.

[0018] Document US 11058325 B2 discloses a patient support device having a patient support surface, a main sensor, a plurality of secondary sensors, a main control device and a secondary control device. The main sensor is a load sensor, which measures the force applied to a component of the patient support surface. The main control device obtains the force measurement from the main sensor. The secondary sensor measures a plurality of secondary parameters, which affect the force measurement performed by the main sensor. The secondary sensor can include a humidity sensor, a pressure sensor, a gyroscope, a magnetometer, an accelerometer, a velocity sensor, a temperature sensor or an angle sensor. The secondary control device processes the output of the secondary sensor to identify whether the force applied to the component of the patient support device is outside the range of force values. US 11058325 B2 does not disclose an operating table system as disclosed herein, which determines the load acting on the load sensor device or the patient support surface, the center of the load, the velocity of the load center or the acceleration of the load center as a first variable, and predicts or calculates another expected second variable, wherein if the two variables deviate too much from each other, an error is detected.

[0019] Document US 7472439 B2 discloses a hospital bed that can be used in a hospital. The diagnostic and control system can monitor or query the functionality or status of electronic components, such as load sensors. The diagnostic and control system can monitor the current status of the operating parameters of these electronic components and align the collected data with a set of standard operating characteristics. In this way, possible errors can be identified when a specific electronic component does not work within the expected and / or predetermined range. US 7472439 B2 does not disclose: calculating expected variables based on the operating parameters of the electronic components, and comparing the expected variables with the operating parameters.

[0020] Document WO 2017003766 A1 describes a personnel support device. A load sensor is integrated into the personnel support device and is connected to a detection circuit. With the aid of the detection circuit, it is possible to determine whether the load sensor is operating in a faulty manner. Two load sensors can be provided, each of which is coupled to an activation circuit. An activation voltage source applies a constant voltage to the two activation circuits. In one embodiment, a control device monitors the total amount of current flowing from the activation voltage source to the activation circuit. When the total amount of current flowing from the activation voltage source to the activation circuit is outside a predetermined range, the control device determines that one of the load sensors is in a faulty state. WO 2017003766 A1 does not disclose calculating another expected variable based on a load or load center determined with the aid of a load sensor, and determining an error when the calculated expected variable deviates too much from the determined load or load center. Summary of the invention

[0021] The object of the present disclosure is to provide a system which is designed in an advantageous manner for detecting faulty sensors in an operating table.

[0022] Additionally or alternatively, the system is designed to be able to detect possible errors in the determination of the load or the load center of the operating table.

[0023] According to a first aspect of the disclosure, a system is provided, which is designed to detect faulty sensors in an operating table and / or to detect errors when determining the load or load center. The system can include: an operating table with an adjustable patient support surface, a load sensor device with a plurality of load sensors, a computing unit, and an error detection unit.

[0024] The patient support surface of an operating table is used to support a patient, for example during a surgical operation. The patient support surface can be designed modularly and have a main support surface section, which can be widened by coupling various auxiliary support surface sections. For this purpose, the main support surface section and the auxiliary support surface section can have mechanical connecting elements, to which the main support surface section and the auxiliary support surface section can be detachably connected. For example, the auxiliary support surface section can be a leg section or a head section. In addition, the auxiliary support surface section can also be an extension section or an intermediate section, which is embedded, for example, between the main support surface section and the head section.

[0025] The load sensor can output a sensor value from which the load acting on the load sensor device and, in addition, the load acting on the patient support surface can be determined. The load acting on the load sensor device can include, in particular, all force variables acting on the load sensor device, i.e., forces and torques. The load sensor can be a force sensor, in particular a weighing cell, which, for example, measures the forces acting on the corresponding sensor. The force sensor can output a corresponding electrical signal, for example, a voltage, as an output signal, from which the respectively measured force can be derived. Furthermore, it can also be provided that the force sensor outputs, for example, in digital form as a sensor value, the specific magnitude of the force respectively measured by it.

[0026] Furthermore, it is conceivable that the load sensor arrangement determines a resulting total force as a function of the sensor values ​​of the individual load sensors, wherein the resulting total force is produced by individual forces acting on the different force sensors.

[0027] The loads acting on the load sensor device include, for example, loads caused by components of the operating table arranged above the load sensor arrangement, and loads caused by a patient supported on the operating table or other objects located on the operating table. In addition, a person may also cause a load acting on the operating table, for example, by standing next to the operating table and supporting himself on the operating table with his hands or other body parts. In addition, external forces generated in different ways may cause loads acting on the operating table. Such loads can also be measured by the load sensor device.

[0028] The load sensor device can be arranged at different positions on the operating table. For example, the load sensor device can be integrated into the column of the operating table. In addition, the load sensor device can be arranged at and adjacent to the interface, which is the interface formed by the column and the patient support surface or the support foot (such as the base). Therefore, the load sensor device can be arranged, for example, between the patient support surface and the column. Alternatively, the load sensor device can be arranged, for example, between the column and the support foot.

[0029] The load sensor device can be integrated in the operating table so that the entire load flows through the load sensor device or is transmitted by it. In particular, the load caused above the load sensor device can flow through the load sensor device or be transmitted by it.

[0030] The load determination unit can be coupled to the load sensor device and obtain a sensor value output by the load sensor. Based on the sensor value, the load determination unit can determine at least one first variable, i.e. exactly one or more first variables. The first variable can be the load, the load center of the load, the speed of the load center or the acceleration of the load center. The load can be the load acting on the load sensor device or the load acting on the operating table or can be the total load of the operating table.

[0031] The load acting on the load sensor device can also be referred to as the measurement load. The measurement load corresponds to the load on the load sensor caused by all persons, objects and forces acting on the operating table. The measurement load corresponds to the load value measured by the load sensor device.

[0032] The load acting on the operating table can be called effective load and corresponds to the load caused by components and personnel not associated with the operating table and external forces and acting on the operating table. The components associated with the operating table are components that are identified from the operating table with the aid of a detection system, such as supporting surface segments or sections and / or other accessories. The influence of the components associated with the operating table is not taken into account in the case of effective load. Only the remaining components of the operating table that are not associated with the operating table contribute to the effective load. This can be, for example, an accessory that cannot be identified from the operating table or can be other objects placed on the operating table. In addition, the patient located on the operating table contributes to the effective load. In addition, all forces acting on the operating table from the outside, such as forces applied to the operating table by personnel and / or objects outside the operating table, contribute to the effective load.

[0033] The total load of the operating table is the load resulting from the measured load and the load caused by components associated with the operating table and located below the load sensor device. The total load therefore takes into account the loads of components that are located below the load sensor device and cannot be measured by the load sensor device and therefore do not contribute to the measured load. The total load is therefore the load resulting from the complete operating table, the patient, components associated with the operating table, components not associated with the operating table and other external forces.

[0034] In summary, the at least one first variable determined by the load determination unit can be selected from the following variables:

[0035] - a measured load, a measured center of the load, a measured velocity of the center of the load and a measured acceleration of the center of the load;

[0036] - the payload, the centre of the payload, the velocity of the centre of the payload and the acceleration of the centre of the payload; and

[0037] -Total load, center of total load, velocity of center of total load and acceleration of center of total load.

[0038] The calculation unit can calculate or predict at least one expected second variable. The at least one expected second variable can be an estimated and / or predicted variable and can be a time-dependent or time-independent expected value. For example, at least one expected second variable can be calculated directly from at least one first variable, or at least one first variable can be further processed first and at least one expected second variable can be calculated based on the result of the further processing. It can be proposed that at least one expected second variable is calculated or predicted after at least one first variable in time. However, it is also possible to calculate or predict at least one expected second variable before at least one first variable in time. The terms "first variable" and "second variable" are only used to distinguish between the two variables. It does not indicate which of the two variables is calculated, determined or predicted first.

[0039] In some embodiments, the computing unit can only predict the at least one expected second variable and in particular cannot calculate it. In some embodiments, the computing unit can only calculate the at least one expected second variable and in particular cannot predict it.

[0040] The error recognition unit can compare a value determined by the load sensor device or the load determination unit with an expected value determined by the calculation unit. To this end, the error recognition unit can compare the sensor value or at least one first variable determined by the load determination unit with at least one expected second variable. The at least one first variable included in the comparison can be at least one first variable from which the at least one expected second variable is calculated. However, it is also conceivable, for example, to use at least one first variable determined by the load determination unit at another point in time, in particular a later point in time, for comparison with the at least one expected second variable.

[0041] If the comparison shows that the deviation of at least one expected second variable from the sensor value or at least one first variable exceeds a preset value, i.e. the difference between the at least one expected second variable and the sensor value or at least one first variable is greater than a preset value, then the error detection unit can detect the presence of an error and / or a possible error. The error may be a defective sensor, i.e. a sensor that does not function properly, or an error in the determination of the load or the load center.

[0042] The error detection unit enables: when a safety-critical state occurs, the user of the operating table is warned in order to ensure the safety of the patient. In addition, measures can be taken to avoid or prevent the safety-critical state.

[0043] The system described here does not require a complete additional sensor set to detect errors and does not necessarily require additional hardware units. Both the calculation and the error detection unit can be implemented as software functions. However, it is also conceivable that the calculation and / or error detection unit is configured as a hardware unit.

[0044] In addition, the computing unit and / or the error recognition unit can be integrated in the operating table or be located outside the operating table. One or both units can be integrated into a computing unit, for example, which is located outside the operating table and is connected to the operating table, for example via radio or fixed wiring.

[0045] According to a second aspect of the present disclosure, when the patient support surface is adjusted, the calculation unit can predict the load center changed by the adjustment as at least one second variable. In addition, the load determination unit can determine the load center after the patient support surface is adjusted based on the sensor value. The load center determined by the load determination unit after the patient support surface is adjusted can be used by the error detection unit as at least one first variable.

[0046] The error detection unit can compare the center predicted by the calculation unit with the center determined by the load determination unit after adjustment of the patient support surface. If the center predicted by the calculation unit and the center determined by the load determination unit deviate by more than a preset value, the error detection unit can detect an error and / or a possible error. As described above, the error can be a defective sensor, i.e. a sensor that does not function properly, or an error in the determination of the load or the load center.

[0047] The present design concept presupposes an adjustment of the patient support surface, which is the only way to detect errors. The patient support surface can be adjusted, for example, by tilting or turning the patient support surface or by longitudinal or vertical shifting. The tilt (English: trend) of the patient support surface is also called Trendelenburg tilt, in which the patient is supported so that the patient's head is facing downwards and the patient's pelvis is higher up. In the reverse Trendelenburg tilt, the patient's head is supported higher and the pelvis is lower down. A tilt (English: tilt) means that the patient support surface is turned sideways. In the longitudinal shift (English: longitudinal shift), the patient support surface is moved along its main axis, while during the vertical shift (English: lateral shift), the patient support surface is moved perpendicular to its main axis.

[0048] The system can also have an optional state estimation unit which estimates the actual center of the load from the center predicted by the calculation unit and the center determined by the load determination unit.

[0049] In some embodiments, the inputs into the state estimation unit, i.e. the center predicted by the calculation unit and the center determined by the load determination unit, can be weighted. For example, the center predicted by the calculation unit and the center determined by the load determination unit can become the load center estimated by the state estimation unit in equal proportions, i.e. 50% each. Other ratios between the center predicted by the calculation unit and the center determined by the load determination unit can also be chosen. For example, it can be provided that the estimated actual load center corresponds 100% to the center determined by the load determination unit. In this case, the prediction made by the calculation unit will not have any influence on the estimated actual load center.

[0050] The state estimation unit can be a pure software function, but can also be formed as a hardware unit. In addition, for example, the state estimation unit can be integrated into the operating table or can be located outside the operating table and integrated into the above-mentioned computing unit, for example.

[0051] The state estimation unit can have a Kalman filter for estimating the actual load center. In particular, the Kalman filter can be a widened or extended Kalman filter or an unscented Kalman filter.

[0052] The calculation unit, the load determination unit and the state estimation unit can work iteratively. Here, the state estimation unit estimates the actual load center at time t, and the calculation unit predicts the load center at time t+1 based on the actual load center at time t estimated by the state estimation unit. In addition, the load determination unit determines the load center at time t+1. Then, the state estimation unit estimates the actual load center at time t+1 based on the load center at time t+1 predicted by the calculation unit and the load center at time t+1 determined by the load determination unit.

[0053] The iterative method can be carried out in the same manner, in that the calculation unit predicts the load center at time t+2 based on the actual load center at time t+1 estimated by the state estimation unit and the state estimation unit then estimates the actual load center at time t+2 based on the load center at time t+2 predicted by the calculation unit and the load center at time t+2 determined by the load determination unit.

[0054] The error detection unit can detect an error and / or a possible error if a plurality of iterations are performed and the error detection unit finds in at least N iterations that the center predicted by the calculation unit and the center determined by the load determination unit differ by more than a predefined deviation. N can be a predefined number.

[0055] Alternatively, the error detection unit can detect an error and / or a possible error if the center predicted by the calculation unit and the center determined by the load determination unit exceed a predefined deviation in at least one iteration. Therefore, in this embodiment, the error detection unit detects an error as soon as it detects for the first time that the center predicted by the calculation unit and the center determined by the load determination unit differ by more than a predefined deviation.

[0056] A third aspect of the present disclosure proposes a system that is identical or similar in many respects to the system according to the second aspect. The difference between the two systems is that the system according to the third aspect uses the speed or acceleration of the load center instead of the position of the load center. When adjusting the patient support surface, the calculation unit is capable of predicting the speed or acceleration of the load center as at least one second variable. After adjusting the patient support surface, the load determination unit is capable of determining at least the speed or acceleration of the load center as at least one first variable based on the sensor value. The error recognition unit is capable of comparing the speed or acceleration of the load center predicted by the calculation unit with the speed or acceleration of the load center determined by the load determination unit, and if the deviation exceeds a preset value, an error and / or a possible error is detected.

[0057] According to a fourth aspect of the present disclosure, the load determination unit is capable of determining the load and / or the load center based on the sensor value. The load and / or the center of the load determined by the load determination unit is a first variable. The calculation unit is capable of calculating a theoretical sensor value used as a second variable. The theoretical sensor value can be calculated, for example, based on one or more of the following parameters: load, coordinates of the load center, sensor value and / or one or more distances between load sensors. The theoretical sensor value is the sensor value that the load sensor should output under the load and / or load center determined by the load determination unit. The error recognition unit is capable of comparing the sensor value output by the load sensor with the theoretical sensor value calculated by the calculation unit. If the deviation between the sensor value output by the load sensor and the theoretical sensor value calculated by the calculation unit exceeds a preset value, the error recognition unit is capable of detecting an error and / or a possible error. The error can be, in particular, an error of at least one load sensor.

[0058] The error detection unit can advantageously detect an error and / or a possible error even if the patient support surface is not adjusted, ie if the patient support surface is in a static state.

[0059] In order to be able to determine the load and the load center, a certain number of load sensors are required. If the load and the load center are to be determined only in one direction, for example in the x direction, two load sensors are required for this purpose. If the measurement is to be carried out in two directions, namely in the x direction and in the y direction, three load sensors are required for a static determination. In one embodiment, the load sensor device can have at least one more load sensor than is required for a static determination. If two load sensors are sufficient for a static determination, the load sensor device can have at least three load sensors. If three load sensors are required for a static determination, the load sensor device can have at least four load sensors.

[0060] At least one additional load sensor achieves a certain redundancy. From a mathematical point of view, there are infinitely many combinations of three or four forces measured by the load sensors, which result in exactly the same load and the same load center. However, according to the solution rules of the static equilibrium system, there is only one correct combination of three or four measured forces that results in a specific load and a specific load center. If one of the load sensors is damaged, it is statistically impossible for this load sensor to randomly adopt the correct value to produce a balanced system. Therefore, the system balance can be characterized by comparing the measured values ​​of the three or four load sensors with the theoretical values, which are the theoretical values ​​that the load sensors should measure for the load center and load to be determined. If the imbalance exceeds a certain threshold value, at least one load sensor does not work properly.

[0061] In some designs, multiple load sensors can be arranged in a single common plane. In some designs, the load sensors can be arranged symmetrically.

[0062] In some embodiments, the load sensors of the load sensor device can be arranged parallel to each other and in a mirrored manner. For example, the load sensor device can have a total of four force sensors or weighing cells. This embodiment has the following advantages: improved accuracy and reliability.

[0063] A plurality of or all load sensors of the load sensor device can be arranged mirror-symmetrically with respect to a first imaginary axis and mirror-symmetrically with respect to a second imaginary axis. The first axis and the second axis can be oriented orthogonally to each other. For example, the first axis can be parallel to the main axis of the patient support surface, while the second axis is perpendicular to the main axis but parallel to the patient support surface. The load sensor device can be arranged between the patient support surface and the operating table column.

[0064] In some designs, the load sensors are arranged in a grid pattern or mesh with multiple load sensors on each "side". In some embodiments, all of the load sensors are arranged in a common plane. For example, the load sensors can be arranged in a 2×2 grid. The load sensors can be arranged in a grid with 2 to 4 load sensors in each dimension, for example.

[0065] The load sensors arranged in mirror-symmetrical manner can be oriented in the same direction. In particular, the load sensors arranged in mirror-symmetrical manner can be oriented parallel to one another. The load sensors can each have a main axis, wherein the main axes are oriented parallel to one another.

[0066] The load sensors of the load sensor arrangement can be identical in structure.

[0067] In some embodiments, the load sensor has an elongated shape. For example, the load sensor can be a rectangular body.

[0068] According to a fifth aspect of the present disclosure, if the load determined by the load determination unit is negative, the error recognition unit can detect a possible error of at least one load sensor.

[0069] When all load sensors are working correctly, the measured load and thus the measured weight should be positive. However, if the measured load is negative, then the operating table has either collided with an obstacle or the load sensor is not working correctly. A negative force threshold can be used to determine whether the load sensor is working properly.

[0070] According to the sixth aspect of the present disclosure, if the load determined by the load determination unit exceeds a preset value and / or the load center determined by the load determination unit is located outside a preset space, the error identification unit is able to detect an error and / or possible error in at least one of the load sensors.

[0071] The operating table is designed for operation under specific conditions. Therefore, unusual load values, for example a load value of 1000 kg, indicate that the load sensor is not functioning properly. The same applies to the determined load center. If the x, y or z component of the center is abnormally high, for example the x coordinate value of the center has a value of 5.32 m, this indicates that the load sensor is not functioning reliably. In the error detection unit, threshold values ​​can be set in order to check whether the measured loads and load centers are credible.

[0072] According to a seventh aspect of the present disclosure, the error identification unit is capable of detecting an error and / or possible error of one of the load sensors if one of the load sensors does not change its sensor value while the other load sensors change their sensor values, or if one of the load sensors changes its value while the other load sensors do not change their sensor values.

[0073] In principle, load sensors are able to detect changes in load, no matter how small. In most cases, if a load change or a change in center occurs, for example due to a longitudinal movement of the patient, all load sensors will change their value. If one of the load sensors does not change its value, this indicates that the load sensor is defective.

[0074] This also applies in the opposite case. If only one load sensor changes its value and the values ​​of all the remaining load sensors remain the same, this indicates that the load sensor that changed its value is defective.

[0075] According to an eighth aspect of the present disclosure, if the load F determined by the load determination unit is 测量 If the following equation (1) is not followed, the error recognition unit can detect an error and / or a possible error of one of the load sensors:

[0076] F 测量 =F 负荷 ·cosα-(1-cosα)·F dl (1)

[0077] Among them, F 负荷 is the load acting on the patient support surface, α is the inclination angle and / or tilt angle of the patient support surface, and F dlis the tared load that includes all loads that are part of the operating table and are located above the load cell. The tilt angle and / or tilt angle α is determined by the weight force F 负荷 and the measured force F 测量 The angle formed by the vectors of force F 测量 Perpendicular to the main surface of the patient support. Equation (1) is only valid if the force sensor is tilted or turned together with the patient support. For example, if the force sensor is placed at the foot of the operating table, then equation (1) does not apply.

[0078] If the patient support surface flips in any direction, the measured weight appears lower to the load sensor because the gravity vector is no longer perpendicular to the load sensor. 负荷 does not correspond to equation (1), the error detection unit can then detect a fault in the load sensor.

[0079] As already described above, the adjustment of the patient support surface can include one or more of the following operations: tilting the patient support surface, turning the patient support surface, moving the patient support surface longitudinally, moving the patient support surface vertically and moving the patient support surface laterally.

[0080] The error recognition unit can detect not only errors of the load sensor but also errors and / or possible errors of other sensors used in the operating table. In some embodiments, the error recognition unit can detect sensor errors of one or more of the following sensors: load sensor, sensor for detecting the tilt of the patient support surface, sensor for detecting the tilt of the patient support surface, sensor for detecting the longitudinal movement of the patient support surface, sensor for detecting the lateral movement of the patient support surface, and column lifting sensor.

[0081] The error detection unit is not able to detect errors of the column lift sensors which measure the lateral movement of the patient support surface in all systems. In some systems, the column lift sensors can be used to determine the tilt and / or roll angle. From the faulty tilt and / or roll angle it can be concluded that at least one column lift sensor may be faulty.

[0082] If the error recognition unit detects an error, it can generate an error signal which indicates that the operating table is in a safety-critical state.

[0083] Furthermore, an acoustic and / or optical warning signal can be generated. Furthermore, a warning signal in the form of a text can be generated, which can be displayed to a user, for example, on a remote control of the operating table. Furthermore, the movement of the operating table can be restricted. For example, the extension and / or tilting and / or turning of the patient support surface and / or the movement of the operating table can be slowed down or stopped. Furthermore, at least one functionality of the operating table can be blocked.

[0084] If the error detection unit again ascertains a safe state of the operating table, the measures taken can be reduced or cancelled.

[0085] According to a ninth aspect of the present disclosure, a method for detecting errors in sensors in an operating table and / or errors in determining a load or a load center is proposed. The operating table includes an adjustable patient support surface for supporting a patient and a load sensor device having a plurality of load sensors that output sensor values. Based on the sensor value, at least one of the following first variables can be determined: load, center of load, speed of the load center, and acceleration of the load center. The load can be a load acting on the load sensor device or a load acting on the operating table or can be the total load of the operating table. Based on at least one first variable, at least one expected second variable can be calculated. The sensor value or at least one first variable can be compared with at least one expected second variable. If the deviation of the sensor value or at least one first variable from at least one expected second variable exceeds a preset value, an error can be detected.

[0086] The method according to the ninth aspect can have all the designs described in this disclosure in conjunction with the systems according to the first to eighth aspects.

[0087] The present disclosure also includes circuits and / or electronic instructions for controlling an operating table as well as a remote control, display, and user interface for use with the operating table. BRIEF DESCRIPTION OF THE DRAWINGS

[0088] Exemplary embodiments of the present disclosure are explained in detail below with reference to the accompanying drawings: In the accompanying drawings:

[0089] Figure 1 A schematic side view showing an operating table with a patient positioned on a patient support surface of the operating table;

[0090] Figure 2 A schematic diagram showing a system architecture of an operating table system having a load sensor device, a load determination unit, a calculation unit, and an error recognition unit according to the present disclosure;

[0091] Figure 3 A schematic diagram of a surgical table according to the present disclosure is shown to illustrate the measured load, the effective load, and the total load;

[0092] Figures 4A to 4C Schematic diagrams showing different embodiments of an operating table according to the present disclosure with a load sensor device in different positions;

[0093] Figures 5A to 5D Schematic diagrams showing different embodiments of an operating table according to the present disclosure and force sensors arranged in parallel and mirror-symmetrically;

[0094] Fig. 6A and 6B A schematic diagram for illustrating the forces acting on the force sensor is shown;

[0095] Fig. 7A and 7B A schematic diagram is shown for illustrating the reduction of lateral forces due to the symmetrical arrangement of the force sensors;

[0096] Figure 8 A schematic diagram is shown for illustrating the determination of a gravity vector when a patient support surface is tilted;

[0097] Fig. 9 A schematic diagram of an operating table system according to the present disclosure is shown having an iterative operating method for detecting errors;

[0098] Fig. 10A and 10B A schematic diagram of an operating table according to the present disclosure is shown for illustrating the movement of the load center when the patient support surface is tilted;

[0099] Fig.11 A schematic diagram showing an iterative method for detecting errors using a Kalman filter;

[0100] Fig.12 A schematic diagram showing a system model of a Kalman filter;

[0101] Fig.13 Schematic diagram showing flip rotation and tilt rotation;

[0102] Fig.14 A schematic diagram showing an operating table system according to the present disclosure having a method for detecting errors by means of system imbalance;

[0103] Fig.15 Show Fig.14 A schematic diagram of the functional manner of the operating table system in; and

[0104] 16a and 16b show schematic diagrams of different simulated system imbalances. DETAILED DESCRIPTION

[0105] In the following description, exemplary embodiments of the present disclosure are described with reference to the drawings, which are not necessarily to scale but merely schematically illustrate the corresponding features.

[0106] It should be noted that the features and components described below can each be combined with one another, regardless of whether they are described in conjunction with a single embodiment. The combination of features in the respective embodiments serves only to illustrate the basic design and function of the claimed device.

[0107] In the figures, identical or similar elements are provided with the same reference symbols wherever this is expedient.

[0108] Figure 1 A mobile operating table 10 is schematically shown, which can be used to support a patient 12 during a surgical operation and for transporting the patient. The mobile operating table 10 comprises, from bottom to top, feet 14 for placing the operating table 10 on the ground, a vertically arranged operating table column 16 comprising the feet 14, and a patient support surface 18 fixed to the upper end of the operating table column. The patient support surface 18 can be firmly connected to the operating table column 16 or alternatively can be detachably fixed to the operating table column 6.

[0109] The patient support surface 18 is modularly designed and is used to support the patient 12. The patient support surface 18 comprises a support surface main section 20 connected to the operating table column 16 and which can be widened as desired by coupling various support surface auxiliary sections. Figure 1 In the embodiment of the present invention, a leg section 22 , a shoulder section 24 and a head section 26 can be coupled to the bearing surface main section 10 as bearing surface auxiliary sections.

[0110] Depending on the type of surgical operation to be performed, the patient support 18 of the operating table 10 can be brought to a suitable height and can be tilted and folded.

[0111] The operating table column 16 is designed to be height-adjustable and has an internal mechanism for setting the height of the patient support surface 18 of the operating table 10. The mechanism is arranged in a housing 28 which protects the components from contamination.

[0112] The foot support 14 has two sections 30, 32 of different lengths. Section 30 is a short section associated with the foot end of the leg section 22, i.e. the end of the patient support surface 18 on which the foot of the patient 12 to be treated lies. Section 32 is a long section associated with the head section 26 of the patient support surface 18.

[0113] Furthermore, the foot 14 can have wheels or rollers, by means of which the operating table 10 can travel on the floor. Alternatively, the foot 14 can be fixedly anchored to the floor.

[0114] For better illustration, Figure 1 A Cartesian coordinate system XYZ is drawn in FIG. The X-axis and the Y-axis are horizontal axes, the Z-axis is a vertical axis. The X-axis extends along the supporting surface subsections 22 , 24 , 26 arranged adjacent to each other.

[0115] Figure 2 The system architecture of the operating table system 100 according to the present disclosure is schematically shown. The operating table system 100 is a system according to the first aspect of the present disclosure and can be operated by the method according to the ninth aspect.

[0116] Except as Figure 1 In addition to the operating table 10 shown in FIG. 1 , the operating table system 100 also has a load sensor device 102, a load determination unit 104, a safety unit 106, a monitoring and calibration unit 108, a data storage device 110, and other components 112 of the operating table system 100. In addition, the safety unit 106 includes an anti-tilt unit 114 and an overload protection unit 116. The monitoring and calibration unit 108 includes a computing unit 117 and an error detection unit 118.

[0117] The load sensor device 102 includes a plurality of load sensors and is designed to measure at least one variable from which the load acting on the load sensor device 102 can be determined. In the present case, the load sensors are force sensors that respectively measure the forces acting on the respective sensor. The sensor values ​​or force values ​​measured by the individual force sensors are output by the load sensor device 102 as signals 120 in digital form. In addition, the load sensor device 102 includes the electronic components required for operating the force sensors.

[0118] The load determination unit 104 receives a signal 120 with measured sensor values ​​or force values ​​and determines therefrom at least one first variable, wherein the first variable can be the following variables: load, center of load, speed of the center of load and / or acceleration of the center of load. As load, the load determination unit 104 can determine a measured load, an effective load and / or a total load.

[0119] In order to be able to process and analyze the force values ​​provided appropriately, the load determination unit 104 requires some data about the geometry and the mass or weight of the operating table 10 and the accessories. These data are stored in a data memory 110 and are provided to the load determination unit 104 by means of a signal 122. In particular, information about the mass and center of gravity of the individual components of the operating table 10 and the accessories can be extracted from these data. The data memory 110 can be expanded via connection modules of the operating table 10.

[0120] The load determination unit 104 generates a signal 124 as an output signal, which contains information about at least one first variable, namely the determined load and / or load center and optionally the speed and / or acceleration of the load center. In addition, the signal 124 contains sensor values ​​output by the load sensor. This information is transmitted to the safety unit 106 and the monitoring and calibration unit 108.

[0121] In the safety unit 106, all available data are analyzed, including the load, center and position data of the operating table 10 and the accessories recognized by the operating table 10. The safety unit 106 decides whether the operating table 10 is safe or in a dangerous situation. The safety unit 106 generates a safety signal 126, which indicates whether the operating table 10 is in a safety-critical state.

[0122] Depending on the severity of the identified situation, the algorithm will react accordingly. For example, the operating table 10 can only output a warning or stop the movement. The warning can be output by the operating table 10 via an acoustic or optical signal or can be output in text form via a remote control. These measures can vary from slowing down the movement speed to stopping the movement and even preventing some functionality and continue until the operating table 10 is in a safe state again.

[0123] It can be provided that the user can deactivate the safety function at any time and the movement of the operating table 10 can be continued at his own risk.

[0124] The anti-tilt unit 114 and the overload protection unit 116 are subunits of the safety unit 106. Depending on the total load and / or the center of the total load, the anti-tilt unit 114 generates a tipping safety signal 128, which indicates whether there is a risk of tipping of the operating table 10. Depending on the payload and / or the center of the payload, the overload protection unit 116 generates an overload protection signal 130, which indicates whether there is an overload risk for the operating table 10 and / or at least one component of the operating table 10. Alternatively, the overload protection unit 116 can use the measured load or the total load and / or the center of one of these loads to generate the overload protection signal 130. Both the tipping safety signal 128 and the overload protection signal 130 are safety signals of the safety unit 106.

[0125] If the foot 14 does not have any wheels or rollers but is firmly connected to the floor, the anti-tilt unit 114 can be deactivated or not implemented in the safety unit 106 .

[0126] Since the system 100 is to reliably detect critical situations, the system 100 also has a monitoring and calibration unit 108. This software module checks the plausibility of the measured values ​​and detects whether the system is operating defectively or whether a calibration or balancing of the system 100 is required. The monitoring and calibration unit 108 generates corresponding output signals 132, 134, which are transmitted to the load determination unit 104 or to the component 112 of the operating table 10.

[0127] The calculation unit 117 integrated into the monitoring and calibration unit 108 receives a signal 124 from the load determination unit 104, which contains information about at least one first variable, i.e. the determined load and / or load center and optionally the speed and / or acceleration of the load center. The calculation unit 117 calculates at least one expected second variable from the at least one first variable.

[0128] The error recognition unit 118 compares the value determined by the load sensor device 102 or the load determination unit 104 with the expected second variable determined by the calculation unit 117, in that the error recognition unit 118 compares the sensor value or at least one first variable output by the load sensor with at least one expected second variable. If the deviation of at least one expected second variable from the sensor value or at least one first variable exceeds a preset value, the error recognition unit 117 detects that an error exists. The error can be, for example, a defective sensor or an error that occurs when determining the load or the load center. The error recognition unit 118 generates an error signal 138, which is transmitted to the safety unit 106. The detected error and the error signal 138 can be interpreted as a possible error or contain a possible error. In some embodiments, it can be proposed that further checks are required until it is found that an error actually exists.

[0129] If the error recognition unit 118 detects an error and / or a possible error, the safety unit 106 is informed by means of an error signal 138. The safety unit 106 can then take necessary measures. As described above, for example, a warning can be output, or the movement of the operating table 10 can be slowed down or stopped.

[0130] Components 112 of operating table 10 continuously generate position data, data for setting up the individual components, and information about accessories identified from operating table 10. These data are provided to system 100 along with signal 136.

[0131] Figure 3 The schematic diagram illustrates different loads that the load determination unit 104 can determine based on the data provided by the load sensor unit 102. Figure 3In FIG. 1 , the measured load, the effective load and the total load are denoted by reference numerals 140 , 142 and 144 . The load determination unit 104 is able to determine the position of the load center belonging to each of these loads as well as the speed and / or acceleration of the load center.

[0132] The measured load is the load acting on the load sensor device 102. The measured load corresponds to the load generated by all persons, objects located above the load sensor, and forces acting on the operating table 10. The measured load corresponds to the load value measured by the load sensor device 102.

[0133] The effective load corresponds to the load caused by components not associated with the operating table 10 as well as persons and external forces and acts on the operating table 10. The influence of the components associated with the operating table 10 and the identified accessories is not taken into account in the effective load. Only the remaining components of the operating table 10, i.e. the components not associated with the operating table 10, contribute to the effective load. This can be, for example, accessories that cannot be identified from the operating table 10. In addition, the patient located on the operating table 10 contributes to the effective load. In addition, all forces that act on the operating table 10 from the outside, such as those applied to the operating table 10 by persons and / or objects located outside the operating table 10, contribute to the effective load. Basically, the effective load is a measured load that is not influenced by known objects such as tabletop components, identified accessories, etc.

[0134] The total load is the load resulting from the measured load and the load caused by the components associated with the operating table 10 and located below the load sensor device 102. Therefore, the total load takes into account the load of the components located below the load sensor device 102 and which cannot be measured by the load sensor device 102 and thus do not contribute to the measured load. Therefore, the total load is the load resulting from the entire operating table 10, the patient, the components associated with the operating table 10, the components not associated with the operating table 10, and other external forces.

[0135] Figures 4A to 4C Different embodiments of an operating table 10 according to the present disclosure are schematically shown.

[0136] In the operating table 10, a load sensor device 102 with a plurality of load sensors is arranged between at least two parts of the operating table. In particular, the at least two parts are substantially immovable relative to one another. In this embodiment, during the operation of the operating table 10, in particular when adjusting the patient support surface 18, for example when tilting and / or turning over and / or moving the patient support surface out, the at least two parts remain substantially immovable relative to one another, i.e. they remain substantially in the same position relative to one another. This applies both to the spacing between the at least two parts and to one or more angles that the at least two parts form relative to one another.

[0137] Load sensor device 102 is preferably integrated into operating table 10 so that the entire load above the load sensor flows through load sensor device 101 or is transmitted thereby.

[0138] The load sensor device 102 can be disposed at various locations in the operating table 10. Figure 4A In the embodiment shown in FIG. 1 , the load sensor device 102 is disposed between the support leg 14 and the operating table column 16. Figure 4B The load sensor device 102 is integrated into the operating table column. Figure 4C In FIG. 1 , the load sensor assembly 102 is adjacent to the interface between the patient support surface 18 and the operating table column 16 .

[0139] Figure 5A The operating table 10 is shown with a load sensor arrangement 102 arranged between the patient support surface 18 and the operating table column 16. The load sensor arrangement 102 comprises four identical load sensors 1a, 1b, 2a and 2b, which are arranged parallel to each other and in a mirror image. Figure 5B and 5C Two different variants with regard to the placement of the force sensors 1a, 1b, 2a, 2b are illustrated in FIG. Figure 5B and 5C The load sensor device 102 is shown along Figure 5A In some designs, the load sensor device 102 can include at least three or at least four force sensors.

[0140] For orienting force sensors 1a, 1b, 2a, 2c, a first axis 210 and a second axis 212 are provided which are perpendicular to one another. First axis 210 extends parallel to a main axis of patient support surface 18 , while second axis 212 extends perpendicularly thereto but parallel to patient support surface 18 .

[0141] The force sensors 1a, 1b, 2a, 2c each have a main axis, which is located at Figure 5B is oriented parallel to the first axis 210. Figure 5C, the main axes of the force sensors 1a, 1b, 2a, 2b are arranged parallel to the second axis 212. In addition, the force sensors 1a, 1b, 2a, 2b are arranged in pairs in mirror symmetry with the axes 210, 212, respectively. The pairs (1a, 1b), (1a, 2a), (1b, 2b) and (2a, 2b) respectively form mirror symmetric force sensor pairs. In some embodiments, the force sensors 1a, 1b, 2a, 2b are arranged in a 2×2 grid as shown. In some embodiments, the grid arrangement has at least two force sensors 1a, 1b, 2a, 2b on each side. In some embodiments, the force sensors 1a, 1b, 2a, 2b are all located in a unique common plane that intersects the first axis 210 and the second axis 212.

[0142] with Figure 5B and 5C The force sensor can also be arranged differently in the sensor device 102. A number of exemplary alternative arrangements of the force sensor in the sensor device 102 are Figure 5D Shown in.

[0143] In Figure 5B Taking the sensor device 102 shown in FIG. 5C as an example, the measured load can be calculated by adding all the forces measured by sensors 1a, 1b, 2a, 2b. The corresponding center can be calculated with the help of the torque compensation equation given below and in Fig. 6A and 6B Calculated using the forces shown in . Fig. 6A A cross-sectional view along the x-axis is shown. Figure 6B A cross-sectional view along the y-axis is shown. The torque compensation equation can be applied in both directions, allowing the x-component and y-component of the center to be determined:

[0144] F 负荷 =F 1a +F 2a +F 1b +F 2b (2)

[0145]

[0146]

[0147] In equations (2) to (4), F 负荷 is the gravitational force generated by the patient. Force F 1a 、F 1b 、F 2a and F 2b is the force measured by sensors 1a, 1b, 2a, 2b. Parameters a and b are the distances between the sensors in the x-direction or y-direction. CG and Y CGis the x-coordinate or y-coordinate of the center of the patient-induced load.

[0148] By adding or subtracting the corresponding components of the operating table 10 and their center values ​​stored in the data memory 110 , the effective load and the total load and their corresponding center values ​​can be calculated.

[0149] exist Figure 5B and 5C The arrangement of the sensors 1a, 1b, 2a, 2b proposed in the invention makes the system relative to the lateral force F r is robust. Due to the symmetrical arrangement, the lateral force F r is offset, as in Fig. 7A and 7B As shown in .

[0150] If the patient support surface 18 is in an inclined position, the compensation of the transverse forces also allows the described system to measure the forces and the center reliably. Figure 8 Show the gravitational vector F 负荷 How is it divided into two components. One component is transverse to the force sensor and is cancelled due to the effects explained above. The second component F 测量 It runs perpendicularly to the main surface of the force sensor or the patient support surface 18 and is reliably measured. Knowing the inclination angle α of the patient support surface 18 , the actual load on the sensor and its center can be calculated.

[0151] Fig. 9 The operating table system 200 according to the present disclosure is schematically shown, and the operating table system is largely similar to the one in Figure 2 2. Elements of the operating table system 200 that are identical or similar to elements of the operating table system 100 are provided with the same reference numerals.

[0152] The operating table system 200 is a system according to the second aspect of the present disclosure. In addition to the operating table 10, the operating table system 200 also includes a load sensor device 102 having a plurality of load sensors, a load determination unit 104, a calculation unit 117, an error recognition unit 118, and a state estimation unit 119. The state estimation unit 119 can be integrated into the monitoring and calibration unit 108 together with the calculation unit 117 and the error recognition unit 118.

[0153] Before describing the various components and functionality of operating table system 200, the physical and mathematical considerations upon which operating table system 200 is based should first be set forth.

[0154] If the patient or the workload of the operating table 10 moves during the tilting or tilting of the patient support 18, the center of the workload moves along a precalculated circular path. If the patient support moves in the longitudinal direction, the workload moves along a linear path. It is therefore possible to estimate the complete path of the workload when adjusting or moving the patient support.

[0155] This consideration helps here to use the position sensors of the operating table 10 to check the load center determined by the load sensors (and vice versa). If the sensors are faulty, the trajectory determined for the workload will not behave as expected. The expected trajectory can be calculated with the help of the kinematics of the operating table 10 and the physical relationships known from classical mechanics.

[0156] Should be based on Fig. 10A and 10B The diagram illustrates this principle. Fig. 10A The operating table 10 is shown with the patient support surface 18 in a horizontal position. Fig. 10A The center of the patient is marked and the COG is marked by the reference numeral 前 The patient support surface 18 is now tilted, so that the center of the patient moves along a circular trajectory. Fig. 10B In the example, after adjusting the patient support surface 18, the center of the patient passes through the COG 后 Characterization. Center COG 后 The center of the patient to be reached due to the tilting of the patient support surface 18 can be determined using the sensor values ​​of the load sensors. In addition, the center of the patient to be reached due to the tilting of the patient support surface 18 can be predicted or predicted or precalculated or estimated. Fig. 10B The predicted center is called COG 预测 If the center COG 后 COG with predicted center 预测 If the deviation is too large, then we can conclude that there is an error.

[0157] The detected error may be caused by a defective sensor. The defective sensor may be, for example, a load sensor, a sensor for detecting the tilting of the patient support surface, a sensor for detecting the tilting of the patient support surface, a sensor for detecting the longitudinal movement of the patient support surface or a sensor for detecting the transverse movement of the patient support surface. However, errors may also occur when determining the load or the load center.

[0158] The mathematical steps for using the operating table system 200 to detect errors are described below.

[0159] The load center, ie a point with x, y and z coordinates in meters, and the joint position representing the tilt and roll of the patient support 18 in degrees and the longitudinal displacement of the patient support 18 in meters are used as input values.

[0160] The velocity of the load center caused by the longitudinal and / or lateral movement of the patient support surface 18 Able to move vertically and lateral displacement The time derivative is determined as:

[0161]

[0162] The velocity of the load center caused by the tilting and / or tilting of the patient support surface 18 Can be determined by the cycle speed.

[0163]

[0164] in and is the rate at which the center of load cycles during tilting or tipping of the patient support surface 18 .

[0165] is the distance between the measured load centre and the axis of rotation of the tilt / roll joint.

[0166] Total speed of the load center By speed and is composed of and can be determined by the sum of:

[0167]

[0168] The above equation implements: Iteratively predicting the estimated load center. If the center X CG The velocity is known, then the estimated position X of the center can be determined after a short period of time T CG+ .

[0169] In order to detect errors, the operating table system 200 is used in Fig.11 Here, the actual load center at time t is As will be further explained below, the load center is the actual load center estimated by the state estimation unit 119 in the previous iteration cycle. The calculation unit 117 calculates the actual load center at time t according to Predict the load center at time t+1 At time t+1, the sensor value of the load sensor is recorded and the load determination unit 104 determines the load center at time t+1 based on the sensor value The state estimation unit 119 then performs a correction step, for which it uses a Kalman filter. The state estimation unit 119 uses the load center predicted by the calculation unit 117 at the time t+1 to calculate the load center. and the load center at time t+1 determined by the load determination unit 104 To estimate the actual load center at time t+1 Therefore, for the Kalman filter use the value and Using these two sources of information—predictions and measurements—leads to more reliable state estimates.

[0170] Subsequently, another iteration cycle is performed, in which the actual load center at time t+1 is used The calculation unit 117 calculates the actual load center at time t+1. Load center at preset time t+2 In addition, the load determination unit 104 determines the load center at time t+2 based on the sensor value of the load sensor recorded at time t+2. With the help of the Kalman filter, the state estimation unit 119 calculates the load center at time t+2 according to the load center predicted by the calculation unit 117. and the load center at time t+2 determined by the load determination unit 104 To estimate the actual load center at time t+2 The method continues accordingly.

[0171] In the monitoring algorithm described above, a Kalman filter is used to iteratively determine the position estimate of the load center in a similar manner. If the measurement of the current position deviates too much from the prediction within a certain time period, then there may be an error in the sensor or in the determination of the load or load center because the load center does not appear to be trustworthy.

[0172] In each iteration cycle, the error recognition unit 118 can calculate the load center predicted by the calculation unit 117. The load center determined by the load determination unit 104 If the deviation or the distance between the two load centers is too great and, for example, exceeds a predefined value or distance, the error detection unit 118 can detect an error and / or a possible error.

[0173] Since the load can reversibly deform the operating table in some positions, the tolerance for detection errors should be large enough to avoid false positive results. Therefore, a tolerance range should be defined that distinguishes between real errors (eg sensor errors) and sensor noise or inaccuracies of the system model.

[0174] The Kalman filter can be simplified by comparing the velocity or acceleration of the load center calculated from the kinematics of the operating table 10 with the velocity or acceleration of the load center derived from the center measurement instead of estimating the position of the load center according to the third aspect of the present disclosure. If the deviation between the velocities or accelerations is too large, then there is an error.

[0175] To illustrate the functionality of the Kalman filter, an exemplary algorithm is provided below that can be performed by the Kalman filter. For simplicity, it is assumed that the tilt rotation axis and the roll rotation axis have the same starting point. The rotation axes of the tilt and roll and the measured center (X CG ) is expressed as the distance (radius of the circular path). The velocity V of the center CG can be determined as follows:

[0176]

[0177] v x，cg =ω y，ls ·r z -ω z，ls ·r y +v x，ls

[0178] v y，cg =ω z，ls ·r x -ω x，ls ·r z +v y，ls

[0179] v x，cg =ω y，ls ·r z -ω z，ls ·r y +v x，ls (8)

[0180] Among them, the applicable ones are:

[0181] r x =X x，cg -X x，ls

[0182] r y =X y，cg -X y，ls

[0183] r z =X z，cg -X z，ls (9)

[0184] For the Kalman filter, a linear, time-invariant system model is used, such as Fig.12 As shown in .

[0185] The Kalman filter is described by the following equation:

[0186] predict:

[0187]

[0188]

[0189] Filtering:

[0190]

[0191]

[0192] Gains:

[0193] K (k+1)= P * (k+1) H T (k+1)( H (k+1) P * (k+1) H T (k+1)+ R (k+1)) -1 (12)

[0194] B and H Can assume the identity matrix or identity matrix I .

[0195] The state of the system after applying the new observation / measurement

[0196] New observation / measurement at time k

[0197] K (m×n) : Kalman gain matrix, used to project the residual onto the correction of the system state

[0198] A (m×m) :: Transition matrix used to forward the system state at the next time point

[0199] P (m×m) ::x k The error covariance matrix

[0200] Q (m×m):: Unsafe process noise introduced due to modeling errors or limit changes

[0201] H (n×m) ::Observation matrix used to project the system state onto observations / measurements

[0202] R (n×n) :: Covariance of measurement noise

[0203] A 3DOF Kalman filter with constant velocity can be assumed as follows.

[0204] The specific filter is based on a linear system with constant velocity:

[0205]

[0206] The process noise matrix is ​​based on white noise:

[0207]

[0208] The initial matrix H is preconfigured as the identity matrix. Therefore, the filter also predicts the complete state vector as the measurement (x, y, z, v x , v y , v z ).

[0209] If instead of considering the position of the center, we consider the velocity of the center, we can simplify the algorithm as follows.

[0210] The starting point is the following premise:

[0211] - tilt as the only source of rotation around the y-axis,

[0212] - flip as the only source of rotation about the x-axis, and

[0213] - Longitudinal movement contributes only to the linear velocity in the x-direction.

[0214] The calculation of the load center velocity can be simplified as follows:

[0215] v x，cg =v ls +w 倾斜 +r z，倾斜

[0216] v y，cg =-w 翻转 ·r z，翻转

[0217] v z，cg =w 翻转 ·r y，翻转 -w 倾斜 ·r z，倾斜 (15)

[0218] It is necessary to distinguish 翻转 and r 倾斜 , because they do not have the same rotation axis source, as in Fig.13 As shown in .

[0219] Fig.14 Schematically illustrates an operating table system 300 according to the present disclosure, which is largely similar to the operating table system described in Figure 2 Components of operating table system 300 that are identical or similar to components of operating table system 100 are provided with the same reference numerals.

[0220] The operating table system 300 is a system according to the fourth aspect of the present disclosure. In addition to the operating table 10, the operating table system 300 also includes a load sensor device 102 having a plurality of load sensors, a load determination unit 104, a calculation unit 117, and an error recognition unit 118. The functionality of the operating table system 300 is Fig.15 Illustration in Chinese.

[0221] The load sensor device 102 of the operating table system 300 has four load sensors 1a, 1b, 2a, 2b, which are arranged Fig.15 1a and 1b, and the load sensors 2a and 2b are spaced apart from each other by a distance. The load sensors 1a and 1b, and the load sensors 2a and 2b are spaced apart from each other by a distance. The load sensors 1a, 1b, 2a, 2b measure the forces acting on them and output sensor values ​​F describing the forces acting on the load sensors 1a, 1b, 2a, 2b. 1a_m 、F 1b_m 、F 2a_m or F 2b_m The load determination unit 104 determines the load according to the sensor value F 1a_m 、F 1b_m 、F 2a_m 、F 2b_m Determine the rectangle 150 with coordinates X a and Y a Load F ga The calculation unit 117 uses the value determined by the load determination unit 104, that is, the load F ga and the coordinate X of the load center a and Y a , and based on these values ​​calculate the theoretical sensor value F 1a_t 、F 1b_t 、F 2a_t 、F 2b_t Theoretical sensor value F1a_t 、F 1b_t 、F 2a_t 、F 2b_t is the load F determined by the load determination unit 104 at the load sensors 1a, 1b, 2a, 2b. ga and has coordinates X a and Y a The error recognition unit 118 recognizes the sensor value F output from the load sensors 1a, 1b, 2a, and 2b. 1a_m 、F 1b_m 、F 2a_m 、F 2b_m The theoretical sensor value F calculated by the calculation unit 117 1a_t 、F 1b_t 、F 2a_t 、F 2b_t For example, the error identification unit 118 can calculate the difference F for each of the load sensors 1a, 1b, 2a, 2b. i_t -F i_m (where i = 1a, 1b, 2a, 2b). Difference F i_t -F i_m Describes the system imbalance. For example, if the difference F i_t -F i_m If one or more of the difference F exceeds a preset value, the error recognition unit 118 detects an error and / or a possible error. In some embodiments, for all load sensors 1a, 1b, 2a, 2b, the difference F i_t -F i_m In particular, the difference F is checked for only one of the load sensors 1a, 1b, 2a, 2b. i_t -F i_m It is sufficient, since possible errors can already be identified from it.

[0222] For example, the system unbalance F simulated in FIGS. 16a and 16b is 1a_t -F 1a_m Plotted over time for sensor 1a. Patient support surface 18 is in a flat position. Curve 160 in FIG. 16a and curve 170 in FIG. 16b give the system imbalance of sensor 1a when operating table system 300 operates without faults. All other curves show the system imbalance F of sensor 1a when an error is artificially induced in sensor 1a. 1a_t -F 1a_mIn FIG. 16 a , curves 161 , 162, 163, 164 show the system imbalance in the case of a human-induced error of −1000 N, −400 N, 400 N or 1000 N. In FIG. 16 b , curves 171 , 172, 173, 174 show the system imbalance in the case of a multiple of 1.4, 1.2, 0.8 or 0.6. The corresponding multiples give the error multiples by which the actual value is multiplied and displayed incorrectly by the sensor 1 a.

[0223] Next, it is explained by way of example how to determine the load Fga_m determined by the load determination unit 104 and the load Fga_m having the coordinates X a_m and Y a_m The load center is used to calculate the theoretical sensor value F 1a_t 、F 1b_t 、F 2a_t 、F 2b_t The theoretical sensor value is the load sensor 1a, 1b, 2a, 2b under load F ga_m and has coordinates X a_m and Y a_m The sensor value that should be output when the load center is

[0224] For load F ga_m and the coordinate X of the load center a_m and Y a_m , the relationships described above in equations (2) to (4) apply:

[0225] F ga_m =F 1a_m +F 1b_m +F 2a_m +F 2b_m (16)

[0226]

[0227]

[0228] Theoretical sensor value F 1a_t 、F 1b_t 、F 2a_t 、F 2b_t According to the coordinate X of the load center a_m and Y a_m and the sensor value F 1a_m 、F 1b_m 、F 2a_m 、F 2b_m It is calculated as follows:

[0229]

[0230]

[0231]

[0232]

[0233] For all load sensors 1a, 1b, 2a, 2b, the theoretical sensor value F 1a_t 、F 1b_t 、F 2a_t 、F 2b_t with the corresponding measured sensor value F 1a_m 、F 1b_m 、F 2a_m 、F 2b_m The difference between is the same. For example, for load sensor 1a, the difference Δ can be determined as follows:

[0234] Δ=|F 1a_m -F 1a_t | (23)

[0235] If the difference Δ is greater than a preset threshold value, for example 300 N, then it is determined that there is an error, ie, there is a system imbalance. If the difference Δ is less than the threshold value, then the system is operating without fault.

[0236] Exemplary values ​​for the system imbalance are given below: For this purpose, the load cell 1 a is loaded with an error of 500 N.

[0237] Measured sensor values:

[0238] F 1a_m =3178N

[0239] F 2a_m =-1853N

[0240] F 1b_m =3099N

[0241] F 2b_m =-2238N

[0242] Calculated loads and calculated load centres:

[0243] F ga_m =223kg

[0244] X a_m =-58cm

[0245] Y a_m =3cm

[0246] Calculated theoretical sensor value:

[0247] F 1a_t =3670N

[0248] F 2a_t =-2344N

[0249] F 1b_t =2607N

[0250] F 2b_t =-1747N

[0251] Calculate the difference Δ:

[0252] Δ(F 1a )=491N

[0253] Δ(F 2a )=-491N

[0254] Δ(F 1b )=-491N

[0255] Δ(F 2b )=491N

[0256] Since the difference Δ is greater than a preset threshold value, exemplarily 300 N, there is a system imbalance, ie, the system cannot function normally.

[0257] In the following, example values ​​for a system operating without error are given for comparison. In contrast to the above-described system operating without error, no sensor value F is given here. 1a_m Add 500N error. The remaining sensor values ​​F 1b_m 、F 2a_m 、F 2b_m Corresponds to the above sensor values.

[0258] Measured sensor values:

[0259] F 1a_m =2678N

[0260] F 2a_m =-1853N

[0261] F 1b_m =3099N

[0262] F 2b_m =-2238N

[0263] Calculated loads and calculated load centres:

[0264] F ga_m =172kg

[0265] X a_m =-71cm

[0266] Y a_m =0cm

[0267] Calculated theoretical sensor value:

[0268] F 1a_t =2830N

[0269] F 2a_t =-2005N

[0270] F 1b_t =2947N

[0271] F 2b_t =-2086N

[0272] Calculate the difference Δ:

[0273] Δ(F 1a )=152N

[0274] Δ(F 2a )=-152N

[0275] Δ(F 1b )=-152N

[0276] Δ(F 2b )=152N

[0277] The difference Δ is smaller in magnitude than the threshold value of 300 N. According to this, the system is operating without error.

[0278] Exemplary embodiments and variants consistent with the present disclosure are described in the following list of points and options:

[0279] Point 1: A system (100, 200, 300) for detecting errors in sensors in an operating table (10) and / or errors in determining load or load center, comprising:

[0280] An operating table (10) having an adjustable patient support surface (18) for supporting a patient; a load sensor device (102) having a plurality of load sensors (1a, 1b, 2a, 2b) outputting sensor values;

[0281] a load determination unit (104) for determining at least one of the following first variables based on the sensor value: load, load center, speed of the load center and acceleration of the load center, wherein the load is a load acting on the load sensor device (102) or a load acting on the operating table (10) or a total load of the operating table (10);

[0282] a calculation unit (117) which predicts or calculates at least one expected second variable; and an error detection unit (118) which compares the sensor value or at least one first variable with at least one expected second variable and detects an error and / or a possible error if the deviation exceeds a preset value.

[0283] Point 2: The system (100, 200) according to point 1, wherein when the patient support surface (18) is adjusted, the calculation unit (117) predicts the load center changed by the adjustment as at least one second variable,

[0284] The load determination unit (104) determines at least a load center after adjusting the patient support surface (18) as at least one first variable based on the sensor value, and the error detection unit (118) compares the load center predicted by the calculation unit (117) with the load center determined by the load determination unit (104), and if the deviation exceeds a preset value, an error and / or a possible error is detected.

[0285] Point 3: The system (100, 200) according to Point 2 also includes a state estimation unit (119), which estimates the actual load center based on the load center predicted by the calculation unit (117) and the load center determined by the load determination unit (104), wherein the state estimation unit (119) estimates the actual load center based on the weighted value of the load center predicted by the calculation unit (117) and the weighted value of the load center determined by the load determination unit (104).

[0286] Point 4: The system (100, 200) according to Point 3, wherein the state estimation unit (119) has a Kalman filter for estimating the actual load center.

[0287] Point 5: A system (100, 200) according to Point 1, wherein the calculation unit (117), the load determination unit (104) and the state estimation unit (119) work iteratively in such a manner that the calculation unit (117) predicts the load center at time t+1 as at least one second variable based on the actual load center at time t estimated by the state estimation unit (119), the load determination unit (104) determines the load center at time t+1 as at least one first variable and the state estimation unit (119) subsequently estimates the actual load center at time t+1 based on the load center at time t+1 predicted by the calculation unit (117) and the load center at time t+1 determined by the load determination unit (104).

[0288] Point 6: A system (100, 200) according to Point 5, wherein the error identification unit (119) detects an error and / or a possible error if the load center predicted by the calculation unit (117) and the load center determined by the load determination unit (104) each exceed a preset deviation at least within a preset number of iterations.

[0289] Point 7: A system (100, 200) according to Point 5, wherein if the load center predicted by the calculation unit (117) and the load center determined by the load determination unit (104) exceed a preset deviation in at least one iteration, then the error identification unit (119) detects an error and / or a possible error.

[0290] Point 8: A system (100, 200) according to Point 1, wherein when the patient support surface (18) is adjusted, the calculation unit (117) predicts the speed or acceleration of the load center as at least one second variable, the load determination unit (104) determines the speed or acceleration of the load center after adjusting the patient support surface (18) as at least one first variable based on the sensor value, and the error recognition unit (118) compares the speed or acceleration of the load center predicted by the calculation unit (117) with the speed or acceleration of the load center determined by the load determination unit (104), and if the deviation exceeds a preset value, an error and / or a possible error is detected.

[0291] Point 9: The system (100, 200) according to Point 8 further includes a state estimation unit (119), which estimates the actual speed or acceleration of the load center based on the speed or acceleration of the load center predicted by the calculation unit (117) and the speed or acceleration of the load center determined by the load determination unit (104).

[0292] Point 10: The system (100, 200) according to point 9, wherein the state estimation unit (119) has a Kalman filter for estimating the actual speed or acceleration of the load center.

[0293] Point 11: A system (100, 200) according to Point 1, wherein the calculation unit (117), the load determination unit (104) and the state estimation unit (119) work iteratively, in such a manner that the calculation unit (117) predicts the speed or acceleration of the load center at time t+1 as at least one second variable based on the actual speed or acceleration of the load center at time t estimated by the state estimation unit (119), the load determination unit (104) determines the speed or acceleration of the load center at time t+1 as at least one first variable, and the state estimation unit (119) subsequently estimates the actual speed or acceleration of the load center at time t+1 based on the speed or acceleration of the load center at time t+1 predicted by the calculation unit (117) and the speed or acceleration of the load center at time t+1 determined by the load determination unit (104).

[0294] Point 12: A system (100, 200) according to Point 11, wherein the error recognition unit (118) detects an error and / or a possible error if the speed or acceleration of the load center predicted by the calculation unit (117) and the speed or acceleration of the load center determined by the load determination unit (104) respectively exceed a preset deviation at least within a predetermined number of iterations.

[0295] Point 13: A system (100, 200) according to point 11, wherein if the speed or acceleration of the load center predicted by the calculation unit (117) exceeds a preset deviation from the speed or acceleration of the load center determined by the load determination unit (104) in at least one iteration, then the error recognition unit detects an error and / or a possible error.

[0296] Point 14: A system (100, 300) according to Point 1, wherein a load determination unit (104) determines a load and / or a load center as a first variable based on a sensor value, a calculation unit (117) calculates a theoretical sensor value as a second variable, wherein the theoretical sensor value is a sensor value that the load sensor (1a, 1b, 2a, 2b) should output under the load and / or load center determined by the load determination unit (104), and an error recognition unit (118) compares the sensor value output by the load sensor (1a, 1b, 2a, 2b) with the theoretical sensor value calculated by the calculation unit (117), and if the deviation exceeds a preset value, an error and / or a possible error is detected.

[0297] Point 15: The system (100, 300) according to point 14, wherein the error detection unit (118) is able to detect an error and / or a possible error if the patient support surface (18) is not adjusted.

[0298] Point 16: The system (100, 300) according to any of the above points, wherein the load sensor device (102) has at least three load sensors or at least four load sensors (1a, 1b, 2a, 2b).

[0299] Point 17: The system (100, 300) according to any of the above points, wherein the plurality of load sensors (1a, 1b, 2a, 2b) are arranged in a single common plane.

[0300] Point 18: A system (100, 300) according to any of the above points, wherein a plurality of load sensors (1a, 1b, 2a, 2b) are arranged mirror-symmetrically with respect to a first axis (210) and mirror-symmetrically with respect to a second axis (212), and wherein the first axis (210) and the second axis (212) are oriented orthogonally to each other.

[0301] Point 19: A system (100) according to any of the above points, wherein, if the load determined by the load determination unit (104) is negative, then the error identification unit (118) detects a possible error of at least one of the load sensors (1a, 1b, 2a, 2b).

[0302] Point 20: A system (100) according to any of the above points, wherein if the load determined by the load determination unit (104) exceeds a preset value and / or the load center determined by the load determination unit (104) is located outside a preset space, then the error identification unit (118) detects an error and / or possible error of at least one of the load sensors (1a, 1b, 2a, 2b).

[0303] Point 21: A system (100) according to any of the above points, wherein the error identification unit (118) detects an error and / or possible error of one of the load sensors (1a, 1b, 2a, 2b) if one of the load sensors does not change its sensor value while the remaining load sensors change their sensor values, or if the load sensor changes its sensor value while the remaining load sensors do not change their sensor values.

[0304] Point 22: The system (100) according to any of the above points, wherein if the load F determined by the load determination unit (104) in the event of a tilt and / or tilting of the patient support surface (18) 测量 If the following equation is not satisfied, the error recognition unit (118) detects an error and / or a possible error of one of the load sensors (1a, 1b, 2a, 2b):

[0305] F 测量 =F 负荷 ·cosα-(1-cosα)·F dl

[0306] Among them, F 负荷 is the load acting on the patient support surface (18), α is the tilt and / or tilt angle of the patient support surface (18), and F dl is a tared load that includes all loads that are part of the operating table (10) and are located above the load sensors (1a, 1b, 2a, 2b).

[0307] Point 23: A system (100) according to any of the above points, wherein adjustment of the patient support surface (18) includes one or more of the following operations: tilting the patient support surface (18), flipping the patient support surface (18), longitudinally moving the patient support surface (18), vertically moving the patient support surface (18) and laterally moving the patient support surface (18).

[0308] Point 24: A system (100) according to any of the above points, wherein the sensor error is an error in one or more of the following sensors: a load sensor (1a, 1b, 2a, 2b), a sensor for detecting the tilt of the patient support surface (18), a sensor for detecting the flipping of the patient support surface (18), a sensor for detecting the longitudinal movement of the patient support surface (18), a sensor for detecting the lateral movement of the patient support surface (18) and a column lifting sensor.

[0309] Point 25: A system (100) according to any of the above points, wherein the error recognition unit (118) generates an error signal when an error and / or a possible error is detected, so that the error signal indicates a safety-critical state of the operating table (10), generates an acoustic and / or optical warning signal and / or a warning signal in text form, and / or slows down or stops the movement of the operating table (10) and / or prevents at least one functionality of the operating table (10).

[0310] Point 26: The system (100) according to any of the above points, wherein the computing unit (117) predicts the at least one expected second variable.

[0311] Point 27: A method for detecting errors in sensors in an operating table (10) and / or errors in determining a load or a load center, wherein the operating table (10) has an adjustable patient support surface (18) for supporting a patient and a load sensor device (102) having a plurality of load sensors (1a, 1b, 2a, 2b) that output sensor values; determining at least one of the following first variables based on the sensor values: load; load center; speed of the load center and acceleration of the load center, wherein the load is a load acting on the load sensor device (102) or a load acting on the operating table (10) or a total load of the operating table (11);

[0312] predicting or calculating at least one expected second variable; and

[0313] The sensor value or at least one first variable is compared with at least one expected second variable, and an error is detected if the deviation exceeds a preset value.

[0314] Point 28: The method according to point 27, wherein

[0315] If the patient support surface (18) is adjusted, the load center changed by the adjustment is predicted as at least one second variable, the load center after the patient support surface (18) is adjusted is determined as at least one first variable based on the sensor value, and the predicted load center is compared with the determined load center, and an error is detected if the deviation exceeds a preset value.

[0316] Point 29: The method according to Point 27, wherein

[0317] determining the load and / or the load centre as a first variable from the sensor values,

[0318] A theoretical sensor value is calculated as a second variable, wherein the theoretical sensor value is the sensor value that the load sensor (1a, 1b, 2a, 2b) should output when determining the load and / or determining the load center, and the sensor value output by the load sensor (1a, 1b, 2a, 2b) is compared with the theoretical sensor value calculated by the calculation unit (117), and if the deviation exceeds a preset value, an error is detected.

[0319] Point 30: A system (100) for detecting an error of a sensor in an operating table (10), comprising:

[0320] An operating table (10) having an adjustable patient support surface (18) for supporting a patient; a load sensor device (102) having a plurality of load sensors (1a, 1b, 2a, 2b) outputting sensor values;

[0321] a load determination unit (104) for determining at least one load based on the sensor value, wherein the load is a load acting on the load sensor device (102) or a load acting on the operating table (10) or a total load of the operating table; and

[0322] An error recognition unit (118) detects a possible error of at least one of the load sensors (1a, 1b, 2a, 2b) if the load determined by the load determination unit (104) is negative.

[0323] Point 31: A system (100) for detecting an error of a sensor in an operating table (10), comprising:

[0324] An operating table (10) having an adjustable patient support surface (18) for supporting a patient; a load sensor device (102) having a plurality of load sensors (1a, 1b, 2a, 2b) outputting sensor values;

[0325] a load determination unit (104) which determines at least one load and / or a center of load based on the sensor values, wherein the load is a load acting on the load sensor device (102) or a load acting on the operating table (10) or a total load of the operating table; and

[0326] An error recognition unit (118) detects an error and / or a possible error of at least one of the load sensors (1a, 1b, 2a, 2b) if the load determined by the load determination unit (104) exceeds a preset value and / or the load center determined by the load determination unit (104) is located outside a preset space.

[0327] Point 32: A system (100) for detecting an error of a sensor in an operating table (10), comprising:

[0328] An operating table (10) having an in particular adjustable patient support surface (18) for supporting a patient;

[0329] a load sensor device (102) having a plurality of load sensors (1a, 1b, 2a, 2b) that output sensor values; and

[0330] An error recognition unit (118) detects an error and / or a possible error of one of the load sensors (1a, 1b, 2a, 2b) if the load sensor does not change its sensor value while the other load sensors change their sensor values, or if the load sensor changes its sensor value while the other load sensors change their sensor values.

[0331] Point 33: A system (100) for detecting an error of a sensor in an operating table (10), comprising:

[0332] An operating table (10) having an adjustable patient support surface (18) for supporting a patient; a load sensor device (102) having a plurality of load sensors (1a, 1b, 2a, 2b) outputting sensor values;

[0333] a load determination unit (104) for determining at least one load based on the sensor value, wherein the load is a load acting on the load sensor device (102) or a load acting on the operating table (10) or a total load of the operating table; and

[0334] The error detection unit (118) detects that the load F determined by the load determination unit (104) is too large if the patient support surface (18) is tilted and / or tilted. 测量 If the following equation is not satisfied, the error recognition unit detects an error and / or a possible error of one of the load sensors (1a, 1b, 2a, 2b):

[0335] F 测量 =F g ·cosα-(1-cosα)·F dl

[0336] Among them, F g is the load acting on the patient support surface (18), α is the tilt and / or tilt angle of the patient support surface (18), and F dl is a tared load that includes all loads that are part of the operating table (10) and are located above the load sensors (1a, 1b, 2a, 2b).

Claims

1. A system (100, 200, 300) for detecting errors in sensors in an operating table (10) and / or errors in determining load or load center, comprising: An operating table (10) having an adjustable patient support surface (18) for supporting a patient; A load sensor device (102) having a plurality of load sensors (1a, 1b, 2a, 2b) outputting sensor values; a load determination unit (104) for determining at least one of the following first variables based on the sensor values: a load, a center of the load, a speed of the center of the load, and an acceleration of the center of the load, wherein the load is a load acting on the load sensor system (102) or a load acting on the operating table (10) or a total load of the operating table (10); a calculation unit (117) which predicts or calculates at least one expected second variable; and An error detection unit (118) compares the sensor value or the at least one first variable with the at least one expected second variable and detects an error and / or a possible error if a deviation exceeds a predefined value.

2. The system (100, 200) according to claim 1, wherein When the patient support surface (18) is adjusted, the calculation unit (117) predicts the load center changed by the adjustment as the at least one second variable, The load determination unit (104) determines at least a load center after adjustment of the patient support surface (18) as the at least one first variable based on the sensor value, and The error detection unit (118) compares the load center predicted by the calculation unit (117) with the load center determined by the load determination unit (104) and detects an error and / or a possible error if the deviation exceeds a predefined value.

3. The system (100, 200) according to claim 2 further comprises a state estimation unit (119), which estimates an actual load center based on the load center predicted by the calculation unit (117) and the load center determined by the load determination unit (104), wherein the state estimation unit (119) estimates the actual load center in particular based on a weighted value of the load center predicted by the calculation unit (117) and a weighted value of the load center determined by the load determination unit (104).

4. The system (100, 200) according to claim 3, wherein the state estimation unit (119) has a Kalman filter for estimating the actual load center.

5. The system (100, 200) according to claim 1, wherein the calculation unit (117), the load determination unit (104) and the state estimation unit (119) work iteratively, in that the calculation unit (117) predicts the load center at time t+1 as the at least one second variable based on the actual load center at time t estimated by the state estimation unit (119), the load determination unit (104) determines the load center at time t+1 as the at least one first variable, and the state estimation unit (119) subsequently estimates the actual load center at time t+1 based on the load center at time t+1 predicted by the calculation unit (117) and the load center at time t+1 determined by the load determination unit (104).

6. A system (100, 200) according to claim 5, wherein the error identification unit (119) detects an error and / or a possible error if the load center predicted by the calculation unit (117) and the load center determined by the load determination unit (104) each exceed a preset deviation at least in a preset number of iterations.

7. A system (100, 200) according to claim 5, wherein if the load center predicted by the calculation unit (117) and the load center determined by the load determination unit (104) exceed a preset deviation in at least one iteration, then the error identification unit (119) detects an error and / or a possible error.

8. The system (100, 200) of claim 1, wherein When adjusting the patient support surface (18), the calculation unit (117) predicts the velocity or acceleration of the load center as the at least one second variable, The load determination unit (104) determines at least a velocity or an acceleration of the load center after the adjustment of the patient support surface (18) as the at least one first variable based on the sensor value, and The error recognition unit (118) compares the speed or acceleration of the load center predicted by the calculation unit (117) with the speed or acceleration of the load center determined by the load determination unit (104) and detects an error and / or a possible error if the deviation exceeds a preset value.

9. The system (100, 200) according to claim 8 further comprises a state estimation unit (119), which estimates the actual speed or acceleration of the load center based on the speed or acceleration of the load center predicted by the calculation unit (117) and the speed or acceleration of the load center determined by the load determination unit (104).

10. The system (100, 200) according to claim 9, wherein the state estimation unit (119) has a Kalman filter for estimating the actual speed or acceleration of the load center.

11. The system (100, 200) according to claim 1, wherein the calculation unit (117), the load determination unit (104) and the state estimation unit (119) work iteratively, in that the calculation unit (117) predicts the actual speed or acceleration of the load center at time t+1 as the at least one second variable based on the actual speed or acceleration of the load center at time t estimated by the state estimation unit (119), the load determination unit (104) determines the speed or acceleration of the load center at time t+1 as the at least one first variable, and the state estimation unit (119) subsequently estimates the actual speed or acceleration of the load center at time t+1 based on the speed or acceleration of the load center at time t+1 predicted by the calculation unit (117) and the speed or acceleration of the load center at time t+1 determined by the load determination unit (104).

12. A system (100, 200) according to claim 11, wherein the error identification unit (118) detects an error and / or a possible error if the speed or acceleration of the load center predicted by the calculation unit (117) and the speed or acceleration of the load center determined by the load determination unit (104) respectively exceed a preset deviation at least within a preset number of iterations.

13. A system (100, 200) according to claim 11, wherein if the speed or acceleration of the load center predicted by the calculation unit (117) and the speed or acceleration of the load center determined by the load determination unit (104) exceed a preset deviation in at least one iteration, then the error recognition unit detects an error and / or a possible error.

14. The system (100, 300) of claim 1, wherein The load determination unit (104) determines the load and / or the load center as a first variable based on the sensor value, The calculation unit (117) calculates a theoretical sensor value as the second variable, wherein the theoretical sensor value is a sensor value that the load sensor (1a, 1b, 2a, 2b) should output when the load and / or load center is determined by the load determination unit (104), and The error detection unit (118) compares the sensor value output by the load sensor (1a, 1b, 2a, 2b) with the theoretical sensor value calculated by the calculation unit (117) and detects an error and / or a possible error if the deviation exceeds a predefined value.

15. The system (100, 300) according to claim 14, wherein the error recognition unit (118) is able to detect an error and / or a possible error if the patient support surface (18) is not adjusted.

16. The system (100, 300) according to any of the preceding claims, wherein the load sensor device (102) has at least three load sensors or at least four load sensors (1a, 1b, 2a, 2b).

17. The system (100, 300) according to any one of the preceding claims, wherein a plurality of said load sensors (1a, 1b, 2a, 2b) are arranged in a single common plane.

18. The system (100, 300) according to any one of the preceding claims, wherein a plurality of the load sensors (1a, 1b, 2a, 2b) are arranged mirror-symmetrically with respect to a first axis (210) and mirror-symmetrically with respect to a second axis (212), and Wherein the first axis and the second axis (210, 212) are oriented orthogonally to each other.

19. A system (100) according to any of the above claims, wherein if the load determined by the load determination unit (104) is negative, then the error identification unit (118) detects a possible failure of at least one of the load sensors (1a, 1b, 2a, 2b).

20. A system (100) according to any of the above claims, wherein if the load determined by the load determination unit (104) exceeds a preset value and / or the load center determined by the load determination unit (104) is located outside a preset space, then the error identification unit (118) detects an error and / or possible error of at least one of the load sensors (1a, 1b, 2a, 2b).

21. A system (100) according to any of the preceding claims, wherein the error identification unit (118) detects an error and / or a possible error of one of the load sensors (1a, 1b, 2a, 2b) if one of the load sensors does not change its sensor value while the remaining load sensors change their sensor values, or if the one load sensor changes its sensor value while the remaining load sensors do not change their sensor values.

22. The system (100) according to any one of the preceding claims, wherein the load F determined by the load determination unit (104) is 测量 The error recognition unit (118) detects an error and / or a possible error of one of the load sensors (1a, 1b, 2a, 2b) if the following equation is not observed: F 测量 =F 负荷 ·cosα-(1-cosα)·F dl where F 负荷 is the load acting on the patient support surface (18), α is the tilt and / or tilt angle of the patient support surface (18), and F dl is a tared load that includes all loads that are part of the operating table (10) and are located above the load sensors (1a, 1b, 2a, 2b).

23. A system (100) according to any of the above claims, wherein adjustment of the patient support table (18) includes one or more of the following operations: tilting the patient support surface (18), flipping the patient support surface (18), moving the patient support surface (18) longitudinally, moving the patient support surface (18) vertically and moving the patient support surface (18) laterally.

24. A system (100) according to any of the above claims, wherein the sensor error is an error of one or more of the following sensors: a load sensor (1a, 1b, 2a, 2b), a sensor for detecting the tilt of the patient support surface (18), a sensor for detecting the flipping of the patient support surface (18), a sensor for detecting the longitudinal movement of the patient support surface (18), a sensor for detecting the lateral movement of the patient support surface (18) and a column lifting sensor.

25. A system (100) according to any of the above claims, wherein the fault identification sensor (118) generates an error signal when an error and / or a possible error is detected, so that the error signal indicates a safety-critical state of the operating table (10), generates an acoustic and / or optical warning signal and / or a warning signal in text form, and / or slows down or stops the movement of the operating table (10) and / or prevents at least one functionality of the operating table (10).

26. The system (100) according to any of the above claims, wherein the calculation unit (117) predicts the at least one expected second variable.

27. A method for detecting errors in sensors in an operating table (10) and / or errors in determining loads or load centres, wherein The operating table (10) has an adjustable patient support surface (18) for supporting a patient and a load sensor device (102) having a plurality of load sensors (1a, 1b, 2a, 2b) for outputting sensor values; Determine at least one of the following first variables based on the sensor value: load; load center; speed of the load center and acceleration of the load center, wherein the load is a load acting on the load sensor device (102) or a load acting on the operating table (10) or a total load of the operating table (10); predicting or calculating at least one expected second variable; The sensor value or the at least one first variable is compared with the at least one expected second variable and an error and / or a possible error is detected if the deviation exceeds a predefined value.

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