Patent Application
20250072829
This application claims the benefit of priority under 35 U.S.C. § 119 of German Application 10 2023 124 033.1, filed Sep. 6, 2023, the entire contents of which are incorporated herein by reference.
The invention relates to a process and a system for automated fluid balancing for a patient.
It is an object of the invention to provide a process and a system which can be used during the care of a patient lying in a bed. The process and the system are intended to reduce the risk of the patient suffering damage to his or her health.
The problem is solved by a process with features according to the invention and by a system with features according to the invention. Advantageous embodiments are disclosed. Advantageous embodiments of the process according to the invention are, if appropriate, also advantageous embodiments of the system according to the invention and vice versa.
The process according to the invention and the system according to the invention are capable of automatically performing a fluid balance for a patient and thereby providing a fluid balance for the patient. The process according to the invention is carried out using the system according to the invention.
A reference time period is predefined which has a length of 24 hours, for example. The fluid balance calculated according to the invention is the difference between the total amount of fluid supplied to the patient during the reference time period and the total amount of fluid leaving (discharged from) the patient during this reference time period. The amount is preferably given as a mass. The total amount of fluid supplied to the patient in the reference time period also includes the fluid that the patient actively ingests, for example by drinking from a drinking vessel. The total amount of fluid leaving the patient during the reference time period also includes the fluid that the patient sweats out or actively excretes outside the bed.
If the difference and therefore the fluid balance is greater than zero, the patient has taken in fluid during the reference time period on balance, otherwise the patient has given out fluid on balance.
The patient lies in bed continuously or at least temporarily during the reference time period. At least one movable object is used to care for the patient, or at least one movable object can be used. Moveable means that the object can be moved during the care of the patient and relative to the patient. The object or at least one, preferably each object that is used or can be used is provided with a machine-readable marking (label, identification, indicia). This marking distinguishes the object from another object or from each other object used, or at least from each different object. At the very least, however, each used or usable object that can hold and provide a fluid is provided with a machine-readable marking.
The marking of an object is stored on an NFC tag, for example, whereby the NFC tag takes the form of an RFID tag, e.g. Alternatively, the marking may take the form of a barcode or QR code on the object. The marking can also comprise a sequence of alphanumeric characters and/or at least one symbol. The marking can also comprise several components. The marking may also include the contour and/or the color or at least one color of the object.
A computer-evaluable objects list is predefined (given). This objects list is stored in a system data memory, for example. It comprises an entry for each used or usable marked object. The entry comprises information about the machine-readable marking of the object and at least one of the following pieces of information:
The system according to the invention comprises a reading unit with at least one reader (reading device) and a camera unit with at least one camera (image acquisition device). Each reader has a respective reading area. The reader is able to read a machine-readable marking when the marking is located in the reading area. Each camera has a respective field of view (field of vision). The bed is located in the respective reading area of each reader and in the respective field of view of each camera during the reference time period. Preferably, neither the bed nor a reader nor a camera is moved during the reference time period, in particular not moved with respect to each other.
The camera or each camera is capable of generating at least one image, preferably a sequence of images. These images show the bed, optionally the patient in the bed and optionally the object or each object and the person or each person, provided that this object and/or this person are in the camera's field of view. The camera is capable of generating a signal, this signal comprising the generated image or sequence of images. The reader or each reader is capable of reading the respective machine-readable marking of an object in the reading area of the reader and generating a signal comprising the reading result.
The system according to the invention also comprises a bed scale. The bed scale is capable of measuring the current weight of the bed. If the patient is in bed at the time of measurement, the measured weight includes the weight of the patient in addition to the weight of the bed including the weight of optional bedding. The measured weight can be used to clearly determine whether the patient is in bed at the time of measurement or whether the bed is empty at the time of measurement.
A signal processing unit of the system has at least temporary read access to the objects list. The signal processing unit can be a component of a portable computer, for example a smartphone or a tablet, or a component of a stationary computer, for example a PC.
The respective signal of the reader or each reader and of the camera or each camera is transmitted to the signal processing unit, preferably wirelessly by radio waves, alternatively by means of a data cable. The signal processing unit processes the received signals.
The process according to the invention comprises the following steps, and the system according to the invention is configured to perform the following steps:
The bed scale repeatedly measures the current weight of the bed during the reference time period. The signal processing unit determines a first time point and a subsequent second time point, whereby the bed scale has measured the current weight of the bed at both time points and the patient is lying in bed at both time points. Preferably, the first time point is in the first third, particularly preferably in the first eighth of the reference time period, and the second point in time is in the last third, particularly preferably in the last eighth of the reference time period. Preferably, the bed scale measures the current weight at least three times during the reference time period, particularly preferably at a fixed sampling rate.
The signal processing unit derives at least one weight difference. The weight difference or a weight difference is the difference between the weight of the patient at the second point in time and the weight of the patient at the first point in time-more general; the difference between the weight at an earlier time point and the weight at a later time point. This weight difference does not depend on the weight of the bed, because the bed scale weighs the weight of the bed at both the first and second time points, and the patient is in bed at both the first and second time points.
The reading unit reads the respective marking of an object in the reading area of a reader. The camera unit generates at least one image, preferably a sequence of images, whereby the image or each image shows at least the bed, as well as every movable object and every person who comes into the vicinity of the bed and thus into the field of view of a camera of the camera unit.
The signal processing unit detects any object that comes into the vicinity of the patient and/or is removed from the vicinity of the patient in the reference time period span and therefore comes into the respective reading area of at least one reader and/or into the field of view of at least one camera. For this detection, the signal processing unit uses the signal of a reader or each signal of the readers and the signal of a camera or each signal of the cameras.
It is possible that the signal processing unit identifies and detects an object both on the basis of a signal from the reading unit and on the basis of a signal from the camera. For example, the reading unit reads a machine-readable marking, and image processing identifies an optically detectable marking of the same object in an image from the camera.
The signal processing unit calculates a fluid balance for the patient. The term fluid balance has already been defined above. The fluid balance refers to the given reference time. To calculate the fluid balance, the signal processing unit uses
The signal processing unit determines which objects came into the vicinity of the bed and which objects were removed again based on a signal from the reading unit and/or a signal from the camera unit.
For each used or usable object and therefore also for each detected object, the objects list contains information about the empty weight of this object and/or the amount of fluid that this object can hold.
The process according to the invention and the system according to the invention can be used for a patient, in particular while the patient is in a hospital, in a care facility or at home and while the patient is receiving medical care and/or nursing care. The patient may suffer damage to his/her health if he/she does not drink enough fluids within the reference time period. The fluid supplied should at least replace the fluid discharged to a sufficient extent. If the fluid balance is negative and less than a predefined lower threshold, there is a risk that the patient will become dehydrated. Dehydration (exsiccosis) can lead to the patient's water and electrolyte balance being disturbed and the patient's health suffering as a result. If, on the other hand, the fluid balance is positive and greater than a predefined upper threshold, there is a risk of fluid settling in the patient's tissue and oedema developing, which is also undesirable.
The fluid balance for the patient in the reference time period is influenced by different influencing variables. Because the system according to the invention comprises different sensors and the objects list and the process according to the invention processes signals from these sensors and the objects list, many of these different influences can be quantitatively determined in order to calculate the fluid balance.
The invention can be used in conjunction with the step of weighing the patient outside the bed, in particular immediately before the reference time period and/or immediately after the reference time period. It is possible to determine the difference between these two patient weights. However, the invention eliminates the need to weigh the patient outside the bed. Especially in everyday clinical practice, there is often a lack of staff and time for this. In addition, the invention makes it possible to install and connect the components of the system according to the invention once for a patient and then to calculate the fluid balance repeatedly for different periods of time, even for different patients, without human intervention being required for the calculation. In addition, it is often not sufficient for providing a reliable fluid balance if the patient is weighed once before and once after the reference time period.
According to the invention, a reading unit and a camera unit are used. In particular, this feature enables the signal processing unit to recognize which objects come into the vicinity of the bed and thus into the vicinity of the patient in the bed and which objects are removed from the bed and thus from the patient. From the objects list, the signal processing unit obtains information on the amount of fluid that each object is capable of holding and is therefore supplied to the patient when the object comes into the vicinity of the patient. It is also often possible to determine whether or not an object containing fluid is actually brought to the patient's mouth. The objects list also makes it possible to distinguish between the process of delivering fluid to a patient and the process of using an object near the patient without delivering fluid to the patient, such as a cutlery set or a book or even a medical instrument.
In one embodiment, the bed scale measures the current weight of the bed more than twice during the reference time period, preferably at a predefined sampling rate. The signal processing unit determines a time course of the weight of the bed, for which it receives and processes a signal from the bed scale. The signal processing unit uses the time course of the bed weight to calculate the fluid balance for the patient. The determined time course of the bed weight covers at least a time span between the first time point and the second time point, optionally the entire reference time period.
Thanks to this embodiment, the signal processing unit is in many cases able to determine with greater certainty the amount of fluid the patient has consumed (taken in) while lying in the bed. By processing signals from the reading unit and from the camera unit, the signal processing unit detects the event that an object is brought to the patient's body and later removed again, or determines that such an event has not occurred. By evaluating the objects list, the signal processing unit recognizes the amount of fluid this object is able to hold and/or what this object weighs without fluid (empty weight). The time course of the bed weight provides information on how the measured weight of the bed with the patient and therefore the patient's weight has changed. This information is always available in connection with the respective times of measurement or detection. The signal processing unit uses this information to determine how much fluid the patient has actually consumed. Thanks to the signals from the reading unit and the camera unit, this situation can be distinguished from a situation in which the patient picks up an object in bed or an object is brought to or into the bed without the patient ingesting fluid.
In a further development of this embodiment, the signal processing unit automatically searches for an exit time point, a subsequent return time point and a third time point between these two time point. The signal processing unit carries out the search in such a way that these three time points cumulatively have the following properties:
In particular the signal processing unit uses the time points, and the first time point is the exit time point and the second time point is the return time point.
As already mentioned, the signal processing unit uses a measured value from the bed scale to determine whether the patient was inside or outside of the bed at the time of measurement. It is possible, but thanks to the bed scale not necessary, that an additional sensor is used for this determination.
If the signal processing unit has found three such time points, it performs the following steps:
At the third time point, i.e. in the time span between the exit time point and the return time point, the patient may have excreted fluid outside the bed, for example on a toilet, but may also have consumed fluid outside the bed. The measured difference approximates the balance between fluid output and fluid intake in the time span between the exit and return time points. This configuration can be used in combination with the process of weighing the patient at least once outside the bed. Thanks to this further development, however, it is not necessary to weigh the patient during the out-of-bed time span.
In one embodiment, the system comprises at least one volume flow sensor. The volume flow sensor is able to measure the volume flow of a fluid through a fluid guide unit, alternatively or additionally the mass flow of the fluid. More specifically, the volume flow sensor directly measures the volume flow or the mass flow or a variable that correlates with the volume flow and/or with the mass flow.
According to the embodiment, the volume flow sensor measures the volume flow or mass flow of a fluid through a fluid guide unit while this fluid guide unit is connected to the patient's body. The fluid can flow through the fluid guide unit into the patient's body or flow out of the patient's body through the fluid guide unit. It is possible for a fluid to flow into the patient's body through a fluid guide unit and for the same or another fluid to flow out of the patient's body and through another fluid guide unit. For example, an infusion solution flows from a bag into the patient's body through the fluid guide unit, and urine flows out of the body and into a urine bag. At least in a time span between the first time point and the second time point the fluid guide unit is connected with the patient's body. The volume flow or the mass flow is measured at least in this time span,
In one embodiment, a fluid guide unit is used in such a way that fluid flows through the fluid guide unit in two opposite directions in succession. Preferably in this case, the volume flow sensor also determines the current flow direction. The signal processing unit receives a signal from the volume flow sensor and uses the measured volume flow to calculate the fluid balance.
This embodiment further improves the accuracy and reliability with which the fluid balance is calculated according to the invention.
In one embodiment, the system according to the invention comprises a urine bag scale. This urine bag is connected to the patient at least temporarily during the reference time period. The patient releases urine into the urine bag by means of a tube and preferably by means of a catheter. The signal processing unit determines a time course of weight of the urine bag and processes a signal from the urine bag scale for this purpose. The time course is measured at least in a time span between the first time point and the second time point. The signal processing unit uses the time course to calculate the fluid balance.
According to this embodiment, the signal processing unit processes the time course of the weight of the urine bag. This enables the signal processing unit to determine the volume flow or mass flow into the urine bag on the one hand. On the other hand, it is able to detect the event that the urine bag is replaced or emptied. This process usually leads to a sudden change in the measured weight of the urine bag.
In one embodiment, the system according to the invention comprises a table scale. The table scale is able to measure the weight of a table. During the reference time period, this table is at least temporarily in the vicinity of the patient. The table can stand on a floor or be connected to the bed. Objects that are used or can be used for the care of the patient can be placed on this table. Some of these objects may contain fluids, such as drinks or solid food. The signal processing unit determines a temporal course of a weight of the table. For doing so, the signal processing unit processes a signal from the table scale. The temporal course covers at least a time span between the first time point and the second time point. The signal processing unit uses the determined time course to calculate the fluid balance.
Thanks to this embodiment, the signal processing unit is in particular able to detect the process of a container with fluid being placed on the table, emptied step by step and then removed from the table again. Preferably, the signal processing unit also detects this container using the signals from the reading unit and/or the camera unit. By reading access to the objects list, the signal processing unit determines how much this container weighs and/or how much fluid this container can hold. Because different pieces of information are combined, the reliability with which the amount of fluid is calculated increases, whereby the patient consumes this amount of fluid from the container.
According to the invention, the reading unit comprises at least one reader. The camera unit comprises at least one camera. In one embodiment, the reading unit comprises at least two readers and/or the camera unit comprises at least two cameras. Preferably, the viewing directions of the readers differ from one another, and the viewing directions of the cameras also differ from one another. The signal processing unit determines the respective movement of each object relative to the bed during the reference time period and additionally identifies this object by means of the marking. In particular, this feature enables the signal processing unit to decide in many cases whether fluid in this object is being brought to the patient and/or fluid is being discharged from the patient and/or neither fluid is brought to the patient nor fluid is discharged from the patient. The signal processing unit uses each determined relative movement to calculate the fluid balance.
The patient usually consumes fluid from a container at least once during the reference time period. This container is configured to hold a drinkable fluid and to be brought to the patient's mouth. For example, the container is placed on a support surface of a patient table and the patient takes the container and drinks from it. Or the container is held in front of the patient's mouth. According to the invention, this container is also provided with a unique machine-readable marking. The weight of the container and/or the amount of fluid that the container can hold is stored in the objects list.
With the following configuration, the amount of fluid that the patient drinks from a container during the reference time period is taken into account in the fluid balance with a relatively high degree of reliability. The signal processing unit performs the following sequence at least once:
For this detection and determination, the signal processing unit uses at least one signal from the reading unit, at least one signal from the camera unit, and the objects list.
Thanks to the machine-readable markings and the camera unit, the movement of an object relative to the patient's bed can be easily tracked. Therefore, the signal processing unit is able to detect that an object in the shape of a container is brought to the patient's mouth. Furthermore, the signal processing unit is able to detect the events that fluid is spilled or that the patient brings the container to the mouth but does not drink.
The following embodiment takes into account the possibility that the patient excretes fluid while lying in bed and this fluid is absorbed by textiles, whereby these textiles are located in the bed and there between the patient and the bed or on the patient's body. The textiles include, in particular, a bed pad or the patient's clothing. For example, the patient sweats out fluid. Because this fluid remains in the bed, it does not lead to a change in the weight measured by the bed scale or the optional table scale.
According to this embodiment, the signal processing unit is configured to detect the event that the used object is replaced by a fresh object, for example that the patient's bedding and/or clothing are changed. For this detection, the signal processing unit uses a signal from the reading unit and/or a signal from the camera unit.
Before the replacement, the object has absorbed moisture that the patient has excreted into the bed. As a rule, the fresh object is of the same type as the replaced object, but fresh and therefore dry. The difference between the weight of the used object and the weight of the fresh object is therefore approximately equal to the weight of the fluid that the patient has released into the used and then replaced object in bed. It is possible that the weight of the used object before replacement and the weight of the fresh object are measured. Thanks to the following implementation, however, the need to measure the weight of this object separately is avoided.
According to this implementation, the weight of the bed is measured on the one hand at a time before the replacement, i.e. at a time when the old object, which may have absorbed fluid, is still in the bed. On the other hand, the weight of the bed is measured after the replacement, i.e. at a time when the fresh object is in the bed, i.e. an object that has not yet absorbed a significant amount of fluid from the patient. Either the patient is in bed at these two time points, or the patient is out of bed at these two time points. As already explained, the signal processing unit can clearly decide whether the patient was in bed or out of bed at the time of measurement based on the weight measured by the bed scale at the time of measurement. The measured weight of the bed before the replacement minus the measured weight of the bed after the replacement provides an approximation of the weight of the fluid that the patient released into the object before the replacement.
Another implementation does not necessarily require that the object that receives or can receive fluid from the patient is replaced in the reference time period and that this replacement is detected. According to this other implementation, the signal processing unit detects two time points in the reference time period, whereby the current weight of the bed has been measured at these two time points and the patient was not in the bed. The signal processing unit calculates the difference between the bed weight at the later time point and the bed weight at the earlier time point. In many cases, this difference corresponds sufficiently accurately to the amount of fluid that the patient excreted into the bed between the earlier and later time points.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which preferred embodiments of the invention are illustrated.
In the drawings:
Referring to the drawings,
The fluid balancing system 20 is used to determine a fluid balance for a patient 10. The fluid balance relates to a reference time period T and is the difference between the total amount of fluid supplied to the patient 10 in the reference time period T and the total amount of fluid leaving the patient 10 in the reference time period T. The reference time period T has a length of 24 hours, for example.
During the reference time period T, the patient 10 lies continuously or at least temporarily in a bed, in this case in a patient bed 30, which is located in a room 12 of a hospital. During the reference time period T, the patient bed 30 remains in place. It is possible for the patient 10 to temporarily leave the patient bed 30. The bed can also be a normal sleeping bed or a couch and be located in a room of an apartment.
The patient 10 is wearing clothing 38 while lying in the patient bed 30. The patient 10 is covered with bedding 34 or is lying on bedding 34, the bedding 34 including, for example, a comforter (duvet) and a pillow. There is also a bed pad 36 between the patient 10 and the patient bed 34.
Next to the patient bed 30 is a patient table 40 on which objects can be placed. The patient table 40 comprises a storage surface 40.1, an articulated support arm 40.2 and a stand. In addition, next to the patient bed 30 is a mobile holding device 84 in the manner of a mobile clothes rack, on which an infusion bag 82 hangs. During the reference time period T, a tube 56 connects the infusion bag 82 to the body of the patient 10, either continuously or at least temporarily. A fluid from the infusion bag 82 flows through the tube 56 into the body of the patient 10. A holding device 54 on the patient bed 50 holds a urine bag 50. A tube 58 connects the body of the patient 10 to the urine bag 50, continuously or at least temporarily.
The fluid balancing system 20 of the embodiment example comprises
The bed scale 32 is able to measure the weight of the patient bed 30. In the embodiment example, the patient bed 30 is placed on an external bed scale 32. When the patient 10 is lying in the patient bed 30, the bed scale 32 measures the sum of the weight of the patient bed 30 and the weight of the patient 10. When the patient 10 has left the patient bed 30, the bed scale 32 measures the weight of the empty patient bed 30.
The table scale 42 is able to measure the weight of the patient table 40. In the embodiment example, the patient table 40 stands on the table scale 42. If there is at least one object on the storage surface of the patient table 40, the table scale 42 additionally measures the weight of the object or each object on the storage surface.
The urine bag scale 52 is able to measure the weight Gew (50) of the urine bag 50. The volume flow sensor 80 measures the volume flow Vol′ (56) or the mass flow from the infusion bag 82 through the tube 56. It is possible that fluid is supplied to the body of the patient 10 from another container or device, or fluid is aspirated or otherwise discharged, and the corresponding volume flow or mass flow is also measured. The corresponding sensor may be a component of the device. The sensors 32, 42, 52 and 80 measure the respective physical quantity repeatedly, preferably at a fixed sampling frequency.
Several movable objects 60 are used to care for the patient 10 while he or she is lying in the patient bed 30. By way of example, the movable objects 60 shown are a drinking bottle 64, a cup 66, the bedding 34, the bed pad 36 and the clothing 38 of the patient 10.
At least one, preferably each, object 60 is provided with a respective machine-readable marking 62, but at least each object which can receive fluid is provided with a respective machine-readable marking 62. This marking 62 distinguishes this object 60 from any other, or at least from any different, object used to care for the patient 10. Different examples of the same object 60 may therefore have the same marking 62. For example, the marking 62 takes the form of an RFID tag, a bar code, a QR code, a particular pattern or symbol, or a sequence of alphanumeric characters. The color and/or the contour of the object 60 can also be used alone or as a color-contour combination as the marking 62. Preferably, the marking 62 is applied to an object several times (at several locations on the respective object) so that at least one marking 62 can be read.
The fluid balancing system 20 comprises a reading unit 72 having at least one reader 74, preferably a plurality of readers 74, and a camera unit 76 having at least one camera 78, preferably a plurality of cameras 78. The reader or each reader 74 has a reading area. The camera or each camera 78 has a field of view Bf with a central viewing direction (viewing axis). Preferably, the fields of view differ from one another, and at least two directions of view are arranged at an angle or at an angle to one another.
Preferably, each reader 74 and each camera 78 is fixedly mounted, for example on a ceiling or a wall of the room 12 or on the patient table 40 or on the patient bed 30. The reader 74 and the camera 78 therefore maintain their position relative to the patient bed 30 during the reference time period T. During the reference time period T, the patient bed 30 is therefore continuously located in the reading area or each reading area and in the field of view or each field of view.
The reader or each reader 74 is capable of reading or otherwise detecting the respective marking 62 of each object in the reading area of the reader 74. Read (62) refers to a read result of the reader 74. Preferably, the reader 74 repeatedly scans the marking 62 at a scanning frequency. The camera or each camera 78 is capable of capturing one image Abb(60) at a time, preferably a sequence of images at a sampling rate. Each reader 74 and each camera 78 generates a signal with the respective read result Read (62) or the respective image Abb(60) or the sequence of images. The image Abb(60) of a camera 78 therefore shows
The fluid balancing system 20 further comprises a signal processing unit 22 with a data memory 24 and a processor 26. The processor 26 has at least temporary read access to the data memory 24 and executes a stored program. The signal processing unit 22 can be a component of a smartphone or tablet or other portable computer.
The signals just described are transmitted to the signal processing unit 22, preferably wirelessly via electromagnetic radio waves 90.
The signal processing unit 22 receives a signal from each reader 74 and each camera 78 and processes the received signals. By evaluating the signal from a reader 74, the signal processing unit 22 detects and identifies each machine-readable marking 62 in the reading area of the reader 74 and thereby detects and identifies the marked object 60. Optionally, the signal processing unit 22 determines how an object 60 with a particular marking 62 moves relative to the patient bed 30 based on a varying field strength of the signal from the reader 74. An image processing unit of the signal processing unit 22 processes the signal from a camera 78 and thereby detects each person and each object in the field of view of the camera 78.
In one embodiment, the image processing unit applies a classifier. This classifier detects and classifies objects in an image Abb(60) of the camera 78. Preferably, the classifier is trained in advance with a random sample, for which a machine learning process is used. The classifier is implemented, for example, as a neural network. The configuration with the classifier creates redundancy and increases the reliability that a movement of an object 60 is correctly detected: An object 60 can be classified on the one hand on the basis of its marking 62 and on the other hand on the basis of its contour.
Overall, the signal processing unit 22 uses the classification to determine the respective position and movement of each object 60 having a marking 62 relative to the patient bed 30 and thus relative to the patient 10. In addition, the signal processing unit 22 determines whether an object 60 has been at the mouth of the patient 10 for a sufficiently long time span. If this object 60 is the drinking bottle 64 or the cup 66, this detection is an indication that the patient 10 is ingesting fluid from this object 60 or spilling fluid. This distinction cannot be made reliably simply by evaluating a signal from a scale.
In addition, the signal processing unit 22 receives a signal from each of the bed scale 32, the table scale 42, the urine bag scale 52 and the volume flow sensor 80, preferably also wirelessly via radio waves 90. In the embodiment example, the signal processing unit 22 determines the following time courses in the reference time period T:
The signal processing unit 22 preferably compensates for short-term oscillations over time by calculation. Such oscillations are caused by short-term and small movements of the patient 10 or a caregiver or even an external vibration source and do not significantly affect the fluid balance. For example, the signal processing unit 22 applies a low-pass filter to the signal from the sensor 32, 42, 52, 80.
At least temporarily, the signal processing unit 22 has read access to a computer-evaluable objects list 70. For example, the objects list 70 is stored in the data memory 24. This objects list 70 contains an entry for each object 60 that is detectable on the basis of a marking 62 and/or by the optional classifier described above. This entry contains
In the case of a drinking vessel as object 60, the information includes, for example, information about the volume and/or the empty weight of the drinking vessel. It is of course possible that the object cannot hold fluid or is not used to hold fluid. If the object is a plate or a bowl and can hold food, the listing comprises information about the average amount of fluid contained in the solid food consumed.
The signal processing unit 22 calculates a fluid balance for the patient 10. In the embodiment example, this fluid balance is the mass or also the volume of fluid that has been supplied to the patient 10 in total in the reference time period T, minus the mass or also the volume of fluid that the patient 10 has discharged in total in the reference time period T.
The calculated fluid balance can be positive or negative. If the fluid balance is positive, the patient has consumed (taken in) more fluid on balance in the reference time period T than he or she has excreted. Otherwise, he or she has excreted more fluid than he or she has consumed. In one embodiment, a value range with an upper threshold and optionally a lower threshold is predefined. The upper threshold is greater than zero, the lower threshold is less than zero. The fluid balance in the reference time period T for patient 10 should lie within this range of values. If the fluid balance is less than the lower threshold, then patient 10 has consumed too little fluid in the reference time period T. There is then a risk that patient 10 will become dehydrated. If the fluid balance is greater than the optional upper threshold, there is a risk that fluid will be deposited in patient's 10 tissue, which is also undesirable.
Preferably, the signal processing unit 22 checks whether the fluid balance for the reference time period T is within the range of values or whether it is less than the lower threshold or greater than the upper threshold. If the fluid balance is outside the range of values, the signal processing unit 22 generates a corresponding message and causes this message to be output in at least one form that can be perceived by a human, preferably by a receiver outside the room 12. Preferably, the message indicates whether the patient has consumed too much or too little fluid. In one embodiment, a corresponding message is also generated and output if the fluid balance is within the value range. A fluid balance far outside the value range can still be an indication that the fluid intake or a fluid intake was not detected or that a device in the system is operating incorrectly.
Patient 10 consumes (takes in) fluids, in particular through the following actions:
In particular, the patient discharges (releases) 10 fluid through the following actions:
The following events do not usually affect the fluid balance:
Note: Because the signal processing unit 22 determines time courses and derives differences from them, the weight of the empty patient bed 30 or the weight of the empty patient table 40 is not necessarily required.
In the embodiment example, the possibility that objects are placed on the patient table 40 and/or removed from the patient table 40 one after the other or simultaneously is taken into account. Each object changes the weight of the patient table 40, and the table scale 42 weighs this weight. The weight of the object on the patient table 40 thus influences the time course of the weight of the patient table 40, whereby the signal processing unit 22 determines this time course as described above. The signal processing unit 22 also identifies each object 60 that is placed on the patient table 40 or removed from the patient table 40 by means of the marking 62, at least if this object 60 is capable of receiving fluid. By reading the objects list 70, the signal processing unit 22 determines how much fluid an identified object 60 is capable of holding. The signal processing unit 22 determines how much fluid the patient 10 has consumed in total from objects placed on the patient table 40 in the reference time period T. For this purpose, the signal processing unit 22 uses the determined time course of the weight of the patient table 40 and the amount of fluid that an identified object 60 on the patient table 40 can hold according to the objects list 70. In particular, the signal processing unit 22 determines that an object changes the weight of the patient table 40 but does not hold any fluid and therefore does not contribute to the fluid balance, for example cutlery or a book. If an object 60 does not bear a marking, this object is preferably disregarded when calculating the fluid balance. In addition, the signal processing unit 22 optionally determines the event that the patient 10 spills fluid from an identified drinking vessel 60 and takes this approximately into account when calculating the fluid balance.
It is possible that a full drinking vessel, for example the drinking bottle 64 or the cup 66, was placed on the patient table 40 before drinking and the empty drinking vessel is placed back on the patient table 40 after drinking. This changes the measured weight of the patient table 40. Consideration is given to the possibility that a caregiver holds a drinking vessel 64, 66 in front of the patient's 10 mouth and the patient 10 drinks from the drinking vessel 64, 66 without placing the drinking vessel 64, 66 on the patient table 40. In this case, the drinking vessel 64, 66 does not change the measured weight of the patient table 40.
The image processing unit of the signal processing unit 22 detects the event that a drinking vessel 64, 66 is brought to the mouth of the patient 10 and the event that the drinking vessel 64, 66 is moved away from the mouth of the patient 10 again. The signal processing unit 22 identifies the drinking vessel 64, 66 by means of the marking 62 and determines by image evaluation that this drinking vessel 62 is located in front of the mouth of the patient 10. The signal processing unit 22 determines how much fluid this drinking vessel is capable of holding by reading access to the objects list 70. Preferably, the signal processing unit 22 uses the assumption that the patient 10 ingests this amount of fluid while the drinking vessel 64, 66 is held in front of his mouth.
In one embodiment, the possibility is taken into account that fluid from a drinking vessel 64, 66 does not enter the body of the patient 10, but is poured out or spilled. This event can also be detected by the image evaluation unit and the amount of fluid spilled can be approximately determined from the movement of the drinking vessel 64, 66.
While specific embodiments of the invention have been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2023 124 033.1 | Sep 2023 | DE | national |
