AT513091B1 - Method and device for determining the change in water accumulation in a body part - Google Patents

Abstract

The invention relates to a method and a device for determining the change in a water accumulation in a body part, namely in the foot and / or lower leg (1), wherein three-dimensional images are created and evaluated by the body part with at least one image acquisition unit (3). According to the invention, it is provided that, based on the images depicting the body part, at least one output variable lying on the surface of the body part, namely a measuring point (27, 29) and / or a measuring line (33, 34, 35) or curve is selected and defined in that at least one parameter dependent on the volume of the body part and consequently as the water accumulation, namely the position and / or the distance (A) of the output variable, is compared with at least one reference variable selected from the recorded images, namely a reference point (37 ), a reference line (38) or curve and / or a reference plane (25) is determined, - that the determination of the characteristic is repeated after a predetermined period of time, in particular in the same procedure, and - that a change in the characteristic as a measure of a Change in water retention in the body part is considered.

Description

Austrian Patent Office AT 513 091 B1 2014-12-15

Description: [0001] The invention relates to a method according to the preamble of claim 1. Furthermore, the invention relates to a device according to the preamble of claim 14.

According to a measurement of the lower leg or feet of a person, wherein the geometry of the respective body part is measured with the aid of cameras in order to detect early leg edema. Thus, for example, in a home monitoring application with heart failure patients can be detected early when problems with the cardiovascular system of a patient occur.

Heart failure (heart failure) is a serious disease of the heart, in which the heart is hardly able to pump blood in sufficient quantity through the body as a result of pre-existing diseases. One of the consequences of heart failure may be fluid accumulation in the patient's legs (right heart failure) or in the lungs (left heart failure) (lung or leg edema). Such edema is a symptom that indicates serious physiological problems and generally requires increased therapy and control by the physician. Early detection of such edema may help the physician to initiate the necessary therapy in time to prevent serious cardiac derailment.

Edema can be detected in different ways. A somewhat specific but relatively sensitive approach is the regular control of patient body weight. The fluid accumulated in the legs or lungs causes an imbalance in the fluid balance of the patient: less fluid is excreted than absorbed. This leads to an increase in weight of the patient. Typical values would be weight gains of about 2 kg within 2 days. However, the problem is that such weight fluctuations can also be triggered by numerous other causes, e.g. changed eating and drinking behavior.

Another method of detecting edema is based on the fact that different tissues have different electrical properties, in particular impedances. By impedance measurement, e.g. the proportion of fatty tissue, muscle tissue, air (in the lungs) or water in the body can be estimated. In the case of edema, since the proportion of water in individual body regions increases (lung or legs), impedance detection can also be used to detect edema.

Heart failure patients can also be cared for with the help of home monitoring systems. Among other things, attempts are made to apply the abovementioned methods for detecting edema not only once at the doctor, but regularly at the patient's home. The weight is measured once a day by the patients and these weight values are transmitted to a data center. Frequently, other parameters are also recorded, e.g. Blood pressure, heart rate (pulse), well-being, medication, etc. If edema forms in the legs or lungs of the patient, it is often associated with an increase in weight and / or a change in other parameters (blood pressure, heart rate, etc.). ).

US 5 824 029 A "Implantable medical system for performing transthoracic impedance measurements associated with cardiac function" describes a method for impedance measurement with implanted devices, wherein therein is the application of the impedance measurement in the monitoring of the electrodes of the implant. This method is extended in US Pat. No. 7,313,434 B2 "Impedance monitoring for detecting pulmonary edema and thoracic congestion", US Pat. No. 5,876,353 A and US Pat. No. 5,958,861 A, in order to measure the impedance between the housing of an implanted cardiac pacemaker and its electrodes To close fluid collections within the lungs. Disadvantage of such methods is that on the one hand a device must be implanted, on the other hand only edema detected in the lungs, but not in the legs - as they often occur in right-sided heart failure ,

The fluid accumulation in the legs changes the shape of the legs - they swell. This swelling of the legs can be detected by various measuring methods.

Known in this context is the measurement of the leg with tape measure at different points of the foot. However, the measurement must be performed by trained personnel, is highly dependent on the type of measurement and is not suitable for use in home-monitoring scenarios.

An established measurement method for determining the leg volume is the water displacement method, which measures how much water is displaced from a vessel when the patient is climbing his leg into the vessel. The volume of the displaced water corresponds exactly to the volume of the leg. Rabe E. et al. describe in Rabe E, Stücker M, Ottillinger B. Water displacement leg volumetry in clinical studies - A discussion of error sources. In BMC Medical Research Methology 2012, 10: 5 possible sources of error in this measurement method. Regardless of the sources of error described therein, this method is also poorly suited for use in home monitoring applications.

Optical 3D scanner or 3D image recording units are devices that can record three-dimensional images of objects with the help of stereoscopic images. Such devices are used in medicine for numerous tasks and can also be used advantageously in the context of the present invention.

Elbischger et al. describe in Elbischger P, Jerolitsch-Binder J, Prasser M, Menard C. A novel measuring system for the accurate and efficient determination of extremity volume. In: Proceedings of the eHealth2011,26.-27.5.2011 in Vienna, p129-134 a procedure, in which the volume of this limb can be determined by taking a limb of a patient with the help of a stereo camera.

Kau CH, Cronin A, Durning P, Zhurov AI, Sandham A, Richmond S. A new method for the 3D measurement of postoperative swelling following orthognathic surgery. Orthod Craniofac Res. 2006 Feb; 9 (1): 31-7. describes the use of 3D laser scanners to monitor swelling after surgery.

Rana M, Gellrich NC, Joos U, Piffkö J, Kater W. 3D evaluation of postoperative swelling using two different cooling methods following orthognathic surgery: a randomized observer blind prospective pilot study. Int J Oral Maxillofac Surg. 2011 Jul; 40 (7): 690-6. Epub 2011 Mar 15 uses optical methods to compare different therapies for reducing swelling.

Under the trade name Kinect a 3D camera (RGB-D camera) is sold, which was actually developed as a controller for a game console. Due to its spatial resolution of 640 x 480 pixels and a depth resolution of 11-bit, the accuracy of the field of view is approx. 1 mm.

Body carts with integrated impedance measurement are used today for the determination of body fat percentage. Usually the impedance of the tissue between left and right foot is measured.

Although with the currently available sensors and evaluation in many cases an edema can be detected, but the detection is not sufficiently accurate, it is often only at a time when the edema is already very advanced and is usually not suitable for use in home monitoring scenarios.

The primary object of the invention is to determine the change in the accumulation of water in certain parts of the body, namely in the foot and / or in the lower leg. This provision should be quick, easy and accurate and should be able to be performed without the use of trained personnel. Another special object of the invention is to be able to detect leg edema prematurely and with high accuracy or to detect cardiac insufficiency.

These objects are achieved in a method of the type mentioned above with the features mentioned in the characterizing part of claim 1. A device of the type mentioned is characterized according to the invention with the features specified in the characterizing part of claim 10. According to the invention, geometric parameters are specified or determined on the foot or on the leg and the temporal change of these parameters is observed. In the case of changes in the characteristic, these can be recorded and evaluated in a corresponding manner.

Above all sizes are used as parameters, which are primarily influenced by the accumulation of water in the respective body part. The selected output quantities or measuring points and measuring lines should be as strong as possible and the selected reference quantities or reference points, reference lines and reference planes should be influenced as little as possible by water accumulation or be fixed points.

The repetition of the measurement to determine how the parameters have changed, can take place at predetermined times regularly or irregularly. As a rule, relative changes in the accumulation of water are found. If a calibration is carried out with reference to a given or volume-determined water accumulation as initial measurement, a quantitative statement can also be made about accumulated quantities of water.

It is advantageous if the output variable is determined by - as a measurement point or measurement line lying in the instep area of the foot point or lying in the instep area of the foot line or curve is selected and / or - by as a measurement line from the ankle and or the outermost ankle elevation to the lower calf end on the inner side of the lower leg is selected to be a line or curve and / or by using as a measurement line a circumference of the lower leg approximated by a circular line in a height range of approximately 60% to 70% of the lower leg, calculated from the sole of the foot or the foot ridge.

Measuring points or measuring lines, which are in the instep area, give a good statement, since the instep area increases or swells predestined when water accumulates in the legs. Also, the inside of the lower leg in the area from the ankle up to the lower end of the calf is subject to a characteristic change, as long as water accumulates in the leg.

Furthermore, the upper calf portion is predestined affected by water retention in the leg. Here, the circumference of the lower leg in the calf area can be measured on the given height range. Changes in the parameter, which serves as the output variable and is used as a reference for further measurements, i. Changes in the magnitude of the output, i. against a detected measuring line enclosing the lower leg, give a statement about water retention in the leg.

It is advantageous if, as a reference point, the foot point lying on the sole of the foot or of the footing plane of a vertical line extending through the measurement point lying on the surface of the instep is used for the sole of the foot or for the supporting plane, and / or - that a reference line is determined, by drawing a connecting line lying on the inner side of the lower leg between the outermost ankle elevation and the lower end of the calf or between the endpoints of a fixed measurement line or curve running on the inside of the lower leg from the outermost ankle elevation to the lower end point of the calf and / or - that a reference plane is determined by determining a plane containing the heel surface and the toe or ball surfaces of the foot, or by using the foot ridge as a reference plane, and / or 3/13 Austrian Patent Office AT 513 091 B1 2014-12- 15 - that a reference line e is determined by a, possibly approximated by a circular line, circumference of the lower leg on a height range of about 60 to 70% of the lower leg, calculated from the sole of the foot or the foot ridge, is determined.

As a reference point for a measuring point or a measuring line on the instep either a point on the footprint of the foot or a point on the sole of the foot is used. Such points are advantageously determined by forming a vertical line through the respective measuring point or by projecting the measuring line onto the sole of the foot or onto the foot point.

As a reference line for lying on the inside of the leg measurement line can advantageously be used a straight line which connects the end points of the measurement line. The distance between the two lines, in particular the maximum distance and / or the area enclosed by the two lines, gives a statement about the accumulation of water.

When measuring the lower leg advantageously the output variables and the reference variables are determined in chronological succession in the same way.

It is advantageous if, as a parameter - the height of the measuring point in the instep area above its base on the sole of the foot or above its base on the supporting plane is determined and used and / or - the maximum distance or the area between the measuring line through the measuring points between the area of the outermost elevation of the inner ankle and the lower end area of the calf on the inner side of the lower leg and a straight line connecting these two areas or the outermost measuring points, and / or - the circumferential, area or radius difference of two, optionally, approximated by a circular line, the circumferential lines of the leg is used, which peripheral lines were taken at successive times.

In the latter case, for example, the detected during a subsequent measurement measurement perimeter taken as a measurement line and the difference to an already established perimeter in the circumference or in the radius or in the enclosed area used as a parameter. It could also be the average distance of the circumference related to the foot axis used to determine the characteristic. It is advantageous, however, if the first defined circumferential line around the calf area is used as the reference line and the position or the distance of a peripheral line obtained in the following measurements is used as a measuring line to this reference line for evaluation.

In practice, it is advantageously possible to proceed in such a way that a point cloud is created for the three-dimensional image of the surface of the recorded body part obtained with the three-dimensional image recording method or the surface is simulated with a point cloud and the output variable and reference variable based on the points of this point cloud be formed. Such a formation of a point cloud with the 3D cameras used according to the invention is not a problem for the expert in the field of image analysis and is achieved by conventional means. The selection of the measuring points and measuring lines or of the reference points, reference lines and reference planes from this point cloud can be done either by manual input or selection or with appropriate programs, the point cloud from the desired points due to certain predetermined or existing characteristics for these points can determine. As fixed points for such investigations, for example, the ankle lift, the end points of the toes, the heel, the heel and ball surfaces or the contours of the sole or of the foot and the lower leg can be used. It is advantageous if the measurement point is selected from a subset of the point cloud, the subset comprising the points located in the instep area of the foot and the foot points located on the sole of the foot or foot contact area from the perpendicular through the measurement point Sole of foot or footprint includes and / or - the measurement line or curve is formed with points of the point cloud, which is on the inside of the leg in the area between the elevation of the inner malleolus and the area of the lower end of the calf, and / or - the measuring line formed by a peripheral line around the lower leg is formed with points of the point cloud, which lie in a peripheral region of the lower leg, wherein the peripheral region in a range of 60 to 75% of the height of the lower leg, measured from the footprint of the foot or sole.

In order to improve the validity of the measurements obtained, it can be provided that, in particular approximately simultaneously, with the determination of the core size, the weight of the person to be measured is determined and evaluated together with at least one characteristic. Furthermore, it is also possible that characteristics determined in the individual determination processes are compared with one another and / or with predetermined threshold values. Even so, the significance of the measurements made can be increased.

A further improvement can be achieved in that the color information of the image of the body part, in particular the mutual ratio of red, blue and yellow light, determined and evaluated together with at least one characteristic and / or by image recording in the infrared range temperature information of Body part determined and evaluated together with at least one characteristic. In leg edema due to cardiac problems it can be assumed that the skin is purple to reddish discolored. On the other hand, red discoloration indicates inflammatory processes. If the color is brown, venous insufficiency may be the cause of any volume changes.

If the image recording in addition to visible also uses infrared light, it can be concluded from the image data on the temperature of the leg. This can also distinguish between edema of cardiac cause and e.g. Inflammatory processes (which are associated with an increase in temperature in the affected areas) can be distinguished.

The sensor can also be improved by having the device at the base on which the person is located during the measurement, at least one temperature sensor and / or at least one pressure sensor and the values obtained by these sensors of the distance and / or Position determination unit for evaluation and / or storage are supplied. By measuring further parameters in the test person's standing area, ie on the soles of the feet, the accuracy of the change detection can be improved. Thus, with the help of an array of pressure sensors, the support surface can be recognized, which increases in the case of edema due to the swelling. By temperature measurement, e.g. the distinction of inflammatory processes can be improved.

It is advantageous that the method for detecting the occurrence and / or the change and / or the assessment of the change of edema in the foot and / or lower leg and / or heart failure is used.

A device of the type mentioned above is characterized in that - a point cloud generator is connected to the image recording unit, which creates a point cloud of the surface of the body part comprehensive or performing point cloud with the recorded image of the body part and based on the points of the point cloud output variables and generates reference variables, and - that the point cloud generator and / or the image pickup unit, a distance and / or attitude determination unit for determining the position and / or the distance of an output variable, namely a measurement point and / or a measurement line or curve of a reference variable, namely a reference point and / or a reference line or curve and / or a reference plane possesses, wherein the determination of the distance and / or the position is carried out with mathematical or statistical algorithms and a change of the distance and / or the position as a parameter and measure of the Wasseransammlu ng in the body part and / or for the dependent of the accumulation of water volume of the body part for output and / or storage in a memory is available. Such a device has a simple structure and is easy to operate or can be implemented by a person skilled in the art with methods, programs and components known in the field of image processing. SUMMARY OF THE INVENTION

For operation, it is advantageous if the device has a comparator for detecting and / or displaying changes in the characteristics recorded in successive determination operations or in measurements taken in temporal succession.

The efficiency of the device is increased when the device is connected to a balance or integrated into a balance or placed on a balance so that it is easy for a user to determine both the measures regarding the change in water retention and its weight and to be able to evaluate. Thus, the person using the scale can be informed simultaneously about the change in the accumulation of water and its weight. The device according to the invention can be integrated into a balance or combined with it to form a structural unit, wherein the weight measured values as well as the characteristic quantities can be stored and / or displayed. It is expedient if the device according to the invention has a memory for the initial values and / or the dimensions and / or the reference quantities already obtained by the person to be measured in order to avoid a remeasurement for the following measurements.

It can be provided that the device according to the invention has a storage unit for the recorded images. Any desired 3D cameras or optical sensors which are sensitive to at least one color spectrum may be used as image recording units. These cameras or sensors are arranged separately from one another in a corresponding spatial arrangement in order to be able to record three-dimensional images.

In principle, it is also possible that a projection unit is provided, which projects an image, in particular a grid, on the leg to be measured in order to make better the finding and determination of the output variables and reference variables.

The cameras can be arranged at different locations and record the leg from different perspectives; Such images can also be done by means arranged in spatially different positions mirror with a camera. The captured images are then assembled into a 3D image.

It is also possible to connect the device according to the invention with a balance in such a way that the image recording is triggered by the weight measurement and is then performed when it has been recognized by the balance that the body is no longer moving.

It is also possible that the output variables or reference variables are determined on the body part of the person to be examined, for example by marking with markers which adhere to the body surface and remain recognizable. Advantageously, such markings can also be applied to the device or the footprint area for the foot, wherein such markings can be easily recognized by the image processing units used.

In the following the invention will be explained in more detail with reference to the drawing, for example.

Fig. 1 shows schematically a lower leg or foot and a schematically constituted inventive device.

FIG. 2 shows a possibility for determining output and reference variables or the geometric parameters.

FIG. 3 shows another possibility for determining output and reference variables. 6/13 Austrian Patent Office AT 513 091 B1 2014-12-15 [0050] FIG. 1 shows a possible embodiment of the invention. Shown are a lower leg 1 and a foot of a person. The height A of the midfoot or instep is measured with a device according to the invention, which comprises an image recording unit 3 or sensor unit, and transmitted as a measure of a water accumulation to a memory unit 4, in which this parameter is stored. A number of measurements are taken at intervals and in a comparison unit 5 the measured values can be compared with each other. Based on the comparison, it is concluded that there is a change in the accumulation of water in the leg, and it can be decided, as shown in FIG. 8, whether the person's leg has or does not have edema, or whether heart failure is present.

FIGS. 2 and 3 show possibilities for determining the geometric parameters. Reference quantities are searched for and e.g. marked reference points 22, 23, 24, 29, 30, 32, 35 fixed to the foot and / or lower leg, which are a reference size, e.g. form a riot level or reference plane 25. The distinctive points may be specifically color-coded or tattooed, or they may be defined as uniquely identifiable locations on the foot when the images are taken, such as the tip 24 of a toe, the innermost point 23 between two toes, a distinctive point of a toenail, the outermost point 29 of the inner ankle elevation 32, the inner lowest point 22 of the heel surface, etc. Another prominent point 27 can be searched at the metatarsus; the normal distance A of this point 27 to the reference plane 25 is used as a parameter.

Reference variables or output variables can also be derived from striking reference variables or output variables. For example, the intersection between the shortest connections between two distinctive points can be determined. The point 27 at the metatarsus could e.g. as the point of intersection between the connection of the foremost point 24 of the innermost (largest) toe with the outermost point of the lateral malleolus with the connection between the foremost point of the outermost toe and the innermost point 29 of the medial malleolus 32.

According to FIG. 3, three marked points 33, 34, 35 are drawn on a lower leg 31 seen from the rear above the inner ankle 32. These points and any other points lying therebetween on the surface of the skin are determined or specified, and the curvature of the measurement line or curve defined by these points is determined and used as a parameter. Alternatively, a triangle can also be placed through the three points and the height of this triangle can be determined as a parameter, i. the normal distance of the point 34 from the line passing through the points 33 and 35 straight lines 38th

In Fig. 2, the measurement of the circumference of the lower leg is shown in a predetermined height H above the plateau or reference plane 25 of the leg. At the predetermined height H, a circumferential line 36 is determined or measured, and the change in the circumferential line with respect to the radius and / or diameter and / or relative position to the foot axis with measurements taken in temporal succession is used as a parameter.

The outlines of the leg shown in Figures 1 to 3 could already represent abstracted views of the captured 3D images, namely point clouds or slices through point clouds extracted from the recorded three-dimensional images. In these images, the corresponding points 2, 37, 27, 22, 23, 24, 29, 32, 33, 34, 35 could then be marked and used for the respective successive measurements. A storage of these points can be done in the memory unit 4. The recording and the storage of the reference points or reference lines or reference planes are advantageous for successive measurements in order to always be able to create the same starting position for successive measurements and to be able to detect the position or the distance or a change of these parameters relative to this starting position. The reference points or reference lines or reference planes can lie on the leg, but also on the measuring device itself or in the surroundings thereof, in particular on the stand surface. For the diagnosis of edema, it can be provided that both a change in the body weight in the direction of a higher value, and a change in the accumulation of water in the direction of a higher value, need to be identified together in order to justify or remedy the diagnosis of edema. It is also possible to specify threshold values for the increase in weight or the increase in the accumulation of water in the body part, which must be exceeded in order to allow inferences about edema.

The measurement and reference lines can have any predefined course and be formed by straight lines or curves.

It is quite possible to define or use a plurality of output variables and / or reference variables in the course of a measurement and to determine a plurality of parameters based on these variables. The bases of individual points are determined by the intersection of a perpendicular to the reference plane with this plane, which runs vertically through the point. 8.13

Claims (17)

Austrian Patent Office AT 513 091 B1 2014-12-15 Claims 1. A method for determining the change in a water accumulation in a body part, namely in the foot or in the lower leg (1), wherein three-dimensional images are created and evaluated by the body part with at least one image acquisition unit (3) are, characterized in that - based on the representations of the body part at least one lying on the surface of the body part output variable, namely a measuring point (27, 29) and / or a measuring line (33, 34, 35) or curve selected and set - that at least one of the volume of the body part and consequently as dependent on the water accumulation parameter, namely the position or the distance (A) of the output over at least one selected from the recorded images or in this fixed reference size, namely a reference point (37) , a reference line (38) or curve and / or e in reference plane (25), it is determined that the determination of the parameter is repeated after a predetermined period of time, in particular in the same procedure, and that a change in the parameter is regarded as a measure of a change in the accumulation of water in the body part. 2. The method according to claim 1, characterized in that the output variable is determined by - as a measuring point lying in the instep area of the foot point (27) or as a measuring line lying in the instep area of the foot line or curve is selected. 3. The method according to claim 1 or 2, characterized in that the output variable is determined by - as a line of measurement from the ankle or the outermost ankle lift (32) to the lower calf end on the inside of the lower leg extending line or curve is selected. 4. The method according to any one of claims 1 to 3, characterized in that the output variable is determined by - as a measuring line, optionally approximated by a circular line, peripheral line (36) of the lower leg on a height range (H) of about 60% to 70 % of the lower leg, calculated from the sole of the foot or the level of support (25) of the foot. 5. The method according to any one of claims 1 to 4, characterized in that as a reference point (37) lying on the sole of the foot or the support plane (25) base of a through the lying on the surface of the instep measuring point (27) extending perpendicular (28) to the sole of the foot or to the supporting plane (25); or that a reference line (38) is determined by a connecting line lying on the inner side of the lower leg between the outermost ankle lift (32) and the lower end of the calf or between the end points of a fixed calf Measuring line (33, 34, 35) or curve is drawn on the inside of the lower leg from the outermost ankle lift (32) to the lower end point of the calf or - that a reference plane (25) is determined by one of the heel surface and the Or by using the footing plane (25) of the foot as the reference plane d, or - that a reference line is determined by a circumferential line (36) of the lower leg, possibly approximated by a circular line, on a height range (H) of approximately 60 to 70% of the lower leg, calculated from the sole of the foot or from the contact plane (25). of the foot, is determined. 9/13 Austrian Patent Office AT 513 091 B1 2014-12-15 6. The method according to any one of claims 1 to 5, characterized in that as a parameter - the height (A) of the measuring point (27) in the instep area above its base on the sole of the foot or above its base on the supporting plane (25) determined and used or the maximum distance or area between the measurement line (33, 34, 35) through the measurement points between the region of the outermost elevation (32) of the inner ankle and the lower end region of the calf on the inner side of the lower leg and one of these two regions or the outermost measuring points of the measuring line (33, 34, 35) connecting lines (38) is determined and used as a reference line or - the circumferential, area or radius difference of two, possibly approximated by a circular line, peripheral lines (36) of the leg (1 ), which peripheral lines (36) were taken at successive points in time. 7. The method according to any one of claims 1 to 6, characterized in that for the obtained with the three-dimensional image recording method three-dimensional image of the surface of the recorded body part creates a point cloud or the surface is replicated with a point cloud and the output size and reference size based on the points This point cloud can be formed. 8. The method according to any one of claims 1 to 7, characterized in that - the measuring point (27) is selected from a subset of the point cloud, wherein the subset located in the instep area of the foot points and on the sole or the footprint (25) foot points (37) from the perpendicular (s) passing through the measuring point (27) to the sole of the foot or to the footprint (25), or - the line of measurement is formed with points of the cloud on the inside of the leg (1) lie in the region between the outermost elevation (32) of the medial malleolus and the region of the lower end of the calf, or - the measurement line formed by a peripheral line (36) around the lower leg is formed with points of the plotted cloud located in a peripheral region of the caliber Lower leg, the peripheral area being in a range of 60 to 75% of the height of the lower leg as measured by the footprint (25) of the foot or foot sole, lies. 9. The method according to any one of claims 1 to 8, characterized in that in particular approximately simultaneously, with the determination of the characteristic, the weight of the person to be measured is determined and evaluated together with at least one characteristic. 10. The method according to any one of claims 1 to 9, characterized in that the color information of the image of the body part, in particular the mutual ratio of red, blue and yellow light, determined and evaluated together with at least one characteristic. 11. The method according to any one of claims 1 to 10, characterized in that determined by image recording in the infrared range temperature information of the body part and evaluated together with at least one characteristic. 12. The method according to any one of claims 1 to 11, characterized in that the parameters determined in the individual determination operations are compared with each other and / or with predetermined threshold values. 13. The method according to any one of claims 1 to 12, characterized in that the method for detecting the occurrence, or the change and / or the assessment of the change of edema in the foot, or in the lower leg and / or heart failure is used. 10/13 Austrian Patent Office AT 513 091 B1 2014-12-15 14. A device for determining the change in a water accumulation in a body part, namely in the foot or lower leg (1) of a human, comprising an image acquisition unit (3) for creating at least a three-dimensional image of the body part, in particular for carrying out the method according to one of claims 1 to 13, characterized in that - a point cloud generator (6) is connected to the image acquisition unit (3), which creates a point cloud covering or representing the points of the surface of the body part with the image taken by the body part and based on the points of the point cloud output quantities and Creates reference variables, and - that to the point cloud generator (6) or the image pickup unit (3) a distance and / or attitude determining unit (7) for determining the position and / or the distance of an output variable, namely a measuring point or a measuring line or curve of a reference size, namely a Reference point or a reference line or curve or a reference plane possesses, wherein the determination of the distance or the position with mathematical or statistical algorithms takes place and a change of the distance or the position as a parameter and measure of the water accumulation in the body part or for the of Water collection dependent volume of the body part for output and / or storage in a memory (4) is available. 15. The apparatus according to claim 14, characterized in that the device has a comparator (5) for detecting and / or displaying changes in the recorded in successive determinations or obtained in temporal succession measurements measurements obtained. 16. The apparatus of claim 14 or 15, characterized in that the device comprises a scale or is arranged on a scale and the weight value obtained by the balance of the distance and / or position determination unit (7) for evaluation and / or storage is supplied. 17. The device according to one of claims 14 to 16, characterized in that the device has a footprint for the person for the duration of the measurement, wherein on the footprint at least one temperature sensor and / or at least one pressure sensor is arranged and obtained from these sensors Values of the distance or position determination unit (7) are supplied for evaluation and / or storage. For this 2 sheets drawings 11/13