Determining the initial velocity of a urine stream

Abstract

The invention relates to a method (and associated device) for determining the initial velocity of a urine stream using a radar device, particularly one positioned in a toilet. The invention notably allows this initial velocity to be determined using the radial velocity. Abstract figure: Figure 5

Description

Title of the invention: Determination of the initial velocity of a urine stream

[0001] This description relates to devices and methods for determining the ejection velocity of urine from a toilet user. Such a determination is particularly applicable in the context of health tests: the urine flow rate and associated information make it possible to determine the health status of the user's urinary system. State of the art

[0002] The document Qi (Qi, Y.; Kong, H.; Kim, Y. Estimation of Urine Flow Velocity Using Millimeter-Wave FMCW Radar. Sensors 2022, 22, 9402. https: / / doi.org / 10.3390 / s22239402) presents a history of measurement methods related to urination and the advantages of having such measurements. This document further introduces a theoretical method for measuring urine flow velocity using a radar positioned horizontally and aligned with the urine stream, since the radar only measures radial velocity. Aligning the radar with the urine stream to obtain a urine stream velocity similar to the radial velocity, and the horizontal position of the stream to allow the use of a free-fall equation with zero vertical velocity in the initial condition, makes the approach more theoretical than practical: it is difficult to guarantee that the user will urinate directly toward the radar under real-world conditions. Summary of the invention

[0003] It is desirable to have a measurement system that does not present the aforementioned drawbacks. More specifically, the present description proposes using a radar, for example placed inside a toilet, to measure the initial velocity of a urine stream exiting the urethra even when the stream is not radially oriented with respect to the radar.

[0004] In particular, the description relates to a measurement method for a user's urine stream during urination, the measurement method using a radar sensor arranged on the wall of a toilet bowl, the method comprising at least the following steps: - the emission by the radar sensor of a radar signal, directed towards the urine stream, - the reception by the radar sensor of a radar signal emitted by the radar sensor and reflected by the urine stream. - the processing of the received radar signal to determine a value of the velocity of the urine jet exiting the urethra, called the initial velocity V0.

[0005] Such a radar sensor is not positioned in line with the jet and therefore measures in particular the radial velocity, and not the actual velocity of the urine jet.

[0006] In one embodiment, the processing includes the calculation of a distance-Doppler response of the urine jet, i.e. the calculation of a radial velocity of the urine jet (the component of the velocity projected onto the axis between the urine jet and the radar sensor) and a radial distance of the urine jet (i.e. the distance between the urine jet and the radar sensor).

[0007] More specifically, the treatment comprises a correspondence between the distance-Doppler response, which takes into account the measured radial velocity of urine stream drops, and a mathematical model of the free fall of a urine drop from the urethra, which takes into account the simulated initial velocity of a urine drop. The distance-Doppler response is calculated for a given time t and represents a spatial view of the urine stream drops. With this time-space equivalence, the method makes it possible to generate data for calculating the initial velocity V0.

[0008] In one embodiment, the processing includes a regression of the calculated distance-Doppler response by a simulated distance-Doppler response, by modifying the modeled initiative velocity of the free fall, the calculated initial velocity being chosen as the modeled initial velocity determined at the end of the regression.

[0009] In particular, the mathematical model includes the expression of a function of the radial distance and the radial velocity as a function of a polynomial (in particular of degree 3), the polynomial being obtained from a free fall equation of a drop of urine from the urethra and one of the coefficients of the polynomial being expressed as a function of the initial velocity.

[0010] In particular, the treatment includes an interpolation of the polynomial, using radial velocity and radial distance values ​​from the calculated distance-Doppler response in order to know, via interpolation, the value of the coefficient expressed as a function of the initial velocity.

[0011] According to another embodiment, the treatment comprises a reconstruction of a urine stream by the free fall of a drop of urine from the urethra. This method can notably be carried out with a radar device comprising several transmitting and receiving antennas.

[0012] In one embodiment, the radar sensor operates by frame, each frame being generated by a plurality of chirps, and the transmission and reception steps being implemented for each chirp.

[0013] The radar sensor can be a “Frequency Modulated Continuous Wave” type radar sensor, FMCW, or the radar signal can be FMCW.

[0014] In one embodiment, the method includes a preliminary step, using a urine detector to determine the presence of a urine stream, the method includes, in response to said detection, a step of activating the radar sensor.

[0015] According to another aspect, the description relates to a computer program comprising instructions capable of implementing a method as described above when the instructions are executed by a processor.

[0016] According to another aspect, the description relates to a radar device comprising: - a housing, suitable for being positioned on the inside wall of a toilet bowl, - a radar sensor, housed in the casing, and capable of emitting radar waves towards a stream of urine, the radar sensor being capable of implementing the method as described above.

[0017] In particular, the radar sensor may include a single transmitting and / or receiving antenna.

[0018] Alternatively, the radar sensor includes at least two transmitting antennas.

[0019] According to another aspect, the description relates to a measurement method for a user's urine stream during urination, the measurement method using, the method comprising at least the following steps: - the emission by the radar sensor of a radar signal, directed towards the stream of urine, - the reception by the radar sensor of a radar signal emitted by the radar sensor and reflected by the urine stream, - the processing of the received radar signal to determine a value of the velocity of the urine jet exiting the urethra, called the initial velocity V0.

[0020] The characteristics described above apply to this aspect in a similar or identical manner. Presentation of the figures

[0021] The following figures will help to facilitate understanding of the invention: - [Fig. 1]: [Fig. 1] schematically presents a cross-sectional view of toilets equipped with a radar device according to one embodiment of the description, - [Fig.2]: [Fig.2] presents a more detailed view of the housing of a radar device associated with a urine analysis device, according to one embodiment of the description, - [Fig.3]: [Fig.3] schematically presents a view of the components of a radar device according to one embodiment of the description, as well as its ecosystem, - [Fig.4]: [Fig.4] schematically presents a more detailed view of the housing of a radar device associated with a urine analysis device, according to one embodiment of the description, - [Fig. 5]: [Fig. 5] shows a user sitting on a toilet equipped with a radar sensor. - [Fig.6]: [Fig.6] presents a flow curve of a urine stream as a function of time (from "A new procedure of analysis and modelling ofmale urine flow rate", Gammie et al. DOI:10.1109 / CHICC.2015.7259937), - [Fig.7]: [Fig.7] presents a reconstruction of a distance-velocity map, homogeneous to a distance-Doppler map, from a model of the free fall of a drop of urine, - [Fig.8]: [Fig.8] shows a calculated distance-Doppler response and a superposition between [Fig.7] and the distance-Doppler response, - [Fig.9]: [Fig.9] presents a diagram representing a method for determining VO according to a general description, - [Fig. 10]: [Fig. 10] presents two embodiments, one of which has two variants, of the treatment step of the process of [Fig. 9] of the invention, with prior detection of urine, - [Fig. 11]: [Fig. 11] presents a diagram representing a measurement method according to an embodiment of the invention, with prior detection of urine. Detailed description

[0022] Figure 1 schematically illustrates a radar device 100 mounted on a toilet 102. As is known, the toilet 102 comprises a water tank 104, a bowl 106, a seat 108, and a lid 110. The identification device 100 can be arranged on an internal wall 112 of the toilet bowl 106. Advantageously, the radar device 100 is entirely contained within the toilet bowl, thus allowing it to be discreet.

[0023] In one embodiment, the radar device 100 can be positioned in the toilet so as to be in the path of a stream of urine secreted by a user during urination, particularly when a user is urinating while seated in the toilet. The position of the urine analysis device in the toilet is then suitable for any type of user, male or female, regardless of age. The user can then urinate in the toilet without worrying about the position of the urine analysis device.

[0024] The positioning of the radar device 100 also allows it to be positioned on the trajectory of a flush from the reservoir 104. The identification device 100 can thus be rinsed when the toilet is flushed.

[0025] An attachment can be provided to hold the radar device 100 on the inner wall of the bowl: suction cup, magnet (with support glued to the wall), hook reaching the rim of the bowl, etc.

[0026] The radar device 100 can communicate with a mobile terminal 114 (such as a smartphone) and / or an external server 116. In one embodiment, the radar device 100 communicates with the mobile terminal 114 (for example, directly via Bluetooth such as Bluetooth Low Energy) and the mobile terminal 114 communicates with the server 116 (via a cellular or Wi-Fi connection). In another embodiment, the radar device 100 can communicate directly with the server 116 via a cellular network.

[0027] With reference to [Fig. 2], the radar device 100 may include a housing 200 inside which a radar sensor 202 is positioned (shown schematically in dashed lines). The housing 200 is sized to be positioned in the toilet bowl 106 of the toilet 102. Due to its positioning in an area exposed to various liquids or solids, the housing 200 is watertight. In one embodiment, the housing 200 includes a collection orifice 204, suitable for receiving urine dripping onto the housing 200. In this embodiment, the radar device 100 is part of a urine analysis device that includes, in particular, the housing 200. The housing 200 may include a front cover 206 and a rear cover 208, which can be assembled and disassembled to allow access to the interior of the housing 200. The urine analysis device has been described in documents WO2021 / 175909, WO2021 / 175944, WO2023036805, WO2023036806, WO2023036808, and WO2023036809.

[0028] Figure 3 shows, in a schematic diagram 300, the components that the radar device 100 can comprise, and the general ecosystem. The radar device 100 includes a control circuit 302 with a processor 304, a memory 306, and an I / O (input / output) interface 308 configured to send and receive data from the control circuit 302. A communication module 310 can be provided to exchange data with an external terminal (for example, a smartphone). The communication module 310 can be a wireless module, such as Wi-Fi, Bluetooth, Bluetooth Low Emission, etc. The control circuit 302 can, in particular, communicate with the radar sensor 202 to send acquisition instructions and receive radar data for processing.

[0029] The radar device 100 may include a battery 312 which supplies the components with energy.

[0030] Memory 306 can store instructions which, when executed by processor 304, implement the method(s) of this description. The methods are preferably performed locally by processor 304 of the radar device 100. This allows feedback to the user without requiring a connection, particularly with an external terminal (such as a smartphone).

[0031] The radar device 100 can communicate, using the communication module 310 and a communication network 314, with an external mobile terminal 316, of the mobile terminal type ("smartphone"). The mobile terminal 316 includes a control circuit 318 with a processor 320, a memory 322, and an I / O interface 324 configured to send and receive data from the control circuit 302. The external terminal 316 further includes a user interface 326 for interacting with the user. The processor 320 and the memory 322 can implement an application that allows the external terminal 316 to communicate with the measuring device 100. The user interface 326 can, in particular, display information to the user.

[0032] The radar device 100 can also communicate with a server 328, either directly via the communication network 314 or via the external terminal 316. The server 328 comprises a control circuit 330 with a processor 332, a memory 334, and an I / O interface 336 configured to send and receive data from the control circuit 302. The server 328 can store the measurements taken by the radar device 100 (cloud architecture). The server 328 can also perform data processing.

[0033] The communication network 314 can be heterogeneous: short-range wireless (Bluetooth, Wi-Fi, etc.), long-range wireless (cellular, etc.), wired (Ethernet, etc.).

[0034] Figure 4 describes in more detail an example of a radar sensor 202. The radar sensor 202 comprises a transmitter 402, a receiver 404, and control circuitry 406. The transmitter 402 includes at least one transmitting antenna 408 and a wave generator 410. The receiver 404 includes at least one receiving antenna 412. Depending on the variants and embodiments, the transmitter 402 may include only one transmitting antenna 408, or the transmitter 402 may include at least two transmitting antennas 408.

[0035] The control circuitry 406 includes, in particular, a processor 414 and a memory 416, to drive the transmitter 402 and process the signals received by the receiver 404. The control circuitry 406 of the radar sensor 202 can be integrated or partially integrated with the control circuitry 302 of the radar device 100. The term "control circuitry 302, 406" will be used hereafter to refer to either one or the other. The radar sensor 202 uses, in particular, the Doppler-Fizeau effect generated by a moving object to obtain, among other things, the velocity of said object and / or the distance between said object and the radar sensor 202. The velocity is referred to as radial, since it is solely the velocity component projected onto an axis connecting said object and the radar sensor 202. Similarly, the radial distance will be referred to, since it is the distance along this axis.

[0036] The wave generator 410 and the Tx antenna generate electromagnetic waves wTx, emitted in the direction of a field of view FoV (“Field of view” in English), visible in [Fig. 5]. These electromagnetic waves are partially reflected by the obstacles they encounter, namely the user's body (especially the buttocks), creating an echo represented by the wRx waves in [Fig. 5], which is received by the Rx antenna 404. The control circuitry 302, 406 processes the echoes to generate radar data. The control circuitry 302, 406 can convert the analog signals generated by the wave generator 310 and received by the Rx antenna into digital signals. Filters, amplifiers, etc., are typically provided in the radar sensor 202.

[0037] The radar sensor 202 can be compact, on the order of a few centimeters, or even less than 1 cm. For example, the radar sensor 202 can be contained in a cube of 1 cm x 1 cm x 1 cm.

[0038] The field of view (FoV) is typically a solid angle, which covers a volume of space from the radar sensor 202. The FoV is generally defined by two aperture angles. The axis of symmetry of each angle is called the radar axis.

[0039] The radar sensor 202 can be a frequency-modulated continuous wave radar, known as FMCW (Frequency Modulated Continuum Wave), meaning that the radar sensor emits a frequency-modulated signal (called a "chirp" in established terminology, a term that can be translated as "frequency sweep" in French, but the English term is commonly used). In other words, during the pulse, of duration T, the frequency of the emitted chirp varies over a range. Several modulations are possible: sawtooth modulation, triangular modulation, frequency-shift keying, step modulation, etc. The radar sensor can also be an ultra-wideband radar, known as UWB (Ultra Wide Band). The UWB radar emits wave patterns of a few nanoseconds that are repeated.The study of delays allows us to determine distances, and the study of variations in delay allows us to determine speeds.

[0040] The radar sensor 202 can emit a succession of chirps, the succession being called a "frame" (an English term that can be translated as "window" in French, but the English term is commonly used). In one embodiment, a frame comprises between 16 and 256 chirps, or even between 32 and 64 chirps (for example, 128 chirps). More specifically, a frame can be decomposed as follows: N.(PRT)=N.(t_chirp + t_pause), where PRT is the pulse repetition time, t_chirp is the duration of a chirp, t_pause is the pause time before the next chirp, and N is the number of chirps. The PRT can last between 300 µs and 500 µs. The pause can last 1 µs. A frame can thus last a few milliseconds.

[0041] Frequency modulation makes it possible to create, after mixing the transmitted and received signals, filtering, etc., a signal, called an intermediate frequency signal, whose frequencies are proportional to the distance objects that generate the echoes. A Fourier transform applied to this intermediate frequency signal highlights the associated frequencies and distances. By analyzing the phase variations of the Fourier transforms over successive chirps, the Doppler frequencies, which are related to the object's velocity, can be identified. The 202 radar sensor can obtain the velocity and distance for each object. In particular, the 202 radar sensor can generate a "Distance-Doppler" map (or "Distance-Doppler" map, according to common terminology), which represents the distance (in meters on the x-axis) and velocity of a moving object within the field of view (FoV) (in m / s on the y-axis), as shown in [Fig. 7], which will be presented later. A Distance-Doppler map can be calculated for each frame.

[0042] Within the frames, the "Distance-Doppler" map is obtained using FFTs (fast Fourier transforms) and their evolution between successive chirps. The "Distance-Doppler" maps are known and will not be described in further detail.

[0043] Using in particular chirps, the radar sensor 202 can also calculate a distance between itself and a moving object.

[0044] A frame can last 100ms. Therefore, twenty successive frames take 2s. More generally, in the case of an FMCW radar, a chirp can last between 100 and 200ms.

[0045] In the illustrated examples in the description, the radar sensor 202 is an Infineon BGT60UTR1 IC FMCW radar whose frequency can vary between 58 GHz and 63.5 GHz during a chirp. This range allows a bandwidth of more than 5 GHz, which ensures sufficient accuracy for the use described. Other frequency values ​​can be used, particularly around the values ​​described. This radar sensor includes three Rx antennas and one Tx antenna. In the illustrated example, the chirp includes sawtooth frequency modulation.

[0046] To promote signal quality, the radar device 100 is arranged in the bowl so that the FoV field of view of the radar sensor 202 is oriented towards the opening of the bowl, which means that a user sitting on the seat 108 is in the radar coverage and in particular his buttocks, his genitals and the exit orifice of the urethra, which is the origin of the user's urine stream.

[0047] Figure 5 schematically illustrates a user 500 seated on a toilet bowl 106. radar device 100 is positioned in volume V of bowl 106 and radar sensor 202 emits radar waves (referenced wTx) towards the urine jet 502 (generated by the user), which returns reflected radar waves (referenced wRX).

[0048] The description will now detail one or more embodiments to enable, through radar signal processing, the determination of the speed value

[0049]

[0050]

[0051]

[0052]

[0053]

[0054]

[0055]

[0056]

[0057]

[0058]

[0059]

[0060]

[0061] The initial velocity of the urine stream as it exits the urethra. This velocity value is called the initial velocity V0. There are several methods for calculating the initial velocity V0. Implementation method using distance-Doppler response In one embodiment, the method uses a "Distance-Doppler" map, also referred to interchangeably as a distance-Doppler response hereafter. In particular, in one embodiment, the radar device 100 allows, notably via a theoretical model, the determination of the initial velocity V0 from two data points: the radial velocity Vrad(t) and the radial distance D(t) (also referred to hereafter as the range R(t) in English). Depending on the embodiment, knowledge of the urethra's position in the radar's frame of reference, i.e., the distance between the radar sensor 100 and the urethra, denoted z0, can be used to finalize this determination. The theoretical model is notably that of the free fall of a drop of urine. Modeling and theoretical developments The modeling is based on two different aspects. First, it is assumed that the stream of urine can be modeled as a freely falling drop. In this hypothesis, the components of the position P(t), i.e. x(t), y(t) and z(t) of the droplet and of the velocity vector, i.e. Vx(t), Vy(t) and Vz(t), projected onto an orthonormal coordinate system centered on radar sensor 202 are: XO + VXJ >0 = J o + v y ^ 'Z(O =z0+V.0(f) - 7? V y (t)=V y o gt The constant g is gravity; xO, yO, zO are the coordinates of the urethra (therefore the origin of the drop of the urine stream) in an orthonormal frame, typically centered on the radar (with a positive zO); VxO, VyO and VzO are the components of the initial velocity V0 of the drop of the urine stream. Secondly, it is assumed that, during the radar acquisition time 202 takes to determine V0, the urine stream is in steady state, meaning that the time derivative of the particle derivative in Lagrangian reference is zero. In other words, each drop of urine follows the same trajectory as the previous drop and the drop following. Thus, obtaining the trajectory of the urine jet in space and at a given point corresponds to obtaining the trajectory of a urine drop in time, and vice versa.

[0062] The consequence of this assumption is that a distance-Doppler map obtained at a given time, representing the entire urine stream as a function of its radial distance and radial velocity, also represents the evolution of the distance and radial velocity over time. Thus, with the assumptions made, there is a correspondence between spatial and temporal data. Typically, the spatial data are measured via a distance-Doppler response, and the temporal data are simulated according to the model.

[0063] Figure 6 illustrates a 600 curve of urine flow rate as a function of time. Over a fairly short time interval, the curve can be considered to vary little, a fortiori at the maximum (zone 602).

[0064] Thus, using the equations of free fall, it is possible to calculate, for a urine droplet, by fixing initial values, at a given sampling point, the time evolution of its position R(t) and its velocity vector V(t). Since, by iteration, the velocity vector V(t) is known, it is possible to calculate the time evolution of Vrad(t) by a dot product. Recall that Vrad is the radial component of the velocity of the urine droplet. In this way, it is possible to calculate, over a time window Int=[Tinf ; Tsup], the values ​​of R(t) and Vrad(t).

[0065] Figure 7 illustrates a graph 700 representing the pairs [R(t); Vrad(t)], with the radial distance on the x-axis, in meters (called "range" in English), and the radial velocity on the y-axis, in meters per second, for a plurality of t's chosen from the Int window, with the initial condition R = 40 cm and a velocity V0 of 2 m / s (with Vz < 0, Vx < 0, and Vy arbitrary). Adding a set of pairs [R(t); Vrad(t)] creates a curve 702. This graph 700 is homogeneous in its representation to a Distance-Doppler response acquired over a given t (at least over the t's associated with a frame, i.e., a quasi-instantaneous time for the urine stream).

[0066] Figure 8 represents a map 802 illustrating a Distance-Doppler response acquired over a given time t, with t being part of Int. Map 804 represents curve 702 superimposed on map 802. A correspondence between the two curves is noted, which in particular justifies a posteriori the assumptions made above on the modeling of the urine stream.

[0067] Two variants for calculating the initial velocity V0 will be presented, using the correspondence between measured spatial data (via, in particular, a distance-Doppler response) and simulated temporal data. The first variant uses this correspondence via a regression of a simulated distance-Doppler curve. on a measured distance-Doppler curve. The second variant uses this correspondence via an interpolation of a polynomial expressed as a function of time.

[0068] Variant by regression (curve fitting)

[0069] In this variant, the aim is to match as closely as possible the measured Distance-Doppler map (i.e. calculated using radar data) (illustrated in [Fig.8]) with the radar sensor 202 and the simulated Distance-Doppler map (illustrated in [Fig.7]). It is possible to modify the values ​​of V0 (and also PO) in the simulation of the free-falling water droplet and see which values ​​generate the curve closest to the distance-Doppler response measured by the radar. This is therefore a regression, and more precisely, a curve fitting. Thus, the calculated initial velocity V0 is chosen as the simulated initial velocity V0 after the regression (i.e., the one that provides the best regression). Various metrics allow us to mathematically define the concept of the best regression (closest distance, least squares, etc.).

[0070] In this variant, the data R(t) and Vrad(t) for a given t are used, so that the value of the initial velocity V0 is thus known using a Distance-Doppler response.

[0071] By multiplying the acquisitions of Distance-Doppler responses, it is possible to implement this method several times to average or see the evolution of V0 over time and take the maximum.

[0072] Variant by interpolation

[0073] In this variant, a temporal reconstruction of the urine drop is made from the measured Distance-Doppler.

[0074] At any given moment, the radar sensor 202 can measure the radial velocity, which is expressed as follows: 100751

[0076] In vector form, the radial velocity is expressed as follows:

[0077] ~ Th T 7 + Xt)+ XÔ

[0078] which can be rewritten in this form, with R(t) as the radial distance between the droplet of the urine stream and the radar sensor 202:

[0079] — _ x( / ) + g(f) ra^f) — * radlt)

[0080] Using the dot product equation, it is possible to obtain:

[0081]

[0082]

[0083]

[0084]

[0085]

[0086]

[0087]

[0088]

[0089]

[0090]

[0091]

[0092]

[0093]

[0094]

[0095]

[0096]

[0097] Thus, by calculating the dot product of two velocity vectors, we obtain the following equations: 1^.^=^4)0,) + XA'y(t) +40^401 ^^))=5^5)144^) + > +44W] and finally vradit^=xfà^ + By combining this equation with that of the free fall of a droplet from the urine stream, which gives x(t), y(t) and z(t), we obtain: 4) 00 = 04 + 44 4)00=yov J\ / u J, o = o + (Xo" + T*3 Substituting these equations, we obtain: o + V^ + y()V o+V^ +z0V ^+(^- Vra^ = + |ko + ^0 + + Xo y o + y y^ +z y^ + x0V x 0 + y o V^ o + ^0 Thus we have: + bt2 + and + d With Ig1 a = b^-^gc= vl-^g Thus, we find in one of the coefficients, here the coefficient c, the value of the initial velocity V0, with the initial height of the urethra zO. Under the preceding assumptions, knowing the distance-Doppler map at a given time t is equivalent to knowing the evolution of R(t) and Vrad(t) for a urine droplet over a time interval. Therefore, by acquiring a distance-Doppler map of a user's urine stream, it is possible to calculate the product Vrad(t)R(t) for a plurality of t's for a urine droplet, meaning there are enough values ​​to interpolate the third-degree polynomial.

[0098] Thanks to this interpolation, the coefficient c can be estimated. Therefore, it is sufficient to know the initial height of the urethra zO to determine V0.

[0099] According to the present embodiment, a Distance-Doppler map is sufficient to calculate V0. However, a Distance-Doppler map can be generated using only one receiving antenna and one transmitting antenna. Alternatively, with multiple antennas, it is possible to generate a more precise Distance-Doppler map.

[0100] Embodiment by jet reconstruction

[0101] In this embodiment, several antennas are used. With several antennas, it is possible to precisely trace the shape of the jet. By matching a mathematical model of a freely falling droplet, particularly with the angle of arrival of the jet, it is possible to determine the initial velocity V0.

[0102] In one embodiment, the use of at least three receiving antennas allows for more precise localization of the radar echo source in space. These three antennas allow, among other things, the determination of the echo's angle of arrival. By combining this information with the radial position and velocity, the position of the urine droplet (in spherical coordinates) can be calculated.

[0103] By knowing the position of all the drops of the urine stream and using the free fall equations, it is possible to determine the initial parameters position (PO) and velocity (V0) which minimize the error between the radar measurement and the theoretical equation.

[0104] In one embodiment, the antennas have a characteristic gain. This gain can be used, with prior knowledge of the antenna orientation, to extract the angle of arrival of the targets from the amplitude profile on the distance-Doppler map.

[0105] The determination of the antenna orientation can be standardized for any product or measurement using a sensor (e.g., accelerometer, gyroscope, magnetometer, etc.)

[0106] Description of measurement methods

[0107] In one embodiment, the radar device 100, by means of one or more frames, can allow the initial velocity V0 of the urine jet to be calculated.

[0108] In one embodiment, the radar sensor 202 emits a chirp and receives a reflected signal. This reflected signal is then processed by a processor (either the control circuitry 406 of the radar sensor 202, or the control circuitry 302 of the radar device 100) to generate, in particular, after the emission of a plurality of chirps and the reception of the reflected signals (i.e., an image), a "distance-Doppler" map.

[0109] In the present description, the moving object is a drop of urine. By drop of urine, we also mean a urine front, that is to say, the air-urine interface of a Urine volume. A urine stream typically comprises a plurality of successive urine fronts. Map 802 thus illustrates radar signals that correspond to successive urine fronts forming a stream.

[0110] The control circuitry 302, 406 can extract these properties (radial distance, radial velocity and dispersion) using algorithms, including image analysis and pixel counting.

[0111] Different information can be extracted from such maps. First, a single "distance-Doppler" map provides enough information to determine V0, meaning that in a single frame, the radar device 100 can calculate V0. Battery consumption is thus minimized.

[0112] Fig. 9 illustrates a diagram 900 representing the steps of a method for determining the initial velocity V0 of a urine stream from a user 500 sitting on a toilet 106. The steps of the method 900 can be implemented by the control circuitry 302, 406.

[0113] In step 902, the control circuitry drives the radar sensor 202 to emit signals. In step 904, the control circuitry drives the radar sensor 202 to receive emitted signals that have been reflected by droplets of the urine stream. Steps 902 and 904 can be repeated several times to create an image. In step 906, the control circuitry processes the reflected signals to determine the initial velocity V0 of the user's urine stream.

[0114] In an additional step 908, the initial velocity data V0 can be assigned to a user profile stored in the memory of the radar device.

[0115] The treatment includes the embodiments described above.

[0116] In the embodiment using a distance-Doppler response, a distinction is made at less two variants, represented on diagrams lOOOi, lOOOii of [Fig. 10] and called "by regression" and "by interpolation".

[0117] For the l0OOi regression variant, processing 906 more specifically comprises the regression 1002i of the distance-Doppler response by a simulated curve homogeneous to a distance-Doppler response. The curve is simulated from the free-fall equations of a urine droplet, and the regression includes a variation of the initial free-fall conditions, including in particular the initial velocity V0, and, if necessary, a variation of the initial position. The details of this step have been explained previously. Processing 906 then includes the extraction of the initial velocity V0 obtained from the regression 1002i.

[0118] For the l0OOii interpolation variant, the treatment 906 includes the interpolation of a degree 3 polynomial obtained, in particular, from the free-fall equation of a drop of urine. In the variant described above, this is the product R(t)Vrad(t), which is expressed as a degree 3 polynomial in t. The values ​​of R(t)Vrad(t) for Different values ​​of t are obtained from the measured distance-Doppler response (for a given t), with the previously described correspondence between the spatial and temporal domains. Process 906 then includes the extraction 1004Ü of the initial velocity V0 from the coefficient values ​​of the interpolation polynomial. For this extraction, the control circuitry can use an estimate of z0 made based on the determination of the user's sex.

[0119] In embodiment lOOOiii which uses jet reconstruction, processing 906 includes jet reconstruction 1002iii and then determination 1004iii of V0 from the reconstructed jet.

[0120] User detector

[0121] In order to trigger radar acquisition only when a stream of urine is in progress (particularly to save battery power), a urine detector 210 can be placed in the toilet. More specifically, the urine detector is mounted in the radar device 100. The urine detector 210 can detect the presence of a stream of urine. The urine detector 210 can include a temperature sensor 220 mounted in the housing 200, for example, at the collection port 204. When urine above 35°C flows over the housing, the temperature sensor 220 will detect a sudden temperature increase. The urine detector 210 is then configured to associate this sudden temperature increase with the presence of a stream of urine on the housing 200.

[0122] Figure 11 illustrates a diagram 1100 representing a method of activating the radar sensor 202. In step 1102, the urine detector detects the presence of a stream of urine. In step 1104, in response to said detection, the control circuitry 302, 406 commands the radar sensor 202 to perform method 900.

[0123] In another embodiment, the urine sensor is replaced by a user presence sensor. This sensor can be a load cell or an optical sensor. However, such a presence sensor cannot inform the radar sensor 202 that urine is being emitted, but only that a user is seated. Therefore, the radar sensor can be provided with prospective waves a few seconds before urination occurs to ensure that it acquires radar signals reflected by the urine stream.

[0124] In another embodiment, the method 900 can be triggered directly by the user by means of a command sent to the radar sensor 202, for example by means of a mobile terminal 114 and / or by a physical button arranged near the toilet and operable by the user when he sits on the toilet bowl.

[0125] Integration of a radar sensor into a urine analysis device

[0126] In one embodiment, the radar device is integrated into a urine analysis device. The urine analysis device has been described in documents WO2021 / 175909, WO2021 / 175944, WO2023036805, WO2023036806, WO2023036808, and WO2023036809. This integration of the radar device into a urine analysis device was presented in document EP4349257.

Claims

Demands

1. A measurement method relating to a user's (900) urine stream during urination, the measurement method using a radar sensor (202) arranged on a wall (112) of a toilet bowl (106), the method comprising at least the following steps: - the emission (902) by the radar sensor (202) of a radar signal, in the direction of the urine stream, - the reception (904) by the radar sensor (202) of a radar signal emitted by the radar sensor (202) and reflected by the urine stream, - the processing (906) of the received radar signal to determine a value of the velocity of the urine stream exiting the urethra, called the initial velocity (V0).

2. Measurement method according to claim 1, wherein the processing includes the calculation of a distance-Doppler response of the urine stream.

3. Measurement method according to claim 2, wherein the processing includes a correspondence between the distance-Doppler response, which takes into account the measured radial velocity of drops from the urine stream, and a mathematical model of modeling a free fall of a urine drop from the urethra, which takes into account the simulated initial velocity (V0) of a urine drop.

4. Method according to claim 3, wherein the processing comprises a regression of the calculated distance-Doppler response by a simulated distance-Doppler response, by modifying the modeled free-fall initiative velocity, the calculated initial velocity (V0) being chosen as the modeled initial velocity determined at the end of the regression.

5. Measurement method according to claim 3 or 4, wherein the mathematical model includes the expression of a function of the radial distance and the radial velocity as a function of a polynomial, in particular a polynomial of degree 3, the polynomial being obtained from a free-fall equation of a drop of urine from the urethra and one of the coefficients of the polynomial being expressed as a function of the initial velocity (V0).

6. A measurement method according to claim 5, wherein the processing includes an interpolation of the third-degree polynomial, using values ​​of radial velocity (Vrad(t)) and radial distance (R(t)) of the calculated distance-Doppler response in order to know, via interpolation, the value of the coefficient expressed as a function of the initial velocity V0.

7. A measurement method according to claim 1, wherein the treatment comprises a reconstruction of a urine stream by a free fall of a drop of urine from the urethra.

8. A measurement method according to any one of claims 1 to 7, wherein the radar sensor (202) operates by frame, each frame being generated by a plurality of chirps, and the transmission and reception steps being implemented for each chirp.

9. Measurement method according to any one of claims 1 to 8, wherein the radar sensor (202) is a Frequency Modulated Continuum Wave (FMCW) radar sensor, or the radar signal is FMCW.

10. Measurement method according to any one of claims 1 to 9, comprising a preliminary step, using a urine detector (210) for detecting the presence of a stream of urine, the method comprising in response to said detection, an activation step (1104) of the radar sensor (202).

11. Computer program comprising instructions capable of implementing a method according to any one of claims 1 to 10 when the instructions are executed by a processor.

12. Radar device (100) comprising: - a housing (200), suitable for being positioned on an internal wall of a toilet bowl (106), - a radar sensor (202), housed in the housing (200), and suitable for emitting radar waves in the direction of a jet of urine, the radar sensor (202) being suitable for implementing the method according to any one of claims 1 to 10.

13. Radar device (100) according to claim 12, wherein the radar sensor (202) comprises a single transmitting antenna (408).

14. Radar device (100) according to claim 12, wherein the radar sensor (202) comprises at least two transmitting antennas (408).

Images