The present invention relates generally to monitoring techniques based on Doppler ultrasound.

Ultrasound is one of the most widespread and versatile techniques capable of forming acoustic images, or images obtained using acoustic radiation, and more precisely ultrasound. Such radiations, like X-rays, have the ability to penetrate light-opaque bodies allowing the visualization of the internal morphology of anatomical structures.

Doppler ultrasound (ecodoppler) is a technique used in medicine for the anatomical and functional study of (arterial and venous) blood vessels. It is based on the Doppler effect, the operating principle of many ultrasound techniques in which it is necessary to explore moving biological tissues (Doppler flowmetry, echocardiography, etc.) ln the phenomenon of the reflection of a wave by a medium at rest, the frequency of the reflected wave is the same as that of the incident one. When, on the other hand, the reflecting or diffusing part is in motion, it determines a frequency of the reflected acoustic wave different from the incident one. As a rule, portable Doppler probes are based on manual operation, i.e. the detection is corrected analogically in a completely manual way by the medical or paramedical staff employed in the examination. The operator applies the Doppler probe to the biological tissue to be examined, which, in the case of a flowmetry examination aimed at exploring the presence/absence of blood flow, detects the movement of the blood flow inside intratexesal arteries/veins of compatible caliber and transfers the information of presence of flow through an amplified sound signal, according to the acoustic features, of "arterial or venous pulse" to the operator.

Postoperative monitoring of transplanted microsurgical patches may include the detection of blood flowmetry at an hourly rate in the first 24 hours, every 2 hours in the following 48 hours, and every 3 hours until the 5th postoperative day. The iteration of the postoperative monitoring procedure involves the Continuous involvement of medical and paramedical staff employed in detecting the blood flow of the patch with high costs for carrying out the process. Furthermore, the "human" error caused by inaccurate readings in the timing or incorrect positioning of the probe could lead to a missed or late warning of the doctor in charge of the procedure, with the risk of failure thereof in case of postoperative thrombotic complication, with consequent necrosis of the transferred biological tissues. In addition, postoperative monitoring can sometimes be difficult to carry out as measurements must be made in anatomical districts that are not easily accessible and more complicated to manage, such as the oral cavity.

An object of the present invention is to at least partly obviate the drawbacks of the prior art systems.

In view of these objects, a cylindrical-shaped Doppler probe of different sizes according to the intended application, a main detection unit, a server and a configured mobile device constitute an innovative system for exploring the morphology of biological tissues and, in Doppler ultrasound, for the identification and features (direction and speed) of a flow of a patient's body fluid, comprising

a portable Doppler probe configured to be applied to the body of the patient, wherein said probe comprises a phased array matrix of transducers, each transducer being configured to

- emit in use a respective output ultrasound signal directed towards the body of the patient,

- receive a respective input ultrasound signal reflected by the body of the patient, and

- convert the input ultrasound signal into an electrical reading signal,

wherein said phased array matrix is configured to sweep the target with an ultrasound beam, and

a main detection unit configured to

- wirelessly communicate with the portable probe, and

- construct an image of a reflecting biological surface according to the features of the reflected ultrasound waves,

- identify a body fluid in motion and calculate the speed and direction thereof based on the reading signals provided by the array of transducers.

In particular, the transducers of the phase array matrix are configured to emit the respective output signals with a controlled phase difference one with respect to the other in such a way that said output signals overlap to form said ultrasound beam traveling in a direction dependent on said phase difference.

In particular, the system further comprises

a server configured to

- communicate with the main detection unit through a network of computer connections, and

- collect data identifying patient, morphology of the investigated tissue/organ, calculated direction and speed of the body fluid, provided by the main detection unit, and

a mobile device configured to

- communicate with the server through the network of computer connections, and

- display information based on the data identifying patient, morphology of the organ and data of calculated direction and speed of the body fluid.

The main detection unit can also be configured for

- compare the calculated speed of the body fluid with a predetermined threshold, and

- provide a warning signal when the calculated speed of the body fluid is above or below the predetermined threshold, and

wherein the mobile device is configured to

- generate an acoustic and/or visual signal when the main detection unit provides a warning signal.

The system according to the invention allows the values detected by the Doppler probe to be communicated autonomously or "on command" without human intervention. The detected values are sent to the server and can be consulted by mobile device or web application lt is also possible to activate the detection of patient values remotely on specific needs.

The automation of the process therefore brings two advantages: frequent and non-binding measurements by the medical/nursing staff of the hospital ward, and a continuous real-time monitoring able to warn the doctor in case of existing or incumbent problems for the patient on registered mobile devices and on web administration panel. Further features and advantages of the system according to the invention will become apparent from the following detailed description of an embodiment of the invention, made with reference to the accompanying drawings, provided for illustrative and non-limiting purposes only, in which

figure 1 shows an architectural scheme of a system for monitoring a flow of a body fluid of a patient by Doppler echography;

figure 2 shows the operating principle of a phased array; and

figure 3 shows a phased array matrix of transducers.

In figure 1 , reference numeral 10 indicates a portable Doppler probe configured to be applied to a patient's body, for example by means of a bandage. The probe 10 comprises a phased array matrix of transducers 1 1 (represented schematically in figure 3). Each transducer is configured to

- emit in use a respective output ultrasound signal directed towards the body of the patient,

- receive a respective input ultrasound signal reflected by the body of the patient, and

- convert the input ultrasound signal into a reading signal.

With reference to figure 2, the operating principle of the phased array is shown. For simplicity of representation in figure 2 a linear array is shown; it is understood, however, that in the present invention the phased array principle is applied to a two-dimensional matrix of transducers. The transducers 1 1 are powered by a transmitter 1 1 a and are configured to emit the respective output signals with a controlled phase difference with respect to one another. This can be achieved in a per se known manner by associating the transducers with 1 1 respective phase variators 1 lb governed by an electronic control circuit 1 lc on board the probe 10. The individual output signals in the form of spherical waves overlap to form a plane wave, and therefore an ultrasound beam traveling in a specific direction (indicated by the arrow oriented at an angle Q with respect to the normal to the phased array) depending on the phase difference imposed by the control circuit 1 l c. The phased array is therefore configured to vary the phase difference between the transducers 11 so as to vary the direction of the ultrasound beam generated by the combination of the individual output signals to sweep the target into the patient's body. Figure 3 shows a transducer matrix 1 1 in which the principle described above is applied. As is generally known for phased arrays, the probes based on this principle are able to perform three-dimensional volumetric inspections by appropriately establishing the delay laws between the various elements of the array. For example, it is possible to define an activation pattern of the various elements of the array, which can be different for transmission and reception. A possible pattern is represented by the dotted area P in figure 3, and a possible trajectory T of the pattern P is represented by the dashed arrow T. Once the patterns and the trajectories have been defined, it is possible to calculate the delay laws to focus and/or deflect the ultrasound beam in 2 or 3 dimensions according to the symmetry of the array.

The phased array principle, applied according to the invention to a dot matrix sensor, therefore allows detecting the blood flow even if the probe containing the sensor is not oriented transversely with respect thereto. This feature constitutes an innovative advantage of our device since it has the ability to identify and detect blood flow independently of a forced position and of the operator.

With reference to figure 1 , the probe 10 further comprises a supply 12, in particular a rechargeable battery, and an antenna 13 for wireless connections.

Reference numeral 20 indicates a main detection unit, which must be positioned in the vicinity of the patient and of the probe 10, in particular in the same room. The main detection unit 20 is configured to communicate wirelessly with the portable probe 10, via an antenna 21. The main detection unit 20 is further configured to calculate the direction and speed of the body fluid based on the reading signals provided by the transducer array 1 1. For this purpose, the main detection unit 20 can be provided with an operating system located on a hard disk and software designed to allow decoding of the signal received by the probe 10.

The main detection unit 20 is provided with connection means 22 to allow wired and/or wireless connectivity with a network of computer connections 23, for example the Internet. The main detection unit 20 is also connected to an external power source. Reference numeral 30 indicates a server, for example a cloud server. The server 30 is configured to communicate with the main detection unit 20 through a network of computer connections 23. The server 30 is further configured to collect data identifying the patient, data of the morphology of the tissues and data of the calculated direction and speed of the body fluid, provided by the main detection unit 20. For this purpose, the server 30 comprises an application server 31 and a data storage server 32.

Reference numeral 40 indicates mobile devices. Each mobile device 40 is configured to

- communicate with the server 30 through the network of computer connections 23, and - display information based on the data identifying patient, and data of calculated speed of the body fluid.

For this purpose, the mobile device can for example be provided with a web application. The server 30 then provides for the collection of the data of all the patients of the hospital structure concerned and the regular sending of the data to the application of the mobile device 40.

The main detection unit 20 can further be configured to

compare the calculated speed of the body fluid with a predetermined threshold, and - provide a warning signal when the calculated speed of the body fluid is above or below the predetermined threshold. ln this case, each mobile device 40 can be configured to

- generate an acoustic or visual signal, such as a push notification, when the main detection unit 20 provides a warning signal. The application for mobile device therefore notifies the doctor with predetermined alarms and other notification systems if the patient has any complications detected.

As described above, the configuration of the Doppler probe 10 described above is able to perform dot-matrix detections based on the phased array concept. This feature, unlike the sensors used in other known solutions, makes the system able to "read" the flowmetry even when the probe is not perfectly transverse to the blood flow. Despite the traditional Doppler systems, which employ medical and paramedical staff in the flow-meter detection, which directs the Doppler probe in the correct angle with respect to the blood flow in order to receive the sound of the presence of flow, the Doppler probe 10 described above is

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placed on an area of the affected tissue where the presence of flow is detectable. The phased array based dot matrix operating principle allows the reading of the flowmetry without the need for an orientation orthogonal to the blood flow to be monitored, and also in case of slight displacement of the probe. This detection methodology is based on the operating principles of radar systems. The solution described above allows the flowmetry measurements to be programmed and the doctor to be alerted in real time should post-operative complications occur. Moreover, it is possible to analyze the graph of the readings on the mobile device and on the web application so as to monitor the conditions of the tissues, for example in the case of transplanted tissues.