RU194365U1 - Ultrasonic handheld transducer for remote blood flow assessment - Google Patents

Abstract

A useful model of an ultrasonic portable sensor for remote blood flow assessment relates to medical devices, in particular to angiology, and can be used to non-invasively determine the blood flow of individual microvasculature using the telemedicine technology based on the Doppler effect. The proposed device allows you to expand the arsenal of technical tools used in the field of angiology by creating a technical tool that provides the ability to provide a qualified medical assessment of blood flow parameters remotely - when the patient is in community-acquired conditions, such as at home. This technical result is achieved due to the fact that the ultrasonic portable sensor for remote blood flow assessment, consisting of an ultrasound probe, which includes emitting and receiving piezoelectric elements, and an inseparably connected cable of an electronic unit containing an ultrasonic frequency generator, the first output of which is connected through the cable to the radiating piezoelectric element, and the second to the reference input of the mixer, the high-frequency amplifier, the input of which is connected through the cable to a small piezoelectric element, and the output is connected to the signal input of the mixer, the output of which is connected to the input of the Doppler frequency signal amplification channel, an analog-to-digital converter (ADC) and a random number generator, a shaper of a radio signal at jumping frequencies, a message generation unit and a power amplifier with an antenna, while the second output of the random number generator is connected to the control input of the message generation unit, the information input of which a connected to the ADC output, whose input is connected to the outlet channel gain of the Doppler signal. 2 C.p. f-ly, 2 ill.

Description

The utility model relates to medicine, in particular to angiology, and can be used for non-invasively determining, based on the Doppler effect, the blood flow of individual vessels of the microvasculature (arterioles, venules, capillaries, etc.).

The use of ultrasound dopplerography is the most common and convenient non-invasive method for the diagnosis of cardiovascular diseases, which allows you to identify features of the regulation of blood flow. Devices of this type are successfully used not only in angioneurology, but also in vascular surgery (rapid assessment of atherothrombotic diseases of peripheral vessels), neurosurgery, phlebology (surgical investigation of venous and arterial blood flow) and other areas.

The well-known hardware complex "VASCULAB SP25A" described in the article "Comparison of the data of ultrasound dopplerography of the saphenous veins of the lower extremities and the clinical manifestations of varicose veins", Visualization in the clinic, 1996, N 9, p. 30-35). To study the hemodynamics of the subcutaneous vessels, this complex uses an ultrasonic sensor with an operating frequency of 8 MHz, operating in a continuous-wave Doppler mode. The disadvantage of this device is, in particular, the relatively low carrier frequency, which does not allow the study of vessels with a large depth.

The ultrasonic Doppler blood flow indicator has a higher working frequency (20 MHz) according to the certificate for utility model RF N 4074, IPC A61F 9/00, which contains a sensor with receiving and emitting piezoelectric elements, the latter being connected to the generator, and the receiving piezoelectric element, high-frequency amplifier , a mixer, a low-frequency amplifier are connected in series and together with the generator are located in the sensor housing, into which an additional channel is introduced, consisting of a low-pass filter, a low-frequency amplifier and a phase shifter I. The signal from two channels is fed to the input of a standard sound card, where the analog signal is converted to digital. By setting the phase shifter, a clear image of the dopplerogram is achieved and the blood flow is estimated from it.

The disadvantages of this blood flow indicator are the difficulty of adjusting the phase shifter, low sensitivity and noise immunity of the device in terms of the possibility of selection of the components of the Doppler signal corresponding to various vessels of the microvasculature.

The invention of Patent RU No. 2152173, A61B 8/06 "Ultrasonic Doppler blood flow indicator" is aimed at improving these performance indicators. The indicated indicator contains a sensor and a personal computer (PC). The sensor includes an ultrasonic head and an electronic (conversion-amplifying) unit. The ultrasonic head is placed emitting and receiving piezoelectric elements. A high-frequency amplifier (UHF), a reference (working) frequency generator, mixers, a delay line, intermediate-frequency amplifiers (cascade of signal preprocessing), a two-channel amplifier, and voltage regulators are mounted on the converter-amplifier device board. The sensor using a removable cable through a switching device is connected to the input of the sound card located in the PC. The sound card is connected to the PC software card (PC), as well as to sound control devices (for example, speakers) and the monitor included with the PC. The software includes a noise reduction program. Input and control of digital processing of information in a PC is carried out using the keyboard, mouse, etc.

An ultrasound head with pre-applied gel paste is placed on the patient’s skin in a diagnosed place. The reference (ultrasonic) frequency generator generates a sinusoidal voltage of 25 MHz, supplied to the emitting piezoelectric element and mixer. An emitting piezoelectric element converts an electrical signal into an acoustic wave, which propagates through the patient's body, reflected from the bloodstream. In this case, a Doppler frequency shift occurs. A receiving piezoelectric element converts an acoustic wave with a Doppler shift into an electrical signal, which is amplified in the UHF and fed to the mixer. Further, the signals enter the signal preprocessing stage, the input circuits of which are simultaneously low-pass filters corresponding to the sound frequency range. Then the signals enter the input circuit of the main amplifier, in which they are additionally filtered out. Thus, the Doppler signal of the sound range is filtered and amplified to a value that makes it possible to convert it from analog to digital in an analog-to-digital converter (ADC) located on the sound card in a PC. After processing in accordance with the specified software and reverse (digital-to-analog) conversion, the signal is fed to the speakers (headphones) and displayed on a PC monitor.

The invention described above was used in a prototype manufactured and tested at the MINIMAX enterprise in St. Petersburg.

The closest serial analogue of this device is the MINIDOP Ultrasonic Doppler Diagnostic Operative Diagnostic Tool for Blood Flow Velocity, TU 9442-005-17201375-2003, BIOSS Company, Zelenograd. The main focus of this medical device was its portability and convenience practical application that does not require a PC connection.

Indeed, this “Indicator” is one of the few devices of this type on the domestic medical equipment market that has such small overall dimensions (100 × 64 × 25 mm) and a mass of not more than 170 grams (with a power source). As indicated in the "Operation Manual" (MDIO 3.950.000.000 OM), it is intended for use in stationary conditions of medical institutions, as well as in "ambulance", (www.medrk.ru).

The use of this device at home is not possible, since the only means of indicating the result of blood flow velocity measurements is the tone of the sound signal in the headphones, which, firstly, significantly limits its functionality, and, secondly, requires significant skills and experience for interpretation results available only to medical specialists in this field (Lelyuk V.G., Lelyuk S.E. "Fundamentals of clinical interpretation of data from ultrasound angiological studies", . Cheb. method manual, Moscow, 2005. 38, "Ultrasound diagnosis in abdominal and vascular surgery", ed GI Kuntcevich -... MN, 1999, 256).. This kind of payment for simplifying the device is its significant drawback, limiting the possibility of application in a number of important and relevant fields, primarily in the field of telemedicine.

As you know, in January 2018, Federal Law of July 29, 2017 N 242-ФЗ "On Amending Certain Legislative Acts of the Russian Federation on the Use of Information Technologies in the Field of Health Care" entered into force (hereinafter - the Law on Telemedicine). According to this document, the concept of telemedicine technologies is introduced in the legal field and remote consultations of the patient with a doctor (paramedic) are allowed.

On September 1, 2018, a new national standard GOST R 57757-2017 “Remote assessment of the parameters of functions vital to human life” was put into effect - in fact, the first regulatory act in the field of telemedicine. The specified standard contains general requirements for technologies for the remote acquisition and processing of information, its transmission and evaluation by a doctor (paramedic) in order to increase the availability and quality of medical care, primarily for people living in large, sparsely populated areas, for people with limited mobility, elderly, persons with disabilities due to pathology of internal organs and people with visual impairment.

In accordance with clause 5.2.1 of this standard, at the stage of fixing vital parameters of a person, which include blood flow characteristics, the composition of measuring devices should include application devices for smartphones and computers that provide registration and subsequent remote assessment of these parameters by a doctor.

The MINIDOP ultrasonic Doppler indicator described above does not have such capabilities. Therefore, the ultrasonic Doppler sensor described above, which is part of the ultrasonic Doppler indicator according to patent RU No. 2152173, is selected as the closest analogue of this utility model. The disadvantage of this device is that it cannot play the role of an application to a smartphone, since it does not contain the means of generating digital messages that could be perceived by the smartphone and transmitted to them in a remote center for subsequent analysis by a medical specialist, as required by the aforementioned GOST R 57757-2017 .

Thus, the technical problem to be solved by the proposed technical solution is the lack of a portable ultrasonic Doppler sensor in the existing arsenal of medical equipment that allows for the possibility of a qualified medical assessment of blood flow parameters remotely when the patient is in community-acquired conditions, for example, at home.

The solution to this problem is the technical task of the proposed utility model, which consists, accordingly, in expanding the arsenal of technical means of telemedicine in terms of angiology.

The expected technical result is the implementation of this purpose.

This technical result is achieved due to the fact that the ultrasonic portable sensor for remote blood flow assessment, consisting of an ultrasonic probe, which includes emitting and receiving piezoelectric elements and an inseparably connected cable of an electronic unit containing an ultrasonic frequency generator, the first output of which is connected through a cable to the radiating piezoelectric element, and the second to the reference input of the mixer, UHF, the input of which is connected through a cable to the receiving piezoelectric element and the output is connected to the signal input of the mixer, the output of which is connected to the input of the Doppler frequency signal amplification channel, characterized in that an ADC and a series-connected random number generator, a shaper of the radio signal at jumping frequencies, a message generation unit and a power amplifier with an antenna, while the second output of the random number generator is connected to the control input of the message generation unit, the information input of which is connected to the output of the ADC, the input of which is connected ene yield a channel gain of the Doppler signal.

In a preferred embodiment of the ultrasonic portable sensor, the circuit included in its electronic unit, consisting of a random number generator, a shaper of a radio signal at jumping frequencies, a message generation unit and a power amplifier, can be implemented as a Bluetooth 4.0 BLE audio interface module.

In another preferred embodiment of the ultrasonic portable sensor, a circuit consisting of a random number generator, a shaper of a radio signal at jumping frequencies, a message generation unit and a power amplifier can be made in the form of a short-range hopping module in the range 433 or 868 MHz.

The essence of the utility model is illustrated in FIG. 1 and FIG. 2.

In FIG. 1 is a structural diagram of the ultrasonic portable sensor under consideration.

In FIG. 2 shows a photograph of a prototype of the proposed ultrasonic portable sensor.

In the above figures, the following notation is used: 1 - ultrasonic probe; 2 - cable; 3 - electronic unit; 4 - generator of ultrasonic frequency; 5 - radiating piezoelectric element; 6 mixer; 7 - receiving piezoelectric element; 8 - UHF; 9 - channel amplification of the Doppler signal; 10 - ADC; 11 - shaper radio signal at jumping frequencies; 12 - random number generator; 13 - block forming messages; 15 - antenna.

The considered ultrasonic portable sensor for remote blood flow assessment consists (Fig. 1) of an ultrasonic probe 1, which includes emitting 5 and receiving 7 piezoelectric elements, and an inseparably connected cable 2 of an electronic unit 3 containing an ultrasonic frequency generator 4, the first output of which connected via cable 2 to the emitting piezoelectric element 5, and the second to the reference input of the mixer 6, UHF 8, the input of which is connected via cable 2 to the receiving piezoelectric element 7, and the output is connected to the signal input of the mixer 6 the output of which is connected to the input of the Doppler frequency signal amplification channel 9, the output of which is through an ADC 10 and a circuit consisting of a random number generator 12, a generator of a radio signal at jumping frequencies, a message generating unit 13, and a power amplifier 14 connected to the antenna 15. In this case, the second output of the random number generator 12 is connected to the control input of the message generation unit 13, the information input of which is connected to the output of the ADC 10, the input of which is connected to the output of the additional amplification channel 9 Rovsky signal.

A prototype of the sensor under consideration (Fig. 2) was implemented at the applicant enterprise using the elements included in the “MINIDOP” Ultrasound Doppler Diagnostic Diagnostic Diagnostic for Blood Flow Velocity TU 9442-005-17201375-2003: MDIO 3.950.000.0001 electronic unit with ultrasound probe at a frequency of 8 MHz (version 3) and a cable 80 cm long.

The role of the chain is “random number generator 12 — transmitter of the radio signal at the jumping frequencies — message generation unit 13 — power amplifier 14” shown in FIG. 2, performs in this sample the Bluetooth 4.0 BLE audio interface module on the CSR8630 microassembly (arduino.ua). This module is compatible with most modern smartphones and provides high quality signal playback in the audio range.

The role of the chain shown in FIG. 2, can also perform a "short range" hopping module on the integrated circuit (IC) of the Semtech Corporation SX1272 transceiver using the 860-1050 MHz band and LoRa technology. The indicated transceiver, although it relates, in accordance with the Decision of the State Commission on Radio Frequencies of May 7, 2007 No. 07-20-03-001 (Appendix 10) to devices of "short range", has a range of up to 15 km, which allows servicing using the proposed medical device, significant territories, providing access to the Internet of Things network (icquest.ru/news). Distinctive features of this IC are: extremely low power consumption, high sensitivity, a wide range of measurement and regulation of the received signal power level, the ability to work without degradation at low (up to 1.8 V) supply voltage, the use of frequency hopping technology ("jumping in frequencies ") and effective use of the limited frequency range without collisions in multiple access and the effect of" fading "of signals and using the LBT (" listening to the air before transmission ") technique due to interference.

Thus, the possibility of practical implementation and further expansion of the scope of practical application of the proposed utility model is not in doubt.

The considered ultrasonic portable sensor for remote assessment of blood flow works as follows.

An ultrasonic probe 1, inseparably connected by a cable 2 with a small-sized portable electronic unit 3, is installed in the right place on the patient's body. The ultrasonic frequency generator 4 generates a sinusoidal voltage of the selected frequency in the megahertz frequency range, supplied to the emitting piezoelectric element 5 and mixer 6. The emitting piezoelectric element 5 converts the electric signal into an acoustic wave, which propagates through the patient’s body, reflected from the blood flow moving through the vessel. When reflected from the bloodstream, a Doppler frequency shift occurs. The velocity of blood in the vessel V is associated with the Doppler shift ΔF known ratio

V = ΔF × C / 2f × cosa,

where C is the speed of ultrasound in the human body (taken equal to 1540 m / s);

f is the frequency of ultrasonic vibrations (usually from 2 to 25 MHz);

and - the angle between the axis of the probe and the direction of blood flow.

The receiving piezoelectric element 7 converts the received acoustic wave with a Doppler shift into an electric signal, which is amplified in the UHF 8 and fed to the signal input of the mixer 6. The Doppler component (Doppler signal) allocated by the mixer 6 is fed to the Doppler signal amplification channel 9. The signal is amplified in it to the value necessary to convert the analog signal to digital. An amplified low-frequency Doppler signal is fed to the input of an analog-to-digital converter (ADC) 10. It should be noted that in the closest analogue, the ADC is part of the sound card that is a PC accessory. In the considered utility model, the ADC 10 is installed inside the electronic unit 3.

As noted above, in order to achieve the required communication range and noise immunity in the proposed device, using the carrier frequency jump technology (FHSS - Frequency Hop Spread Spectrum), widely used in modern mobile communication systems, in particular, its variant known as hopping technology. The applicant company has previously obtained patents for inventions for a number of methods and systems using hopping signals (in the field of alarm) (RU No. 2351066, G08B 25/10, G08B 29/00, RU No. 2351066, G08G 1/123, Н04В 14 / 04, RU No. 2342264, B60R 25/00, etc.). The transfer of the code information message to the carrier frequencies of the hopping signal and its broadcasting are carried out as follows.

The activation command received from the output of the ADC 10 starts the random number generator 11, which generates a binary M-bit code Z of a randomly uniformly distributed number. The random number generator 11 supplies the Z code to the transmitter 12 of the radio signal at jumping frequencies. That is, the specified shaper receives the Z code in the range from 0 to (2 ^M -1). According to this code, the shaper 12 of the radio signal at jumping frequencies generates a frequency F _m , the value of which can be determined by the formula (1)

where F ₀ is the minimum frequency (at Z = 0);

ΔF is the step of the frequency grid.

Moreover, for the maximum value of F _{m max} frequency F _{m the} following formula is valid (2)

The generated frequency F _m , is fed to the first input of message generation unit 13. In this block, the bits are sequentially formed:

- MARKER, consisting of the number P of logical units strictly defined for a given system and one logical zero. MARKER is used to determine the number Z in a hop message;

- ADDRESS identifying the identification code of the ultrasonic portable sensor;

- INFORMATION defining the informational part of the hoping message;

- CONTROL AMOUNT designed to confirm the correctness of the received hopping message.

CONTROL AMOUNT is unambiguously calculated depending on the generated ADDRESS and INFORMATION codes. The information is encoded messages generated from Doppler signals emitted in the electronic unit 3. These encoded messages are received at the second input of the message generating unit 13, the first input of which is supplied with a carrier frequency signal from the output of the shaper 11 of the radio signal at jumping frequencies. The high-frequency signal coming from the output of the message generating unit 13, carrying the hopping message, is amplified in the power amplifier 14 and radiated through the antenna 15 into the air. Depending on the application scenario of the proposed ultrasonic portable sensor in a geographically distributed telemedicine system according to GOST R 57757-2017, the frequency range of the radio signal at jumping frequencies and its range may vary. So, when using for receiving a smartphone, the frequency range, divided into several tens of frequency channels, is, as a rule, 2.402-2480 GHz, allocated for Bluetooth radio communication. The band of each channel is 1 MHz, the channel spacing is 140-175 kHz. Information is transmitted in batch form. In this case, frequency manipulation is used. The packet data rate is about 721 Kbps. The power of the emitted signal in all built-in Bluetooth microchips does not exceed 1-10 mW, which ensures a communication range of 10 to 100 m. Accordingly, the connection of the sensor with the smartphone is provided mainly indoors. If it has at least one or several access points of the Wi-Fi network, then the received medical information can be transferred via the Internet to the cloud data storages for the use of this information by medical specialists.

When using the ultrasonic portable sensor in question with a radio network of short-range devices operating in accordance with the aforementioned Decision of the State Radio Frequency Commission dated May 7, 2007 No. 07-20-03-001 in the ranges 433 MHz (Appendix 1) or 868 MHz (Appendix 10), the range of the sensors in question can reach several kilometers, which allows them to be used for direct exchange of medical data via the Internet with cloud storage and centers for monitoring the health status of the patient ENTOV even in the absence of nearby network access points Wi-Fi. This use case for medical devices was described by the applicant company earlier in the patent for utility model RU No. 189998 "Home telemedicine hub".

Thus, the combination of common and the closest analogues and distinctive essential features of the proposed utility model allows to obtain the expected technical result, which consists in implementing the function of the proposed device - expanding the arsenal of medical equipment in the field of angiology by including a portable Doppler sensor in it, which allows qualified medical evaluation of the patient’s blood flow parameters remotely - when finding pats Inpatient conditions, such as at home.

Claims (3)

1. An ultrasonic portable sensor for remote assessment of blood flow, consisting of an ultrasound probe, which includes an emitting and receiving piezoelectric elements, and an inseparably connected cable of an electronic unit containing an ultrasonic frequency generator, the first output of which is connected through a cable to the radiating piezoelectric element, and the second - to the reference input of the mixer, a high-frequency amplifier, the input of which is connected through a cable to the receiving piezoelectric element, and the output is connected to the signal input of the mixer, the output of which It is connected to the input of the Doppler frequency signal amplification channel, characterized in that an analog-to-digital converter and a circuit consisting of a random number generator, a shaper of a radio signal at jumping frequencies, a message generation unit and a power amplifier are connected to its electronic unit, the output of which is connected to the antenna, while the second output of the random number generator is connected to the control input of the message generation unit, the information input of which is connected to the analog output to-digital converter having an input coupled to an output channel Doppler signal amplification. 2. The ultrasonic portable sensor according to claim 1, characterized in that the circuit consisting of a random number generator, a shaper of a radio signal at jumping frequencies, a message generation unit and a power amplifier is made in the form of a Bluetooth 4.0 BLE audio interface module. 3. The ultrasonic portable sensor according to claim 1, characterized in that the circuit consisting of a random number generator, a shaper of a radio signal at jumping frequencies, a message generation unit and a power amplifier is made in the form of a “short-range” hopping module of the 433 MHz range or 868 MHz.

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