Measuring system for arterial condition

Abstract

The described technology includes a method and a system for audio-based measurement of the condition and subsequent classification of arteries, as well as a means of displaying the arterial condition for monitoring progress. The technology uses external sensors, specifically MEMS-based microphones, which are placed on the skin surface near the stent. These sensors detect the sounds of blood flow, including those caused by constrictions and turbulence. The captured sounds are filtered and pre-processed by signal processing algorithms. Subsequently, classification programs based on artificial intelligence are used to characterize the condition of the artery. The innovation of this technology lies in its ability to monitor the condition of arteries by analyzing flow sounds. This provides a simple, cost-effective, and patient-friendly method for detecting arterial narrowing and changes in blood flow, particularly in the vicinity of stents. The technology also offers the capability to generate alerts in critical situations and, if necessary, transmit them to clinical partners.

Description

[0001] In the case of narrowing of the arteries, a stenosis (A), stents (B) are usually implanted in, for example, coronary / femoral / carotid arteries before a so-called bypass operation.

[0002] By reducing the vessel's cross-section, blood flow is restricted, thus accelerating in the area of ​​the restriction and slowing down before and after the restriction. In the worst case, this can lead to a complete blockage of the artery, with corresponding consequences for the patient.

[0003] The narrowings are either expanded with a balloon (E) installed on a catheter (D) and then the stent (B) is placed at this point on the vessel wall (C), which has been expanded with the balloon so that it sits firmly in place.

[0004] Alternatively, so-called self-expanding stents are used, which are made of shape memory materials, e.g. nitinol.

[0005] The treated vessels are highly likely to close again in the future, forming a condition known as restenosis. This gradual closure is usually unnoticeable to the patient. Regular monitoring in a medical setting is essential. Diagnosis is made using diagnostic systems, particularly ultrasound and computed tomography, but also cardiological functional diagnostics.

[0006] However, due to the metal structures of the stents, even with these systems it is difficult to accurately and reliably identify any narrowing of the vessel within the stent.

[0007] An alternative, simple, inexpensive diagnostic method that can also be used independently by the patient in their own environment is not known, but would be necessary and helpful.

[0008] The blood flow is altered in flow velocity by deposits and the constrictions caused by them, and turbulences also occur before and after the constrictions (F).

[0009] Using external audio sensors (1) placed directly on the skin surface near the stent, especially with dedicated microphones (e.g., MEMS-based), the resulting flow noise can be recorded. Turbulence (F) or flow restrictions (G2) can be segmented, analyzed, and subsequently characterized using electronic filters, signal processing algorithms (e.g., discrete wavelet transform, power spectral density, Fourier frequencies), and subsequent classification programs based on artificial intelligence (e.g., Resnet, k-means).

[0010] This makes it possible to distinguish an artery with normal blood flow (G1) from a narrowed artery (G2). It also allows for monitoring the progression of the disease and detecting and identifying changes.

[0011] Our measuring system comprises a measuring sensor (1) placed on the skin surface and integrated into a housing (2).

[0012] The sensor housing can be fixed to the skin surface using tape or an adhesive surface.

[0013] The recorded data is filtered and preprocessed by the electronics (3) located in the housing, and then digitized. The data is either temporarily stored or transferred to a processing system (4) for later use.

[0014] The data can be transmitted via a cable connection (5) or via a wireless connection (6).

[0015] The measurement can be triggered and stopped manually via a switch (7) or alternatively via a corresponding software interface.

[0016] The calculated and analyzed measurement data and the progress control are displayed on a computer display (8).

[0017] The elements (1), (3)-(8) can, of course, also be housed in a common sensor housing (2). Furthermore, the sensor housing can also be connected to an existing computer system such as a smartphone (9) or tablet computer.

[0018] The measurement data can also be transmitted to a clinical partner (10). If a critical condition is detected, a corresponding warning is generated by the system (11) and, depending on the settings, also forwarded to a clinical partner.

[0019] Ideally, the system is used for the first time after stent placement. This first measurement can then be taken as the normal value (G1) with which subsequent measurements can be compared. In addition, the location of the ideal measurement should be roughly marked to ensure repeatability with regard to the measurement location. Should the stent close again in the following days, weeks, or months, this will result in a change in the audio profile, particularly in the analyzed and extracted parameters that characterize blood flow velocity and turbulence caused by deposits before, inside, and after the stent (G2). This can then be used to demonstrate deterioration and change over time and as an indication of a new narrowing or a degree of stenosis (12). This information can then be used for prediction and prevention or to plan a future clinical-therapeutic intervention. Referenzen [1] Larson, E., Lee, T., Liu, S., Rosenfeld, M., and Patel, S. Accurate and privacy preserving cough sensing using a low-cost microphone. UbiComp '11 (2011), 375-384. [2] Yatani, K., and Truong, K. Bodyscope: A wearable acoustic sensor for activity recognition. UbiComp '12 (2012), 341-350. [3] Klum, Michael, et al. „Wearable multimodal stethoscope patch for wireless biosignal acquisition and long-term auscultation.“ 2019 41 st Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC). IEEE, 2019. [4] Cotur, Yasin, et al. „Stretchable composite acoustic transducer for wearable monitoring of vital signs.“ Advanced functional materials 30.16 (2020): 1910288. [5] Salvi R, Fuentealba P, Henze J, Bisgin P, Sühn T, Spiller M, Burmann A, Boese A, Illanes A, Friebe M (2021). Vascular Auscultation of Carotid Artery: Towards Biometric Identification and Verification of Individuals. sensors. 2021; 21(19):6656. https: / / doi.org / 10.3390 / s21196656 [6] Sühn T, Spiller M, Salvi R, Hellwig S, Boese A, Illanes A, Friebe M (2020). Auscultation System for Acquisition of Vascular Sounds - Towards Sound-Based Monitoring of the Carotid Artery. Med Devices (Auckl). 2020;13:349-364 https: / / doi.org / 10.2147 / MDER.S268057 List of reference symbols A Representation of a stenosis (narrowing of an artery) B Stent or support structure in a blood vessel C Vessel wall of a blood vessel D Catheter system E Balloon to dilate the blood vessel F Turbulence of the blood flow G1 normal blood flow or blood flow after stent implantation G2 restricted blood flow due to restenosis 1 measuring sensor for recording blood flow and turbulence noise before, inside and after the stent 2 Housing of the measuring system 3 Measuring electronics 4 Processing system 5 Cable connection 6 wireless connection 7 switches 8 Computer system 9 Smartphone or tablet 10 clinical partners 11 Warning signal 12 Representation of the measurement curve and the parameters over time QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited non-patent literature

[0000] Klum, Michael, et al. „Wearable multimodal stethoscope patch for wireless biosignal acquisition and long-term auscultation.“ 2019 41 st Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC). IEEE, 2019

[0019] Cotur, Yasin, et al. „Stretchable composite acoustic transducer for wearable monitoring of vital signs.“ Advanced functional materials 30.16 (2020): 1910288

[0019] Salvi R, Fuentealba P, Henze J, Bisgin P, Sühn T, Spiller M, Burmann A, Boese A, Illanes A, Friebe M (2021). Vascular Auscultation of Carotid Artery: Towards Biometric Identification and Verification of Individuals. Sensors. 2021; 21(19):6656. https: / / doi.org / 10.3390 / s21196656

[0019] Sühn T, Spiller M, Salvi R, Hellwig S, Boese A, Illanes A, Friebe M (2020). Auscultation System for Acquisition of Vascular Sounds - Towards Sound-Based Monitoring of the Carotid Artery. Med Devices (Auckl). 2020;13:349-364 https: / / doi.org / 10.2147 / MDER.S268057

[0019]

Claims

[1] A method for diagnosing the condition of an artery, the method comprising the steps of: • Detecting flow sounds from an artery using a sensor placed on the skin surface near the artery. • Filtering and preprocessing of the captured flow noise. • Applying signal processing algorithms to the preprocessed data to identify turbulence or blood flow restrictions. • Applying classification programs based on artificial intelligence to characterize the condition of the artery. [2] A system for diagnosing the condition of an artery, comprising: • A sensor for detecting flow sounds in the blood flow region of the artery, the sensor being placed on the skin surface near the artery. • Electronics for filtering, preprocessing and digitizing the recorded flow noise. • A processing system for applying signal processing algorithms and classification programs based on artificial intelligence to characterize the arterial condition. [3] The system of claim 2, wherein the sensor is mounted in a housing that can be fixed to the skin surface either with tapes or an adhesive surface. [4] The method according to any one of the preceding claims, wherein the detected flow sounds are additionally used to characterise the artery condition and to identify specific deposits or narrowings in the blood vessel. [5] The method according to any one of the preceding claims, wherein the classification programs are used to generate a time course of the arterial condition to monitor changes over time. [6] The system according to any one of the preceding claims, wherein the sensor housing comprises an adaptive attachment device that can automatically adapt to different skin surfaces. [7] The system of any preceding claim, wherein the processing system includes a database containing a plurality of pre-recorded audio samples of different arterial conditions to increase classification accuracy. [8] The system according to any one of the preceding claims, wherein the processing system is capable of analyzing the acquired data in real time and providing immediate feedback on the arterial condition. [9] The system according to any one of the preceding claims, wherein the sensor housing comprises, in addition to the microphones, further sensors which can measure additional physiological parameters such as temperature or skin conductivity.

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