A multi-modal vital sign monitoring chest belt based on a leather electronic platform and a preparation method thereof

Abstract

This invention, entitled "A Multimodal Vital Signs Monitoring Chest Band Based on a Leather Electronic Platform and Its Preparation Method," belongs to the field of cardiothoracic surgical medical device technology. The technical problem to be solved is the instability of the chest band in monitoring electrocardiograms and its inability to monitor vital signs such as heart sounds. The key technical solution is a multimodal vital sign monitoring chest band based on a leather electronic platform, comprising a first leather piece, a second leather piece, and an elastic band. The elastic band connects the first and second leather pieces into a ring shape. The first leather piece has multiple first functional areas, and the second leather piece has multiple second functional areas. The first leather piece has a cavity containing multiple air bladders, which are positioned within the first functional areas.

Description

Technical Field

[0001] This invention relates to the field of cardiothoracic surgical medical device technology, and in particular to a multimodal vital sign monitoring chest strap based on a leather electronic platform and its preparation method. Background Technology

[0002] Thoracic and cardiovascular surgery is a core treatment for severe cardiovascular diseases such as congenital heart disease, coronary heart disease, aortic disease, lung cancer, and esophageal cancer. Postoperatively, patients experience significant fluctuations in vital signs and are at high risk of various complications such as arrhythmia, hypothermia, and respiratory failure. Therefore, it is necessary to conduct real-time, continuous, and precise monitoring of multiple vital signs, including body temperature, pulse, respiration, electrocardiogram, and heart sounds, so that medical staff can promptly detect abnormalities and intervene. This is crucial for reducing postoperative mortality and promoting early postoperative recovery.

[0003] In current clinical practice, postoperative vital sign monitoring in cardiothoracic surgery mainly relies on bedside wired monitoring equipment. Although these devices have high monitoring accuracy, they have drawbacks such as large size and complex wiring. When worn, the patient's range of motion is strictly limited, making it difficult to carry out early rehabilitation training and hindering postoperative recovery. Furthermore, the equipment cannot move with the patient and cannot cover the monitoring scenarios when the patient is out of bed.

[0004] Currently, some wearable chest strap monitoring products have emerged on the market. While they can alleviate the inconvenience of vital sign monitoring to some extent, these products still have many shortcomings: First, the biosensors of existing wearable monitoring chest straps are mostly attached to the carrier surface by external methods such as pasting or sewing. The fit between the sensor and the skin is easily affected by the patient's movements, which can lead to signal drift and data distortion. Second, most products use fabric bases, which have poor breathability. Postoperative patients have high skin sensitivity, and long-term wear can easily cause skin stuffiness, redness, and contact dermatitis, reducing patient compliance. Third, when biosensors are pasted or attached to the carrier surface, they are prone to detachment during long-term use, leading to signal transmission interruptions and other malfunctions, making it difficult to guarantee the stability of long-term continuous monitoring. Summary of the Invention

[0005] The purpose of this invention is to provide:

[0006] A multimodal vital signs monitoring chest band based on a leather electronic platform and its preparation method are proposed to solve the technical problems of the chest band's instability in monitoring electrocardiogram and its inability to monitor vital signs such as heart sounds.

[0007] Terminology Explanation: Unless otherwise defined, all technical terms in this document have the same meanings as commonly understood by one of ordinary skill in the art to which the subject matter of the claims pertains. Unless otherwise stated, all patents, patent inventions, and publications cited in this document are incorporated herein by reference in their entirety. If multiple definitions exist for terms in this document, the definitions in this chapter shall prevail.

[0008] It should be understood that the above brief description and the following detailed description are exemplary and for illustrative purposes only, and do not limit the subject matter of the invention in any way. In this invention, the singular is used in conjunction with the plural unless otherwise specifically stated. It should also be noted that, unless otherwise stated, the use of “or” or “or” means “and / or”. Furthermore, the use of the term “comprising” and other forms such as “including,” “containing,” and “contains” are not limiting.

[0009] In a first aspect, the present invention provides: a multimodal vital sign monitoring chest band constructed based on a leather electronic platform, comprising a first leather piece, a second leather piece, and an elastic band, wherein the elastic band is located between the first leather piece and the second leather piece, connecting the first leather piece and the second leather piece into a loop; The first leather piece has multiple first functional areas, and the second leather piece has multiple second functional areas; the first leather piece has a cavity, and the cavity has multiple airbags, which are disposed in the first functional areas.

[0010] The first preferred option is that both the first and second leather pieces are tanned natural leather materials that retain a three-dimensional interwoven collagen fiber network structure.

[0011] The second preferred option is that both the first and second leather pieces are provided with signal shielding areas, which shield signal interference between the first functional area and between the second functional area.

[0012] Secondly, the present invention provides: a method for preparing a multimodal vital sign monitoring chest band based on a leather electronic platform, for preparing the aforementioned multimodal vital sign monitoring chest band based on a leather electronic platform, further comprising the following steps: The genuine leather material is tanned, cleaned and dried to obtain the first leather piece and the second leather piece; The leather is processed according to the first and second functional zones. An antibacterial modified layer is provided on the skin-contacting side of the first and second leather pieces; The first leather piece, the second leather piece, and the elastic band are sealed together to form a chest strap.

[0013] The first preferred option is that both the first and second functional areas include a heart sound functional area and an electrocardiogram and respiratory functional area. The heart sound functional area includes one or more of the following: piezoelectric heart sound functional area, capacitive heart sound functional area, and acoustic heart sound functional area.

[0014] Furthermore, the method for preparing the electrocardiogram and respiratory functional areas includes the following steps: At room temperature, the leather is immersed in an aqueous solution of pyrrole monomer with a concentration of 0.1 mol / L to 0.5 mol / L for 1 to 4 hours; The leather is transferred to an aqueous solution containing 0.1 mol / L to 0.3 mol / L ferric chloride or ammonium persulfate oxidant, and the reaction is carried out at 0℃-10℃ for 4-12 hours to complete the in-situ polymerization. The leather was washed until the solution was neutral, and then dried at 40°C for 24 hours to form a polypyrrole / leather composite conductive electrode. The polypyrrole / leather composite conductive electrode is communicatively connected to an additional impedance detection module to detect thoracic impedance.

[0015] Furthermore, the method for preparing the piezoelectric heart sound functional area includes the following steps: The leather is locally thinned or microstructured to reduce its thickness to 0.3-0.5 mm; A piezoelectric film with a thickness of 20-50 μm is attached or embedded on the surface of the region to form a piezoelectric layer, and conductive electrode leads are connected to both sides of the piezoelectric film. A microporous elastic buffer layer is disposed beneath the piezoelectric film.

[0016] Furthermore, the method for preparing the capacitive heart sound functional area includes the following steps: A lower electrode layer is formed on the leather surface by screen printing or spraying. The lower electrode layer is a conductive layer with a thickness of 10μm-30μm printed using silver paste or carbon paste. A microporous elastomer material with a thickness of 100μm-300μm is coated on top of the lower electrode layer as a dielectric layer; After the dielectric layer dries and cures, an electrode layer is printed on its surface. The upper electrode layer is exactly the same as the lower electrode layer, forming a capacitor structure.

[0017] Furthermore, the method for preparing the acoustic heart sound functional area includes the following steps: By using molding or interlayer separation technology, local cavity structures with a diameter of 5mm-20mm are formed inside the leather, creating a semi-enclosed acoustic cavity; An acoustic sensing unit is embedded in the cavity and connected to the signal processing circuit via a flexible cable.

[0018] The second preferred option is to construct an antibacterial modified layer by in-situ reduction with silver ions or cross-linking with chitosan, so that the antibacterial components adhere to the surface of the leather collagen fibers.

[0019] The beneficial effects of this invention are as follows: 1. The expansion of the air bladder allows the chest strap to be worn on the patient. The air bladder pushes the first leather piece tightly against the patient's chest skin, ensuring that the acoustic, electrical, and mechanical signals from the patient's chest are transmitted to the first functional area, guaranteeing the accuracy of the monitored vital signs. Furthermore, the sensors for monitoring the patient's vital signs are the first and second leather pieces themselves, eliminating concerns about sensors falling off.

[0020] 2. Leather has good breathability. When combined with an antibacterial modified layer and heating and heat preservation function, it is beneficial to patients and can effectively improve comfort. It is less likely to cause skin allergies and improves patients' wearing compliance. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the overall structure of the chest band.

[0022] Figure 2 This is a schematic diagram illustrating the first functional area of ​​the first leather piece.

[0023] Figure 3 It is a cross-sectional view showing the internal structure of the first leather piece.

[0024] Explanation of reference numerals in the attached drawings: 1. First leather piece; 2. Second leather piece; 3. Elastic band; 4. First functional area; 5. Signal shielding area; 6. Airbag. Detailed Implementation

[0025] The following non-limiting embodiments are intended to enable those skilled in the art to gain a more comprehensive understanding of the present invention, but do not limit the invention in any way. The following content is merely an exemplary description of the scope of protection claimed by the present invention, and those skilled in the art can make various changes and modifications to the present invention based on the disclosed content, and such changes should also fall within the scope of protection claimed by the present invention.

[0026] Reference Figure 1 The multimodal vital signs monitoring chest band based on the leather electronic platform includes a first leather piece 1, a second leather piece 2, and an elastic band 3. The first leather piece 1 is used to fit the patient's chest, the second leather piece 2 is used to fit the patient's back, and the elastic band 3 connects the first leather piece 1 and the second leather piece 2 from the side, so that the first leather piece 1, the second leather piece 2, and the elastic band 3 form a ring. After the patient wears it, the elastic band 3 is under the patient's armpit and relies on elastic tension to pull the first leather piece 1 and the second leather piece 2 to fit the patient.

[0027] Reference Figure 2and Figure 3 The first leather piece 1 has a double-layer structure. It can be made by stacking two pieces of leather and sewing them together, or by folding a single piece of leather and sealing the edges. The key is to create a cavity inside the first leather piece 1; no specific limitation is made here. The layer of the first leather piece 1 that adheres to the patient's chest is divided into multiple first functional zones 4 (dashed ellipses in the figure). By processing the first functional zones 4 differently, different zones 4 can be transformed into sensors with different monitoring capabilities and different functional elements. For example, they can replace heating wires to heat and keep the patient warm, promote blood circulation, raise local tissue temperature, dilate blood vessels, and accelerate blood flow, helping to deliver more oxygen and nutrients to tissues and organs while removing metabolic waste, improving local blood circulation, and relieving symptoms such as cold hands and feet and numbness in the limbs. Alternatively, they can form electrodes for transcutaneous electrical nerve stimulation, stimulating nerves through the skin to relieve muscle pain, postoperative pain, and neuralgia.

[0028] The first leather piece 1 is an electron-free layer that does not adhere to the patient's chest, thus shielding sound, electrical, and mechanical signals and preventing the external environment from affecting the monitoring effect of the first functional area 4.

[0029] Reference Figure 3 Multiple airbags 6 are fixed inside the first leather piece 1. These airbags 6 are interconnected through tubes, so that when one airbag 6 is inflated, all airbags 6 will inflate. The airbags 6 correspond to the first functional area 4. After the patient wears the garment, airbags 6 are inflated. The inflated airbags push the layer of the first leather piece 1 closest to the patient against the patient's skin. Regardless of the patient's movements, the first leather piece 1 remains in close contact with the patient's skin, ensuring stable measurement of the patient's vital signs.

[0030] The second leather piece 2 is a single layer of leather, divided into multiple second functional areas. By processing these second functional areas differently, they can be transformed into sensors with different monitoring capabilities and different functional elements. A signal shielding area 5 (the area between the dashed and dotted ellipses in the figure) surrounds the first and second functional areas. This shielding is achieved through electron removal processing of the first and second leather pieces 1 and 2, preventing interference between the first and second functional areas. The first and second leather pieces 1 and 2 possess the elasticity of ordinary leather. Under the tension of the elastic band 3, the second leather piece 2 can adhere tightly to the patient's back skin. The inflation of the air bladder 6 in the first leather piece 1 also pulls on the second leather piece 2, making it adhere even more closely to the skin. In some other embodiments, the second leather piece 2 can also be a double-layered structure like the first leather piece 1. Depending on the needs of the second functional areas, the air bladder 6 can be used to make the second leather piece 2 fit more closely to the back.

[0031] It is understandable that both the first functional area 4 and the second functional area are part of the first leather piece 1 and the second leather piece 2, merely representing divisions within the leather area. Both the first functional area 4 and the second functional area are connected to a monitoring device via data cables. The monitoring device collects vital sign data and control signals from the first functional area 4 and the second functional area to control their functions and analyze the collected data.

[0032] Both the first leather piece 1 and the second leather piece 2 are made of tanned natural leather, retaining their three-dimensional interwoven collagen fiber network structure. This network consists of multi-level fiber bundles, with continuous microporous channels and a flexible support frame inside, serving as both a support carrier for a conductive network and a medium for transmitting mechanical vibrations.

[0033] This invention also discloses a method for preparing a multimodal vital sign monitoring chest band based on a leather electronic platform, used to prepare the aforementioned multimodal vital sign monitoring chest band based on a leather electronic platform, comprising the following steps: S1, substrate material preparation.

[0034] Using chrome-tanned or vegetable-tanned natural leather as the base material, preferably cowhide or sheepskin with a thickness of 0.6mm-1.2mm. To remove residual lipids and surface impurities, the leather is ultrasonically cleaned in deionized water for 20-40 minutes, followed by drying in a forced-air drying oven at 40℃-50℃ for 12 hours. This yields the first leather piece 1 and the second leather piece 2.

[0035] S2, according to the specific functions implemented by the first functional area 4 and the second functional area, the first leather piece 1 and the second leather piece 2 are processed. For ease of description, and because the processing technology of the first leather piece 1 and the second leather piece 2 is the same, leather is used to represent the first leather piece 1 and the second leather piece 2 below.

[0036] The first functional area 4 includes a heart sound function area, an electrocardiogram and respiratory function area, and a heating and heat preservation area. The second functional area also includes a heart sound function area, an electrocardiogram and respiratory function area, and a heating and heat preservation area.

[0037] S2.1 employs a polypyrrole (PPy) / leather composite conductive electrode structure in the ECG and respiratory function areas. Specifically: The electrode is immersed in a 0.1 mol / L-0.5 mol / L pyrrole monomer aqueous solution at room temperature for 1-4 hours, allowing the monomer molecules to fully penetrate into the interstitial spaces of the collagen fibers. Subsequently, it is transferred to an aqueous solution containing 0.1 mol / L-0.3 mol / L ferric chloride or ammonium persulfate oxidant, and reacted at a low temperature of 0℃-10℃ for 4-12 hours to complete in-situ polymerization.

[0038] During polymerization, pyrrole monomers undergo oxidation and nucleation on the surface of collagen fibers and grow along the fiber axis to form a conductive polymer layer. Fibers are then connected via conductive bridging to form a continuous three-dimensional pathway. After the reaction, the solution is repeatedly washed with deionized water until neutral, and then dried at 40°C for 24 hours. By adjusting the monomer concentration and reaction time, the bulk conductivity of the composite electrode can be controlled within the range of 1 S / cm to 80 S / cm. This conductive region is symmetrically arranged on both sides of the chest band, with pre-installed flexible wire connection ends.

[0039] Breathing impedance detection is achieved based on the aforementioned PPy / leather composite conductive electrode pair. After fabrication, the two electrodes are connected to another impedance detection module. During testing, a sinusoidal alternating current signal with an amplitude of less than 1mA and a frequency of 10kHz-100kHz is applied, and the thoracic impedance is calculated by synchronously sampling voltage changes.

[0040] Because the polymerization reaction occurs within the collagen network, the resulting conductive structure is embedded and forms a network structure with the fiber skeleton, rather than a simple surface coating. This allows it to maintain stable conductivity during bending, stretching, and respiratory deformation. The PPy / leather composite electrode is positioned on the inner left and right sides of the chest band for ECG signal acquisition and simultaneously forms a pair of electrodes for thoracic impedance detection. By applying a high-frequency microcurrent to detect impedance changes caused by chest expansion, respiratory monitoring is achieved.

[0041] S2.2, the heart sound functional area is selected from the leather base located in the center of the chest band. Through structural regulation and functional material compounding, a mechanical-electrical or acoustic conversion structure is formed on the leather.

[0042] Based on their working principles, heart sound functional areas can be divided into: piezoelectric type, capacitive type, and acoustic type.

[0043] Methods for preparing piezoelectric heart sound functional areas: The leather is locally thinned or microstructured in a predetermined area to reduce its thickness to 0.3-0.5 mm, thereby enhancing vibration coupling sensitivity and forming a vibration concentration zone. A flexible PVDF piezoelectric film with a thickness of 20-50 μm is attached or embedded into the surface of this area to form a piezoelectric layer, which is then fixed using a medical-grade flexible adhesive layer. Conductive electrode leads are connected to both sides of the piezoelectric film. The flexible adhesive layer can be a medical-grade polyurethane (PU) pressure-sensitive adhesive or a modified acrylic copolymer.

[0044] To improve low-frequency response performance, a microporous elastic buffer layer can be placed beneath the piezoelectric film to enhance the mechanical amplification effect. The microporous elastic buffer layer acts as a vibration amplifier at the microscopic level. When it senses the vibration of a heartbeat, it generates high-frequency micro-compression, amplifying the invisible, minute vibration into a dramatic deformation that the piezoelectric film can detect. The microporous elastic buffer layer can be made of polyurethane microfoam material.

[0045] Leather itself possesses excellent vibration transmission and damping properties, serving as both a flexible support layer and a vibration coupling layer in this structure, thus forming a leather-based electronic piezoelectric heart sound sensing structure. Low-frequency vibrations generated by the heart are transmitted through the chest wall to the skin, where they are mechanically amplified and buffered by the leather layer, then act on the piezoelectric layer to generate an electrical signal. The heart sounds are monitored based on the output voltage amplitude.

[0046] Methods for preparing capacitive heart sound functional areas: A lower electrode layer is formed on the leather surface by screen printing or spraying. The lower electrode can be printed as a conductive layer with a thickness of 10μm-30μm using silver paste or carbon paste. Subsequently, a microporous elastomer material with a thickness of 100μm-300μm is coated on top of it as a dielectric layer. This dielectric layer can be improved by incorporating soluble salt particles to form a microporous structure.

[0047] After the dielectric layer dries and cures, an electrode layer is printed on its surface again. The upper electrode layer is identical to the lower electrode layer, forming a sandwich capacitor structure. The microporous elastomer material of the dielectric layer is PDMS (polydimethylsiloxane). During the preparation process, thousands of tiny "pyramids" or "cylinders" can be pressed into the mold. When the upper and lower electrode layers are pressed on these "small pillars", there are a lot of gaps between the pillars, which can convert the tiny pressure into geometric deformation.

[0048] The leather serves as a flexible support and vibration transmission layer at the bottom. When heart sounds vibrate on the leather, they cause a slight displacement of the upper electrode, resulting in periodic changes in the electrode spacing and fluctuations in capacitance, thus enabling low-frequency vibration detection. By comparing the capacitance response amplitude under standard heart sound frequencies with the capacitance changes caused by vibration, the patient's heart sounds can be monitored.

[0049] Methods for preparing acoustic heart sound functional areas: Using molding or interlayer separation techniques, local cavity structures with a diameter of 5mm-20mm are formed inside the leather, creating a semi-enclosed acoustic cavity. A micro-MEMS acoustic sensing unit is embedded within this cavity and connected to a signal processing circuit via a flexible cable. The leather, in close contact with the skin, acts as a flexible diaphragm. When the vibration of heart sounds is transmitted to the leather, it moves the air within the cavity, which then activates the micro-MEMS acoustic sensing unit. In this structure, the leather serves as both a vibration coupling layer and an acoustic impedance matching layer. The porous structure effectively matches acoustic impedance and filters environmental noise, improving the coupling efficiency of low-frequency heart sound signals. By comparing and analyzing the collected heart sound signals with those acquired by a standard electronic stethoscope, waveform correlation coefficients and signal-to-noise ratios are calculated to monitor the patient's heart sounds. The leather serves as the core carrier and acoustic coupling layer, rather than a simple external microphone module.

[0050] S2.3 The heating and heat preservation area can adopt the preparation method used in "A leather heating device with high conductivity and uniform heating and its preparation method" disclosed in Chinese Patent No. CN117500103A.

[0051] It is understandable that S2.1-S2.3 are merely used to distinguish the steps and do not have an actual order.

[0052] S3, an antibacterial modified layer is introduced on the side of the first leather piece 1 and the second leather piece 2 that is in contact with the skin.

[0053] Specifically, leather is immersed in a 0.01-0.05 mol / L silver nitrate solution for 30 minutes, allowing silver ions to adsorb onto the surface of collagen fibers. Then, a 0.05 mol / L glucose solution is added, and the mixture is reacted at room temperature for 2 hours, causing the silver ions to be reduced in situ, forming nano-silver particles that are fixed to the fiber surface. Alternatively, a 1-2 wt% chitosan solution can be uniformly coated onto the leather surface and fixed by glutaraldehyde vapor cross-linking. Antibacterial properties are tested using the inhibition zone method or colony counting method, with Staphylococcus aureus and Escherichia coli being the preferred targets; the antibacterial rate can reach over 99%. The antibacterial layer is constructed through in-situ reduction of silver ions or chitosan cross-linking, ensuring that the antibacterial components are stably attached to the collagen fiber surface and are not easily detached in sweaty conditions, thus guaranteeing the safety of continuous monitoring.

[0054] S4, package.

[0055] After completing the fabrication of each functional area, the ECG electrodes, respiratory electrodes, and heart sound module are connected to a separate central signal processing unit via flexible wires and locally encapsulated using medical-grade silicone rubber. An airbag 6 is fixed inside the first leather piece 1. Finally, the first leather piece 1 and the second leather piece 2 are sewn together or heat-pressed onto the elastic band 3 to form an adjustable-length chest band structure.

[0056] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, and is not intended to limit the scope of protection of the present invention. Simple modifications or equivalent substitutions made by those skilled in the art to the technical solution of the present invention do not depart from the essence and scope of the technical solution of the present invention.

Claims

1. A multimodal vital sign monitoring chest band based on a leather electronic platform, characterized in that: It includes a first leather piece (1), a second leather piece (2) and an elastic band (3), wherein the elastic band (3) is located between the first leather piece (1) and the second leather piece (2) and connects the first leather piece (1) and the second leather piece (2) into a ring shape; The first leather piece (1) is provided with a plurality of first functional areas (4), and the second leather piece (2) is provided with a plurality of second functional areas; the first leather piece (1) has a cavity, and the cavity is provided with a plurality of airbags (6), and the airbags (6) are disposed in the first functional areas (4).

2. The multimodal vital sign monitoring chest band based on a leather electronic platform as described in claim 1, characterized in that: Both the first leather piece (1) and the second leather piece (2) are tanned natural leather materials that retain a three-dimensional interwoven collagen fiber network structure.

3. The multimodal vital sign monitoring chest band based on a leather electronic platform as described in claim 1, characterized in that: Both the first leather piece (1) and the second leather piece (2) are provided with signal shielding areas (5), which shield the signal interference between the first functional area (4) and between the second functional area.

4. A method for preparing a multimodal vital sign monitoring chest band based on a leather electronic platform, characterized in that: The method for preparing the multimodal vital sign monitoring chest band based on a leather electronic platform as described in any one of claims 1-3 further includes the following steps: The genuine leather material is tanned, cleaned and dried to obtain the first leather piece (1) and the second leather piece (2); The leather is processed according to the first functional area (4) and the second functional area. An antibacterial modified layer is provided on the skin-contacting side of the first leather piece (1) and the second leather piece (2); The first leather piece (1), the second leather piece (2), and the elastic band (3) are encapsulated to form a chest strap.

5. The method for preparing a multimodal vital sign monitoring chest band based on a leather electronic platform according to claim 4, characterized in that: Both the first functional area (4) and the second functional area include a heart sound functional area, an electrocardiogram and respiratory functional area, and a heating and insulation area. The heart sound functional area includes one or more of the piezoelectric heart sound functional area, capacitive heart sound functional area, and acoustic heart sound functional area.

6. The method for preparing a multimodal vital sign monitoring chest band based on a leather electronic platform according to claim 5, characterized in that: The preparation method for the electrocardiogram and respiratory function areas includes the following steps: At room temperature, the leather is immersed in an aqueous solution of pyrrole monomer with a concentration of 0.1 mol / L to 0.5 mol / L for 1 to 4 hours; The leather is transferred to an aqueous solution containing 0.1 mol / L to 0.3 mol / L ferric chloride or ammonium persulfate oxidant, and the reaction is carried out at 0℃-10℃ for 4-12 hours to complete the in-situ polymerization. The leather was washed until the solution was neutral, and then dried at 40°C for 24 hours to form a polypyrrole / leather composite conductive electrode. The polypyrrole / leather composite conductive electrode is communicatively connected to an additional impedance detection module to detect thoracic impedance.

7. The method for preparing a multimodal vital sign monitoring chest band based on a leather electronic platform according to claim 5, characterized in that: The preparation method of the piezoelectric heart sound functional area includes the following steps: The leather is locally thinned or microstructured to reduce its thickness to 0.3-0.5 mm; A piezoelectric film with a thickness of 20-50 μm is attached or embedded on the surface of the region to form a piezoelectric layer, and conductive electrode leads are connected to both sides of the piezoelectric film. A microporous elastic buffer layer is disposed beneath the piezoelectric film.

8. The method for preparing a multimodal vital sign monitoring chest band based on a leather electronic platform according to claim 5, characterized in that: The method for preparing a capacitive heart sound functional area includes the following steps: A lower electrode layer is formed on the leather surface by screen printing or spraying. The lower electrode layer is a conductive layer with a thickness of 10μm-30μm printed using silver paste or carbon paste. A microporous elastomer material with a thickness of 100μm-300μm is coated on top of the lower electrode layer as a dielectric layer; After the dielectric layer dries and cures, an electrode layer is printed on its surface. The upper electrode layer is exactly the same as the lower electrode layer, forming a capacitor structure.

9. The method for preparing a multimodal vital sign monitoring chest band based on a leather electronic platform according to claim 5, characterized in that: The method for preparing an acoustic heart sound functional area includes the following steps: By using molding or interlayer separation technology, local cavity structures with a diameter of 5mm-20mm are formed inside the leather, creating a semi-enclosed acoustic cavity; An acoustic sensing unit is embedded in the cavity and connected to the signal processing circuit via a flexible cable.

10. The method for preparing a multimodal vital sign monitoring chest band based on a leather electronic platform according to claim 4, characterized in that: The antibacterial modified layer is constructed by in-situ reduction of silver ions or cross-linking fixation of chitosan, so that the antibacterial components are attached to the surface of leather collagen fibers.

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