A re-use prevention disposable electrode knife

Abstract

The application relates to the field of electrode knives, in particular to a reusable-preventing disposable electrode knife. The electrode knife comprises a knife head body, an insulating handle, an electric connection interface located at the tail of the insulating handle and a reusable-preventing function module integrated in the handle. The reusable-preventing function module is jointly formed by a disposable fuse circuit unit and a chemical state indicating unit. The electrode knife not only physically blocks the possibility of repeated use, but also significantly improves the safety and reliability of surgical operation through multiple security mechanisms, and has substantial value for reducing iatrogenic infection and improving the standardization level of operation.

Description

Technical Field

[0001] This application relates to the field of electrode knives, and in particular to a disposable electrode knife designed to prevent reuse. Background Technology

[0002] In the field of surgical medicine, high-frequency electrosurgical units are a common surgical instrument widely used for tissue cutting and electrocoagulation hemostasis. To ensure surgical safety and avoid cross-infection, disposable high-frequency electrosurgical units are gradually becoming the mainstream. In existing technologies, disposable electrode knives typically prevent reuse through structural design or simple physical destruction, such as using easily breakable mechanical structures or removable labels. However, these methods have significant limitations: the mechanical structure may be accidentally damaged when not in use, causing premature failure of the instrument, while labels are easily tampered with or ignored, failing to fundamentally eliminate the risk of reuse.

[0003] Further analysis reveals that the main problem with existing anti-reuse mechanisms lies in the lack of reliable and irreversible electrical or chemical verification mechanisms. Because high-frequency electrosurgical units (ESUs) require direct contact with human tissue and operate at high temperatures, their usage status is difficult to accurately determine through external observation. Methods relying on manual marking or vulnerable structures are susceptible to subjective factors or the operating environment, potentially leading to misjudgments or deliberate circumvention. For example, some reused ESUs may be misused again due to the absence of obvious external damage, potentially causing patient infections or decreased surgical outcomes. Furthermore, existing technologies lack real-time indication of the usage process, preventing medical personnel from visually confirming whether the device is in its first-time usable state, increasing operational uncertainty.

[0004] Given the above shortcomings, it is of great significance to develop a new type of disposable electrode knife that can achieve anti-reuse through both electrical and chemical mechanisms. Utility Model Content

[0005] The purpose of this application is to overcome at least one deficiency of the prior art and provide a disposable electrode knife that is not reusable. This electrode knife not only physically blocks the possibility of reuse, but also significantly improves the safety and reliability of surgical operations through multiple protection mechanisms, which has substantial value for reducing iatrogenic infections and improving the standardization of surgery.

[0006] To achieve the above objectives, this application discloses a disposable electrode knife that is designed to prevent reuse. The electrode knife includes a blade body, an insulating handle, an electrical connection interface located at the tail of the insulating handle, and an anti-reuse functional module integrated inside the handle.

[0007] The anti-reuse function module consists of a one-time fuse circuit unit and a chemical state indicator unit. The one-time fuse circuit unit is located in the circuit between the electrical connection interface and the cutting head, and includes a low-melting-point metal fuse, a current-limiting resistor, and a visual indicator element; the visual indicator element is preferably a miniature light-emitting diode. When the electrical connection interface is first connected to the high-frequency generator and powered on, current flows through the fuse circuit unit, and the visual indicator element illuminates and remains lit for a preset duration, which is determined by the heat capacity characteristics of the current-limiting resistor and the fuse. Subsequently, the metal fuse melts due to the Joule heating effect, thus permanently breaking the circuit and preventing the electrode cutting head from forming a circuit again.

[0008] The chemical state indicator unit is a separate module located on the surface of the electrode knife handle. It contains an oxygen-sensitive indicator material that remains inactive in the sealed packaging environment. When the electrode knife is removed from the aseptic packaging, the indicator comes into contact with oxygen in the air and undergoes an irreversible oxidation reaction, resulting in a noticeable color change and providing a visual warning that the knife has been activated.

[0009] This dual mechanism ensures the reliability of the anti-reuse function: the electrical fuse mechanism physically eliminates the possibility of secondary power-on, while the chemical indicator mechanism provides pre-use status confirmation. The two work together to significantly improve the safety level. The entire electrode knife is designed for single use in both structure and materials, eliminating the need for complex judgments and greatly reducing clinical management costs and risks.

[0010] The beneficial effects listed above are not exhaustive of all advantages. Other potential beneficial effects and detailed technical implementation methods will be further disclosed in the embodiments or other descriptive sections of this application. Attached Figure Description

[0011] A better understanding of various aspects of this disclosure will be achieved by reading the following detailed description in conjunction with the accompanying drawings. The positions, dimensions, and extents of the structures shown in the drawings, etc., do not always represent actual positions, dimensions, and extents. In the drawings: Figure 1 This is a schematic diagram of the structure of one embodiment disclosed in this application. Detailed Implementation

[0012] The present disclosure will now be described with reference to the accompanying drawings, which illustrate several embodiments of the present disclosure. However, it should be understood that the present disclosure can be presented in many different ways and is not limited to the embodiments described below; in fact, the embodiments described below are intended to make the disclosure more complete and to fully illustrate the scope of protection of the present disclosure to those skilled in the art. It should also be understood that the embodiments disclosed herein can be combined in various ways to provide further additional embodiments.

[0013] It should be understood that the same reference numerals denote the same elements in all the accompanying drawings. For clarity, the dimensions of certain features may be modified in the drawings.

[0014] It should be understood that the terminology used in this specification is for describing specific embodiments only and is not intended to limit this disclosure. All terms used in this specification (including technical and scientific terms) have the meanings commonly understood by those skilled in the art, unless otherwise defined. For the sake of brevity and / or clarity, techniques, methods, and apparatus known to those skilled in the art may not be discussed in detail; however, where appropriate, such techniques, methods, and apparatus should be considered part of this specification.

[0015] Unless otherwise specified, the singular forms “a,” “the,” and “the” used in this specification include the plural forms. The terms “comprising,” “including,” and “containing” used in this specification indicate the presence of the claimed feature but do not exclude the presence of one or more other features. The term “and / or” used in this specification includes any and all combinations of one or more of the relevant listed items.

[0016] Referring to the accompanying drawings, the electrode knife of this embodiment includes a blade body 1, an insulating handle 2, an electrical connection interface located at the tail of the insulating handle 2, and an anti-reuse function module 3 integrated inside the handle. The blade body 1 is made of 316L medical-grade stainless steel and precision-milled using five axes to form a cutting section with a cutting edge radius of 0.2mm. Its end is electrically connected to a 0.8mm diameter TU1 oxygen-free copper conductor using a 300W Nd:YAG laser welding machine under a protective atmosphere. The weld penetration is 0.3mm and the tensile strength is not less than 85MPa. The insulating handle 2 is made of ISO 10993 certified medical-grade polycarbonate material, using an injection molding process at a mold temperature of 95℃ to cover the internal components. Its surface has a 0.5mm deep cross-mesh anti-slip pattern and screen-printed operation indicator markings. The electrical connection interface conforms to ISO standards. The B-type interface specification specified in standard 80369-7:2016 has three gold-plated contact pins with a diameter of 1.2mm, corresponding to the positive, negative and signal detection lines of the power supply respectively. The gold plating layer is 3μm thick and the contact resistance is less than 20mΩ. The anti-reuse function module 3 is composed of a one-time fuse circuit unit 301 and a chemical state indication unit 302. The two units 301 and 302 achieve irreversible state indication through physical melting and chemical discoloration respectively and work independently.

[0017] Furthermore, the one-time fuse circuit unit 301 is located in the main power circuit between the electrical connection interface and the cutter head body 1. It includes a Sn42Bi58 eutectic alloy fuse with a rated fusing characteristic of 1A / 250V. The fuse has a cylindrical structure with a diameter of 0.2mm and is connected to a 96% alumina ceramic base by resistance spot welding. The solder joint diameter is 0.4mm and the shear strength is not less than 40N. A metal film current-limiting resistor with a resistance of 2.2kΩ±1% and a power rating of 0.5W is bonded to an FR-4 PCB board with conductive silver epoxy resin. The adhesive layer thickness is 0.1mm and the thermal conductivity is 1.5W / m·K. A 0402 packaged miniature light-emitting diode 3011 with an operating voltage range of 2.8-3.5V is also included. These components are connected in series with a fuse-resistor-LED topology through copper-plated wires with a diameter of 0.3mm. The insulation layer of the wires is made of polyimide material and has a withstand voltage rating of 300V.

[0018] The low-temperature fusing characteristics of the metal fuse are achieved by selecting Sn42Bi58 alloy with a melting point of 138℃. This alloy has a resistivity of 11.4μΩ·cm and a thermal conductivity of 18W / m·K, which is used to achieve rapid fusing with low heat accumulation. The precise resistance value of the current limiting resistor is achieved by magnetron sputtering deposition of a 50nm thick nickel-chromium resistive film with a temperature coefficient of 50ppm / ℃ and a maximum operating temperature of 125℃, which is used to limit the circuit current to 1.2mA and precisely control the heating power. When the electrical connection interface is first connected to the high-frequency generator, the generator identifies the device type through the signal detection pin and outputs a DC detection voltage of 3.3V±0.1V. The current flows through the current-limiting resistor and the fuse to form a complete circuit. After obtaining an operating voltage of 2.8V or higher, the miniature LED 3011 emits green visible light with a wavelength of 565nm, a light intensity of 120mcd, and a viewing angle of 120°. The duration of the light emission is determined by the resistance heating power Q=I²Rt and the fuse heat capacity C=m·c. The fuse mass is 2.5mg and the specific heat capacity is 0.21J / g·K. The calculated melting time is 1.2±0.3 seconds. Subsequently, when the fuse reaches its melting point of 138℃, it undergoes a liquid phase change and contracts into a spherical shape under the action of surface tension, thus permanently breaking the circuit. After breaking, the insulation resistance is greater than 100MΩ.

[0019] Based on this, the chemical state indicator unit 302 is independently encapsulated within a transparent polycarbonate observation window with a surface diameter of 3 mm on the insulating handle 2. The observation window has a light transmittance of 92% and a haze of less than 1%. It contains an annular sealed cavity with a height of 0.8 mm and an oxygen-sensitive indicator encapsulated within the cavity. This indicator is composed of FeSO4·7H2O crystals with a particle size distribution of 5-10 μm, NH4SCN powder, and hydroxypropyl methylcellulose gel matrix mixed in a mass ratio of 1:1.5:3. It remains colorless in a nitrogen environment under sealed packaging, where the oxygen concentration is below 0.1%. The redox properties of the indicator are achieved through the valence state transition from Fe²⁺ to Fe³⁺, with a Gibbs free energy change of -78.9 kJ / mol and an equilibrium constant of 2.4 × 10¹³, which is used to generate a color change through the formation of a complex. After the aseptic packaging of the electrode knife is removed, external oxygen permeates into the cavity through a 0.1 mm thick polytetrafluoroethylene microporous breathable membrane on the observation window. The breathable membrane has a uniform microporous structure with a pore size of 0.22 μm and a porosity of 35%, with a gas permeation rate of 8.5 × 10⁻⁻⁻⁶. 8 The indicator, with a concentration of mol / m²·s·Pa, undergoes an irreversible oxidation reaction when the oxygen partial pressure reaches 15 kPa. Fe²⁺ reacts with SCN⁻ to form a deep red Fe(SCN)²⁺ complex with a stability constant of 4.2 × 10², a maximum absorption wavelength of 480 nm, and a molar absorptivity of 1.2 × 10⁻⁶. 4 The color change is completed within 45 seconds and the color difference ΔE > 40, with a concentration of L / mol·cm, forming a permanent visual warning.

[0020] Understandably, the output interface and power supply specifications of the high-frequency generator are existing technologies. Its output characteristics comply with the safety requirements of IEC 60601-2:2016 standard for medical high-frequency surgical equipment, with an output impedance of 50Ω and a fundamental frequency of 500kHz. Through the irreversible electrical disconnection of the aforementioned fuse circuit unit and the irreversible color change of the chemical indicator unit, a complementary anti-reuse protection mechanism is formed in both physical and chemical dimensions. The fuse circuit ensures the physical interruption of the electrical circuit and withstands a voltage of 500VAC after disconnection. The chemical indicator provides intuitive visual confirmation of the status, and the color difference complies with the ISO3864-1 safety marking standard. This ensures that the failure of any single mechanism will not affect the overall anti-reuse effect, thereby reliably guaranteeing surgical safety and preventing cross-infection.

[0021] While exemplary embodiments of this disclosure have been described, those skilled in the art will understand that various changes and modifications can be made to the exemplary embodiments of this disclosure without departing from the spirit and scope thereof. Therefore, all changes and modifications are included within the scope of protection of this disclosure as defined by the claims. This disclosure is defined by the appended claims, and equivalents of those claims are also included.

Claims

1. A re-use resistant, disposable electrode knife characterized by, It comprises: a blade head body, an insulating handle, an electrical connection interface at the tail of the insulating handle, and a reusable prevention function module integrated in the handle; the reusable prevention function module is composed of a disposable fuse circuit unit and a chemical state indication unit; the disposable fuse circuit unit is arranged in a loop between the electrical connection interface and the blade head, and contains a low-melting-point metal fuse, a current-limiting resistor, and a visual indication element; when the electrical connection interface is first connected to a high-frequency generator and powered on, the current flows through the fuse circuit unit; the chemical state indication unit is a separate module located on the surface of the electrode handle, and internally encapsulates an indicator material sensitive to oxygen.

2. The anti-reuse, single-use electrode knife of claim 1, wherein, the visual indication element is a micro light-emitting diode.

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