Intravenous drug extravasation monitoring method based on optical detection

Abstract

The invention discloses an intravenous drug extravasation monitoring method based on optical detection. The method comprises the following operation steps: transmitting an optical signal to subcutaneous tissue and receiving a reflected signal before infusion, and calibrating initial reflectivity; continuously monitoring and calculating the real-time reflectivity in the infusion process; calculating a reflectivity change gradient value based on the initial reflectivity and the real-time reflectivity; the gradient value is compared with a preset first threshold value and a preset second threshold value, whether exosmosis exists or not is judged according to the comparison result, the exosmosis liquid is judged to be hypotonic liquid, isotonic liquid and hypertonic liquid in an assisted mode, and meanwhile alarm instructions of corresponding levels are triggered. According to the invention, the near-infrared light and high-speed photoelectric detection technology is utilized, and the instantaneous gradient change of the optical characteristics of the subcutaneous tissue is captured, so that extremely early recognition and graded alarm of an extravasation event are realized, and timely intervention is facilitated to reduce tissue damage.

Description

Technical Field

[0001] This invention belongs to the field of medical device and clinical monitoring technology, and relates to a method for monitoring extravasation of intravenous drugs based on optical detection; specifically, it relates to an optical detection method for real-time monitoring of whether extravasation of drugs occurs during intravenous infusion. Background Technology

[0002] Intravenous infusion is a fundamental and crucial clinical treatment method. However, when infusing hypertonic, high-viscosity, or high-pressure injection solutions such as iodine contrast agents, there is a risk of extravasation into tissues outside the blood vessels. Extravasation can cause pain and swelling at the injection site, and in severe cases, may lead to skin ulcers, tissue necrosis, or even compartment syndrome, not only increasing patient suffering but also potentially delaying diagnosis and causing medical disputes.

[0003] Currently, there are some technologies and devices available for monitoring extravasation in clinical practice, such as alarms based on changes in tissue impedance, local temperature sensing, or hydraulic pressure monitoring. However, most of these technologies rely on sufficiently significant macroscopic changes in tissue physical properties after extravasation occurs (such as increased impedance due to swelling, temperature changes, or increased pressure) to trigger an alarm, inherently resulting in a monitoring delay. They cannot identify extravasation the moment the drug begins to leak from the blood vessel, thus hindering truly early intervention. Summary of the Invention

[0004] Purpose of the invention: The purpose of this invention is to provide an optical detection-based method for monitoring intravenous drug extravasation that can identify and alarm at the initial stage or even instant of extravasation, and minimize the amount of drug extravasation and corresponding tissue damage.

[0005] The technical solution of the present invention is: the intravenous drug extravasation monitoring method based on optical detection described in the present invention, the detection system on which it depends consists of a light source module, a signal detection module, a signal processing module and a feature display module; The light source module uses a light-emitting diode light source; the signal detection module is a high-speed photodetector; the signal processing module is used for data storage, real-time calculation and comparison; the feature display module includes three sets of LED display lights for isotonic state, hypotonic state and hypertonic state and a buzzer.

[0006] Furthermore, this includes the following steps: Step (1) Before the infusion begins, an initial light signal is emitted to the subcutaneous tissue at the infusion site of the recipient, and the initial reflected light signal reflected by the subcutaneous tissue is received. The initial reflectivity is determined based on the initial light signal and the initial reflected light signal. Step (2) During the infusion process, a monitoring light signal is continuously emitted to the subcutaneous tissue, and the real-time reflected light signal reflected by the subcutaneous tissue is received in real time. The real-time reflectivity is calculated based on the monitoring light signal and the real-time reflected light signal. Step (3) Calculate the gradient value of reflectance change based on the initial reflectance and the real-time reflectance; Step (4) compare the reflectance change gradient value with the preset gradient threshold, determine the leakage status based on the comparison result and trigger the corresponding alarm indication.

[0007] Furthermore, the initial light signal in step (1) is emitted by a near-infrared light source, and the initial reflection signal is received by a high-speed photodetector.

[0008] Furthermore, the method for determining the initial reflectivity in step (1) includes: The initial light intensity emitted is The initial optical signal; Obtain during the initial detection period The initial reflected light intensity sequence collected internally; Calculate the average reflected light intensity of the initial reflected light intensity sequence ; and based on formula The initial reflectivity is calculated.

[0009] Furthermore, the initial reflected light intensity sequence is specifically as follows: ;in, , This is the detection interval of the photodetector. This is the initial detection period. It is a positive integer.

[0010] Furthermore, the monitoring light signal mentioned in step (2) is emitted by a near-infrared light source, and the real-time reflected light signal is received by a high-speed photodetector.

[0011] Furthermore, the real-time reflectivity mentioned in step (2) is calculated based on the following formula: In the formula, For the first The real-time reflected light intensity received at the next sampling time.

[0012] Furthermore, the reflectance gradient value mentioned in step (3) is calculated based on the following formula: In the formula, For the first One gradient value; For the first Reflectance at the next sampling time For the first Reflectance at the next sampling time; The interval between detections by the photodetector; when hour, Initial reflectivity .

[0013] Furthermore, the preset gradient threshold in step (4) includes a first threshold and a second threshold; The first threshold is less than zero, and the second threshold is greater than zero. The first and second thresholds are used to define the boundaries of the range where extravasation occurs.

[0014] Furthermore, the specific steps in step (4) of comparing the reflectance change gradient value with a preset gradient threshold include: If the reflectance change gradient value is between the first threshold and the second threshold, it is determined to be in an isotonic state, and an alarm is triggered. If the reflectance change gradient value is less than or equal to the first threshold, it is determined to be a low-permeability state and an alarm is triggered. If the reflectance change gradient value is greater than or equal to the second threshold, it is determined to be a high-permeability state, and an alarm is triggered.

[0015] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages: 1. By utilizing the speed of light, drug extravasation can be identified and injection can be terminated the instant extravasation occurs, thus avoiding further damage; 2. Based on the osmotic pressure of the extravasated drug, the present invention guides the clinical selection of the correct antidote for symptomatic treatment to reduce tissue damage; 3. The detection system of the intravenous drug extravasation monitoring method based on optical detection of the present invention consists of a light source module, a signal detection module, a signal processing module, and a feature display module. The light source module uses a light-emitting diode (LED) light source, emitting a near-infrared beam with a wavelength of 950nm and an initial emitted light intensity of 20 dBm (i.e., 100 mW). This light intensity parameter balances the penetration of human tissue and safety. The signal detection module is a high-speed photodetector with a detection bandwidth of 50GHz and a detection interval t set, for example, 20 ps, ​​which can realize high-frequency light signal acquisition to ensure the capture of light intensity changes at the moment of extravasation. The signal processing module has the functions of data storage (e.g., for storing gradient thresholds), real-time calculation, and comparison. The feature display module includes three sets of LED indicators (green light, corresponding to isotonic state; blue light, corresponding to hypotonic state; and red light, corresponding to hypertonic state) and a buzzer to meet the warning needs in a clinical environment. Attached Figure Description

[0016] Figure 1 This is an operation flowchart of an embodiment of the present invention; Figure 2 This is a flowchart illustrating the calculation of the initial reflectivity in an embodiment of the present invention. Detailed Implementation

[0017] The specific technical solution of the present invention will be further described in detail below with reference to specific examples.

[0018] As shown in the figure, the intravenous drug extravasation monitoring method based on optical detection described in this invention relies on a detection system consisting of a light source module, a signal detection module, a signal processing module, and a feature display module. Among them, the light source module adopts a light-emitting diode (LED) light source, and the emitted beam wavelength is a near-infrared beam with a wavelength of 950nm. The initial emitted light intensity is 20 dBm (i.e. 100 mW). This light intensity parameter takes into account both the penetration of human tissue and safety. The signal detection module is a high-speed photodetector with a detection bandwidth of 50GHz and a detection interval time t set, for example, 20 ps, ​​which can realize high-frequency optical signal acquisition and ensure the capture of the instantaneous change in light intensity during the extravasation. The signal processing module has functions for data storage (e.g., for storing gradient thresholds), real-time computation, and comparison. The feature display module includes three sets of LED indicator lights (green light, corresponding to isotonic state, blue light, corresponding to hypotonic state, and red light, corresponding to hypertonic state) and a buzzer, thereby meeting the warning needs in clinical environments.

[0019] Reference Figure 1 A method for monitoring intravenous drug extravasation based on optical detection includes the following steps: Step (1): Before the infusion begins, an initial light signal is emitted to the subcutaneous tissue at the recipient's infusion site, and the initial reflected light signal reflected by the subcutaneous tissue is received. The initial reflectivity is determined based on the initial light signal and the initial reflected light signal. In this embodiment, a high-speed photodetector (i.e., the signal detection module mentioned above) is used to receive the real-time reflected light signal. The light source module and the signal detection module are fixed to the recipient's infusion site (such as the superficial vein area of ​​the forearm) with a medical adhesive patch to ensure that the light emitted from the light source irradiates the subcutaneous tissue perpendicularly, the receiving surface of the detector is aligned with the reflected light path, and the distance between the detector and the skin surface is maintained at 2 mm to avoid pressure affecting the optical properties of the tissue. See details. Figure 2 Step (1) includes: (11) The initial light intensity emitted is The initial light signal; wherein, the light source module emits near-infrared light with an intensity of 100 mW; (12) Obtaining the initial detection period The initial reflected light intensity sequence acquired internally; specifically, the initial reflected light intensity sequence is... ,in, , This refers to the detection interval of the photodetector; the signal detection module in During the calibration period, with The light signals reflected back from the subcutaneous tissue are continuously collected at intervals to obtain an initial reflected light intensity sequence containing a large number of data points. ; (13) Calculate the average reflected light intensity of the initial reflected light intensity sequence. The signal processing module performs necessary filtering on the original sequence and calculates its average reflected light intensity. ; (14) Based on the formula The initial reflectivity was calculated. In this embodiment, the average reflected light intensity The calculated value is, for example, 18.5mW; subsequently, the signal processing module uses the formula... Calculate the initial reflectivity and obtain This value It is stored as the baseline reference value of the optical characteristics of the current monitoring site; Step (2): During the infusion process, a monitoring light signal is continuously emitted into the subcutaneous tissue, and the real-time reflected light signal reflected by the subcutaneous tissue is received in real time. The real-time reflectivity is calculated based on the monitoring light signal and the real-time reflected light signal. Specifically, the intravenous infusion device is started, and the above-mentioned detection system is activated to enter the real-time monitoring mode. The light source module continuously emits monitoring light (light intensity is maintained). The signal detection module remains unchanged. Real-time reflected light intensity is continuously collected at intervals; for each sampling time... The signal processing module immediately follows the formula Calculate the corresponding real-time reflectance In this embodiment, within a short time window after the infusion begins, the reflected light intensity and calculated reflectivity are obtained from four consecutive sampling points. For example, the first sampling... Calculated Second sampling Calculated Third sampling Calculated Fourth sampling Calculated This enables real-time digital conversion of optical signals; Step (3): Based on the initial reflectivity and real-time reflectivity, calculate the reflectivity change gradient value; specifically, the signal processing module calculates the reflectivity change gradient value according to the stored formula. Calculation, where ;when At that time, the value is the initial reflectivity stored in step (1). Substitute the above example data into the calculation:

[0020] This allows the absolute difference in reflectivity to be converted into an instantaneous rate of change over time, thereby quantifying the dynamic process and enabling real-time observation of any leakage. Step (4): Compare the reflectance change gradient value with a preset gradient threshold, determine the extravasation state based on the comparison result, and trigger the corresponding alarm indication; specifically, the signal processing module compares the calculated instantaneous gradient value with preset dual thresholds (i.e., the first threshold and the second threshold; in this embodiment, the first threshold is preset). Second threshold The system performs real-time comparisons and drives the feature display module to execute corresponding alarm commands based on the comparison results. Specifically: like If the condition is as described above, it is determined to be in an isotonic state, and the feature display module will show a solid green light. It should be noted that this range includes the ideal state of no extravasation (i.e., when...). (Time-bound) and isotonic extravasation with extremely slow changes and acceptable clinical risk (i.e.) When the value is approximately equal to 0); like If the condition is high permeability, an alarm will be triggered, and the red light on the feature display module will flash. like If the condition is low, it is determined to be a low-permeability state, triggering an alarm, and the blue light on the feature display module will flash.

[0021] Applying the above data: Gradient value of reflectivity change Since the value is zero, the system determines that there is no leakage, and the green light on the feature display module remains constantly lit; reflectivity change gradient value Because of this value The system immediately determined it to be a low-osmotic extravasation state, and the feature display module flashed a blue light; subsequently... and The value also satisfies The system maintains an alarm state; as a comparison scenario, if a calculated gradient value is... Because it satisfies Under certain conditions, the system will determine that the system is in an isotonic state, and the green light on the feature display module will remain constantly lit.

Claims

1. A method for monitoring intravenous drug extravasation based on optical detection, characterized in that, Its detection system consists of a light source module, a signal detection module, a signal processing module, and a feature display module; The light source module uses a light-emitting diode light source; the signal detection module is a high-speed photodetector; the signal processing module is used for data storage, real-time calculation and comparison; the feature display module includes three sets of LED display lights for isotonic state, hypotonic state and hypertonic state and a buzzer.

2. The method for monitoring intravenous drug extravasation based on optical detection according to claim 1, characterized in that, Includes the following steps: Step (1) Before the infusion begins, an initial light signal is emitted to the subcutaneous tissue at the infusion site of the recipient, and the initial reflected light signal reflected by the subcutaneous tissue is received. The initial reflectivity is determined based on the initial light signal and the initial reflected light signal. Step (2) During the infusion process, a monitoring light signal is continuously emitted to the subcutaneous tissue, and the real-time reflected light signal reflected by the subcutaneous tissue is received in real time. The real-time reflectivity is calculated based on the monitoring light signal and the real-time reflected light signal. Step (3) Calculate the gradient value of reflectance change based on the initial reflectance and the real-time reflectance; Step (4) compare the reflectance change gradient value with the preset gradient threshold, determine the leakage status based on the comparison result and trigger the corresponding alarm indication.

3. The method for monitoring intravenous drug extravasation based on optical detection according to claim 1, characterized in that, The initial light signal in step (1) is emitted by a near-infrared light source, and the initial reflection signal is received by a high-speed photodetector.

4. The method for monitoring intravenous drug extravasation based on optical detection according to claim 1, characterized in that, The methods for determining the initial reflectivity in step (1) include: The initial light intensity emitted is The initial optical signal; Obtain during the initial detection period The initial reflected light intensity sequence collected internally; Calculate the average reflected light intensity of the initial reflected light intensity sequence ; and based on formula The initial reflectivity was calculated. .

5. The method for monitoring intravenous drug extravasation based on optical detection according to claim 4, characterized in that, The initial reflected light intensity sequence is specifically as follows: ;in, , This is the detection interval of the photodetector. This is the initial detection period. It is a positive integer.

6. The method for monitoring intravenous drug extravasation based on optical detection according to claim 1, characterized in that, The monitoring light signal mentioned in step (2) is emitted by a near-infrared light source, and the real-time reflected light signal is received by a high-speed photodetector.

7. The method for monitoring intravenous drug extravasation based on optical detection according to claim 1, characterized in that, The real-time reflectance mentioned in step (2) is calculated based on the following formula: In the formula, For the first The real-time reflected light intensity received at the next sampling time.

8. The method for monitoring intravenous drug extravasation based on optical detection according to claim 1, characterized in that, The reflectance gradient value mentioned in step (3) is calculated based on the following formula: In the formula, For the first One gradient value; For the first Reflectance at the next sampling time; For the first Reflectance at the next sampling time; The interval between detections by the photodetector; when hour, The initial reflectivity.

9. The method for monitoring intravenous drug extravasation based on optical detection according to claim 1, characterized in that, The preset gradient threshold mentioned in step (4) includes a first threshold and a second threshold; The first threshold is less than zero, and the second threshold is greater than zero. The first and second thresholds are used to define the boundaries of the range where extravasation occurs.

10. The method for monitoring intravenous drug extravasation based on optical detection according to claim 1, characterized in that, The specific steps in step (4) of comparing the reflectance change gradient value with the preset gradient threshold include: If the reflectance change gradient value is between the first threshold and the second threshold, it is determined to be in an isotonic state, and an alarm is triggered. If the reflectance change gradient value is less than or equal to the first threshold, it is determined to be a low-permeability state and an alarm is triggered. If the reflectance change gradient value is greater than or equal to the second threshold, it is determined to be a high-permeability state, and an alarm is triggered.

Images