Quick exchange coronary distal diagnostic and therapeutic catheter

Abstract

This invention relates to the field of medical catheter technology and discloses a rapid-exchange distal coronary artery diagnostic and therapeutic catheter, comprising a catheter body and an injection connector mounted on the tail end of the catheter body. The catheter body has multiple drug delivery ports on its tip wall, and a rapid-exchange channel on the outer side of the tip. This rapid-exchange channel extends axially and is independently configured from the lumen of the catheter body for guidewire passage. With this invention, when the catheter reaches the distal coronary artery, contrast agents or drugs can be injected without withdrawing the guidewire, making the operation convenient. Furthermore, because the guidewire does not occupy the lumen of the catheter body, the outer diameter of the catheter body is minimized, effectively improving the catheter's permeability within the blood vessel.

Description

Technical Field

[0001] This invention relates to the field of medical catheter technology, and in particular to a rapid-exchange distal coronary diagnostic and therapeutic catheter. Background Technology

[0002] With the development of PCI technology, there are increasingly more cases where it is necessary to infuse contrast agents into the distal coronary arteries to verify whether the guidewire is in the true lumen; to inject drugs into the distal coronary arteries to alleviate no-reflow; or to inject biological agents into the distal coronary arteries to protect acutely necrotic myocardial cells. Clinically, aspiration catheters and microcatheters are commonly used to achieve these purposes.

[0003] However, neither microcatheters nor aspiration catheters are specifically designed for distal coronary artery drug delivery. They are complex to operate, requiring the guidewire to be removed after the catheter is in place and then reinserted and removed after drug delivery. This can easily lead to complications and increases the cost of the procedure. Summary of the Invention

[0004] To address the shortcomings of the prior art, this invention provides a rapid-exchange coronary distal diagnostic and therapeutic catheter. By setting a rapid-exchange guidewire channel, the guidewire does not need to be withdrawn during drug administration, thereby improving operational convenience.

[0005] This invention provides a rapid-exchange distal coronary diagnostic catheter, comprising a catheter body and an injection connector mounted on the tail end of the catheter body. The catheter body has multiple drug delivery ports on its tip wall, and a rapid-exchange channel on the outer side of the tip. This rapid-exchange channel extends axially and is independently configured from the lumen of the catheter body for guidewire passage. The guidewire passes only through the rapid-exchange channel. During drug administration, there is no need to remove the guidewire; the drug, biological agent, or contrast agent reaches the drug delivery port along the lumen of the catheter body, delivering the medication in a uniform atomized manner. This convenient operation effectively avoids complications.

[0006] The head end of the catheter body is provided with a quick-exchange short tube, and the lumen of the quick-exchange short tube constitutes the quick-exchange channel.

[0007] The connection between the rapid exchange tube and the main body of the conduit has a smooth curved transition.

[0008] The tip of the catheter body is spindle-shaped, and the overall radial dimension of the quick-exchange short tube after it is connected to the tip of the catheter body is not greater than the radial dimension of the non-tip end of the catheter body.

[0009] The length of the fast exchange channel is 5 ± 0.5 cm.

[0010] The present invention also provides a catheter-based drug delivery control method, applied to the aforementioned rapid exchange coronary distal diagnostic and therapeutic catheter, comprising: Acquire the patient's electrocardiogram (ECG) signal, identify the cardiac cycle based on the ECG signal, and determine the diastolic time window within each cardiac cycle; Based on the target dosing parameters and the duration of the diastolic time window, determine the single injection volume and injection rate within each diastolic time window; Within each diastolic time window, the infusion pump is controlled to inject the drug solution into the catheter body at the injection rate. Outside of the diastolic time window, the infusion pump is controlled to stop injecting or reduce to a maintenance rate.

[0011] Further, the step of identifying the cardiac cycle based on the electrocardiogram signal and determining the diastolic time window within each cardiac cycle includes: Identify the peak value of the R wave in the electrocardiogram signal and obtain the interval between adjacent R waves as the duration of the current heartbeat cycle; The start and end times of diastole are determined based on the current cardiac cycle duration and a preset diastolic percentage coefficient, wherein the start time of diastole is the time elapsed after the peak value of the R wave and the preset duration of the systolic phase.

[0012] Furthermore, the method also includes: The transmission delay time of the drug solution from the injection connector to the drug delivery port is determined based on the inner diameter, effective length, and drug solution viscosity of the catheter body. The injection start time of the infusion pump is advanced by the transport delay time relative to the start time of the diastolic time window, so that the actual time when the drug solution arrives at the administration port and is released falls within the diastolic time window.

[0013] Furthermore, the method also includes: accumulating and calculating the actual total injection volume during the drug administration process, and comparing the actual total injection volume with the target drug administration volume; When the remaining dose is less than the single bolus dose corresponding to a single diastolic time window, administration is terminated after administering only the remaining dose in the last bolus cycle.

[0014] According to yet another embodiment of the present invention, a computer-readable storage medium is also provided, wherein a computer program is stored therein, wherein the computer program is configured to perform the steps in any of the above method embodiments when executed.

[0015] The present invention has the following beneficial effects: By configuring a rapid exchange channel at the tip of the catheter body, the guidewire passes through the rapid exchange channel only to guide the catheter body to establish a pathway in the blood vessel. During drug administration, there is no need to remove the guidewire. The drug, biological agent, or contrast agent reaches the drug delivery port along the lumen of the catheter body, and is delivered in a uniform atomized manner. The operation is convenient and effectively avoids the occurrence of complications. Moreover, the guidewire does not occupy the lumen of the catheter body, and the outer diameter of the catheter body is minimized, making it smoother to push in the blood vessel. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of the diagnostic and therapeutic catheter in this invention; Figure 2 This is a schematic diagram of the distal end of the catheter body in this invention; Figure 3 This is a cross-sectional view of the distal end of the catheter body along the axial direction in this invention; Figure 4 for Figure 3 A cross-sectional view along the AA direction; Figure 5 This is a schematic diagram of the drug delivery control terminal interface.

[0017] Reference numerals: 1. Catheter body; 2. Injection connector; 3. Guide wire; 4. Quick exchange tube; 5. Drug delivery port. Detailed Implementation

[0018] The technical solutions of the present invention will now be described with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0019] In this invention, directional terms such as "upper," "lower," "left," and "right" may be defined relative to the orientation of the components shown in the accompanying drawings. It should be understood that these directional terms can be relative concepts, used for relative description and clarification, and can change accordingly depending on the orientation of the components in the accompanying drawings.

[0020] Example 1 like Figure 1 and Figure 3As shown, this invention provides a rapid-exchange distal coronary artery diagnostic catheter, comprising a catheter body 1, an injection connector 2, and a guidewire 3. The catheter body 1 has a hollow chamber, and its tail end is connected to the injection connector 2. Multiple drug delivery ports 5 are provided on the wall of its tip. A rapid-exchange channel is located on the outer side of the tip of the catheter body 1. This rapid-exchange channel extends axially and is independently configured from the lumen of the catheter body 1, allowing the guidewire 3 to pass through and guide the catheter body 1 to establish a pathway in the blood vessel. Because this catheter is equipped with a rapid-exchange channel, the guidewire only passes through this channel, while the hollow chamber of the catheter body 1 runs the entire length, serving as an independent drug delivery chamber. During drug delivery, the medication is injected into the injection connector 2 via a syringe, travels along the drug delivery chamber of the catheter body 1 to the drug delivery ports 5, and is administered to the distal coronary artery without the need to remove the guidewire. The medication is atomized and uniformly delivered at the drug delivery ports 5, making operation convenient and effectively avoiding complications. Furthermore, because the guidewire 3 does not occupy the lumen of the catheter, the outer diameter of the catheter body 1 is minimized, resulting in smoother advancement within the blood vessel.

[0021] The catheter body 1 is made of medical-grade polymer material, specifically polyether block amide (Pebax). This material combines good flexibility with a certain degree of pushing stiffness and is a widely used tube material in the field of coronary interventional catheters. The effective length of the catheter body 1 is 135cm-150cm, and 140cm is used in this embodiment. The outer diameter of the catheter body 1 is 0.90mm-1.10mm, and 0.97mm (approximately 2.9F) is used in this embodiment. The inner diameter is 0.60mm-0.80mm, and 0.70mm is used in this embodiment. The wall thickness is 0.135mm. This outer diameter allows the catheter body 1 to pass smoothly through the lumen of a 6F guiding catheter (inner diameter approximately 1.78mm) and maintain a small footprint within the coronary artery (the inner diameter of the proximal coronary artery is typically 3.0-4.5mm), reducing obstruction to blood flow.

[0022] For example, the catheter body 1 features a segmented, gradually varying hardness design along the axial direction. The proximal segment (the first 60% of the catheter length from the injection connector 2, approximately 84 cm) uses a high-hardness Pebax 7233 material (Shore hardness 72D) to provide sufficient pushing force transmission capability. The intermediate transition segment (60%-80% of the area, approximately 28 cm) uses a medium-hardness Pebax 6333 material (Shore hardness 63D) to achieve a smooth transition from the proximal rigid segment to the distal flexible segment. The distal segment (80%-100% of the area, approximately 28 cm) uses a low-hardness Pebax 4033 material (Shore hardness 40D) to provide good flexibility to follow the tortuous course of the coronary artery. The segments are connected by thermofusion welding, with a weld joint length of 2 mm, a welding temperature of 230°C-250°C, and a holding time of 3-5 seconds, ensuring that there are no obvious abrupt hardness changes or outer diameter expansion at the transition points between segments.

[0023] Further preferred, such as Figure 2 As shown, a quick-exchange short tube 4 is provided at the tip of the catheter body 1. The lumen of the quick-exchange short tube 4 constitutes the quick-exchange channel. Preferably, as shown... Figure 4 As shown, the rapid exchange tube 4 can be integrally formed with the tip of the catheter body 1. In other embodiments, an independent short tube can also be bonded or sleeved to the tip of the catheter body 1. When sleeved, the short tube is a double-lumen tube, with the thin lumen serving as the rapid exchange channel and the thick lumen serving as the outer sleeve sleeved on the catheter body 1.

[0024] To ensure a smooth connection at the tip of the catheter body 1, the connection between the quick-exchange short tube 4 and the catheter body 1 has a smooth curved transition.

[0025] The quick-exchange channel serves as a guiding channel for the guide wire 3, and it is necessary to ensure the stability of the guide wire 3 during transport. Preferably, the length of the quick-exchange channel is 5±0.5cm, that is, the length of the quick-exchange short tube 4 in this scheme is 5±0.5cm.

[0026] Further preferred, such as Figure 2 and Figure 3 As shown, the tip of the catheter body 1 is spindle-shaped. The overall radial dimension of the quick exchange tube 4 after being connected to the tip of the catheter body 1 is not greater than the radial dimension of the non-tip end of the catheter body 1, so as to ensure that there is no local bulging of the catheter as a whole, thereby further improving the smoothness of the catheter body 1 in the blood vessel.

[0027] like Figure 2As shown, there are 2-4 drug delivery holes 5, evenly distributed circumferentially at the distal end of the catheter body 1. Alternatively, multiple groups can be arranged along the length to ensure diffuse drug release and reduce blood flow impact. In this embodiment, there are 3 drug delivery holes 5, with an axial spacing of 1.5mm-2.5mm between adjacent holes 5; in this embodiment, 2mm is used. The axial distance from the distal drug delivery hole 5 to the tip of the catheter body 1 is 3mm-5mm; in this embodiment, 4mm is used.

[0028] The drug delivery orifice 5 is manufactured using a laser drilling process. The laser source is an ultraviolet nanosecond pulsed laser with a wavelength of 355 nm, a pulse width of 20 ns, and a single pulse energy of 50 μJ. The diameter of each drug delivery orifice 5 is 0.1 mm to 0.2 mm; in this embodiment, it is 0.15 mm. The orifice axis is aligned with the radial direction of the catheter body 1 (i.e., perpendicular to the tube axis). During the laser drilling process, a 0.5 mm diameter stainless steel mandrel is inserted into the tube cavity as a protective lining to prevent damage to the opposite tube wall after the laser penetrates the tube wall. After drilling, the orifice morphology is inspected under 100x magnification using an optical microscope to confirm the absence of burrs and heat-affected zone cracks.

[0029] For example, the three drug delivery ports 5 are positioned 4 mm, 6 mm, and 8 mm from the tip of the catheter body 1 along the axial direction. In the circumferential direction, the three drug delivery ports 5 can optionally be evenly distributed in different quadrants of the catheter body 1, i.e., the first port is located at 0°, the second at 120°, and the third at 240°, allowing the drug solution to diffusely release from three different radial directions of the catheter body 1, reducing the impact on the blood vessel wall caused by concentrated release on one side. Optionally, the drug delivery ports 5 can also be configured in multiple groups along the axial direction, for example, two groups of three, with a group spacing of 5 mm, to increase the axial coverage of the drug release, ensuring diffuse drug release and reducing blood flow impact.

[0030] More preferably, the catheter body 1 has imaging markings on its wall to show the placement position of the catheter in conjunction with X-rays.

[0031] Example 2 In another embodiment of the present invention, a drug delivery control method is provided for use with the rapid-exchange distal coronary diagnostic catheter. This method acquires the patient's electrocardiogram (ECG) signal to identify the cardiac cycle, determines the diastolic time window with lower coronary blood flow velocity within each cardiac cycle, and centrally controls the infusion pump to inject the drug solution into the catheter body during the diastolic time window. The injection is stopped during systole, thereby releasing the drug solution into the target vessel segment through the drug delivery port 5 during periods of lower coronary blood flow velocity.

[0032] Among them, such as Figure 5As shown, the drug delivery control method operates on a control terminal that is communicatively connected to the infusion pump. The control terminal can be a tablet computer or a medical workstation, requiring no modification to the mechanical structure of the catheter body. The control terminal receives real-time ECG signals from the patient's ECG monitor in the operating room via a standard data interface, and simultaneously connects to the infusion pump's drive control board via an RS485 serial communication interface to issue injection rate commands. During PCI, the patient is routinely connected to ECG monitoring equipment according to surgical protocols; therefore, acquiring ECG signals does not require any additional hardware. The method specifically includes the following steps: S100: Acquire the patient's electrocardiogram (ECG) signal, identify the cardiac cycle based on the ECG signal, and determine the diastolic time window within each cardiac cycle.

[0033] Specifically: S110 acquires the patient's electrocardiogram signal and performs R-wave detection.

[0034] The control terminal acquires real-time electrocardiogram (ECG) signals from a patient-connected ECG monitor in the operating room via a standard analog signal interface or digital communication protocol. The sampling rate of the ECG signal is set to no less than 250Hz. This sampling rate meets the precise time positioning requirements of the QRS complex in the ECG signal. The typical width of the QRS complex is 60-100ms, and the time resolution corresponding to a 250Hz sampling rate is 4ms, ensuring that the positioning accuracy of the R-wave peak is within ±4ms. After acquiring the ECG signal, the control terminal performs real-time R-wave detection. The R-wave detection algorithm uses the first-order differential thresholding method, which is suitable for embedded control scenarios due to its low computational complexity and strong real-time performance.

[0035] The specific execution process of the first-order difference threshold method is as follows: Continuously acquired electrocardiogram signal sample sequences Calculate the first difference point by point The absolute value of the difference, |d(n)|, is taken as the slope index. An adaptive detection threshold is set. The adaptive detection threshold The initial value is set to 30% of the ECG signal amplitude range, and is dynamically updated based on the average of the differential peak values ​​within the previous 5 cardiac cycles after each successful R-wave detection. Specifically, the value is taken from the time corresponding to the previous 5 R-waves. The arithmetic mean of the peak values ​​is used, and 40% of this mean is taken as the new threshold. .when upper Furthermore, if a zero-crossing point from positive to negative occurs within the subsequent 10 sampling points, that zero-crossing moment is determined to be the peak moment of the R-wave, and is denoted as . .

[0036] For example, assume the patient's current heart rate is 72 beats / min and the ECG signal sampling rate is 250Hz. In a typical ECG signal, the signal amplitude at the peak of the R wave is approximately 1.2mV, with a baseline of 0mV. The rising edge of the R wave spans approximately 3 sampling points (12ms), with the amplitude increasing from 0.1mV to 1.2mV. The differential value corresponding to this rising edge is approximately... mV / point. The differential peak values ​​of the first 5 R-waves were 0.35 mV / point, 0.38 mV / point, 0.36 mV / point, 0.37 mV / point, and 0.39 mV / point, with a mean of 0.37 mV / point. Therefore, the updated adaptive threshold... =0.37 × 40% = 0.148 mV / point. When |d(n)| of subsequent sampling points reaches 0.148 mV / point or higher and crosses zero, it is confirmed as an R-wave detection event. At a heart rate of 72 beats / min, the interval between adjacent R waves is approximately 833 ms (208.3 sampling points). The detection algorithm needs to complete one R-wave identification within each 833 ms cycle. Since the first-order difference operation only involves one subtraction and one comparison operation, the time taken for a single operation is much less than the 4 ms sampling interval, which meets the real-time requirements.

[0037] S120 determines the duration of the cardiac cycle based on the R-wave interval and calculates the diastolic time window parameters.

[0038] After detecting each R-wave peak, the control terminal calculates the time interval between the current R-wave and the previous R-wave, i.e., the RR interval. To eliminate the influence of single RR interval fluctuations caused by factors such as respiratory sinus arrhythmia on the diastolic window calculation, the control terminal takes the moving arithmetic mean of the three most recent consecutive RR intervals as the current effective cardiac cycle duration, denoted as the effective cycle. The window width of this moving average filter is selected as 3. If the window is too narrow (e.g., 1), there will be no filtering effect; if the window is too wide (e.g., 10), the response to sudden changes in heart rate will be sluggish. 3 is the empirically optimal value for balancing filtering effect and response speed.

[0039]

[0040] After determining the effective period, the control terminal determines the diastolic time window based on the systolic duration estimation method in clinical cardiac electrophysiology.

[0041] It should be noted that in clinical practice of coronary intervention, the duration of ventricular systolic phase is not simply linearly related to heart rate, but rather approximately proportional to the square root of the RR interval. This empirical relationship stems from the Bazett formula's modification of the QT interval. The control terminal uses the following formula to estimate the systolic phase duration. :

[0042] Where k is the systolic coefficient, which represents the proportion of ventricular mechanical contraction time relative to the entire cardiac cycle. The systolic coefficient k ranges from 0.30 to 0.40; in this embodiment, k = 0.35, a value recommended in clinical cardiac electrophysiology literature for patients with normal sinus rhythm. The effective cycle is measured in seconds.

[0043] The start of the diastolic time window is the peak value of the R wave. After that The duration of the time, the end time is the expected arrival time of the next R wave (i.e. (Including the effective period). Diastolic duration .

[0044] To prevent the natural fluctuations in heart rate from causing the injection tail segment to unexpectedly intrude into the initial stage of the next systolic phase, the control terminal applies a safety margin coefficient α to the diastolic duration. Here, α = 0.80, which represents the actual effective injection window. Only 80% of the diastolic duration is used for injection, with the remaining 20% ​​used as a protective zone.

[0045]

[0046] For example, when the patient's heart rate is stable at 72 beats / min, the effective period = 60 / 72 = 0.833s = 833ms. Substituting these values ​​into the formula, the systolic duration is calculated as follows: ms. Diastolic duration: ms. Valid push window: In 833ms heart rate cycles, the first 320ms is the systolic phase (the infusion pump stops), the following 410ms is the effective injection window (the infusion pump injects at the set rate), and the last 103ms is the guard band (the infusion pump stops, waiting for the next R wave). For example, when the heart rate increases to 90 beats / min, the effective cycle = 60 / 90 = 0.667s = 667ms. ms, ms, ms. It can be seen that the effective injection window is effectively shortened when the heart rate increases, and the available time for each injection decreases from 410ms to 305ms.

[0047] S200, based on the target dosing parameters and the duration of the diastolic time window, determine the single injection volume and injection rate within each diastolic time window.

[0048] Before administering the medication, the operator inputs the target dosing parameters through the human-machine interface of the control terminal. The target dosing parameters include the target total dosage. (Unit: mL) and target dosing duration (Unit: seconds). The control terminal calculates the total number of heartbeat cycles N expected to occur within the target dosing duration based on the target dosing duration and the current effective cycle:

[0049] The control terminal evenly distributes the target total dosage across N cardiac cycles, with each cycle containing a single bolus dose. for:

[0050] Injection rate within each diastolic window Divide the total injection volume to be completed within this window by the window duration:

[0051] For example, the surgeon sets a target total dosage. =2.0 mL, target dosing time =120s. Under the condition of a patient's heart rate of 72 beats / min (effective cycle 833ms): the total number of heart cycles N = 120 / 0.833 = 144.0, rounded to 144 cycles. Single injection volume =2 / 144=0.01389mL. Effective injection window. =410ms=0.410s. Injection rate =0.01389 / 0.410=0.03388mL / s=2.03mL / min. This rate value is within the adjustable range of a standard micro-infusion pump (0.01-5.00mL / min), and the stepper motor of the pump can accurately execute this rate command. For example, when the heart rate is 90 beats / min, N=120 / 0.667=180 cycles. =305ms = 0.305s When the heart rate increases, although the injection volume decreases with each bolus, the injection rate actually increases slightly because the injection window also shortens. The control terminal is set to an upper limit of 5 mL / min for the injection rate. When this limit is exceeded, the control terminal will The injection rate was set to 5 mL / min. The actual injection volume per cycle was adjusted accordingly, and the total dosing time was extended to ensure that the total dosing volume met the target.

[0052] S300, within each diastolic time window, control the infusion pump to inject the drug solution into the catheter body at the injection rate, and control the infusion pump to stop injecting during periods outside the diastolic time window.

[0053] Specifically, it includes the following steps: S310 performs pipeline filling to eliminate transmission delays during the startup phase.

[0054] Because the effective length of the catheter body 1 reaches 1400 mm, after the liquid is pushed in from the injection connector 2, its liquid front needs to travel for a period of time to reach the distal drug delivery port 5. During the initial stage before the tubing is fully filled with liquid, the "on-off" rhythm of the injection cannot create a synchronized release effect at the drug delivery port. Therefore, the control terminal performs a tubing filling operation before entering the cardiac-synchronized injection mode.

[0055] The control terminal calculates the total volume of the tubing lumen based on the physical parameters of the catheter body 1. And the tube filling and transmission delay time τ. Total volume of the tube cavity:

[0056] Where d = 0.7 mm is the inner diameter of the catheter body 1, and L = 1400 mm is the effective length of the catheter. The injection rate during the filling stage is set as follows: mL / min (this value is an empirically chosen value that balances filling speed and safety), then the filling time During the 21.6s filling phase, the infusion pump continuously injects medication at a constant rate of 1.5 mL / min without cardiac synchronization control. After filling, all space within the tubing is filled with the medication. Subsequently, the infusion pump's injection / stop command is transmitted to the administration port as a pressure wave. The propagation speed of the pressure wave in the liquid-filled tubing is approximately 1500 m / s (speed of sound in water). The pressure wave propagation time from proximal to distal end is... ms, this value is less than any time window of the heartbeat cycle and can be ignored.

[0057] S320, enter heart rate synchronized injection mode, control the injection pump according to the diastolic window rhythm.

[0058] After the tubing is filled, the control terminal enters the heartbeat-synchronized injection mode. In this mode, the control terminal executes the following timing control logic within each heartbeat cycle: (1) The current peak moment of the R-wave is detected. Then, start a countdown timer, with the initial value set to... ms. Subtracting 1ms represents a conservative compensation for pressure wave transmission, ensuring that the actual release start time of the drug solution at the administration port 5 is no later than the start time of diastole.

[0059] (2) When the countdown reaches zero (i.e.) After The control terminal sends a "start injection" command to the injection pump via an RS485 interface, the command carrying injection rate parameters. The stepper motor driver of the syringe pump starts the motor within 10ms after receiving the command, beginning to move at... The rate propels the syringe piston.

[0060] (3) After the "Start Betting" command is issued, During the specified time, the control terminal sends a "stop injection" command to the infusion pump. The stepper motor of the infusion pump brakes within 5ms of receiving the stop command. The infusion pump then remains stationary, awaiting the detection of the next R-wave.

[0061] It should be noted that, in another embodiment of the present invention, the control terminal controls the infusion pump to reduce to a maintenance rate rather than completely stop during the period outside the diastolic time window. The maintenance rate is set to 5%-10% of the injection rate; in this embodiment, it is 8% of the injection rate. That is, when the injection rate is 2.03 mL / min, the maintenance rate is 2.03 x 8% = 0.16 mL / min. The purpose of the maintenance rate here is to maintain a small flow of medication within the tubing during systole, preventing the risk of blockage caused by blood flowing back into the lumen through the infusion port after complete cessation. When the catheter infusion port diameter is small (less than or equal to 0.1 mm) or the medication viscosity is high, using the maintenance rate mode can reduce the probability of tubing blockage. In maintenance rate mode, the amount of medication released during systole is... mL, representing a single injection volume The 6.1% effect has a negligible impact on the efficacy of diastolic-concentrated administration.

[0062] (4) After the next R wave is detected, repeat steps (1) to (3). Repeat this process until the drug administration is completed.

[0063] For example, taking a patient's steady-state heart rate of 72 beats / min as an example, the complete temporal process within one cardiac cycle is described: the R-wave peak is detected at t=0ms. The timer is set to... At t=319ms, the control terminal sends a "start injection" command, with an injection rate of 2.03 mL / min. At t=329ms (10ms after the command), the infusion pump motor starts, and the medication begins to be injected into the catheter. Since the tubing is already full of medication, the pressure wave reaches the administration port within 0.93ms, meaning at t=329.93ms, medication begins to be released from administration port 5. Since this is only 9.93ms away from the theoretical start of diastole (t=320ms), it falls at the beginning of the diastolic window (320ms-730ms), with a deviation of only 2.42% of the total window length, meeting clinical requirements. At t=729ms (319ms + 410ms), the control terminal sends a "stop injection" command. At t=734ms (5ms after the stop command), the infusion pump motor brakes, and the injection stops. Release from administration port 5 terminates at t=734.9ms. The total effective release duration was 734.9-329.93 seconds. 405ms, compared to the set value Compared to 410ms, the effective utilization rate is 405 / 410 = 98.8%. At t=833ms, the next R-wave arrives, and a new cycle begins.

[0064] The S400 performs adaptive heart rate regulation and safety protection during drug administration.

[0065] Specifically, it includes the following sub-steps: S410 updates cardiac parameters in real time and adaptively adjusts the injection rate.

[0066] During simultaneous drug administration, the patient's heart rate may fluctuate due to surgical stimulation, drug effects, or autonomic nervous system regulation. The control terminal updates the effective period in real time each time a new R wave is detected. and The three parameters are updated, and the next injection cycle will use them. This adaptive mechanism requires no manual intervention from the surgeon.

[0067] When the effective period shortens (heart rate increases), The injection volume per cycle is shortened accordingly, but the injection volume per cycle is reduced. Remain unchanged (by) (locked at dosing initiation), therefore the injection rate The injection rate will increase. Conversely, the injection rate will decrease when the heart rate slows down. The control terminal sets the minimum effective injection window threshold to 150ms, so that when... When the calculated result is less than 150ms (corresponding to a heart rate of approximately 133 beats / min), the mechanical response time of the infusion pump (10ms for start-up + 5ms for braking = 15ms) accounts for 10% of the window. At this time, the control terminal skips the current cardiac cycle and does not administer an injection, but instead adds the injection volume of that cycle to subsequent cycles with wider windows for compensation.

[0068] For example, during a drug administration process, the patient's heart rate briefly accelerates to 110 beats / min: effective period = 60 / 110 = 0.545s = 545ms. ms, =545-258=287ms =0.8 × 287 = 230ms > 150ms, so synchronous betting can still be performed. At this point, the betting rate is updated to... =0.01389 / 0.23=0.0604mL / s=3.62mL / min. If the heart rate further accelerates to 140 beats / min, the effective period = 429ms. =229ms, =200ms =160ms > 150ms, still barely meets the execution conditions. =0.01389 / 0.160=0.0868mL / s=5.21mL / min, which exceeds the upper limit of 5mL / min, so it is locked at 5mL / min. The actual single injection volume =5 / 60×0.160=0.01333mL, and the shortfall of 0.01389-0.01333=0.00056mL is accumulated to be compensated in subsequent cycles.

[0069] S420 performs arrhythmia detection and mode switching protection.

[0070] After each update of the effective cycle, the control terminal synchronously calculates the coefficient of variation (CV, standard deviation divided by mean) of the most recent three RR intervals. When CV > 25%, it is determined that the patient's current heart rhythm has irregular fluctuations (possibly caused by atrial fibrillation, frequent premature beats, etc.). At this time, the prerequisite for heart rhythm synchronization is not met because the calculation of the diastolic window depends on the predictability of the RR interval. When the interval variation is too large, the calculated window may deviate from the actual diastolic period, causing the drug to be released during the systolic phase.

[0071] The control terminal automatically switches modes when CV > 25%: from cardiac-synchronized bolus injection mode to constant-rate dosing mode. In constant-rate dosing mode, the infusion pump operates at a constant rate. Continuous injection is no longer modulated by the heart rate cycle. At the same time, the control terminal displays a message on the interface stating "Irregular heart rate, switched to constant rate mode," reminding the operator that the current drug delivery mode has degraded.

[0072] Once the heart rhythm recovery rule is met (CV ≤ 20% for 10 consecutive RR intervals), the control terminal prompts the operator that they can manually restore the heart rhythm synchronization mode. Automatic reversal is prohibited; the reversal decision must be confirmed by the operator to avoid repeated mode switching during the transition period of heart rhythm instability.

[0073] S430, performs cumulative dose monitoring and determines dosing termination.

[0074] The control terminal continuously accumulates the actual total injection volume throughout the entire drug administration process. This value is calculated from the encoder displacement data of the syringe pump stepper motor. At this point, the injection volume corresponding to each microstep of the syringe pump is a known calibration constant (depending on the syringe inner diameter). The cumulative number of steps multiplied by the single-step injection volume gives the result. .

[0075] The dosing termination condition is that one of the following two conditions is met first: (1) ; (2) Actual administration time ≥ and ≥0.95× (That is, at least 95% of the target amount was completed within the specified time).

[0076] When the remaining dosage Less than a single injection volume At that time, the control terminal injects only during the last injection cycle. This means sending a stop command to avoid overdosing due to rounding up the cycle.

[0077] For example, in this embodiment, when the drug administration is performed up to the 142nd cardiac cycle, =142×0.01389=1.972mL, =2.0-1.972=0.028mL> =0.01389mL, normal injection of 0.01389mL in cycle 143. Updated to 1.986 mL. =0.014mL≈ In cycle 144, a normal injection of 0.01389 mL was administered. =2mL, to achieve Dosing is terminated. If some cycles are skipped (without a bolus) due to heart rate fluctuations, the actual number of cycles may exceed 144. The control terminal will then... The process terminates immediately upon reaching the target, without being limited by the expected number of cycles, and so on.

[0078] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A rapid-exchange distal coronary diagnostic catheter, comprising a catheter body and an injection connector mounted on the tail end of the catheter body, characterized in that, The catheter body has multiple drug delivery holes on its tip wall, and a rapid exchange channel on the outer side of the tip. The rapid exchange channel extends axially and is independently configured from the lumen of the catheter body for guidewire passage.

2. The catheter according to claim 1, characterized in that, The head end of the catheter body is provided with a quick-exchange short tube, and the lumen of the quick-exchange short tube constitutes the quick-exchange channel.

3. The catheter according to claim 2, wherein the connection between the rapid exchange short tube and the catheter body has a smooth curved transition.

4. The catheter according to claim 2, characterized in that, The tip of the catheter body is spindle-shaped, and the overall radial dimension of the quick-exchange short tube after it is connected to the tip of the catheter body is not greater than the radial dimension of the non-tip end of the catheter body.

5. The catheter according to any one of claims 1-4, characterized in that, The length of the fast exchange channel is 5 ± 0.5 cm.

6. A catheter-based drug delivery control method, characterized in that, The rapid-exchange distal coronary catheter according to any one of claims 1-5 comprises: Acquire the patient's electrocardiogram (ECG) signal, identify the cardiac cycle based on the ECG signal, and determine the diastolic time window within each cardiac cycle; Based on the target dosing parameters and the duration of the diastolic time window, determine the single injection volume and injection rate within each diastolic time window; Within each diastolic time window, the infusion pump is controlled to inject the drug solution into the catheter body at the injection rate. Outside of the diastolic time window, the infusion pump is controlled to stop injecting or reduce to a maintenance rate.

7. The drug administration control method according to claim 6, characterized in that, The step of identifying the cardiac cycle based on the electrocardiogram signal and determining the diastolic time window within each cardiac cycle includes: Identify the peak value of the R wave in the electrocardiogram signal and obtain the interval between adjacent R waves as the duration of the current heartbeat cycle; The start and end times of diastole are determined based on the current cardiac cycle duration and a preset diastolic percentage coefficient, wherein the start time of diastole is the time elapsed after the peak value of the R wave and the preset duration of the systolic phase.

8. The drug administration control method according to claim 6, characterized in that, The method further includes: The transmission delay time of the drug solution from the injection connector to the drug delivery port is determined based on the inner diameter, effective length, and drug solution viscosity of the catheter body. The injection start time of the infusion pump is advanced by the transport delay time relative to the start time of the diastolic time window, so that the actual time when the drug solution arrives at the administration port and is released falls within the diastolic time window.

9. The drug administration control method according to claim 6, characterized in that, The method further includes: accumulating the actual total injection volume during the administration process and comparing the actual total injection volume with the target administration volume; When the remaining dose is less than the single bolus dose corresponding to a single diastolic time window, administration is terminated after administering only the remaining dose in the last bolus cycle.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the drug administration control method as described in any one of claims 6-9.

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