An automated mapping system and method for a drug for a neurogenic arrhythmia

Abstract

The application discloses a kind of neurogenic arrhythmia drug automated mapping system and method.The system and method include optical path host system, excitation light source controller, temperature control heating bath with double-chamber isolation structure, multi-channel micro-dosing module, stimulator and system controller, when executing, separate fixed ganglion and heart specimen, send synchronous hardline trigger signal, response signal output electric stimulation and perfusion drug, acquire dual-channel camera acquisition signal and joint analysis.The application can control trigger synchronization time difference within 100 microseconds, and double isolation nerve and myocardial environment in physical and electrical level, provide high spatiotemporal resolution automated mapping evaluation.

Description

Technical Field

[0001] This application relates to an automated drug mapping system and method for neurogenic arrhythmias, belonging to the field of medical equipment and biomedical electrophysiological mapping technology. Background Technology

[0002] Autonomic dysfunction of the cardiovascular system, especially overactivation of the sympathetic nervous system and abnormal release of neuropeptide neurotransmitters, is one of the key pathophysiological mechanisms inducing neurogenic arrhythmias such as ventricular tachycardia and ventricular fibrillation. In the fields of basic medicine and drug development, precise screening and evaluation tools are needed for drugs targeting myocardial electrophysiological interventions mediated by neuropeptides or autonomic nervous activity.

[0003] Current conventional electrophysiological mapping techniques have significant limitations in screening such drugs. On the one hand, traditional point-based data acquisition methods cannot reflect the dispersion of action potential conduction at the whole organ level, making it difficult to capture and analyze complex electrical alternation phenomena caused by spatial heterogeneity. On the other hand, existing mapping devices often rely on multiple independent subsystems, each with its own independent internal clock and control logic, resulting in excessively large trigger synchronization time differences between devices. For millisecond or even sub-millisecond ion channel dynamics events, this can cause phase misalignment between neural stimulation signals and the induced myocardial response signals. Furthermore, existing experimental devices lack an integrated environmental control mechanism for perfusion drug delivery and neural modulation. When performing drug intervention on isolated hearts, traditional baths cannot effectively isolate the local microenvironment of nerves and the heart, making it difficult to precisely limit drug diffusion and often causing non-specific interference with drug targets. This directly leads to severe time lag and spatial errors in pharmacodynamic evaluation data, hindering the screening process of innovative antiarrhythmic drugs. Summary of the Invention

[0004] This application provides an automated drug mapping system and method for neurogenic arrhythmias, which solves the technical problems in the prior art, such as excessive trigger synchronization time difference caused by device splicing, lack of integrated physical isolation between drug perfusion and neuromodulation, and inability to capture multidimensional electrophysiological parameter changes under neuromodulation at a high resolution at the whole organ level.

[0005] This application provides an automated drug mapping system for neurogenic arrhythmias, including an optical host system, an excitation light source controller, a temperature-controlled heating bath, a multi-channel micro-programmed drug delivery module, a stimulator, and a system controller. The optical host system includes a fluorescence beam splitter and a dual-path back-illuminated scientific CMOS camera, configured to simultaneously record transmembrane action potential signals and intracellular calcium ion signals from an isolated heart specimen. The temperature-controlled heating bath has a dual-chamber isolation structure, including an upper chamber configured to fix sympathetic ganglia and a lower chamber configured to fix the isolated heart specimen. An array of electrodes is disposed inside the upper chamber, and a transparent observation window is disposed in the lower chamber. A perforated diaphragm allowing sympathetic nerve fibers to pass through connects the upper and lower chambers. The multi-channel micro-programmed drug delivery module is equipped with a liquid valve configured to infuse the intervention drug and perfusion fluid into the lower chamber. The system controller is electrically connected to the liquid valve, the stimulator, the excitation light source controller, and the dual-path back-illuminated scientific CMOS camera, and is configured to perform synchronous hard-wired triggering operations.

[0006] In some implementations, the system controller is configured to perform sub-millisecond global hardware-level hard-wired synchronization trigger scheduling. The system controller coordinates the timing of the liquid circuit valves, the stimulator, the excitation light source controller, and the dual-channel back-illuminated scientific CMOS camera to ensure that the transistor-to-transistor logic synchronization time difference between the multi-channel micro-programmable drug delivery module, the stimulator, the excitation light source controller, and the dual-channel back-illuminated scientific CMOS camera when receiving trigger commands is strictly limited to a parameter range of less than 100 microseconds.

[0007] In some implementations, the system controller internally incorporates a field-programmable gate array (FPGA) and a high-frequency clock oscillator. The system controller connects to the external trigger pins of the liquid valve, the stimulator, the excitation source controller, and the dual-channel back-illuminated scientific CMOS camera via multiple independently outputting pulse-width modulation (PWM) signal interfaces. The FPGA generates and distributes trigger edge commands for multiple state machines based on a global reference clock signal generated by the high-frequency clock oscillator. A global synchronous trigger reference is constructed by strictly aligning the rising edges of the multiple PWM signals, and different delay compensation time parameters are specifically configured to precisely match the inherent mechanical response delay and electrical rise-edge delay of the liquid valve and the excitation source controller during the physical actuation process.

[0008] In some embodiments, the outer shell of the temperature-controlled heating bath is made of polycarbonate, and the perforated diaphragm is made of flexible silicone rubber. The calibration system also includes a micro-positive pressure pump in fluid communication with the bottom of the lower chamber, configured to continuously pump fluid into the lower chamber to maintain a higher hydrostatic pressure in the lower chamber relative to the upper chamber.

[0009] In some embodiments, the central region of the flexible silicone rubber perforated diaphragm is provided with a matrix arrangement of micropore array structures that allow a single sympathetic nerve fiber to pass through. The diameter of each individual pore within the micropore array structure is configured to range from 10 micrometers to 50 micrometers. Furthermore, the micro-pump is additionally equipped with a flow acquisition sensor and a pressure closed-loop feedback control loop. The system controller continuously reads the real-time flow rate data fed back by the flow acquisition sensor and dynamically adjusts the output motor speed of the micro-pump to maintain a stable positive isolation pressure differential boundary between 0.5 kPa and 2.0 kPa relative to the hydrostatic pressure inside the lower chamber and the upper chamber.

[0010] In some embodiments, the sampling rate of the two dual-channel back-illuminated scientific CMOS cameras is configured to 5 kHz, and the quantum efficiency of both dual-channel back-illuminated scientific CMOS cameras reaches 95%. The fluorescence beam splitter is disposed on the optical path exit side of the light-transmitting observation window and splits the received fluorescence signal into a first beam and a second beam with different center wavelengths, which are respectively projected onto the photosensitive target surfaces of the two dual-channel back-illuminated scientific CMOS cameras.

[0011] In some embodiments, the fluorescence beam splitter includes a dichroic mirror and a bandpass filter array. The cutoff wavelength of the dichroic mirror is configured to a fixed value between 600 nm and 650 nm to separate the voltage-sensitive fluorescence spectrum corresponding to the transmembrane action potential signal and the calcium ion indicator fluorescence spectrum corresponding to the intracellular calcium ion signal.

[0012] This application provides an automated mapping method for drugs causing neurogenic arrhythmias, applied to a mapping system. The mapping system includes a temperature-controlled heating bath, a multi-channel micro-programmable drug delivery module, a stimulator, a system controller, an excitation light source controller, and a dual-channel back-illuminated scientific CMOS camera. The temperature-controlled heating bath has an upper chamber, a lower chamber, and a perforated diaphragm separating the upper chamber and the lower chamber. The upper chamber is provided with an array of electrodes. The mapping method includes separating the sympathetic ganglion and the isolated heart specimen through the perforated diaphragm and fixing them in the upper and lower chambers, respectively; sending a synchronous hard-wired trigger signal to the multi-channel micro-programmed drug delivery module, the stimulator, the excitation light source controller, and the dual-channel back-illuminated scientific CMOS camera through the system controller; responding to the synchronous hard-wired trigger signal, using the stimulator to output a high-frequency electrical stimulation signal to the array electrodes to perform an intervention action on the sympathetic ganglion, and infusing the intervention drug into the lower chamber according to a programmed gradient through the multi-channel micro-programmed drug delivery module; acquiring the transmembrane action potential signal and intracellular calcium ion signal corresponding to the isolated heart specimen collected by the dual-channel back-illuminated scientific CMOS camera and performing multi-parameter joint analysis.

[0013] In some embodiments, acquiring the transmembrane action potential signal and intracellular calcium ion signal corresponding to the isolated heart specimen acquired by the dual-path back-illuminated scientific CMOS camera and performing multi-parameter joint analysis includes quantifying and extracting isochronous conduction heat maps, action potential time history parameters, calcium transient time history parameters, and electrical alternation amplitude difference maps from the transmembrane action potential signal and the intracellular calcium ion signal, and performing feature vector splicing analysis.

[0014] In some embodiments, the quantitative extraction of action potential time-course parameters includes calculating the time-course cutoff points when the transmembrane action potential depolarization amplitude reaches 10% and 90%, respectively; calculating the corresponding action potential time-course change based on the time-course cutoff points and mapping it to a two-dimensional spatial grid coordinate system on the surface of the ex vivo heart specimen to generate a spatial distribution scatter matrix; and comparing the fluctuation amplitude of the action potential time-course change in adjacent cycles within a continuous high-frequency nerve impulse stimulation cycle to construct the electrical alternation amplitude difference map and generate a comprehensive efficacy judgment result.

[0015] In some embodiments, the process of using the stimulator to output a high-frequency electrical stimulation signal to the array electrodes includes generating a constant current pulse sequence with a set pulse width and injecting a stimulating charge into the sympathetic ganglion within a time window of 0.1 milliseconds to 1.0 milliseconds, locking the value of the set pulse width.

[0016] In some embodiments, the process of administering interventional drugs to the lower chamber via the multi-channel micro-programmed drug delivery module in a programmed gradient includes preloading a multi-dimensional gradient drug delivery configuration table containing multiple discrete concentration nodes into the system controller, and driving a flow regulating valve to sequentially change the concentration parameters of the administered interventional drugs according to the time interval sequence set in the multi-dimensional gradient drug delivery configuration table.

[0017] The technical solution provided in this application has the following beneficial effects: This system eliminates the communication delay between discrete devices in existing in vitro mapping systems. Through direct hardware-level triggering intervention, the system-level triggering synchronization time difference is controlled within a parameter range of 100 microseconds. This establishes a tight time correspondence between high-frequency exogenous neurostimulation and optical mapping sampling. Through a dual-chamber isolated temperature-controlled bath structure and a positive pressure compensation mechanism, physical and electrical dual isolation is achieved between the sympathetic nerve electrical stimulation area and the cardiac specimen drug perfusion area, avoiding neural short circuits and electrode polarization problems caused by backflow of neurotransmitter-containing drug solutions. Combining a dual-optical-path high spatiotemporal resolution acquisition mechanism and an automated multi-parameter joint analysis method, this application provides an automated evaluation tool with high spatiotemporal resolution, high repeatability, and high targeting accuracy for the study of neurotransmitter-mediated arrhythmia pathogenesis and high-throughput screening of intervention drugs. Attached Figure Description

[0018] Figure 1 This is a three-dimensional structural schematic diagram provided in an embodiment of the present invention.

[0019] Figure 2 This is a schematic internal cross-sectional view of the temperature-controlled heating bath provided in an embodiment of the present invention.

[0020] Figure 3 This is a hardware connection logic block diagram of the system controller provided in an embodiment of the present invention.

[0021] Figure 4 This is a flowchart illustrating the automated drug mapping method for neurogenic arrhythmias provided in this embodiment of the invention.

[0022] Figure 5 This is a schematic diagram of the optical path structure of the optical path host system provided in an embodiment of the present invention.

[0023] Explanation of reference numerals in the attached figures:

[0024] In the diagram: 101-Temperature-controlled heating bath, 102-Optical path main unit system, 103-Excitation light source controller, 104-Multi-channel micro-programmable drug delivery module, 105-Stimulator, 106-System controller, 201-Upper chamber, 202-Lower chamber, 203-Flexible silicone rubber perforated diaphragm, 204-Array electrode, 205-Transparent observation window, 206-Micro positive pressure pump, 207-Flow acquisition sensor, 301-Field-programmable gate array, 302-High-frequency clock oscillator, 501-Fluorescence beam splitter, 502-First-channel scientific CMOS camera, 503-Second-channel scientific CMOS camera, 504-Dichroic mirror, 505-Bandpass filter group. Detailed Implementation

[0025] To make the objectives, technical solutions, and beneficial effects of this application clearer, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the application. All other embodiments obtained by those skilled in the art based on the embodiments in this application without inventive effort are within the scope of protection of this application.

[0026] Example 1

[0027] Combination Figures 1 to 3 ,as well as Figure 5 As shown, this embodiment of the invention provides an automated mapping system for drugs treating neurogenic arrhythmias. This system integrates extrinsic cardiac neuromodulation and integrated mapping technologies for screening and evaluating the effects and efficacy of interventional drugs. From the overall structural layout, as... Figure 1 As shown, the calibration system is mainly assembled and coupled from a temperature-controlled heating bath 101, an optical path host system 102, an excitation light source controller 103, a multi-channel micro-programmable drug delivery module 104, a stimulator 105, and a system controller 106. Because this system involves high-bandwidth image acquisition and hardware control, it is equipped with a power supply module to power each power-consuming module, and an industrial-grade LCD display terminal to present experimental process images and thermal results.

[0028] like Figure 1 and Figure 2As shown, the temperature-controlled heating bath 101 employs a dual-chamber isolation structure designed for joint mapping needs. The outer shell of the temperature-controlled heating bath 101 is made of polycarbonate material with excellent thermal stability and insulation properties. Through a built-in temperature sensor and feedback control module, the bath maintains the environmental control range of the tested specimen between room temperature and 70°C, with a temperature adjustment accuracy of ±0.1°C. The inner silicone design stabilizes and fixes tissues, eliminating heat loss from the external environment. The temperature-controlled heating bath 101 is physically divided into two independent spaces: an upper chamber 201 and a lower chamber 202. The upper chamber 201 serves as a neurointervention chamber, configured to fix the bilateral stellate ganglia and other sympathetic ganglia attached to the isolated heart specimen. An array of electrodes 204 is laid and fixed inside the upper chamber 201. These electrodes are preferably made of micro-platinum-iridium alloy, with a medical-grade silicone insulating layer coated on their surface to limit leakage current, allowing for precise contact with the ganglia. The lower chamber 202 serves as the myocardial mapping chamber, configured as the main body for fixing isolated heart specimens. The bottom and side walls of the lower chamber 202 are equipped with light-transmitting observation windows 205 made of quartz material with high light transmittance, so that the fluorescence signal at the bottom can pass through without damage.

[0029] A flexible silicone rubber perforated diaphragm 203 is disposed between the upper chamber 201 and the lower chamber 202. The central region of this flexible silicone rubber perforated diaphragm 203 contains a matrix of micropores arranged to allow a single sympathetic nerve fiber to pass through a fixed array of micropores. The diameter of each individual pore within the micropore array is strictly configured between 10 and 50 micrometers. This specific size range precisely encompasses the physical diameter of the desheathed postganglionic sympathetic nerve fibers, while the capillary resistance generated by the pore size prevents the free permeation of large volumes of fluid. A micro-positive pressure pump 206 is fluidly connected to the bottom of the lower chamber 202. This micro-positive pressure pump 206 is additionally equipped with a flow acquisition sensor 207 and a pressure closed-loop feedback control circuit. The system controller 106 continuously reads the real-time flow rate data fed back by the flow acquisition sensor 207 and dynamically adjusts the output motor speed of the micro-positive pressure pump 206 to continuously pump fluid into the lower chamber 202, maintaining a stable positive isolation pressure differential boundary between 0.5 kPa and 2.0 kPa relative to the upper chamber 201. By using the micro-positive pressure pump 206 to maintain the liquid level in the lower chamber 202, the continuously upward micro-pressure differential can block the fluid, preventing the perfusion fluid carrying the targeted neurotransmitter from flowing back into the upper chamber 201 and causing short circuits in nerve endings, thus achieving dual isolation of electrical stimulation and drug perfusion at both the physical and electrical levels.

[0030] like Figure 1 and Figure 5As shown, the optical mapping function relies on the core module of the system, namely the optical path host system 102. The optical path host system 102 adopts the OMS-PCIE-2002 dual-camera fluorescence mapping host. The optical path host system 102 is aligned with the light-transmitting observation window 205, and uses the internal fluorescence beam splitter 501 to realize the direct output and separation of dual signals within the closed optical system. The fluorescence beam splitter 501 contains a dichroic mirror 504 and a bandpass filter group 505. The cutoff wavelength of the dichroic mirror 504 is configured as a fixed value between 600 nm and 650 nm. After the mixed fluorescence generated by the excitation of the isolated heart specimen passes through the observation window and enters the beam splitter, the dichroic mirror 504 reflects signals with wavelengths below the cutoff threshold as the first beam and transmits signals with wavelengths above the cutoff threshold as the second beam, separating the voltage-sensitive fluorescence spectrum corresponding to the transmembrane action potential signal and the calcium ion indicator fluorescence spectrum corresponding to the intracellular calcium ion signal. The separated beams are projected onto the photosensitive surfaces of the first scientific CMOS (complementary metal-oxide-semiconductor) camera 502 and the second scientific CMOS camera 503, respectively.

[0031] Both cameras employ back-illuminated scientific CMOS sensors with a quantum efficiency of 95%. The camera pixel sizes range from 6.5 μm × 6.5 μm to 11 μm × 11 μm, with a maximum single-channel resolution of 2048 × 2048 pixels. The dynamic range of the analog-to-digital conversion is as high as 50,000:1, and each channel has a bit depth of 12 bits. By adjusting the optomechanical components, the system can be configured with an adjustable object distance from 5 cm to 30 cm. The camera achieves a maximum frame rate of 3.5 kHz in region-of-interest mode. Under windowed readout at a specific resolution, the maximum sampling rate of both cameras can be configured to reach 5 kHz. The overall acquisition wavelength range covers 300 nm to 800 nm, and it is compatible with various sensitive dyes, ensuring non-destructive continuous capture of millisecond-level calcium transients induced by high-frequency neural impulses.

[0032] The excitation light source controller 103 is driven by a multi-channel constant current source and connected to a constant current driven fluorescent marking LED (light-emitting diode) lamp array located on the side of the bath. This light source supports constant and feedback light control, with a maximum load of 1 ampere. Based on a solid-state drive circuit, the light source feedback response time under its closed-loop control is limited to ≤60 microseconds.

[0033] The multi-channel micro-programmed drug delivery module 104 adopts an eight-channel perfusion system architecture, possessing the capability for rapid, micro-programmed drug delivery through multiple channels. It is equipped with multiple fluid circuit valves and provides 11 independent BNC (coaxial cable connector assembly) cascade interfaces. Utilizing a drive air pump as the fluid power source, the module responds to external electrical signals to open the corresponding channels, infusing interventional drugs and nutrient perfusion fluid into the lower chamber 202 according to a pre-set program. The system's overflow prevention alarm and memory function ensure the safe delivery of pharmacological reagents.

[0034] like Figure 3 As shown, the system employs hardware-level interconnection. The system controller 106 uses the OMSC801 fluorescence labeling system controller as the central control and scheduling unit. Internally, the system controller 106 includes a field-programmable gate array 301 and a high-frequency clock oscillator 302. The system controller 106 provides up to eight pulse output channels with a maximum output frequency of 30 kHz, and four channels of 16-bit resolution analog data input interfaces, with an analog input sampling rate up to 12.5 kHz.

[0035] The system controller 106 is physically connected via multiple independently outputting pulse width modulation (PWM) signal interfaces to the external trigger pins of the liquid valve, stimulator 105, excitation source controller 103, and two scientific CMOS cameras, respectively. The system controller 106 is configured to perform sub-millisecond-level global hardware-level hardwired synchronous trigger scheduling. The field-programmable gate array 301, based on a global reference clock signal generated by a high-frequency clock oscillator 302, uses logic gates to generate and distribute trigger edge commands for multiple state machines. The system constructs a global synchronous trigger reference by strictly aligning the rising edges of the multiple PWM signals. The system controller 106 is specifically configured with different delay compensation time parameters to precisely match the inherent mechanical response delay and electrical rise edge delay of the liquid valve and excitation source controller 103 during the physical driving process. The system uniformly coordinates the timing operation of each component, ensuring that the transistor-transistor logic synchronization time difference between all devices when receiving trigger commands and starting actual operation is strictly limited to a parameter range of less than 100 microseconds.

[0036] By adopting a highly integrated hardware architecture and a hard-wired synchronization mechanism driven by a field-programmable gate array, this calibration system can eliminate time lag and data misalignment caused by equipment splicing within the system.

[0037] It should be noted that the above descriptions of the micro-positive pressure pump 206 and various camera models are merely examples, and the various hardware modules of this application are not limited to these. Those skilled in the art can also achieve the purpose of this application by using similar alternative devices with equivalent performance. During system operation, the raw data generated is directly written to a data storage array constructed from solid-state drives, and subsequent data processing and result rendering are performed by data processing analysis software on a high-performance computer node.

[0038] Example 2

[0039] Based on the calibration system architecture of Embodiment 1 above, combined with Figure 4As shown, this embodiment of the invention provides an automated mapping method for drugs causing neurogenic arrhythmias. The mapping method mainly includes sample preprocessing and environment assembly S401 to multi-source data demodulation and quantification joint analysis S404.

[0040] Sample pretreatment and environmental assembly (S401) were performed to prepare a whole ex vivo heart specimen including bilateral stellate ganglia. The sympathetic ganglia and the main body of the ex vivo heart specimen were physically separated using the microporous structure of a flexible silicone rubber perforated diaphragm (203), and fixed above the array electrodes (204) of the upper chamber (201) and the light-transmitting observation window (205) of the lower chamber (202), respectively. During this process, the temperature in the temperature-controlled heating bath (101) was maintained within the physiological range of 37 ± 0.1 °C. Transmembrane voltage-sensitive dyes and intracellular calcium ion concentration-sensitive dyes were simultaneously loaded onto cardiomyocytes via aortic cannulation or intracellular perfusion channels.

[0041] The synchronous baseline construction and control signaling distribution S402 is executed to record the cardiac optical action potential trajectory and intracellular calcium concentration amplitude in the resting state as a control baseline. The system controller 106 synchronously sends hardware-level hard-wired trigger pulse sequence signals to the multi-channel micro-programmed drug delivery module 104, stimulator 105, excitation light source controller 103, and dual-channel back-illuminated scientific CMOS camera according to the preset experimental protocol.

[0042] In the intervention execution and high-frequency timing delivery S403, in response to the emitted synchronous hard-wire trigger signal, the system uses the stimulator 105 to output a high-frequency electrical stimulation signal to the array electrodes 204 of the upper chamber, performing an intervention action on the sympathetic ganglion and inducing the release of neurotransmitters such as neuropeptide Y. The stimulator internally generates a constant current pulse sequence with a set pulse width, locking the set pulse width value within a time window between 0.1 ms and 1.0 ms to inject stimulation charges into the sympathetic ganglion. During this period, the intervention drug is infused into the lower chamber 202 according to a programmed gradient through the multi-channel micro-programmed drug delivery module 104. A multi-dimensional gradient drug delivery configuration table containing multiple discrete concentration nodes is pre-loaded into the system controller 106. The system controller 106 drives the flow regulating valve to progressively change the concentration parameters of the infused intervention drug according to the time interval sequence set in the multi-dimensional gradient drug delivery configuration table.

[0043] In a specific timing control variant, the programmed drug delivery sequence is configured as follows: At time T0, main perfusion is initiated and a 20-second resting baseline signal is recorded. At time T1, the system controller issues a command to trigger channel 3 within the eight-channel perfusion system to switch to a reservoir containing BIBO-3304 (a neuropeptide Y receptor antagonist) at a concentration of 1 μmol / L, and controls a micro-pump to perfuse the target lower ventricle at low pressure for 180 seconds to ensure transmembrane drug absorption by myocardial tissue. At time T2, the system controller 106 sends a trigger pulse up to 30 kHz to activate the stimulator 105, causing it to output a ganglion electrical stimulation signal at a frequency of 10 Hz. This extended stimulation process is configured to last for 2 minutes. Simultaneously with the electrical stimulation, the excitation light source is directly triggered to reach the set power intensity, and a dual-channel scientific CMOS camera is simultaneously activated to perform a 120-second high-speed data stream disk writing and acquisition.

[0044] The S404 multi-source data demodulation and quantization joint analysis is performed. The computing node acquires a set of mixed data frames from a dual-channel back-illuminated scientific CMOS camera, separates the transmembrane action potential signal and intracellular calcium ion signal corresponding to the isolated heart specimen, and performs multi-parameter joint analysis. The software's internal digital signal processing thread cleans up low-frequency drift and background noise through an online digital filtering algorithm, finds the baseline and reverses the polarity, and plots a one-dimensional waveform of the action potential and calcium transient.

[0045] The system uses feature vector calculation to quantify and extract isochronous conduction heatmaps, action potential time history parameters, calcium transient time history parameters, and electrical alternation amplitude difference maps from transmembrane action potential signals and intracellular calcium ion signals, and performs multidimensional feature vector splicing analysis. Based on the temporal sequence of electrical excitation at different ventricular wall sites, timestamps for each point are extracted and pseudo-color mapped to generate isochronous conduction heatmaps.

[0046] The quantitative extraction of action potential time history parameters includes calculating the coordinates of time history cutoff points at each pixel when the transmembrane action potential depolarization amplitude reaches 10% and 90% of its maximum amplitude. Based on the difference between the time history cutoff points, the corresponding action potential time history change is calculated, and the change value of each pixel is mapped to a two-dimensional spatial grid coordinate system on the surface of the corresponding ex vivo heart specimen, generating a global spatial distribution scatter matrix. The system achieves the quantitative extraction of this time history parameter through the following mathematical formula:

[0047]

[0048] Among them, APD 10-90 The variable t represents the duration of the action potential that spans from 10% depolarization to 90% repolarization; 90%The variable t represents the cutoff time parameter of the action potential waveform curve when it reaches 90% of the peak absolute amplitude threshold at the falling edge of repolarization; 10% The variable represents the starting time parameter when the rising edge of the waveform curve reaches 10% of the amplitude. By monitoring the change of this time history, the electrical dispersion of each region can be quantified.

[0049] In addition, the system simultaneously measures the calcium transient signal, assessing the amplitude of intracellular calcium ion concentration and the calcium transient time-history parameters. The system performs a subtraction operation, calculating the difference between the relapse time parameter (when calcium fluorescence intensity decays back to the baseline threshold) and the initiation surge time parameter (when calcium fluorescence surges beyond the initial level), to obtain the calcium transient time-history parameters. This calcium transient characteristic is calculated using the following formula:

[0050]

[0051] Among them, CaTD X The variable t represents the calcium transient time series from the start of release to reuptake and recovery to the threshold X; Ca re The variable t represents the relapse time parameter at which calcium fluorescence intensity decays back to the baseline threshold; Ca on The variable represents the parameter indicating the initiation surge moment when calcium fluorescence surges beyond the baseline level.

[0052] Within a continuous high-frequency nerve impulse stimulation cycle, the system further compares the changes in the duration of the action potential and the fluctuation patterns of the calcium transient amplitude between two adjacent cardiac cycles. By calculating the parameter differences between consecutive cycles and assigning color weights, the system can construct a graph reflecting the difference in amplitude of minute electrical alternation. The system analysis module uses multiple parameters, such as conduction velocity, improvement in dispersion, and correction of calcium transient alternation, as criteria to comprehensively assess whether the interventional drug can effectively block the pathogenic signaling pathway, generating a final efficacy assessment result regarding the cardiac safety and therapeutic efficacy of the interventional drug.

Claims

1. An automated drug mapping system for neurogenic arrhythmias, characterized in that, The system includes an optical path host system, comprising a fluorescence beam splitter and a dual-path back-illuminated scientific CMOS camera, configured to simultaneously record transmembrane action potential signals and intracellular calcium ion signals of an isolated heart specimen; an excitation source controller; a temperature-controlled heating bath with a dual-chamber isolation structure, including an upper chamber configured to fix sympathetic ganglia and a lower chamber configured to fix the isolated heart specimen, wherein an array of electrodes is disposed inside the upper chamber and a light-transmitting observation window is disposed in the lower chamber, and a perforated diaphragm allowing sympathetic nerve fibers to pass through connects the upper and lower chambers; a multi-channel micro-programmable drug delivery module, configured with a liquid valve to infuse intervention drugs and perfusion fluid into the lower chamber; a stimulator; and a system controller electrically connected to the liquid valve, the stimulator, the excitation source controller, and the dual-path back-illuminated scientific CMOS camera, configured to perform synchronous hard-wired triggering operations.

2. The automated drug mapping system for neurogenic arrhythmias as described in claim 1, characterized in that, The system controller is configured to perform sub-millisecond global hardware-level hard-wired synchronization triggering and scheduling. The system controller coordinates the timing operation of the liquid valve, the stimulator, the excitation light source controller, and the dual-channel back-illuminated scientific CMOS camera to ensure that the transistor-transistor logic synchronization time difference between the multi-channel micro-programmable drug delivery module, the stimulator, the excitation light source controller, and the dual-channel back-illuminated scientific CMOS camera when receiving trigger commands is strictly limited to a parameter range of less than 100 microseconds.

3. The automated drug mapping system for neurogenic arrhythmias as described in claim 2, characterized in that, The system controller is equipped with a field-programmable gate array (FPGA) and a high-frequency clock oscillator. The system controller is connected to the external trigger pins of the liquid valve, the stimulator, the excitation light source controller, and the dual-channel back-illuminated scientific CMOS camera through multiple independently outputting pulse width modulation (PWM) signal interfaces. The FPGA generates and distributes trigger edge commands of multiple state machines based on the global reference clock signal generated by the high-frequency clock oscillator. A global synchronous trigger reference is constructed by strictly aligning the rising edges of the multiple PWM signals. Different delay compensation time parameters are specifically configured to precisely match the inherent mechanical response delay and electrical rising edge delay of the liquid valve and the excitation light source controller during the physical driving process.

4. The automated drug mapping system for neurogenic arrhythmias as described in claim 1, characterized in that, The outer shell of the temperature-controlled heating bath is made of polycarbonate material, and the perforated diaphragm is made of flexible silicone rubber perforated diaphragm. The system also includes a micro positive pressure pump that is in fluid communication with the bottom of the lower chamber. The micro positive pressure pump is configured to continuously pump fluid into the lower chamber to maintain a higher hydrostatic pressure at the liquid surface in the lower chamber relative to the upper chamber.

5. The automated drug mapping system for neurogenic arrhythmias as described in claim 4, characterized in that, The central region of the flexible silicone rubber perforated diaphragm is arranged in a matrix with a fixed micropore array structure that allows a single sympathetic nerve fiber to pass through. The diameter of each single pore in the micropore array structure is configured to be between 10 micrometers and 50 micrometers. The micro-positive pressure pump is additionally equipped with a flow acquisition sensor and a pressure closed-loop feedback control loop. The system controller continuously reads the real-time flow rate data fed back by the flow acquisition sensor and dynamically adjusts the output motor speed of the micro-positive pressure pump to maintain a stable positive isolation pressure differential boundary between 0.5 kPa and 2.0 kPa relative to the hydrostatic pressure of the fluid in the lower chamber and the upper chamber.

6. The automated drug mapping system for neurogenic arrhythmias as described in claim 1, characterized in that, The sampling rate of the two back-illuminated scientific CMOS cameras is configured to be 5 kHz, and the quantum efficiency of the two dual-channel back-illuminated scientific CMOS cameras is 95%. The fluorescence beam splitter is set on the light path output side of the light-transmitting observation window and splits the received fluorescence signal into a first beam and a second beam with different center wavelengths, which are respectively projected onto the photosensitive target surface of the two dual-channel back-illuminated scientific CMOS cameras.

7. The automated drug mapping system for neurogenic arrhythmias as described in claim 6, characterized in that, The fluorescence beam splitter contains a dichroic mirror and a bandpass filter array. The cutoff wavelength of the dichroic mirror is configured to a fixed value between 600 nm and 650 nm to separate the voltage-sensitive fluorescence spectrum corresponding to the transmembrane action potential signal and the calcium ion indicator fluorescence spectrum corresponding to the intracellular calcium ion signal.

8. An automated method for mapping drugs causing neurogenic arrhythmias, applied to a mapping system, the mapping system comprising a temperature-controlled heating bath, a multi-channel micro-programmable drug delivery module, a stimulator, a system controller, an excitation light source controller, and a dual-channel back-illuminated scientific CMOS camera, wherein the temperature-controlled heating bath has an upper chamber, a lower chamber, and a perforated diaphragm separating the upper and lower chambers, and the upper chamber is provided with an array of electrodes; characterized in that, The procedure includes separating the sympathetic ganglion and the isolated heart specimen through the perforated diaphragm and fixing them in the upper and lower chambers, respectively; sending a synchronous hard-wired trigger signal to the multi-channel micro-programmed drug delivery module, the stimulator, the excitation light source controller, and the dual-channel back-illuminated scientific CMOS camera via the system controller; responding to the synchronous hard-wired trigger signal, using the stimulator to output a high-frequency electrical stimulation signal to the array electrodes to perform an intervention action on the sympathetic ganglion, and infusing the intervention drug into the lower chamber according to a programmed gradient via the multi-channel micro-programmed drug delivery module; acquiring the transmembrane action potential signal and intracellular calcium ion signal corresponding to the isolated heart specimen collected by the dual-channel back-illuminated scientific CMOS camera and performing multi-parameter joint analysis.

9. The automated drug mapping method for neurogenic arrhythmias as described in claim 8, characterized in that, The acquisition of transmembrane action potential signals and intracellular calcium ion signals corresponding to the isolated heart specimen by the dual-path back-illuminated scientific CMOS camera and the subsequent multi-parameter joint analysis include quantifying and extracting isochronous conduction heat maps, action potential time history parameters, calcium transient time history parameters, and electrical alternation amplitude difference maps from the transmembrane action potential signals and intracellular calcium ion signals, and then performing feature vector splicing analysis.

10. The automated drug mapping method for neurogenic arrhythmias as described in claim 9, characterized in that, The quantitative extraction of action potential time-course parameters includes calculating the time-course cutoff points when the transmembrane action potential depolarization amplitude reaches 10% and 90%, respectively. Based on the time-course cutoff points, the corresponding action potential time-course change is calculated and mapped to a two-dimensional spatial grid coordinate system on the surface of the ex vivo heart specimen to generate a spatial distribution scatter matrix. The fluctuation amplitude of the action potential time-course change in adjacent cycles is compared within a continuous high-frequency nerve impulse stimulation cycle to construct the electrical alternation amplitude difference map and generate a comprehensive efficacy judgment result.

Images