Low-voltage nanosecond pulse platform waveform fitting method
By fitting waveforms using a low-pressure nanosecond pulse platform, the optimal pulse width and equivalent number of nanosecond pulses are calculated, overcoming the shortcomings of traditional microsecond and nanosecond ablation, and achieving uniform ablation and improved safety under low pressure.
Patent Information
- Application Number
- CN202610447816.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-04-07
- Publication Date
- 2026-05-12
AI Technical Summary
Traditional microsecond pulse ablation suffers from uneven ablation and missed cells blocked by nerves or blood vessels under low pressure, while high-voltage nanosecond pulses pose risks of hemolysis and structural damage, making it difficult to achieve uniform ablation under low pressure and meet the consistency of transmembrane potential threshold coverage and dose equivalence.
A low-pressure nanosecond pulse platform waveform fitting method is adopted. The optimal pulse width is calculated by the transmembrane voltage formula. Combined with the dose and transmembrane potential accumulation model, the equivalent number of nanosecond pulses and the number of pulse trains are calculated. The nanosecond pulse is fitted to achieve uniform ablation under low pressure, which combines the advantages of microsecond and nanosecond pulses.
It achieves uniform ablation under low pressure, reduces embolism, improves safety, reduces the risk of voltage damage, and avoids the non-uniformity of traditional microsecond ablation and the hemolysis problem of nanosecond ablation.
Smart Images
Figure CN122005049A_ABST
Abstract
Description
Technical Field
[0001] This application belongs to the field of high-frequency pulse control technology, specifically, it relates to a method for fitting waveforms using a low-voltage nanosecond pulse platform. Background Technology
[0002] High-frequency pulsed ablation is used in catheter ablation to alter cell membrane permeability through an electric field. Once the transmembrane voltage threshold is reached, irreversible perforation of the cell membrane occurs. Traditional microsecond pulse width platforms are prone to causing irreversible electroporation under low voltage, but they suffer from uneven ablation and missed cells blocked by nerves or blood vessels. Traditional nanosecond ablation can avoid this drawback, but it requires very high voltage and has problems such as hemolysis, damage to vascular endothelium and smooth muscle, and nerve damage.
[0003] To compensate for the shortened duration of a single pulse, current nanosecond ablation methods often employ higher voltage amplitudes. However, the increased electric field strength may exceed the tolerance thresholds of erythrocyte vascular endothelial smooth muscle and nerves, leading to risks of hemolysis and structural damage. Under low-pressure conditions, especially in bipolar electrode scenarios, the transmembrane potential rises and then falls rapidly, making accumulation difficult. This makes it impossible to directly convert microsecond prescription parameters into nanosecond sub-pulse parameters while simultaneously meeting the consistency requirements of transmembrane potential threshold coverage and dose equivalence.
[0004] Therefore, a fitting waveform generation method for low-pressure nanosecond pulse platforms is needed. Using reference prescription parameters or empirical values, the target ablation effect parameters are calculated to constrain the nanosecond sub-pulse and pulse train structure, achieving the advantages of both nanosecond and microsecond pulses while overcoming their respective drawbacks. Summary of the Invention
[0005] To address the aforementioned problems and technical deficiencies, this application adopts the following technical solution: a method for fitting waveforms using a low-voltage nanosecond pulse platform, characterized by comprising the following steps: Step 1: Obtain the set voltage value, and calculate the optimal pulse width corresponding to the target cell using the transmembrane voltage formula based on the set voltage value; Step 2: Based on the dose and transmembrane potential accumulation model, calculate the number of equivalent nanosecond pulse sub-pulses that can replace the optimal pulse width; Step 3: Calculate the number of pulse trains based on the total dose and the equivalent number of nanosecond pulse sub-pulses set according to the optimal pulse width; fit the nanosecond pulses according to the number of pulse trains and replace the optimal pulse width. Step 4: Store the calculated number of nanosecond fitting values, the number of pulse trains, and the preset parameters into the storage chip of the pulse platform. The pulse platform then calls the stored parameters for energy emission.
[0006] Preferably, the transmembrane voltage formula is as follows: in, Let be the transmembrane voltage, E be the applied electric field strength, g be the relative electropermeability constant of the target cell membrane, and a be the cell radius. Let be the angle between the line connecting a point on the cell membrane and the cell center and the electric field. The charging time constant is 1.32µs.
[0007] Furthermore, the dosage The calculation formula is as follows: Where V is the voltage amplitude, Tp is the pulse width, n is the number of sub-pulses in each pulse train, and N is the number of pulse trains.
[0008] Furthermore, the transmembrane potential accumulation model is based on the calculated cell transmembrane voltage and other determined parameters, so that the voltage accumulation of multiple pulse trains reaches the threshold of the transmembrane voltage. By accumulating the cell membrane transmembrane voltage, the pulse width is increased, and a deeper ablation depth is achieved.
[0009] Furthermore, the voltage accumulation of the multiple pulse trains reaches the threshold of the transmembrane voltage by reducing the pulse interval time. The formula for calculating the required pulse interval time is as follows: Where t is the time required for the pulse interval.
[0010] Furthermore, the voltage accumulation of the multi-pulse train reaching the transmembrane voltage threshold can also be achieved by increasing the voltage amplitude and changing the ramp slopes K1 and K2, specifically including: When the sub-pulse ramping slope K1 is the same in each pulse train, the descent slope K3 is made to be 0 or fixed by fixing the frequency and pulse width. The experiment obtained the number of sub-pulses that were equivalent to a nanosecond pulse and had the same effect as an optimal pulse width pulse, and the descent slope K3 was calculated. When the voltage and external factors are the same, the slopes of the rise and fall are the same, and when the preset rise height is reached, the transmembrane voltage reaches the threshold.
[0011] Furthermore, based on dosage This is equivalent to K2=0 and T1=n t1, calculate the number of sub-pulses n in each pulse train, and fit the effect of microsecond T1 to the nanosecond pulse width t1. This requires n pulses. The theoretical formula for calculating the number of sub-pulses is as follows: The actual formula for calculating the number of sub-pulses is as follows: in, This represents the interference coefficient.
[0012] Furthermore, under the condition of setting a high-voltage pulse voltage, t is calculated using a time calculation formula, and then... Input the actual calculation formula for the number of sub-pulses, and find the actual number of sub-pulses n to be fitted. This allows you to combine n nanosecond pulses to form the pulse width of a microsecond pulse.
[0013] Furthermore, after calculating the theoretical number of sub-pulses based on the formula for calculating the number of sub-pulses, the number of combined pulses at the same depth and with a preset nanosecond range is experimentally determined to reach the same depth with a fixed pulse width of microseconds. The value of the relative electrical permeability constant g is then determined. The formula for calculating the relative electrical permeability constant g is as follows: Furthermore, when an overdose is provided, the calculation formula is as follows: When the dose and voltage are the same, the relationship between the number of sub-pulses and the optimal pulse width t is as follows: ; Based on the theoretical calculation formula for the number of sub-pulses, it was determined that the value of the number of sub-pulses n at this time was greater than the value calculated by the conventional dose. Therefore, the value of the number of sub-pulses n calculated by the conventional dose was used as the lower limit threshold to verify the correctness of the number of sub-pulses calculated by the transmembrane potential pulse accumulation model.
[0014] Compared to existing technologies, the beneficial effects of this application are as follows: (1) Based on the set voltage, nanosecond pulse width and frequency, this application calculates the optimal pulse width, and calculates the equivalent number of nanosecond pulses fitting the best pulse width based on the dose and transmembrane potential accumulation model, so as to achieve the combined effect of microsecond platform and high voltage nanosecond platform using low voltage nanosecond platform; (2) This application combines the advantages and disadvantages of the current traditional nanosecond and microsecond platforms. By using the technical parameters accumulated by the existing microsecond platform, it calculates the fitted nanosecond waveform and releases smaller and fewer bubbles than the microsecond platform through the energy emission of the fitted nanosecond waveform, thereby reducing the incidence of embolism. It solves the problems of unevenness, dead angles and large bubbles in traditional microsecond ablation, improves safety, and releases a lower voltage than traditional nanosecond ablation, thereby reducing the problems of hemolysis and damage to smooth muscle and nerves. Attached Figure Description
[0015] In the attached diagram: Figure 1 This is a schematic diagram of the method steps in an embodiment of this application; Figure 2 The pulse width is in the microsecond range according to the embodiments of this application; Figure 3 This is a spherical model of a cell used in an embodiment of this application. Figure 4 This is a diagram showing the transmembrane voltage variation according to an embodiment of this application; Figure 5 This is a transmembrane potential pulse accumulation model for embodiments of this application; Figure 6 The pulse and cell membrane voltage accumulation in the embodiments of this application Figure 1 ; Figure 7 The pulse and cell membrane voltage accumulation in the embodiments of this application Figure 2 . Detailed Implementation
[0016] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of this application, but not all embodiments. Generally, the components of the embodiments of this application described and shown in the accompanying drawings can be arranged and designed in various different configurations.
[0017] Example like Figure 1 As shown, a method for fitting waveforms using a low-voltage nanosecond pulse platform includes the following steps: Obtain the set voltage value, and calculate the optimal pulse width corresponding to the target cell using the transmembrane voltage formula based on the set voltage value; The formula for transmembrane voltage is as follows: in, Let be the transmembrane voltage, E be the applied electric field strength, g be the relative electropermeability constant of the target cell membrane, and a be the cell radius. Let be the angle between the line connecting a point on the cell membrane and the cell center and the electric field. With a charging time constant of 1.32 μs, the spherical model of the cell is as follows: Figure 3 As shown.
[0018] Based on the dose and transmembrane potential accumulation model, the number of equivalent nanosecond pulse sub-pulses that can replace the optimal pulse width is calculated. dose The calculation formula is as follows: Where V is the voltage amplitude, Tp is the pulse width, n is the number of sub-pulses in each pulse train, and N is the number of pulse trains, such as... Figure 2 As shown, the us-level pulse width is the optimal pulse width. N T2 (ns) levels are strung together to fit the function of the us-level pulse width.
[0019] like Figure 4 As shown, the transmembrane potential accumulation model is based on the calculated cell transmembrane voltage and other determined parameters, so that the voltage of multiple pulse trains accumulates to reach the threshold of the transmembrane voltage. By accumulating the cell membrane transmembrane voltage, the pulse width is increased, and a deeper ablation depth is achieved.
[0020] The voltage accumulation of multiple pulse trains reaches the threshold of transmembrane voltage by reducing the pulse interval time. The formula for calculating the required pulse interval time is as follows: Where t is the time required for the pulse interval.
[0021] The threshold for the transmembrane voltage can also be reached by increasing the voltage amplitude and changing the ramp slopes K1 and K2, specifically including: When the sub-pulse ramping slope K1 is the same in each pulse train, the descent slope K3 is made to be 0 or fixed by fixing the frequency and pulse width. The experiment obtained the number of sub-pulses that were equivalent to a nanosecond pulse and had the same effect as an optimal pulse width pulse, and the descent slope K3 was calculated. When the voltage and external factors are the same, the slopes of the rise and fall are the same, and when the preset rise height is reached, the transmembrane voltage reaches the threshold.
[0022] Transmembrane potential pulse accumulation model as follows Figure 5 As shown, the left side represents the pulse train, and the thin line on the right side represents the transmembrane voltage. When the pulse interval is small enough, the voltage accumulated from multiple pulse trains can reach the threshold of the transmembrane voltage. Increasing the voltage amplitude and changing the ramp-up slope can also reach the threshold of the transmembrane voltage. like Figure 6 As shown, green represents a high-voltage pulse, and blue represents the cell membrane voltage that jumps up and down rapidly. like Figure 7 As shown, green represents a high-voltage pulse, and blue represents the cell membrane voltage that accumulates. For low voltage, especially bipolar electrodes, Figure 6 The green pulse voltage is difficult to rise.
[0023] This method of accumulating transmembrane voltage is equivalent to increasing the pulse width, which can achieve ablation at a deeper depth.
[0024] The slope of ascent is the same, while the slope of descent is 0 or fixed. By fixing the frequency and pulse width, the number of effective pulses required to achieve the effect of a single pulse can be determined, and thus the slope of descent can be derived.
[0025] Under the same external conditions such as voltage, the slopes of the rise and fall are the same, so the desired height of the rise—the final value of the transmembrane voltage—can be calculated.
[0026] According to dosage This is equivalent to K2=0 and T1=n t1, calculate the number of sub-pulses n in each pulse train, and fit the effect of microsecond T1 to the nanosecond pulse width t1. This requires n pulses. The theoretical formula for calculating the number of sub-pulses is as follows: The actual formula for calculating the number of sub-pulses is as follows: in, This represents the interference coefficient.
[0027] Given a high-voltage pulse voltage, t is calculated using a time calculation formula, and then... Input the actual calculation formula for the number of sub-pulses, and find the actual number of sub-pulses n to be fitted. This allows you to combine n nanosecond pulses to form the pulse width of a microsecond pulse.
[0028] Based on the theoretical formula for calculating the number of sub-pulses, after calculating the theoretical number of sub-pulses, the number of combined pulses at the same depth and with a preset nanosecond range was experimentally determined to reach the same depth with a fixed pulse width of microseconds. The value of the relative electrical permeability constant g was then determined. The formula for calculating the relative electrical permeability constant g is as follows: Based on the total dose set by the optimal pulse width and the equivalent number of nanosecond pulse sub-pulses, the number of pulse trains is calculated, and a nanosecond pulse is fitted based on the number of pulse trains, replacing the optimal pulse width. When an overdose is administered, the calculation formula is as follows: When the dose and voltage are the same, the relationship between the number of sub-pulses and the optimal pulse width t is as follows: ; Based on the theoretical calculation formula for the number of sub-pulses, it was determined that the value of the number of sub-pulses n at this time was greater than the value calculated by the conventional dose. Therefore, the value of the number of sub-pulses n calculated by the conventional dose was used as the lower limit threshold to verify the correctness of the number of sub-pulses calculated by the transmembrane potential pulse accumulation model.
[0029] The calculated number of nanosecond fitting values, the number of pulse trains, and preset parameters are stored in the storage chip of the pulse platform. The pulse platform then calls the stored parameters for energy emission.
[0030] Based on the set voltage, nanosecond pulse width, and frequency, the optimal pulse width is calculated. The equivalent number of nanosecond pulses fitting the optimal pulse width is calculated using a dose and transmembrane potential accumulation model. A low-voltage nanosecond platform achieves the combined effects of microsecond and high-voltage nanosecond platforms. Combining the advantages and disadvantages of current traditional nanosecond and microsecond platforms, and utilizing the technical parameters accumulated from existing microsecond platforms, a fitted nanosecond waveform is calculated. Through energy emission from the fitted nanosecond waveform, the released bubbles are smaller and fewer than those from microsecond platforms, reducing the incidence of embolism. This addresses the issues of unevenness, dead zones, and large bubbles in traditional microsecond ablation, improving safety. Furthermore, the released voltage is lower than that of traditional nanosecond ablation, reducing hemolysis and damage to smooth muscle and nerves.
[0031] The embodiments described above are merely preferred embodiments of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this application. It should be noted that those skilled in the art can make various modifications, improvements, and substitutions without departing from the concept of this application, and these all fall within the protection scope of this application.
Claims
1. A method for fitting waveforms using a low-voltage nanosecond pulse platform, characterized in that, Includes the following steps: Step 1: Obtain the set voltage value, and calculate the optimal pulse width corresponding to the target cell using the transmembrane voltage formula based on the set voltage value; Step 2: Based on the dose and transmembrane potential accumulation model, calculate the number of equivalent nanosecond pulse sub-pulses that can replace the optimal pulse width; Step 3: Calculate the number of pulse trains based on the total dose and the equivalent number of nanosecond pulse sub-pulses set according to the optimal pulse width; fit the nanosecond pulses according to the number of pulse trains and replace the optimal pulse width. Step 4: Store the calculated number of nanosecond fitting values, the number of pulse trains, and the preset parameters into the storage chip of the pulse platform. The pulse platform then calls the stored parameters for energy emission.
2. The method for fitting waveforms using a low-voltage nanosecond pulse platform according to claim 1, characterized in that, The formula for the transmembrane voltage is as follows: in, Let be the transmembrane voltage, E be the applied electric field strength, g be the relative electropermeability constant of the target cell membrane, and a be the cell radius. Let be the angle between the line connecting a point on the cell membrane and the cell center and the electric field. The charging time constant is 1.32µs.
3. The method for fitting waveforms using a low-voltage nanosecond pulse platform according to claim 2, characterized in that, The dosage The calculation formula is as follows: Where V is the voltage amplitude, Tp is the pulse width, n is the number of sub-pulses in each pulse train, and N is the number of pulse trains.
4. The method for fitting waveforms using a low-voltage nanosecond pulse platform according to claim 3, characterized in that, The transmembrane potential accumulation model is based on the calculated cell transmembrane voltage and other determined parameters, so that the voltage accumulation of multiple pulse trains reaches the threshold of the transmembrane voltage. By accumulating the cell membrane transmembrane voltage, the pulse width is increased, and a deeper ablation depth is achieved.
5. The method for fitting waveforms using a low-voltage nanosecond pulse platform according to claim 4, characterized in that, The voltage accumulation of the multiple pulse trains reaches the threshold of the transmembrane voltage by reducing the pulse interval time. The formula for calculating the required pulse interval time is as follows: Where t is the time required for the pulse interval.
6. The method for fitting waveforms using a low-voltage nanosecond pulse platform according to claim 4, characterized in that, The voltage accumulation of the multi-pulse train reaching the transmembrane voltage threshold can also be achieved by increasing the voltage amplitude and changing the ramp slopes K1 and K2, specifically including: When the sub-pulse ramping slope K1 is the same in each pulse train, the descent slope K3 is made to be 0 or fixed by fixing the frequency and pulse width. The experiment obtained the number of sub-pulses that were equivalent to a nanosecond pulse and had the same effect as an optimal pulse width pulse, and the descent slope K3 was calculated. When the voltage and external factors are the same, the slopes of the rise and fall are the same, and when the preset rise height is reached, the transmembrane voltage reaches the threshold.
7. The method for fitting waveforms using a low-voltage nanosecond pulse platform according to claim 5, characterized in that, According to dosage This is equivalent to K2=0 and T1=n t1, calculate the number of sub-pulses n in each pulse train, and fit the effect of microsecond T1 to the nanosecond pulse width t1. This requires n pulses. The theoretical formula for calculating the number of sub-pulses is as follows: The actual formula for calculating the number of sub-pulses is as follows: in, This represents the interference coefficient.
8. The method for fitting waveforms using a low-voltage nanosecond pulse platform according to claim 7, characterized in that, Given a high-voltage pulse voltage, t is calculated using a time calculation formula, and then... Input the actual calculation formula for the number of sub-pulses, and find the actual number of sub-pulses n to be fitted. This allows you to combine n nanosecond pulses to form the pulse width of a microsecond pulse.
9. The method for fitting waveforms using a low-voltage nanosecond pulse platform according to claim 8, characterized in that, The theoretical number of sub-pulses is calculated using the formula for calculating the number of sub-pulses. Then, by experimentally determining the number of pre-set nanosecond combination pulses at the same depth to achieve a fixed pulse width in microseconds, the value of the relative electrical permeability constant g is determined. The formula for calculating the relative electrical permeability constant g is as follows:
10. The method for fitting waveforms using a low-voltage nanosecond pulse platform according to claim 9, characterized in that, When an overdose is provided, the calculation formula is as follows: When the dose and voltage are the same, the relationship between the number of sub-pulses and the optimal pulse width t is as follows: ; Based on the theoretical calculation formula for the number of sub-pulses, it was determined that the value of the number of sub-pulses n at this time was greater than the value calculated by the conventional dose. Therefore, the value of the number of sub-pulses n calculated by the conventional dose was used as the lower limit threshold to verify the correctness of the number of sub-pulses calculated by the transmembrane potential pulse accumulation model.