Patent Description:
The chronic obstructive pulmonary disease is a progressive disease which may cause obstruction of the lung airways, restricting airflow from going in and out of the lungs, such as asthma, emphysema, and chronic obstructive pulmonary diseases. Therefore, patients with the chronic obstructive pulmonary disease have difficulty in breathing and have symptoms such as coughing, wheezing, shortness of breath, chest tightness, and mucus (asthma attacks), and need clinical treatment, a lot of medical resources are consumed, and hospitalization and life-threatening danger may be caused. The causes of the chronic obstructive pulmonary disease are as follows: airway smooth muscle contraction, secretion of too much mucus by the airway glands, thickening of the airway wall smooth muscles due to inflammation, and changes of anatomical structures of the tissues around the airway.

The pathological hyperplasia and excessive and inappropriate contraction of the airway smooth muscles in the lung airway wall of the patients is one of pathological mechanisms of the chronic obstructive pulmonary disease. Therefore, reducing or eliminating pathologically hyperplastic airway smooth muscles is an option for treating the chronic obstructive pulmonary disease.

At present, the method for treating the chronic obstructive pulmonary disease such as asthma, emphysema and the chronic obstructive pulmonary disease mainly used clinically is using medicine treatments such as adrenaline medicine, theophylline medicine and hormones, or sputum excretion, anti-inflammation and the like for symptomatic treatment, which requires long-term medication, and cannot cure this type of diseases. Moreover, some patients are still unable to effectively control their condition after using inhaled corticosteroids (ICS) and long-acting β receptor agonists (LABA).

An existing minimally invasive ablation technique can reduce the pathologically hyperplastic airway smooth muscles. During the implementation of this treatment, a catheter is positioned in the airway, and electrode arrays on the tail end of the catheter expand to contact with the airway wall. By moving the catheter, energy is gradually transmitted to multiple parts of the trachea to remove the pathologically hyperplastic airway smooth muscles.

The safety and effectiveness of an ablation apparatus used in bronchial radio frequency ablation based on the prior art have defects, for example, the wall attaching condition of the ablation electrodes cannot be monitored and displayed; and for another example, at the moment the ablation is started, the great radio frequency energy is applied, so that the temperature uprush is greater after a set temperature is reached, this kind of suddenly applied and (or) suddenly changed radio frequency energy has the stimulation on the respiratory tract of the patient, and the great temperature uprush has a threat to the safety of the patient. Additionally, in the treatment process of the bronchial radio frequency ablation, the temperature of ablation electrodes is affected by frequent and complicated disturbance due to the change of the airflow caused by the breathing movement of the patient, the sliding of the electrodes caused by the chest movement of the patient, and the change of the attachment degree caused by unstable grip of an operator, and the general proportional integral control algorithm is easy to generate oscillation and overshoot, and is difficult to adapt to these complicated external disturbances, so that the ablation treatment effect is interfered.

The ideal bronchial radio frequency ablation should avoid repeated ablation at the same site. However, due to the carelessness or misoperation of the operator or no reminding function provided in a used apparatus in the practical clinic operation, after once ablation is completed, and the ablation is started again without catheter (electrode) transferring or sufficient transferring amount, which may cause the repeated ablation at the same site, causing permanent and irreversible damage to the airway tissue, or even airway fistula. The present invention adopts the following control mechanisms: the logic relationship among the impedance, power and temperature is defined, the temperature of the site to be ablated is detected before each ablation is applied, if the temperature of the site to be ablated is higher than <NUM> to <NUM>, preferably <NUM>, ablation is not started, and the like, so that a radio frequency generator for ablation of the present invention has a protection mechanism of preventing repeated ablation.

Document <CIT> discloses a multipolar ablation device for transmitting energy in the trachea and bronchi.

Document <CIT> discloses methods and a system for thermally-induced renal neuromodulation. Document <CIT> relates to methods and devices for improved precision in finding one or more nerves and then interrupting the transmission of neural signals through the target nerve.

An objective of the present invention is to provide a safer and more effective device for transmitting energy in the trachea and bronchus aiming at the defects in the prior art.

A radio frequency generator according to the invention is disclosed in the appended claims <NUM>-<NUM>.

A multi-electrode ablation device according to the invention is disclosed in the appended claims <NUM>-<NUM>.

The present invention provides a device with a function of transmitting energy in the trachea and bronchus. The device can be used for delivering a direct current, an alternating current, and a radio frequency energy to a lesion, so as to remove pathologically hyperplastic bronchial smooth muscles, increase the diameter of the trachea during resting, reduce the pathological retraction and respiratory resistance of the bronchial wall, and increase the adjusting compliance of the trachea. The device can be used for the non-medicine treatment of obstructive pulmonary diseases, and for example, used for the treatment of the patients with persistent asthma, pulmonary emphysema, chronic obstructive pulmonary diseases and the like still incapable of being effectively controlled after the administration of medicine (such as corticosteroids and long-acting β receptor agonists).

A radio frequency generator for ablation of the present invention is able to generate and control a direct current, an alternating current and a radio frequency energy, collect, process and display a temperature, impedance or tension signal, and determine the ablation effectiveness according to the change of the impedance or tension signal, and the change of the impedance is one or more of a falling value of impedance, a change rate of impedance, the change in the change rate of impedance, or the change of impedance from falling to rising. Further, the ablation is determined to be effective when the falling value of impedance exceeds <NUM>Ω to <NUM>Ω, or the change rate of impedance is higher than -<NUM>Ω/s to -<NUM>Ω/s, or the change of impedance is from falling to rising.

The radio frequency generator for ablation of the present invention uses a segmentation control method to adjust a radio frequency output power through a closed-loop control system so as to control an ablation temperature, and the segmentation control includes: (<NUM>) a fast heating stage: lasting for <NUM> to <NUM> from the beginning of ablation, where an end point temperature of the fast heating stage reaches <NUM>% to <NUM>% of the ablation temperature; (<NUM>) a slow heating stage: lasting for <NUM> to <NUM> after the fast heating stage, where an end point temperature of the slow heating stage reaches <NUM>% to <NUM>% of the ablation temperature, or is <NUM> to <NUM> lower than the ablation temperature; and (<NUM>) a stability maintenance stage: stably maintaining the temperature after the slow heating stage until the ablation stops.

At the same time, the radio frequency generator for ablation performs dynamic smoothing on the temperature in the process of controlling the ablation temperature, including averaging, weighted averaging or median averaging on a sampling temperature value, the radio frequency generator for ablation is guided to adjust the radio frequency power output according to a temperature value obtained through dynamic smoothing, and the smooth change of the radio frequency output power in the ablation process is thus ensured. An upper limit of a threshold value of the dynamic smoothing is <NUM>/s to <NUM>/s, and a lower limit of the threshold value is -<NUM>/s to -<NUM>/; when the temperature change rate is smaller than the lower limit of the threshold value, a smoothing time window is prolonged; when the temperature change rate is greater than the upper limit of the threshold value, the smoothing time window is shortened; and when the temperature change rate is between the lower limit and the upper limit of the threshold value, the smoothing time window remains unchanged. The upper limit of the threshold value of the dynamic smoothing is <NUM>/s, and the lower limit is -<NUM>/s. A dynamic range of the smoothing time window is <NUM> to <NUM>, preferably <NUM> to <NUM>.

Further, the radio frequency generator for ablation further includes a protection mechanism for preventing repeating ablation. A temperature of a site to be ablated is detected before each ablation is applied. If the temperature of the site to be ablated is higher than <NUM> to <NUM>, ablation is not started.

Further, the radio frequency generator for ablation includes a radio frequency energy transmission/feedback control mechanism: after the radio frequency energy output for <NUM> to <NUM>, a temperature of an ablated tissue reaches a set temperature and is maintained for <NUM> to <NUM>, an over temperature alarm is given when the temperature of the ablated tissue is higher than an over temperature threshold value, and an ablation system automatically stops the radio frequency energy output. The set temperature ranges from <NUM> to <NUM>, and the over temperature threshold value is <NUM> to <NUM> higher than the set temperature. Preferably, the set temperature is <NUM>, and the over temperature threshold value is <NUM> higher than the set temperature.

The objective of the present invention can be achieved by using the multi-electrode ablation device of the embodiment of the present invention. The following embodiments are merely exemplary embodiments of the present invention and are not intended to limit the present invention in any way. Any simple modifications, equivalent variations and modifications made on the above embodiments, within the scope of appended claims, are still within the scope of the techniques and methods of the solution of the present invention.

The present invention relates to a device for achieving a function of transmitting energy in the trachea and bronchus, and further relates to a multi-electrode ablation device. As shown in <FIG>, the device mainly includes a first electrode assembly <NUM>, a second electrode assembly <NUM>, a guiding catheter body <NUM>, a handle <NUM> and a connector <NUM>. As shown in <FIG>, the first electrode assembly <NUM> and the second electrode assembly <NUM> are continuously disposed in an axial direction of the guiding catheter body <NUM>, and a damage-prevention structure <NUM> is disposed at a head end of the electrode assembly and is configured to fix the first electrode assembly <NUM> at the same time. The first electrode assembly <NUM> and the second electrode assembly <NUM> are connected to each other through a support component <NUM>, a near end of the first electrode assembly <NUM> and a far end of the second electrode assembly <NUM> are fixed to the support component <NUM>, a far end of a traction steel wire <NUM> is connected to the damage-prevention structure <NUM> at the head end, and a near end is fixed to the support component <NUM> (as shown in <FIG>), and enters the handle <NUM> through the guiding catheter body <NUM>. A near end of the second electrode assembly <NUM> is fixed to the catheter body <NUM>. As shown in <FIG>, when the handle <NUM> controls the traction steel wire <NUM> to contract towards the near end, the first electrode assembly <NUM> is driven to expand first, at the same time, the second electrode assembly <NUM> synchronously expands, according to the characteristics of the trachea tract, the electrode assembly is designed to be smaller at the far end, and larger at the near end, and a diameter difference is about <NUM> to <NUM>.

The first electrode assembly <NUM> and the second electrode assembly <NUM> are provided with a plurality of electrodes: a first electrode <NUM>, a second electrode <NUM>, a third electrode <NUM>, a fourth electrode <NUM>, a fifth electrode <NUM>, a sixth electrode <NUM>, a seventh electrode <NUM> and an eighth electrode <NUM>, the electrodes are made of stainless steel materials, and have certain elasticity, each electrode is connected to the handle through an independent electrode conductor, and the handle is transmitted to a bronchial radio frequency generator for ablation through the connector <NUM>. In use, each electrode forms a loop with a control circuit board through a trachea tissue, and each electrode can independently detect an attachment impedance value of the electrode and the tissue. When the electrode is well attached (the detected impedance value is <NUM>Ω to <NUM>Ω), the bronchial radio frequency generator for ablation will send radio frequency energy to ablate the lesion tissue, a temperature sensor <NUM> and a temperature sensor <NUM> are respectively disposed on the first electrode assembly <NUM> and the second electrode assembly <NUM>, and can independently detect the temperature of the tissue around the corresponding electrode assembly.

Devices as shown in <FIG> are a second embodiment of the present invention, a first balloon <NUM> and a second balloon <NUM> are disposed under the first electrode assembly <NUM> and the second electrode assembly <NUM>, a near end of the first balloon <NUM> is provided with a balloon first air passage <NUM>, and a near end of the second balloon <NUM> is provided with a balloon second air passage <NUM>. The first balloon <NUM> and the second balloon <NUM> are isolated from each other, and the first air passage <NUM> and the second air passage <NUM> independently provide air for the first balloon <NUM> and the second balloon <NUM>. When the air enters the balloons through the balloon air passages, a first electrode <NUM>, a second electrode <NUM>, a third electrode <NUM>, a fourth electrode <NUM>, a fifth electrode <NUM>, a sixth electrode <NUM>, a seventh electrode <NUM> and an eighth electrode <NUM> expand under pressure, the electrode assemblies expand, the air inflow is controlled by an external air inlet apparatus, the expansion size of the electrode assemblies can be set through the air inflow, and the first electrode assembly <NUM> and the second electrode assembly <NUM> are independently controlled to adapt to the requirements of different sizes of the trachea lesion sites.

The first electrode <NUM>, the second electrode <NUM>, the third electrode <NUM>, the fourth electrode <NUM>, the fifth electrode <NUM>, the sixth electrode <NUM>, the seventh electrode <NUM> and the eighth electrode <NUM> are provided with independent electrode conductors. In use, each electrode forms a loop with a control circuit board through the trachea tissue, and each electrode can independently detect an attachment impedance value of the electrode and the tissue. A temperature sensor <NUM> and a temperature sensor <NUM> are respectively disposed on the electrode assembly <NUM> and the electrode assembly <NUM>, and can independently detect the temperature of the tissue around the corresponding electrode assembly.

The device as shown in <FIG> is a third embodiment, a first annular electrode <NUM> and a second annular electrode <NUM> are spirally disposed on a first balloon <NUM> and a second balloon <NUM>. When the balloons are inflated, outer diameters of the first annular electrode <NUM> and the second annular electrode <NUM> are increased. Independent electrode conductors are disposed on the first annular electrode <NUM> and the second annular electrode <NUM>. In use, each electrode forms a loop with a control circuit board through a trachea tissue, and each electrode can independently detect an attachment impedance value of the electrode and the tissue. A temperature sensor <NUM> and a temperature sensor <NUM> are respectively disposed on the annular electrode <NUM> and the annular electrode <NUM>, and can independently detect the temperature of the tissue around the corresponding electrode assembly.

As shown in <FIG>, an indicating lamp <NUM> is disposed on a handle <NUM>. Theoretically, an impedance value of <NUM>Ω to <NUM>Ω or below after the electrode is attached to the tissue indicates that the radio frequency ablation can be performed. When a bronchial radio frequency generator for ablation detects that the electrode attachment impedance value is <NUM>Ω to <NUM>Ω or below, the indicating lamp becomes green, indicating that the ablation can be performed. When the bronchial radio frequency generator for ablation detects that the electrode attachment impedance value is <NUM>Ω to <NUM>Ω or above, the indicating lamp is red, indicating that the discharging ablation cannot be performed.

As shown in <FIG>, a pressure sensor <NUM> is disposed in a local area of a traction steel wire <NUM>, two ends of the pressure sensor are respectively connected to two ends of the traction steel wire, when the electrode assembly is dragged, the traction steel wire <NUM> is stressed, at this moment, the pressure sensor <NUM> will receive the same tension, through the treatment by the bronchial radio frequency generator for ablation, the tension will be displayed to determine the attachment degree. When the electrode attaches to the tissue, the attachment degree of an electrode arm to the tissue can be determined through determining the traction tension.

As shown in <FIG>, the radio frequency generator for ablation is provided with a touch display screen for displaying a state of electrodes and an adhesion impedance value of the electrodes and the tissue, and one or a plurality of electrodes are able to be controlled to release the energy by clicking the touch display screen.

The guiding catheter body <NUM> can be served as a guiding tube, the guiding tube is provided with a tube cavity accommodating the electrode assembly <NUM> and the electrode assembly <NUM>, the electrode assembles can freely extend and retract in the guiding tube, and liquid, such as anti-inflammatory medicine and anaesthetics can enter the ablation lesion tissue through the tube cavity of the guiding tube so as to relive the pain and complications of a patient.

Clinic application of the multi-electrode ablation device was simulated through isolated tissue tests, and the impedance detection values of an ablation catheter under the conditions of different bronchus sites, different handle grip strengths and different electrode attachment quantities were observed.

Test environment: temperature: <NUM> to <NUM>; and humidity: <NUM>% RH to <NUM>% RH.

Test tissue: <NUM> fresh isolated swine lungs.

Test principle: the isolated swine lungs were soaked in saline water, the ablation catheter was connected onto the radio frequency generator for ablation, the ablation catheter was operated, and the impedance display values on the radio frequency generator for ablation were observed and recorded under the conditions of different bronchus sites, different handle grip strengths and different electrode attachment quantities.

Test sites: superior lobe of left lung, inferior lobe of left lung, superior lobe of right lung, and inferior lobe of right lung.

The impedance detection values under the conditions of the naturally relaxed state and the completely pinched state of the handle of the catheter at different bronchus sites are observed and recorded the results are as shown in Tables <NUM> to <NUM> and <FIG>: The results show that the electrode tension is associated with the impedance detection values.

Different quantities of electrodes are attached to the bronchus, the impedance detection values are observed and recorded, and the results are as shown in Table <NUM> and <FIG>. Different quantities of electrodes are soaked into saline water, the impedance detection values are observed and recorded (with the influence of the attachment pressure excluded), and the results are as shown in Table <NUM> and <FIG>. The results show that different electrode attachment quantities have obvious influence on the impedance detection values, the more the number of electrodes attached, the smaller the impedance detection value, and the electrode attachment quantity can be determined according to the impedance detection value.

The radio frequency is output, the impedance detection values are observed and recorded, the results are as shown in Table <NUM> and <FIG>, and the results show that the radio frequency ablation causes impedance detection value falling, the ablation effectiveness can be determined according to the change of an impedance or tension signal, and the change of the impedance is one or more of the falling value of impedance, the change rate of impedance, the change in the change rate of impedance, or the change of impedance from falling to rising.

The ablation effectiveness of the multi-electrode ablation device of the present invention is investigated by using an animal test. A logic relationship among the impedance, power and temperature is defined, the generated and controlled direct current, alternating current and radio frequency energy are precisely controlled, a temperature, impedance or tension signal is collected, processed and displayed, and the ablation effectiveness is determined according to the change of the impedance signal. The ablation was determined to be effective when a falling value of impedance exceeded <NUM>Ω to <NUM>Ω, or a change rate of impedance is higher than -<NUM>Ω/s to -<NUM>Ω/s, or the change of impedance is from falling to rising.

Specific operations are as follows:
Electrodes of the multi-electrode ablation device of the present invention was put into a site to be tested of a dog lung, and a data interface of the multi-electrode ablation device was connected to a computer. The multi-electrode ablation device was operated for ablation. The computer displayed and recorded the temperature, power and impedance data in the test process. A whole process of the test process was observed by using a bronchial endoscope.

The results are as shown in <FIG> is a tissue impedance change curve of an ablation process in animal tests. The abscissa is the time, the left ordinate is the tissue temperature and the radio frequency output power, and the right ordinate is the tissue impedance. As shown in the figure, after the ablation is started, the tissue impedance starts to fall, additionally, the tissue impedance falling speed was gradually decelerated, and then the tissue impedance gradually starts to rise, indicating that the ablation of the multi-electrode ablation device of the present invention is effective.

The present invention relates to a device with a function of transmitting energy in the trachea and bronchus, and the device uses a segmentation proportional integral control algorithm to perform dynamic smoothening on the temperature. <NUM> to <NUM> from the beginning of the ablation is a fast heating stage, the radio frequency output power rises fast to be <NUM> W or above from <NUM>, and the tissue temperature starts to rise fast. <NUM> to <NUM> is a slow heating stage, the radio frequency output power slowly rises, and starts to gradually fall, and the tissue temperature heating speed starts to be decelerated. After such <NUM> till the ablation stop is a stable maintenance stage, and the radio frequency output power slowly falls and is adjusted slightly so as to maintain the tissue temperature.

A dynamic range of a temperature dynamic smoothening time window is <NUM> to <NUM>. Each time when a temperature change rate is greater than <NUM>/s, the smoothing time window is shortened by <NUM>. Each time when the temperature change rate is smaller than -<NUM>/s, the smoothening time window is prolonged by <NUM>. The temperature change rate is between -<NUM>/s and <NUM>/s, and the smoothening time window remains unchanged. The temperature in the smoothening time window is subjected to average calculation to thus achieve the temperature dynamic smoothening.

The operations of the animal test are the same as those in Embodiment <NUM>.

As shown in <FIG> and <FIG>, <FIG> shows tissue temperature and radio frequency output power curves of an ablation process without adopting segmentation control and temperature dynamic smoothening in the animal test. <FIG> shows tissue temperature and radio frequency output power curves of an ablation process after adoption of segmentation control and temperature dynamic smoothening. The abscissa is the time, the left ordinate is the tissue temperature, and the right ordinate is the radio frequency output power. As shown in the figure, after the ablation is started, the radio frequency output power rises fast within <NUM>, slowly rise and starts to fall within <NUM>, and slowly fall and is adjusted slight after <NUM>. After the ablation is started, the tissue temperature starts to rise fast within <NUM>, slowly rise within <NUM>, and reaches the ablation temperature within <NUM> and maintains at the ablation temperature. The device controlled the radio frequency output power so that the temperature of the ablation electrodes reached the ablation temperature within <NUM>. Additionally, after the ablation temperature is reached, the temperature uprush is less than <NUM>, the tissue temperature is stably maintained at the ablation temperature, and the fluctuation is smaller than <NUM>. In the whole ablation treatment process, the radio frequency output power smoothly changes without suddenly applied and (or) suddenly changed radio frequency energy. When the segmentation control and temperature dynamic smoothening are not adopted, the tissue temperature generates obvious oscillation, and the temperature uprush is greater. After the segmentation control and temperature dynamic smoothening are adopted, the tissue temperature is kept stable, and the temperature uprush is smaller.

The results shows that the radio frequency output power is successfully adjusted by using the closed loop control system by the segmentation control method to control the ablation temperature, and the temperature dynamic smoothening is utilized to overcome various kinds of disturbances. Therefore, the safety and the effectiveness of the system are further ensured, i.e., the conditions of wrong ablation or ablation incapability cannot occur, and the condition of repeated ablation or excessive ablation cannot occur.

The radio frequency ablation device of the present invention includes a radio frequency energy transmission/feedback control mechanism: after the radio frequency energy output for <NUM> to <NUM>, a temperature of an ablated tissue reached a set temperature of <NUM> to <NUM> and is maintained for <NUM> to <NUM>, an over temperature alarm is given when the temperature of the ablated tissue is higher than an over temperature threshold value (<NUM> to <NUM> higher than the set temperature), and an ablation system automatically stops the radio frequency energy output.

Claim 1:
A radio frequency generator for ablation for use in a device for transmitting energy in the trachea and bronchus, the generator being able to
generate and control a direct current, an alternating current and a radio frequency energy,
collect, process and display a temperature, impedance or tension signal, and
determine the ablation effectiveness according to the change of the impedance or tension signal, and the change of the impedance is one or more of
a falling value of impedance,
a change rate of impedance,
the change in the change rate of impedance, or
the change of impedance from falling to rising,
wherein the radio frequency generator for ablation is configured for using a segmentation control method to adjust a radio frequency output power through a closed-loop control system so as to control an ablation temperature, and the segmentation control comprises:
(<NUM>) a fast heating stage: lasting for <NUM> to <NUM> from the beginning of ablation, wherein an end point temperature of the fast heating stage reaches <NUM>% to <NUM>% of the ablation temperature;
(<NUM>) a slow heating stage: lasting for <NUM> to <NUM> after the fast heating stage, wherein an end point temperature of the slow heating stage reaches <NUM>% to <NUM>% of the ablation temperature, or is <NUM> to <NUM> lower than the ablation temperature; and
(<NUM>) a stability maintenance stage: stably maintaining the temperature after the slow heating stage until the ablation stops.