1. Field of the Invention
The present invention relates to a high-frequency surgical device and method for performing high-frequency surgery by supplying high-frequency current to living tissue to be treated.
2. Description of the Related Art
High-frequency surgical devices are generally known to perform high-frequency surgery by utilizing high-frequency power, to fuse a portion of living tissue with another portion of living tissue. The principle of such a high-frequency surgical device is provided below.
When high-frequency power is applied to living tissue, the tissue is warmed by the Joule heat of the tissue per se. Living tissue, when sufficiently warmed, is inherently degenerated and fuses with another portion of living tissue. When both portions of the tissue are pressed and brought into contact with each other in the sufficiently warmed state, both portions of the tissue will fuse with each other. Accordingly, when fusion is desired to be attained between portions of tissue, the portions of tissue should be pressed and contacted with each other with the application of high-frequency power. The Joule heat is known to become higher as the density of high-frequency current becomes higher.
Some well-known high-frequency devices utilize the above principle to occlude a patent foramen ovale (PFO). The PFO is a flap-shaped gap present in a portion of atrial septa which space apart a right atrium of a heart from a left atrium. Generally, the left atrium has a higher pressure than the right atrium, and thus a valve of oval foramen is pressurized and in contact with the atrial septa to close the PFO. However, when a person has a severe cough or is nervous (when the person's lungs are pressurized), for example, the pressure difference may be reversed to temporarily open the flap. At this instant, blood clots that have flowed into the right atrium may likely to pass through the FPO to directly reach the brain, inducing cerebral infarction. For this reason, desirably, the PFO should be occluded.
For example, PCT Publication No. WO2004/086944 discloses a high-frequency device for treating a PFO. In the prior art technique disclosed in the literature, the treatment for occluding a PFO is given by sandwiching the PFO, from its lateral sides, between two high-frequency electrodes, followed by applying high-frequency power to the PFO.
In applying high-frequency power to a PFO for occlusion treatment of the PFO, it is desired that the occlusion treatment is given with the control of the high-frequency power so that no blood clot is caused.
A high-frequency surgical device of the present invention includes:
a treatment section provided with electrodes for supplying high-frequency power to living tissue of a patent foramen ovale;
a high-frequency power supplying section for supplying high-frequency power to living tissue around the electrodes through the electrodes;
a biological information inputting section for inputting biological information from outside;
a blood flow detecting section for detecting intracardiac blood flow information, based on the biological information inputted from the biological information inputting section; and
a control section for controlling high-frequency power to be supplied to the electrodes, based on the intracardiac blood flow information detected by the blood flow detecting section.
A high-frequency surgical method related to the present invention for giving a treatment of occlusion to a patent foramen ovale by supplying high-frequency power to living tissue of the patent foramen ovale through electrodes provided at a distal end side of a high-frequency probe, includes:
a step of positioning and setting electrodes provided at a distal end side of a high-frequency probe, in living tissue of a patent foramen ovale to be treated;
a step of inputting biological information;
a step of detecting timings of the biological information corresponding to a period when blood flow velocity or blood flow volume is large, based on results of detection for the inputted biological information; and
a step of effecting control for supplying the high-frequency power to the electrodes during the period when blood flow velocity or blood flow volume is large, according to the step of detecting timing.
With reference to the drawings, hereinafter will be described some embodiments of the present invention.
As shown in
A high-frequency surgical system is formed by the high-frequency surgical device 1 and the electrocardiogram measuring device 5 as the biological information measuring means. Alternatively, the high-frequency surgical device 1 may be configured to include the electrocardiogram measuring device 5.
The high-frequency probe 2 is formed, for example, of an axial member 6 having a diameter which is small enough to be inserted into a blood vessel. As shown in
The axial member 6 is formed of a material, such as fluorinated resin, having a proper degree of flexibility and good electrical insulation properties as well.
The electrodes 7a and 7b are each formed into an annular shape with a conductive material, such as gold or platinum, so as to be externally exposed at a distal end portion of the axial member 6 having electrical insulation properties.
Also, leads 8a and 8b are inserted through the axial member 6, with distal ends of the leads being connected to the electrodes 7a and 7b, respectively, and with rear ends of the leads being connected to contact points of a connector 9 which is provided at a rear end of the axial member 6. The connector 9 is detachably connected to a connector receiver of the high-frequency power unit 4.
Alternatively to the structure mentioned above, the axial member 6 and the leads 8a and 8b inserted therethrough may be separated from each other, on the rear end side of the axial member 6. Alternatively, the axial member 6 may have a tubular structure with a hollow portion being provided therein.
The high-frequency power unit 4 is provided with a foot switch 15 for an operator to control application (supply)/stoppage of the high-frequency power. The control section 14 effects control for applying/stopping the high-frequency power of the high-frequency power supplying section 11, in response to operational signals from the foot switch 15.
In this regard, in a normal control mode, the control section 14 will apply/stop the high-frequency power of the high-frequency power supplying section 11 in response to the operational signals from the foot switch 15. However, in a control mode of the present embodiment, in which treatment with the high-frequency power is given based on the input of the biological information, the control for applying/stopping the high-frequency power is effected in synchronization with detection signals (or measurement signals) in the electrocardiographic waveform signals derived from the blood flow detecting section 13.
Thus, the high-frequency power unit 4 is provided, at its front panel, with a selection switch 16a so that the operator can select such control modes.
Also, the high-frequency power unit 4 is provided, at its front panel, with a power setting button 16b so that the operator can set and instruct a high-frequency power value. A signal for setting and instructing a value with the power setting button 16b is inputted to the control section 14 through a power setting section 17. The control section 14 controls the high-frequency power supplying section 11 so that the high-frequency power supplying section 11 can output high-frequency power with the high-frequency power value that has been set at the power setting section 17.
Further, the high-frequency power unit 4 is provided, at its front panel, with a displaying section 18 for displaying various types of information under the control of the control section 14.
The blood flow detecting section 13 is provided, in advance, with information on the results of an analysis conducted for the electrocardiographic waveform signals. The analysis, in particular, is on the blood flow velocity in the vicinity of the PFO in a heart, which is a region to be treated with the high-frequency power (high-frequency current). The information on the analytical results is stored in a memory 20, for example, connected to the blood flow detecting section 13.
For example, the memory 20 stores information on the analytical results concerning “electrocardiographic waveform—blood flow velocity” indicating which portion of a signal waveform in the electrocardiographic waveform corresponds to the period of high blood flow velocity.
The information mentioned above corresponds to information on each period from an R wave to a T wave in an electrocardiographic waveform that will be described later. The blood flow detecting section 13 is provided with a specific electrocardiographic waveform detector 19, which detects a specific portion in the electrocardiographic waveform, corresponding to (start and end timings of) each period of high blood flow velocity, upon input of the electrocardiographic waveform signals from the electrocardiogram measuring device 5.
More specifically, the specific electrocardiographic waveform detector 19 includes: a first specific electrocardiographic waveform detector for detecting a first specific electrocardiographic waveform (timing thereof) at which a level of blood flow velocity rises to a first predetermined value or more; and a second specific electrocardiographic waveform detector for detecting a second specific electrocardiographic waveform (timing thereof) at which the level of the blood flow velocity that has risen to the first predetermined value or more drops to a level of a second predetermined value or less.
The specific electrocardiographic waveform detector 19 configuring the blood flow detecting section 13 outputs to the control section 14 a first detection signal that has detected the first specific electrocardiographic waveform and a second detection signal that has detected the second specific electrocardiographic waveform, as blood flow information on high blood flow velocity.
Particularly, the specific electrocardiographic waveform detector 19 has a peak detection circuit for detecting the R wave, which serves as the first specific electrocardiographic waveform detector. The peak detection circuit also serves as a peak detection circuit for detecting the T wave.
In synchronization with the first and second detection signals outputted from the blood flow detecting section 13, the control section 14 temporally controls the timings of supply and stoppage of the high-frequency power from the high-frequency power supplying section 11, for the electrodes 7a and 7b. In this way, the control section 14 temporally controls supply and stoppage of the high-frequency power in synchronization with the specific timings in the electrocardiographic waveform signals corresponding to the period of high blood flow velocity.
The peak detection circuit, to which the electrocardiographic waveform signals are inputted, has a sample-hold (abbreviated as “S/H”) circuit 21 for sampling and holding input signals. The S/H circuit 21 samples and holds the input signals in synchronization with clocks from a clock generation circuit 22 to output the signals that have been sampled and held to a comparator circuit 23 and a memory 24.
The comparator circuit 23 compares an output signal from the S/H circuit 21 with a signal read out and outputted from the memory 24 as a reference signal, to thereby output a signal indicative of the comparison results. When the output signal from the S/H circuit 21 is larger than the reference signal, the comparator circuit 23 effects control for overwriting the reference signal in the memory 24 with the output signal (so as to renew the previous signal).
In this way, as a result of comparison, the comparator circuit 23 outputs the first detection signal that has detected a peak value to the control section 14, at a comparison-result timing when the reference signal of the memory 24 is larger than the output signal from the S/H circuit 21.
Upon input of the first detection signal, the control section 14 starts supplying the high-frequency power to the electrodes 7a and 7b by controlling the high-frequency power supplying section 11, as will be described later.
Also, on or after the timing of inputting an S wave of the electrocardiographic waveform from the timing when the first detection signal has been outputted, the peak detection circuit starts a peak-detecting operation for detecting the T wave. Then, upon detection of the T wave, the peak detection circuit outputs the second detection signal to the control section 14.
With the input of the second detection signal, the control section 14 stops supply of the high-frequency power by the high-frequency power supplying section 11 (specific operations will be explained later as shown in
The present embodiment is to give treatment to the PFO in a heart using the high-frequency power, and thus an explanation hereinafter is given on the PFO in a heart with reference to
As shown in
Also, a right ventricle 36 and a left ventricle 37 are present below the right atrium 32 and the left atrium 33, respectively.
In the present embodiment, in the case where treatment is given for occluding the PFO 31 using the high-frequency probe 2, the high-frequency probe 2 is inserted, for example, into an inferior vena cava 38 communicating with the right atrium 32, as shown by a dash-dot-dot line.
Then, a distal end side of the high-frequency probe 2 is inserted into the right atrium 32 from an opening communicating with the right atrium 32 to set the treatment section 3 provided at the distal end side of the high-frequency probe 2 to the PFO 31, as shown in
As shown in
After positioning and setting in the PFO 35 the treatment section 3 provided at the distal end side of the high-frequency probe 2 as shown in
Thus, the electrodes 7a and 7b are located between the atrial septum 34a and the oval foramen valve 35, so that, when the high-frequency energy is supplied to the electrodes 7a and 7b, an area where the electrodes 7a and 7b are in contact with blood will be small. In this way, it is ensured that a treatment of high-frequency cautery using high-frequency energy for occluding the PFO 31 can be effectively given.
The timing for actually supplying the high-frequency power to the electrodes 7a and 7b of the treatment section 3 is controlled by the control section 14.
In this regard, referring now to
As shown in
The blood flow detecting section 13 of the present embodiment carries out in advance an analysis of blood flow velocity in the atria based on the electrocardiographic waveform. The acquired analytical results show that, as shown in
On the basis of the analytical results, the specific electrocardiographic waveform detector 19 of the blood detecting section 13 detects the R waves and the T waves in the electrocardiographic waveform received from the biological information inputting section 12.
Then, as shown in
Thus, the treatment of flowing high-frequency power only during the periods of high blood flow velocity can prevent blood clots from being formed and thus can contribute to effectively giving the treatment of occlusion to the PFO 31.
Referring now to
First, the high-frequency apparatus 1 is set by the operator as shown in
Then, when the high-frequency surgical device 1 and the electrocardiogram measuring device 5 are turned on by the operator, both of the devices are brought into an operational state.
At step S1, the high-frequency probe 2 is inserted into a blood vessel of the patient by the operator. For example, as shown in
Then, at the subsequent step S2, the distal end side of the high-frequency probe 2 is inserted into the right atrium 32 of the heart 30 by the operator to locate and set the treatment section 3 in the PFO 31 which is positioned deeper than the right atrium. For example, the treatment section 3 is set by the operator as shown in
After positioning the treatment section 3 in the PFO 31 that is the region to be treated, the foot switch 15 is depressed (turned on) by the operator, at step S3.
Then, the control section 14 starts controlling timing for actually applying the high-frequency power from the high-frequency power supplying section 11 to the side of the electrodes 7a and 7b, according to the detection signals from the blood flow detecting section 13. At step S4, the electrocardiographic waveform signals are inputted to the blood flow detecting section 13 from the electrocardiogram measuring device 5 through the biological information inputting section 12.
At step S5, the blood flow detecting section 13 starts an operation for detecting the periods of high blood flow velocity from the electrocardiographic waveform, based on the results of analysis on the waveform. After detecting the periods of high blood flow velocity, the detection signals are outputted to the control section 14. Specifically, the specific electrocardiographic waveform detector 19 of the blood flow detecting section 13 detects the R waves and the T waves as shown in
At step S6, the control section 14 effects control so that the high-frequency power from the high-frequency power supplying section 11 can be applied to the side of the electrodes 7a and 7b only during the periods of high blood flow velocity, in response to the detection signals inputted during the periods of high blood flow velocity.
Then, at step S7, the treatment of high-frequency cautery is given to the PFO 31 with the high-frequency energy only during the periods of high blood flow velocity.
Being given the treatment of high-frequency cautery with the high-frequency energy, a region of the PFO 31 around the electrodes 7a and 7b is heated and damaged for remedy. It should be appreciated that, after the high-frequency cautery treatment, the damaged living tissue heals.
In this way, the high-frequency cautery treatment is given only during the periods of high blood flow velocity. As a result, the blood heated by the high-frequency cautery will move in a short time away from the positions where the blood has been heated, due to the high blood flow velocity.
In other words, although the blood is heated sometime during the high-frequency cautery, the heat energy is diffused in a short time to sufficiently suppress temperature rise in the heated blood, whereby the blood can be effectively prevented from being formed into clots. On the other hand, standing stationarily, the living tissue of the PFO 31 to be treated can store therein the heat of the high-frequency cautery without the heat diffusion. Accordingly, the living tissue is allowed to be damaged by the high-frequency cautery.
At the subsequent step S8, the control section 14 indicates, on the displaying section 18, the high-frequency cautery information on the periods, for example, when the high-frequency cautery is actually performed. In the case where a power value and periods for performing the high-frequency cautery have been set in advance, the control section 14 indicates, on the displaying section 18, the periods of the high-frequency cautery, a cumulative period of the high-frequency cautery, and the like. With the indication of the information, the operator can be notified of the progress in the high-frequency cautery treatment.
When the predetermined period of treatment with the predetermined power value has expired, the control section 14 then effects control so that the displaying section 18 can indicate the fact that the high-frequency cautery treatment has been finished. With the finishing indication, the operator can turn off the foot switch 15, at step S9. Alternatively, it may be so configured that the turning off of the foot switch 15 is performed by the control section 14.
At the subsequent step S10, the operator can take out the high-frequency probe 2 from the vessel to end the treatment of occlusion for the PFO 31.
As described above, the living tissue of the PFO 31 is heated and damaged with the application of the high-frequency power. After the high-frequency cautery treatment, however, the damaged living tissue heals. Usually, the atrial septum 34a and the oval foramen valve 35 are naturally pressed and in contact with each other, and thus the atrium septum 34a and the oval foramen valve 35 are fused during the healing to achieve natural occlusion. In this way, the occlusion of the PFO 31 is completed.
As described above, according to the present embodiment, the R waves and the T waves of high blood flow velocity are detected from the electrocardiographic waveform to enable application of the high-frequency power to the PFO 31 only during the periods of high blood flow velocity. In this way, high-frequency cautery treatment can be given for occluding the PFO. At the same time, blood temperature rise can be suppressed in the region around the PFO 31 during the cautery treatment to prevent the formation of blood clots.
In the explanation provided above, current has been supplied only during the periods of high blood flow velocity, that is, control has been effected so that the high-frequency power can be intermittently supplied. Alternatively, however, the high-frequency power can be increased or decreased according to the blood flow velocity.
For example, when the blood flow velocity is low, or when the blood flows slowly, control may be so effected that the power will be decreased, an example of which is indicated in
With reference to
The ultrasound observing device 52 includes: an ultrasound displaying mode of a color Doppler mode utilizing the Doppler phenomenon; and ultrasound information outputting means.
On the left side, for example, of
The blood flow volume detecting section 51 of the present embodiment analyzes the intracardiac blood flow volume or variation of blood flow volume, based on the ultrasound information which is obtained with the use of the ultrasound probe 53, and stores the information on the analytical results in the memory 20.
Then, based on the information on the analytical results, in the case where the ultrasound signals of the color Doppler mode are actually inputted in the form of the ultrasound information from the ultrasound observing device 52, the blood flow detecting section 51 outputs detection signals to the control section 14 as blood flow information informing of large blood flow volume, at start and end timings of each period when the blood flow volume in the vicinity of the PFO 31, which is located at the boundary of the right and left atria, becomes equal to or larger than a preset value.
For example, the blood flow volume detecting section 51 outputs to the control section 14 the detection signals at the timings of the ultrasound signals corresponding to the start and end of each period which corresponds to the blood flow state as shown in
The control section 14 controls the supply (application) and stoppage of the high-frequency power of the high-frequency power supplying section 11 in synchronization with the detection signals inputted at the start and end timings of each period when the blood flow volume becomes large. Sometimes, there may be a time lag from when the ultrasound observing device 52 has actually produced an ultrasound signal of the color Doppler mode up to when the ultrasound signal is outputted to the biological information inputting section 12. In such a case, the blood flow volume detecting section 51 carries out temporal adjustment by, for example, detecting an ultrasound signal portion at the timing shifted behind by the time equivalent to the time lag. The remaining configuration is the same as the first embodiment.
Specifically, steps S1 to S3 in
Then, at step S5′, the blood flow detecting section 51 detects periods when the blood flow volume is large, the resultant of which is outputted to the control section 14.
At the subsequent step S6′, the high-frequency power supplying section 11 applies the high-frequency power to the electrodes 7a and 7b only during the periods of large blood flow volume, under the control of the control section 14. The steps from step S6′ onward, i.e. steps S7 to S10 are the same as those of
In this way, in the present embodiment, the high-frequency power is supplied to the electrodes 7a and 7b at the distal end of the high-frequency probe 2 only during the periods when the blood flow volume becomes large in the vicinity of the PFO to thereby perform the high-frequency cautery treatment. Specifically, the high-frequency cautery treatment is given during the periods of large blood flow volume to suppress the formation of blood clots and thus to smoothly give the treatment to the PFO.
The description provided above has been given on the case where ultrasound information is used in the color Doppler mode of the ultrasound observing device 52.
The ultrasound observing device 52 has another mode different from the color Doppler mode, that is, a mode for indicating or outputting variation of blood flow at a specific position, with the conversion into a graph (Doppler mode).
Thus, the configuration may be such that the Doppler mode is selected to measure the intra-atrial variation of blood flow, and then, only when the blood is in the process of increasing up to a value equal to or more than a preset value, to apply the high-frequency power.
Similar to the first embodiment, the configuration mentioned above enables application of the high-frequency power to the electrodes 7a and 7b only during the periods when blood is in the process of increasing to thereby effectively give the treatment of occlusion to the PFO 31 by preventing the formation of blood clots.
Thus, according to the present embodiment, the high-frequency power can be applied to the electrodes 7a and 7b only during the periods when the blood flow volume around the PFO 31 is increased. Thus, due to the increase of the blood flow volume, temperature rise of the blood around the PFO 31 can be prevented, whereby the treatment can be given in the state where formation of blood clots is prevented.
Referring now to
As shown in
The remaining configuration of the high-frequency probe 2C is the same as the configuration explained in the first embodiment.
In the high-frequency power unit 4 shown in
Information on the impedance calculated by the impedance calculating section 68 is transferred to the control section 14. The control section 14 can then control the value of the high-frequency power supplied to the side of the electrodes 7a and 7b from the high-frequency power supplying section 11, based on the information on the impedance.
It should be appreciated that the impedance calculating section 68 may calculate (measure) a value of resistance (resistance).
The control section 14 has a function of controlling the operation of actuating and stopping the pump 64. The remaining configuration is the same as that explained in the first embodiment. The present embodiment has been exemplified as a configuration applied to the first embodiment, but may also be applied to the second embodiment.
Similar to the first embodiment, the present embodiment enables application of the high-frequency power to the side of the PFO, as well as the ejection of fluid to the vicinity of the PFO from the fluid ejection port 61 by actuating the pump 64, upon the application of the high-frequency power.
The operation in this case is shown in a timing diagram of
As shown in
It is considered that the timing of applying the high-frequency power and for ejecting fluid may also be realized as follows.
For example, it may be so configured that the fluid is ejected (delivered) after expiration of a predetermined period from the supply of the high-frequency power.
Also, the method for controlling a flow rate of the fluid to be ejected may be realized as follows.
The flow rate of the fluid to be ejected may be controlled in proportion to the power value set by the operator. For example, when the set power value is large, the flow rate of ejection may be increased.
Alternatively, the flow rate of the fluid to be ejected may be controlled in accordance with an impedance value or a resistance value of the living tissue. For example, when the impedance or resistance value is small, the flow rate may be increased.
Alternatively, the flow rate of the fluid to be ejected may be controlled in proportion to the time of application of the high-frequency power. For example, when the time of application is to be long, the flow rate may be increased.
Alternatively, fluid in the reservoir may be cooled to further enhance the effects.
As described above, according to the present embodiment, fluid can be ejected around the PFO synchronizing with the application of the high-frequency power to the electrodes 7a and 7b. Accordingly, temperature rise of blood can be prevented around the PFO, and thus formation of blood clots can be prevented to effectively give the treatment of occlusion to the PFO.
With reference to
In the present embodiment, the electrodes 7a and 7b of the first embodiment are formed into ring-shaped grooves 71 and 71, respectively, along the longitudinal direction, for example, of the electrodes so as to be perpendicular to the longitudinal direction, to thereby enlarge surface areas of the electrodes 7a and 7b. Accordingly, in the present embodiment, by enlarging the surface areas of the electrodes 7a and 7b, areas that will be in contact with living tissue to be treated can be enlarged to suppress the value of the high-frequency current that flows per unit area of the electrodes 7a and 7b.
In this way, the large surface areas of the electrodes 7a and 7b will reduce density of the high-frequency current around the electrodes 7a and 7b. Accordingly, temperature rise can be suppressed when the blood around the electrodes is heated and thus the blood can be prevented from being formed into clots.
Although
In the high-frequency probe 2E, a number of circular recesses or projections 72 are provided on the surfaces of the electrodes 7a and 7b to enlarge the surface areas of the electrodes 7a and 7b. Alternatively, both of recesses and projections may be provided.
In the high-frequency probe 2F, the surfaces of the electrodes 7a and 7b are roughened (like a surface of a file) to provide roughened portions 73 and thus to enlarge the surface areas of the electrodes 7a and 7b.
As described above, in applying the high-frequency power to the PFO through the electrodes 7a and 7b, the blood around the PFO is simultaneously heated.
Therefore, the large surface areas of the electrodes 7a and 7b for the reduction of the current density as shown in
As described above, according to the present embodiment temperature rise of the blood around the electrodes, as well as the formation of blood clots around the electrodes can be prevented in applying the high-frequency power to the electrodes, by enlarging the surface areas of the electrodes and reducing the density of the high-frequency current around the electrodes.
Having described the preferred embodiments of the invention referring to the accompanying drawings, it should be understood that the present invention is not limited to those precise embodiments and various changes and modifications thereof could be made by one skilled in the art without departing from the spirit or scope of the invention as defined in the appended claims.