JPH0464368A - Electromagnetic radiation applicator device - Google Patents

Abstract

PURPOSE: To provide an EMR heating pattern which applies approximately uniform heat to BPH tumor or disease of other tissues connected to the urethra by containing an EMR control source connected to a conductor which is provided in a catheter and formed by electrically winding a coil therearound. CONSTITUTION: An electromagnetic radiation(EMR) applicator device which can be inserted in the urethra is provided with an electromagnetic energy supply 12 having an oscillator for feeding it to an antenna 14 via a coaxial cable 16. The antenna 14 is a microwave helical coil mounted on a catheter 18, its end farthest from the electromagnetic energy supply 12 is soldered to a fixed inner conductor and the other end nearest to the electromagnetic energy supply 12 is soldered to a braided conductor outside the coaxial cable 16. A temperature detector 20 which is dividably insulated is inserted into a flexible tube 22 during the treatment. A microwave power supply control circuit 26 has its output side connected to the electromagnetic energy supply 12 and maintains a sufficient power for holding the tissue temperature from 41.5 deg.C to 47 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electromagnetic radiation device for medical thermotherapy, and more particularly to an electromagnetic radiation applicator device that combines a catheter and a microwave applicator to treat benign prostatic hyperplasia by insertion into the urethra.

Hyperthermia, or induced hyperthermia, is believed to be beneficial in treating a variety of human diseases, including many types of cancer. In particular, various types of malignant tumors appear in many studies to have relatively narrow hyperthermia treatment temperature ranges. Below a threshold temperature of approximately 415 degrees Celsius, thermal destruction of these malignancies is not possible and, in fact, these tumors are stimulated. However, at temperatures above the range of 43 to 45 degrees Celsius, continued exposure causes thermal damage to most common body tissue cells even over relatively short periods of time.

Although some types of skin cancer are known to respond to the direct application of direct surface heating, deeply occurring malignant tumors may be masked by the body's normal blood flow due to the heat transfer properties of the body. Heating to the desired temperature without damaging healthy tissue has been the most difficult. Improvements have been made in electromagnetic radiation (EMR) heating devices, including hyperthermia, to solve this problem. This form of treatment is known as cyathylmy.

EMR heating of a subsurface tumor from an external surface is usually possible by configuration and placement of one or more applicators and appropriate selection of EMR frequency, phase and intensity.

Nevertheless, thermally responsive tissue, i.e., tissue tumors within or in close proximity to organs, are most effectively and completely treated with an EMR-generating applicator positioned within the body as close as possible to the tumor requiring treatment. heated.

EM relatively close to the tumor to be heated by radiation
The advantage of positioning the R applicator is that it allows for improved heating control, more focused heating, and, as a result, less chance of heating adjacent healthy tissue and more of the increased tissue that causes undesirable symptoms. It is a direct treatment.

To bring the applicator close to various diseased tissue tumors such as the esophagus, pharynx, prostate and tumors,
dy passage) is performed by a surgical procedure to allow natural passage. Surgical procedures augment the passageway by cutting away the passageway tissue. The heating method involves placing a small EMR applicator on the tissue or in an incision to directly irradiate the tumor. An illustrative type of body passageway into which an EMR applicator can be inserted is the Southworth
rth) in US Pat. No. 2,407,690. Southworth type body passage EMR
The applicator is formed in a manner that produces a heating pattern that is concentrated at the radiating end of the applicator and decreases from the tip toward the radiant source, usually at an exponential rate.

Tumors discovered along natural body pathways often present unique and difficult problems. For example, diseased tissue tends to spread around and along passageways, often in a relatively thin layer. Typically, the diseased layer is less than 1 centimeter thin and may extend up to 6 to 10 centimeters along the path. The use of Southworth type applicators results in non-uniform radiation heat delivery to the extending tumor. It might have to be hot enough to kill a servant.

Devices are known in which a raised, non-flexible antenna is inserted into the rectum. Examples of such devices are US Pat. No. 4,601,296 to Yerushalmi and Int.
.

Radiation Oncology, Biol, P
19 entitled "Microwave Applicator for Intensive Thermal Therapy for Prostate Cancer" by Mendecki et al.
This was disclosed in an article from 1980.

Helical coil designs have also been used to heat tissue placed within the cylindrical opening of the device. Such a device is disclosed in US Pat. No. 4,527,550, issued to Lagera in July 1985.

Body passage insertable applicator devices for EMR systems are known to include urethral insertion probes with monopolar antennas (Urology, December 1985, No. 26).
Volume No. 66, pp. 572-576, Microwave Surgical Treatment for Prostate Diseases Due to Vapor Pressure, etc.). Also known are helical wound coil applicators having coaxial inner and outer conductors that are electrically connected to a conventional coaxial transmission line at the EMR input and radiate high frequency EMR from the power source to the applicator. The applicator outer conductor is split lengthwise on opposite sides to form first and second outer conductor segments. The inner conductor is electrically connected to the applicator end of one of the segments. A dielectric medium is provided between the applicator inner conductor and the outer conductor, and the outer conductor and termination end are covered with a dielectric covering. substantially over substantially the entire length of the applicator by increasing the thickness of the dielectric sheath exponentially toward the terminal end and making the thickness of the canopy on the terminal end equal to at least half the outer diameter of the applicator. Uniform electrolytic hot water for external use can be obtained.

Those skilled in the art desiring further information regarding this device are referred to US Pat. No. 4,658,836, issued to Paul Eftana on April 21, 1987.

The main feature that distinguishes this invention from previous devices lies in the section of the EMR applicator that can be inserted into the urethra, which is primarily applicable for benign prostatic hyperplasia (BPI).
Provides a generally cylindrical or longitudinally uniform EMR heating pattern necessary to provide substantially uniform heat to tumors or other tissue conditions associated with the urethra.

It is therefore an object of this invention to provide an improved treatment for benign prostatic hyperplasia as well as other diseases of the prostate gland that are locally involved around the urethra.

Other objects of this invention are EMR applications meeting clinical requirements such as high flexibility, sterilization, ease of placement, low cost, urine drainage and complete temperature monitoring along the periphery of the urine wall. The objective is to provide a data device.

Yet another object of the present invention is to generate a generally cylindrical or longitudinally uniform EMR heat pattern necessary to provide substantially uniform heat to BPH tumors or other tissue conditions associated with the urethra. An object of the present invention is to provide an EMR applicator that can be inserted into the urethra.

Yet another object of the invention is to provide an EMR applicator insertable into the urethra that can be positioned relative to the prostate and maintained against displacement from the prostate during treatment.

Briefly, an EMR applicator device insertable into the urethra includes an EMR, control source connected to an electrically coiled conductor on a catheter. The temperature control tube includes at least one detector that determines the temperature around the tissue and generates a control signal for the EMR source.

The catheter includes applicator positioning means for automatically positioning the coiled conductor adjacent the prostate and maintaining that position during treatment. The electric coil is suitably covered and
Generates a generally uniform electric tissue hot water for external use that is to be applied to substantially the entire cross section along the applicator due to the substantially uniform tissue heat.

An advantage of the present invention is the provision of a low cost, optional applicator that is releasably connected to a modified balloon type applicator for the treatment of BPH. BPH is commonly treated with surgery, which has serious side effects. These side effects include bleeding, impotence, anesthesia complications, and technical failure.

Using the combined applicator and catheter device, there is no need for anesthesia or surgery, and the treatment is only one or two hours long compared to a surgical admission.

Other objects and features of the invention will become readily apparent from the above detailed description when read in conjunction with the accompanying drawings.

In Figure 1, electromagnetic radiation (EHR) that can be inserted into the urethra is shown.
) The applicator device has a power e9 of up to 40 kW.
It has an electromagnetic energy source (12) with an oscillator feeding an antenna (14), for example via a coaxial cable (16), at a frequency of 15 MHz. Suitable cables are typically RG-178B cables or the like. The antenna (14) is soldered at the cat end to the solid inner conductor and at the end closest to the electromagnetic energy source (12) to the outer braided conductor of the coaxial cable (16). The catheter (12) is a flannel catheter, for example in dimensions modified as described below.

The coil of the antenna (14) includes one or more of the following physical characteristics: a) an open connection to the tip of the coil and the central coaxial conductor; b) an open connection to the base of the coil and the outer coaxial conductor; c) conductor breaks in the coil windings are eyes or gaps; d) multi-turn coils placed in close proximity in the same area; e) vertically stacked and connected to individual coaxial cables;
multiple coils that modify the heating pattern length using coherent or incoherent phase energy in each coil; f) a straight but flexible conductor rather than a coiled conductor; g) at the tip of the applicator. h) coils with different winding ratios per unit length; i) coils with progressively increasing conductor width;
variation of the diameter of the central conductor within the length of the coil; j) variation of the thickness of the dielectric material or conductor, i.e. the circumference of the coil antenna;

Separably insulated temperature sensor (20) (Fig. 2)
is inserted into the flexible tube (22) (Fig. 1) during treatment. A flexible tube (22) is attached to the catheter (18) adjacent to the antenna (14).

A temperature sensor (20) measures the temperature of the tissue along the length of the catheter (18). The temperature sensor (20) is connected to a temperature detection circuit and a microwave power supply control circuit (26) by four insulated resistive lead cables (24). While a single flexible tube (22) and corresponding temperature sensor (20) are shown, if desired one
It will be readily apparent to those skilled in the art that more than one flexible tube (22) and associated temperature sensor (20) can be used.

A microwave power control circuit (26) is connected at its output to the electromagnetic energy source (12) and maintains sufficient power to maintain tissue temperature between approximately 41.5 and 47 degrees Celsius. The control and display panel (28) has a temperature detection circuit and a microwave power supply control circuit (
26). Control and display panel (28) is EMR energy on7. It has an off switch button (30) and (32) and a temperature controller (34) for setting the desired operating temperature for the temperature detection circuit and microwave power supply control circuit (26).

The temperature detection circuit (Fig. 2) of the temperature detection circuit and microwave power supply control circuit (26) (Fig. 1) is a temperature detector (20).
, which may typically be a pre-calibrated thermistor detector connected to a constant current source (38).

The amplifier (40) is connected to a thermistor or temperature sensor (20).
) and amplifies the thermistor output to its operating level. The high gain comparator (42) is connected to the amplifier (40) and the temperature setting potentiometer (4) of the temperature controller (34) provided on the control and display panel (28) (Fig. 1).
4) to compare the amplified thermistor output with the desired temperature reference voltage and the outputting switch control signal. High gain comparator (42) (second
) has a timer (46) and a two-pole switch (4) on its output side.
8) is connected to the electrically controlled pole connection point of 8). A second temperature sensor (20), lead cable (24) and control circuit (26) can be added for extra monitoring. This can be done with other tissue or with a second flexible tube (22
).

The timer (46) is for EMR power control. Taimaku 4
6) triggers in response to the first receipt of the output from the comparator (46), measures the preselected treatment time, and cuts off the microwave power supply at the end of that timing period. Furthermore, the pole of 2 poles S-I-Nochi (48) is EM
Manually controlled by R energy on/off switches (30) and (32). 2-pole switch...nochi (4
8) is turned on as shown, the control signal or lead wire (
50) to energize the microwave power source, and conversely, when the two-pole switch (48) is switched to the off position opposite to that shown, the EMR power source is turned off. Timer (46), comparator (42), temperature setting potentiometer (44), 2
The pole switch (48) and portions of the control circuitry can be replaced by small computer chips operating in an equivalent manner.

In addition, the temperature detection circuit and microwave power supply control circuit (26
), control and display panel (28) have been shown and described herein, those skilled in the art will recognize that variations may be made to this overall control system if desired. For example, at least portions of the illustrated circuitry may be replaced by a microcomputer system, if desired, or otherwise operated automatically.

A catheter that combines a catheter and an applicator (
18) is, for example, a flexible plastic tubular body (5
2) It is a balloon type urinary catheter having (Figs. 3 and 4), and the tubular body (52) has a partition (
54) The inflated balloon (76) is divided into a catheter discharge tube (56) and a fluid separation tube (58) (Fig. 4).
) having walls forming an air or liquid passage (60) for the air or liquid passageway (60). A temperature sensor flexible tube (22) is attached to the outside of the tubular body (52). The tubular body (52) has a branched open piece (64) and a second side (66).
62), the first side (64) having a central discharge pipe (56)
The waste receptacle is connected to the container and the second side (66) connects the air or fluid passageway (60) to a source of pressurized air or fluid to inflate the balloon after insertion. Or it has a fluid input/output valve (68). This air or fluid source may simply be a syringe.

A coaxial cable (16) (FIG. 3) passes four liquid separation tubes (58) through the output adjacent end of the antenna forming coil to connect to the antenna coil (14) as described above.

A dielectric sheath 1-(70) or tube, for example silicone rubber, is placed over and connected to the spiral metal coil (14) to complete the applicator.

The sheet or canopy (70) is a means of naturally uniforming the external electrically heated water over the length of the applicator. The thickness of the canopy (70) may vary exponentially as necessary to obtain uniform hot water. coil(
14) is positioned relative to a pair of spaced holes (72) and (72) formed in the tubular body (52). A 5 cc ribbed balloon (76) is positioned between the holes (72) and (74) in open communication with the outlet of the air or fluid passageway (60). Thus, by positioning the catheter so that the balloon rests in the neck of the bladder when inflated, the applicator is properly positioned relative to the prostate and is free to move during the hyperthermia treatment.

Figure 6 shows an embodiment of a coaxial cable (16) in which the central coaxial conductor (16a) extends through the center of the coil and tapers to a larger diameter at its ends.

The coil (14) has a coil conductor width increasing toward the insertion tip of the catheter (18). Dielectric canopy (70
) is of varying thickness and tapers along its length to become thinner towards the insertion end of the catheter (18). Coil (1 day) toward the insertion tip of the catheter (1 day)
4) is connected to the central coaxial conductor (16a) by a wire 80, and the opposite end of the coil (14) is connected to the outer coaxial conductor (16b) by a wire (81). Various dimensions are greatly exaggerated for clarity. On the other hand, the variables g, i, and j listed on page 7 are shown in conjunction with FIG. 6, and any of the variables may be used alone or in various other combinations to obtain the desired characteristics of the applicator.

In operation, once the catheter is properly positioned as described above and the timer (46) and temperature setting dials are set as desired, the electromagnetic energy source (12) is turned on by the oscillator or switch button (3o) and the application is turned on. radiates power to the prostate area until the desired temperature is reached,
Once the desired temperature is reached, the ratio 12 (42) outputs a control signal to the oscillator to cause its EMR output to maintain the temperature essentially constant during the selected treatment period. At the end of the treatment period, the oscillator turns off automatically, but the oscillator can also be turned off at any time using the switch button (32).7 The device has a relative permittivity = 69.0 and a conductivity The speci?c-abzo-SAR (speci?c-abzo
rpt+onrate) distribution curve. The test parameters are as follows.

Frequency = 915MHz 5AR at 100% = 145.9W/Kg Forward power = 20W reflective car Watt open when heated = 50 seconds Error range -2.4% As shown in Figure 5, the measurement boundary is 10゜ in the direction,
It was 0 to 2.0 cm in the direction. SAR slope is 200%
It was 20% of the time. The initial temperature rise rate is proportional to these SAR percentages.

Thus, helical coil type applicators provide a long, uniform, shallow heating pattern that is desirable for treating diseased tissue found to be spread around and along body passageways.

Although one embodiment of the invention has been described, it will be apparent to those skilled in the art that various modifications may be made to the details of construction shown and described without departing from the spirit of the invention.

[Brief explanation of the drawing]

The first section is a block configuration diagram showing the EMR applicator device that can be inserted into the urethra, the second section is the functional circuit section showing the temperature detector and the microwave power supply control circuit, and the third section is the EMR applicator that can be inserted into the urethra. 4 is a cross-sectional view of the EMR applicator insertable into the urethra taken along line 4-4 in FIG. 1, and FIG. 5 is an SAR view of the prostate applicator.
The distribution diagram, FIG. 6, is a cross-sectional view taken along line 66 of FIG. 4 showing one embodiment of the coaxial conductor, the coil, and the dielectric material covering the coil. (12) is an electromagnetic energy source, (14) is an antenna, (
16) is a coaxial cable, (18) is a catheter, (20)
) is a temperature sensor, (22) is a flexible tube, (
26) is a temperature detection circuit and a microwave power supply control circuit, (
28) is a control and display panel.

Claims (1)

Claims: 1. Catheter means for insertion into the urethra, an applicator attached to the catheter means, and an applicator sufficient to raise the temperature of the tissue around said applicator to a preselected temperature. applicator means comprising connection means for connecting said applicator to a source of electromagnetic energy and maintaining said preselected temperature during treatment; said applicator means attached to said catheter means while desired by a user; positioning means for positioning and maintaining said catheter means in the urethra so as to remain positioned adjacent prostatic tissue to be treated; and said applicator of said applicator means attached to said catheter means; An electromagnetic radiation applicator device for the treatment of benign prostatic hyperplasia, comprising: and temperature sensor support means for supporting a temperature sensing means for measuring the temperature of tissue around said applicator in conjunction with said applicator in operation. 2. The catheter means has an end portion adapted to extend from the urethra to the bladder when the catheter means is inserted into the urethra, and the positioning means has an end portion adapted to extend from the urethra to the bladder when the catheter means is positioned in the urethra. an inflatable balloon mounted on the exterior of the means and a passageway in communication with the balloon adapted to be connected to a source of pressurized fluid so that the balloon is positioned within the bladder when the catheter means is positioned within the urethra. 2. The electromagnetic radiation applicator device of claim 1, wherein said electromagnetic radiation applicator device is inflated to engage the bladder opening with the urethra and position said catheter means. 3. a fluid-free tube, including an applicator support within the temperature sensor support tube and adjacent the first end of the fluid-free tube, a catheter means for insertion into the urethra, and a coaxial tube mounted on the fluid-free tube; applicator means including an applicator mounted on a cable and the applicator support and connected to the coaxial cable for irradiating electromagnetic energy to adjacent tissue; temperature sensing means comprising a temperature detector for monitoring the temperature of tissue adjacent to the applicator means; electromagnetic energy generating means connected to said applicator means for supplying electromagnetic energy thereto; and a selected reference temperature at which the tissue is to be heated. temperature reference means for setting,
and control means including a comparator connected to the temperature detection means and the temperature reference means and generating a control signal, wherein the electromagnetic energy generation means is connected to the control means and in response to the control signal. An electromagnetic radiation applicator device for the treatment of benign prostatic hyperplasia, supplying sufficient electromagnetic energy to said applicator means to raise the temperature of the tissue to a selected reference temperature, and maintaining the tissue at the selected temperature during treatment. 4. The electromagnetic radiation applicator device of claim 3, wherein the applicator includes a helical coil antenna. 5. The applicator includes an elongate coil wound around the applicator support of the catheter means, the applicator means covering the elongate coil and generating a radiant energy level along the elongate coil sufficient to cause the elongate coil to 4. The electromagnetic radiation applicator device of claim 3, including a sheath of dielectric material that maintains a substantially uniform tissue temperature along the radial axis. 6. The electromagnetic radiation applicator device of claim 3, wherein the catheter means includes means for maintaining portions of the applicator means during treatment of the prostate. 7. The means for maintaining the portion of the applicator means during treatment is
a fluid drain, an inflatable balloon mounted on the exterior thereof adjacent a first end of the fluid drain, and a source of pressurized fluid connected to the balloon, the first end of the fluid drain being 7. The electromagnetic radiation applicator device of claim 6, wherein when positioned within the bladder opening and the inflated balloon, said balloon engages said bladder opening and fixes the position of said applicator means. 8. The temperature sensor support tube includes an elongate tube with a closed end mounted externally to the fluidless tube, and the temperature sensing means is inserted into the elongate tube adjacent to the applicator means to detect the temperature of the tissue adjacent thereto. 4. The electromagnetic radiation applicator device of claim 3, including a temperature detector for measuring the temperature. 9. The electromagnetic radiation applicator device of claim 3, wherein the catheter means includes a liquid drain. 10. A multi-tube urinary catheter having an insertion tip for insertion into the urethra, a fluid drying tube closed at the insertion tip, and a separate open end tube for urination; a coil having an end thereof, an antenna means positioned in said fluid drying tube and moving outside the coil mold comprising a coaxial cable having a central conductor and an outer conductor; dielectric insulation means for preventing contact, the coil being connected to the central conductor of the coaxial coil at an end toward the insertion tip of the catheter, and connected to the central conductor of the coaxial coil at an end opposite the insertion tip of the catheter; A urethral insertion applicator for treating benign prostatic hyperplasia by heating the prostate tissue around the urethra via electromagnetic energy, connected to the external conductor of the urethra. 11. The multi-tube urinary catheter further includes at least one additional fluid drying closed end tube, and at least one fluid drying closed end tube inserted into the at least one additional fluid drying closed end tube to detect the temperature of the prostate tissue. 11. The urethral insertion applicator of claim 10, further comprising: an electromagnetic radiation compatible temperature sensor. 12. The coil has an open connection to the insertion tip of the catheter and the end of the coil facing the central coaxial conductor, an open connection to the insertion tip of the catheter and the end of the coil opposite the outer coaxial conductor, and an open connection to the end of the coil opposite the insertion tip of the catheter and the outer coaxial conductor; The urethral insertion applicator according to claim 10, having a conductor gap. 13. The urethral insertion applicator according to claim 10, wherein the coil has a conductor width that gradually increases toward the insertion tip of the catheter. 14. The urethral insertion applicator of claim 10, wherein the coils have different winding ratios per unit length. 15. The urethral insertion applicator of claim 10, wherein a central coaxial cable conductor extends through the center of the coil, and wherein the diameter of the central coaxial cable conductor changes as it passes through the coil. 16. The urethral insertion applicator of claim 10, wherein the thickness of the dielectric insulation means covering the coil varies along the length of the coil. 17. A flexible catheter for insertion into the urethra; microwave generation means for generating microwaves having a preselected frequency; and comparison means; an applicator means for applying an electrical voltage to the tissue of the prostate surrounding the urethra to heat the tissue; and a microwave compatible temperature sensor for measuring the temperature of the heated tissue; said applicator means for supplying microwaves to said applicator means; said comparison means interconnecting said microwave generating means and said microwave compatible temperature detector to determine the measured temperature level and the preselected temperature level; A thermotherapy control device for benign prostatic hyperplasia, which compares a reference temperature level, outputs a control signal to the microwave generation means, and controls supply of microwave power to the applicator means to control tissue temperature.