JPS62268550A - Laser catheter feedback apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention is generally applicable to Leh! The present invention relates to an improved control system for a reinforced lumen-passable catheter, and more particularly to a control system that utilizes an optical feedback position capable of monitoring the output intensity or energy of a laser beam at the distal tip of the catheter. .

The feedback signal is referenced by comparison to a signal level detected at a point set relatively close to the laser generating element.

BACKGROUND OF THE INVENTION A control 211 device according to the present invention is particularly suited for laser-enhanced lumen-passable angioplasty catheters, which expose occlusions in blood vessels to laser energy, and which expose them to laser energy. It can be treated by reducing or removing part of the blockage. Optical fibers are utilized to transmit laser beam energy from the generator to the occlusion located within the zone to be treated.

Optical fibers are also used to provide illumination and perform optical observations. Laser-enhanced lumen-passable angioplasty catheter devices are extremely useful devices for the treatment of commonly encountered costolimsclerosis and similar diseases.

Atherosclerosis is the most common form of arteriosclerosis as it involves the human heart and circulatory system.
It has typically been treated with drugs, angioplasty catheterization, or open heart bypass procedures. Among these many forms of treatment, the angiogenic force table method has been the treatment of choice under certain conditions. The treatment method is to first place a catheter with a balloon attached to the tip close to the substance forming the occlusion in the blood vessel, and then pass the distal tip of the catheter through the occlusion, and then inflate the balloon to inflate the IT1.
Tension the T1 valve. This technique is effective because it can reopen the blood vessels and often restore substantially normal circulation. However, this method is not suitable for cardiologists,
Particularly dependent on the knowledge of catheter operation, usage and control.

This procedure is typically assisted by fluoroscopy using radiopaque material along the catheter. Furthermore, prior to dilating the blood vessel, angioplasty catheterization is performed to ensure that the blood vessel is not completely occluded until the normal diameter of the distal tip of the catheter will interfere with maneuvering through the occlusion. It is often recognized as a limited technique for patients with

Laser-reinforced lumen-passable angioplasty catheters have been developed for application in surgical procedures. In such a device,
The catheter is equipped with a laser energy source and the laser energy is directed along an optical fiber to the lesion location. One such laser-enhanced lumen-passable angioplasty catheter device is disclosed in co-pending U.S. patent application Ser. and is assigned to the same assignee as the present invention.

In the background art, dilatation catheters are known, and are disclosed in US Pat. No. 4.040.413 and US Pat. No. 4.271.
No. 839 and US Pat. No. 4,299.226. Catheter devices including optical fibers are disclosed in U.S. Pat. No. 3,123,066 and U.S. Pat.
No. 10, U.S. Patent No. 3,858.577, U.S. Patent No. 4.146.019 and U.S. Patent No. 4.273,01
It is disclosed in No. 9. In addition, laser-reinforced catheters
U.S. Patent No. 3.468.098, U.S. Patent No. 3,53
No. 8.919, US Pat. No. 3,843.865, and US Pat. No. 4,266.548@.

As discussed in the aforementioned co-pending US patent application Ser. No. 560.234, a laser-transmitted lumen recirculating angioplasty catheter is disclosed. Other examples of multi-technology catheters include U.S. Pat.
rdiolog V), 50: 80, 81 (19
(December 1982). U.S. Patent No. 4.20
No. 7,874 and the work of the Journal of the American College of Cardiology, which includes a bundle of laser transmission fibers and a centrally located tube that allows vaporized waste material to be removed by suction after exposure to laser beam energy. A catheter guided by an optical fiber is disclosed. When the drilling procedure is completed, a blood sample collected in a transparent external stack provides a visual indication to the operator of the degree of completion of the procedure.

In laser-enhanced lumen-enabled angioplasty catheter devices, the operator has the ability to ensure that the laser energy being directed to the lesion location is within certain desired limits, i.e., the energy is at a certain minimum threshold level. It is desirable to determine a value that is above and does not exceed a certain maximum value, and to be able to know the value rationally. When an indication that the laser beam energy is within predetermined limits is obtained, this technique becomes more reliable, rapid, reproducible, and effective. Since optical fibers are used in conjunction with other electro-mechanical and optical devices, proper evaluation of their operating parameters is desirable. For example, the occurrence of optical fiber ruptures, fractures, or other failures can reduce the available energy level at the distal tip of the catheter, making this approach generally ineffective. On the other hand, when the amount of laser beam energy available at J3 at the distal tip of the catheter is excessive, the quality of the procedure is adversely affected.

The present invention utilizes a ti control device located along an optical fiber segment provided to transmit laser energy from a source to a distal tip. The control device includes an electromechanical shutter and a beam splitter located along the light beam path. An attenuator and a focusing lens are placed perpendicular to the energy beam to
A proportion of the energy is reflected by the splitter, i.e., sampled and directed through an attenuator and a focusing lens to a first detector, which is coupled to a power level monitoring device. An interference filter and a second condensing lens are provided on the catheter side of the beam splitter at right angles to the beam. The distal tip of the optical fiber contains
A fluorescent element is attached. The term ``fluorescence'' is used in a broad sense, such as the response of an element whose response, when irradiated with electromagnetic radiation of a certain wavelength, produces radiation with a second, longer wavelength. One of the reactors is sapphire doped to produce fluorescence when exposed to laser energy.

Because the fluorescence energy produced by Okawa laser energy is at a wavelength very different from that of the laser energy, the fluorescence energy is transmitted through an optical fiber and reflected back to the beam splitter catheter. Reach the opposite surface. Here, the fluorescence energy is reflected by the catheter-facing surface of the beam splitter (dichroic filter) and enters the condenser lens to reach the second detector. The output of the second detector is typically amplified and then applied to a threshold detector. The output of the threshold detector is applied to the shutter device and the laser oscillator power supply.

When the distal portion of the optical fiber, or the distal tip, breaks, the m or output of the fluorescent energy generated by the photoreactive device decreases and the threshold detector responds to a decreasing drop in signal amplitude. . When this change is detected, a signal is generated which is applied through the feedback loop to either stop the laser oscillator or open the shutter device.

With the device of the present invention, the output of the laser oscillator and the output of the optical fiber can be monitored simultaneously. In some applications, an attenuator may be placed in the laser beam path in front of the shutter device. The ratio of the optical fiber output to the laser oscillator output is continuously monitored, so that in the unlikely event that the ratio falls outside a predetermined range due to a failure of the new device, the entire device will automatically stop operating.

OBJECTS AND SUMMARY OF THE INVENTION The present invention provides a device for returning information from the distal tip of a catheter without the need for optical fibers or leads attached to the catheter. Also, the tip of the optical fiber at the end of the catheter is adequately protected. The device according to the invention allows simultaneous measurement or comparison of the laser oscillator output and the catheter output with very fast response times of the feedback device in order to properly monitor the device.

In case of malfunction or when the output exceeds a predetermined range, the device immediately stops working.

In addition to control capabilities, providing a fluorescent lens at the distal tip of the optical fiber provides a convenient means of focusing or diverging the laser beam energy. This lens also provides protection for the tip of the optical fiber. Such a lens also makes it possible to monitor the temperature level seen at the distal tip of the optical fiber. Temperature monitoring is one feature that can be achieved by intermittently pulsing the laser by measuring the response time of the incident fluorescent energy. The catheter output can be monitored in comparison to the laser output to ensure a-operation at the appropriate desired level.

Accordingly, it is a primary object of the present invention to provide an improved feedback control system for a laser-reinforced internal circulation angioplasty catheter device, the improved feedback control system comprising:
In addition to the energy level available from the laser oscillator,
A device is provided for monitoring the energy level available at the distal depth of the laser-enhanced catheter by return from the distal tip.

The catheter is equipped with a device for monitoring the laser output at the distal tip of the catheter compared to the output of the laser oscillator, and without using any additional optical fibers or wires in the catheter to achieve this monitoring function. It is also an object of the present invention to provide an improved laser-reinforced lumenable angioplasty catheter system with a controlled m+ device that uses a return device from the distal tip of the present invention.

Control of laser-reinforced lumen-passable angioplasty catheter device t21
1 u position, using a feedback device with rapid response characteristics to monitor the output at the distal tip of the catheter, and control to stop operation of the device when said output exceeds a predetermined range. It is also an object of the present invention to provide an apparatus.

Other objects of the invention will become apparent to those skilled in the art from consideration of the following description, claims, and accompanying drawings.

EXAMPLE In accordance with a preferred embodiment of the present invention, as shown in FIG. 13
and a catheter containing an optical fiber for transmitting laser beam energy flowing therethrough.

Laser energy is obtained from a laser head 14 driven by a power supply and control unit 15. Laser heads that generate laser energy for laser-enhanced lumen-enabled angioplasty catheter devices are commercially available as power sources and control devices. The energy generated by laser head 14 is transmitted through the wall of the laser head and enters condenser lens 17 via cylinder 16 . Concentrating lens 17 directs energy through a cone indicated at 18 and into optical fiber segment 20 . The optical fiber 20 is
It is of a convenient length, for example 10 meters. The terminal end 21 of the optical fiber segment 2o is designed such that the laser energy passes through the energy cone indicated at 22 and into the condenser lens 24. Condensing lens 2
The beam passing through the electromechanical dual shutter 2 forms a parallel shape or path as shown at 25.
It is preferable to enter 6. In normal operation, the dual shutter 26 passes the beam as shown in FIG.
Electromechanical shutter 26 closes its panel members or vanes 27 and 28 to interrupt the passage of laser beam energy. The laser energy that has passed through the shutter 26 reaches the beam splitter 31 in the form of a beam 3o. Beam splitter 31 is preferably a dichroic filter adapted to substantially or maximally transmit the incident laser beam energy. A small portion or sample of the incident laser energy that is reflected from the face of the beam splitter 310 is shown at 32 and is reflected from the beam splitter 3.
1 and is in equilibrium with that along the beam cylinder shown at 33. Laser beam cylinder 33 passing through condensing lens 34
is a second segment 3 of optical fiber contained within a tube provided within the laser-enhanced lumen-passable angioplasty catheter 11.
Enter 5. The distal tip of the catheter 11 includes a fluorescent element, i.e., a fluorescent v
The t position is provided. Fluorescent devices are typically doped sapphire elements that generate fluorescent or other radiant energy that is emitted at a wavelength that is very different from the wavelength of the incident laser beam energy. The photoreactive sapphire element, ie, the doped sapphire element 37,
Of course, it is a commercially available product. One useful additive is chromium. The sapphire element containing additives is element 37.
Of course, other fluorescent materials can also be used, although these have been found to be preferred for use as construction materials. The materials used are highly transparent to energy within the wavelength of the laser beam and produce fluorescent or other detectable radiant energy at wavelengths very different from the wavelength of the incident laser beam energy. It is desirable to have the characteristics of

The t11 energy generated by the fluorescent sapphire element 370 enters the optical fiber 35 and passes through it as indicated by the arrow 39.
-39, and reaches the catheter-facing surface of the beam splitter 31. In this case, the beam splitter (dichroic filter) reflects the energy at the wavelengths generated by the fluorescent member and reflects the energy at the wavelengths shown by arrow 40-4.
The signal passes through the path indicated by 0 and is finally received at the working surface of the detector 41. This part of the device will be explained in detail below.

Next, regarding the monitoring device for the incident laser light from the laser emitting device, that is, the laser head 14, a sample of the total output energy of the laser is passed from the beam cylinder 32 through the attenuator 43 and the condenser lens 44. Radiant energy detector 4
We reach the operational aspect of 5.

A power level indicator 46 is located in the circuit of the detector 45 to detect the input laser beam reaching the entrance plane of the beam splitter 31.
Displays energy power level.

Additionally, the output of the detector 45 is coupled via conductor 48 through control logic to the power supply and III11 controller 15. A detector such as detector 45, power level indicator 4
6 and the corresponding inputs to the power supply and control device are commercially available.

The light generated and reflected by photoreactive member 37 reaches the second side of beam splitter 31 and is transmitted therethrough following the path indicated by arrows 40-40.

An interference filter 5o is disposed in this passage, and this filter is designed to best transmit about 6940 angstroms of light. This filter is
Typically, the photoreactive member 37 has peak transparency within the range of maximum light generation. The signal generated by detector 41 is transmitted to threshold detector 53 via a conventional preamplification δ52. The output of the threshold detector 53 is referenced by an output laser energy detector and then sent to another logic controller where one output becomes the input of the electronic and mechanical dual shutter 26 and the other output becomes the input 54 to the power supply and control device 15. As mentioned above, when the standardized output of the threshold detector 53 deviates from a predetermined range, the operating blades 27 and 28 of the shutter 26 close,
Transmission of laser beam energy to catheter 11 is completely interrupted and stopped.

Therefore, the laser beam energy passing between focusing lens 24 and focusing lens 34 effectively reduces the amount of energy available to the entire device and the laser-reinforced lumen passable surface canaloplasty catheter 110 distal. It will pass through an evaluation zone to control the amount of energy obtained at the tip.

FIG. 2 shows the optical device of the laser catheter in detail. Similar reference numerals have been used wherever possible for items similar to those shown in FIG.

In the apparatus shown in FIG. 2, a laser head 15A in a laser block is driven by a power source 1'5B to generate a cylindrical laser beam of energy 16.

The focusing lens 17 is a device that focuses the laser beam and directs it into the first optical fiber segment 20, the length of the first optical fiber segment 2o being typically 10 meters.

The controller block generally begins at the terminal end of the first optical fiber segment, as also shown in FIG. Lens 24 is used to collimate the laser beam and the beam is passed through attenuator 60. Attenuator 60 is used to control the transmission of energy through the device. Attenuator 6
The light that has passed through the beam splitter 31 passes through the electronic shutter type dual shutter 26 and reaches the first surface of the beam splitter 31 as before. In this embodiment, the beam splitter 31 uses a dichroic filter. Dichroic filters are, of course, commercially available. Dichroic filter 31 is selected to maximize laser light transmission and reflect a small portion of the solder in the direction of passageway 32, as described for the embodiment of FIG. Attenuator 43 is used to reduce the received energy reaching detector 45 . The output of detector 45 is conveniently displayed on power level indicator 46, as previously described, and is ultimately received at first control input 15G to power supply 15B.

The laser-reinforced lumen-passable angioplasty catheter 11, as shown in FIG. show. A protective shield for the catheter 11, ie a protective outer tube, is shown at 62, but during laser reinforcement F! 'ri
The protective outer tube of the T-through angioplasty catheter device 11 is
It is preferably made of a material or substance approved by the Food and Drug Administration (U.S. Food and Drug Administration), such as polyethylene or its equivalent.

A metal or glass sleeve 63 is attached to house the optical fiber and sapphire element. When using a glass tube, a radiopaque band is attached at 64 and 6.
5 to assist in locating and observing the distal tip of the laser-reinforced lumen-enabled angioplasty catheter 11, and optionally, the optical fiber may be
Devices that extend beyond the distal tip of the catheter sleeve section, such as sleeve PJS11A, can be used to locate the distal tip of the fiber optic section.

To protect the surface of the optical fiber 35, a buffer jacket is used to coat the outer surface. Typically, this buffer jacket is one or more thin films or layers of polyamide material and may optionally further include UV markers (UV n+arker ). Additionally, in some cases it may be desirable to provide the polyethylene sleeve portion 11A with an internal loose TFIJ thin film or layer. Such material may be a compatible polymeric material such as an epoxy material or the like.

In some cases, it is desirable to have a UV marker on this internal film or layer.

In FIG. 3, the individual multilayer structures are shown in partially cutaway form due to limitations of the drafting method.

As shown in FIG.
1 and reaches the detection element 41 through the interference filter 5o and the condenser lens 67. As previously discussed for the embodiment of FIG. 1, the output of threshold detector 53 is the input to electromechanical shutter 26 and
211I'Im input 15D to 5B.

An alternative arrangement of the device according to the invention is to pass the beam energy from the laser device directly to the beam splitter and use the first and second detectors to direct the beam energy from the laser device to a control and monitoring device such as an electromechanical shutter device. You can add a signal to On the catheter side of the beam splitter, a focusing lens is provided to direct laser beam energy into a first optical fiber segment that terminates via a connector to a meter monitoring device. . The output from this 1111m monitor is applied to a second optical fiber segment and then to the distal tip end of the catheter system. This arrangement has the advantage that there is one less lens positioning mechanism and that some lenses can be omitted.

EFFECTS OF THE INVENTION The laser-reinforced lumen-passable angioplasty catheter device with a return device as disclosed herein is extremely reliable and eliminates the need to add optical fibers or leads to the catheter structure. Since it can be used without the need for a catheter, it can be used extremely advantageously as a catheter device.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram illustrating one embodiment of the present invention, illustrating a method for simultaneously monitoring or measuring the output energy of a laser oscillator and the energy received via a transmission device and obtained at the distal tip of a catheter; , FIG. 2 is a schematic diagram showing details of an optical device utilized in a return device of a laser-reinforced lumen-enabled angioplasty catheter in which energy return is obtained from the distal tip of the catheter, and FIG. It is a partial schematic diagram showing only the chip part in detail. (Explanation of symbols) 10... Laser reinforced lumen passable angioplasty catheter device 11... Catheter member 12... Proximal end 13... Distal Chip terminal 14...Laser head 15...Power supply and control device 16...Cylindrical body 17.24.34.44.67...Condensing lens 18.22...Light energy cone 2o...
・First optical fiber segment 21...Terminal end 25.30.32.33...Parallel optical path 26.
...Electromechanical dual shutter 27.28.
... Shutter blade 31 ... Beam splitter 35 ... Second optical fiber segment 37 ...
...Photoresponse reaction element 39.40...Arrow 41.45...Photodetector 43.60...Photoattenuator 46...Power Level indicator 50...Interference filter 52...Preamplifier 53...Threshold detector 54...Power supply and control device input 62...・・・
・Protective shield 63...Sleeve 64.65...Band

Claims (5)

[Claims] (1) A source of laser beam energy, which focuses the laser beam energy from the source onto an optical fiber and transmits the laser beam energy from the proximal end of the catheter device to the distal tip end. a laser-enhanced lumen-threaded angioplasty catheter device comprising a lens device for obtaining a transmission fiber cylinder that transmits the fibers, and a control device disposed along the optical fiber at a proximal end of the catheter device;
Minal angioplastic catheter
(a) a device for generating a laser beam extending along the length of the catheter device for transmitting the laser beam to a distal tip of the catheter and for transmitting the laser beam from the distal tip; a fiber optic cylinder for controlling and discharging a laser beam, a laser beam energy evaluation zone between the generator and the distal tip at the proximal end of the catheter device, and the laser beam energy evaluation zone; (b) the transmission optical fiber cylinder is provided with a device for accessing the laser beam energy within the zone;
(c) a shutter device in the laser beam energy evaluation zone controls laser beam energy passing through the laser beam energy evaluation zone; (d) having a device for interrupting the laser beam;
A beam splitter located within the energy evaluation zone redirects a portion of the laser beam energy passing through the laser beam energy evaluation zone and directs the redirected portion to a first detection device. (e) redirecting the laser beam; and allowing a portion of the laser beam energy that is not redirected to pass through the optical fiber cylinder via the beam splitter device; a photoreactive device disposed adjacent to the fiber optic cylinder that transmits substantially all of the non-redirected laser energy at the distal tip of the catheter along the path of the non-redirected portion; (f) comprising a photoresponsive device that generates radiant energy at a wavelength significantly different from the laser beam energy during a period induced by the laser beam energy; During operation of the device, a device for simultaneously transmitting the stimulated radiation energy from the photoreactor via the fiber optic cylinder to the beam splitter device and a device for transmitting the laser beam energy along the fiber optic cylinder. (g) a device responsive to each of the first detection device and the second detection device; a first signal processing device and a second signal processing device, and (h) a chatter control device closing the shutter device in response to the output of the second signal processing device; A laser-enhanced lumen-passable angioplasty catheter device as described above, characterized in that: interrupting the passage of laser beam energy through the zone. (2) The laser-enhanced lumen-passable angioplasty catheter device according to claim 1, wherein the beam splitter device is a dichroic filter. (3) In claim 1, wherein the photoreaction device is a fluorescent element that emits fluorescent energy when induced by laser beam energy. Luminal angioplasty catheter device. (4) Claim 3, characterized in that the fluorescent element contains an additive and is configured to generate fluorescent light at a wavelength longer than the wavelength of the incident laser beam energy. A laser-enhanced lumen-passable angioplasty catheter device. (5) In claim 1, the optical fiber cylindrical body is arranged at intervals between the first optical fiber segment and the second optical fiber segment, and the beam
A laser-enhanced lumen-passable angioplasty catheter device, particularly characterized in that an energy evaluation zone is disposed intermediate said first optical fiber segment and a spaced second optical fiber segment.