RU2839524C1 - System for intraoperative blood flow imaging during neurosurgical interventions - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention relates to neurosurgery, specifically to systems for intraoperative blood flow evaluation. System for intraoperative blood flow visualization accompanying neurosurgical interventions comprises a laser, an infrared receiving video camera, a laser fixing device for a surgical microscope, and a video camera fixing device for the surgical microscope. Video camera retainer includes a housing configured to be attached to a microscope eyepiece on one side and to a video camera lens on the other side, and comprises an infrared radiation filter and an optical polarizer rotatable about an optical axis of the housing. Laser retainer includes a housing configured for attachment to a side surface of a microscope lens, comprising a laser diode, Peltier element, aspherical lens, two mirrors installed with possibility of controlled redirection of laser radiation from laser diode to lighting zone, light diffuser, biconcave lens, iris diaphragm with an adjustment ring with a scale and a rotating optics holder, wherein all structural components of laser retainer are located inside housing. Video camera fixture and the laser fixture are designed with a possibility of fixing to each other and to the operational exoscope.

EFFECT: use of the invention enables higher simplicity, reliability and adaptability of the system for evaluating blood flow accompanying neurosurgical interventions, as well as ensuring the possibility of its integration into an aggressive environment of an operating room.

4 cl, 5 dwg

Description

The field of technology to which the utility model relates

The invention relates to neurosurgery, namely to systems for intraoperative assessment of blood flow and can be used in neurosurgical interventions.

State of the art

Visualization of cerebral blood flow is an important condition for the successful performance of neurosurgical operations, in particular, during clipping of arterial aneurysms, resection of arteriovenous malformations, creation of microanastomoses, etc., which is caused by increased requirements for maintaining perfusion of brain tissue.

A system [1] for intraoperative blood flow assessment is known, including a laser, a video camera for receiving infrared radiation, a laser fixator for the operating microscope, and a video camera fixator for the operating microscope. The operation of this system is based on the laser speckle-contrast visualization (hereinafter referred to as LSCI) method. The essence of the method is the statistical analysis of interference speckle patterns formed on the surface of a randomly inhomogeneous turbid medium as a result of scattering of laser radiation [2].

This system has several disadvantages. Firstly, the video camera holder for the surgical microscope contains an optical polarizer and a rotating system of infrared radiation filters, made as two separate sets of parts, which complicates and increases the cost of the overall system. Secondly, the laser design elements are located openly, which is unacceptable in the operating room, since it leads to premature failure of parts due to contamination with biological materials (blood, cerebrospinal fluid, bone chips, etc.). Thirdly, the laser radiation flow from the laser diode to the surgical field is redirected using fixed mirrors, which limits the adaptability of the system. The surgical field often has a complex shape, which requires the ability to adjust the direction of its illumination. Fourthly, this system can only be installed on an surgical microscope, which limits the range of its possible applications. Exoscopes are increasingly used in modern operating rooms, but this system is not compatible with them.

Disclosure of invention

The technical result of the proposed invention is an increase in the reliability, adaptability and simplicity of the system for assessing blood flow during neurosurgical interventions, as well as ensuring the possibility of integrating the system into an aggressive operating room environment.

In order to achieve the specified technical result, a system has been developed that includes a laser, a video camera for receiving infrared radiation, a laser clamp for an operating microscope and a video camera clamp for an operating microscope, characterized in that the video camera clamp includes a housing configured to be attached to the eyepiece of the microscope on one side and to the lens of the video camera on the other side, and contains an infrared radiation filter and an optical polarizer configured to rotate around the optical axis of the housing, the laser clamp includes a housing configured to be attached to the side surface of the lens of the microscope, containing a laser diode, a Peltier element, an aspherical lens, two mirrors installed with the possibility of adjustable redirection of laser radiation from the laser diode to the illumination zone, a light diffuser, a biconcave lens, an iris diaphragm with an adjustment ring with a scale and a rotating optics holder, wherein all the structural parts of the laser clamp are located inside the housing, and the video camera clamp and the clamp The lasers are designed with the ability to be fixed to each other and to the operating exoscope.

The proposed system includes a laser diode with a wavelength of 785 nm, a power of 300 mW, an aspherical lens with a focal length of 9.6 mm, on both surfaces of which an antireflective coating is applied for the wavelength range of 600-1050 nm, two mirrors with a diameter of 1 inch, reflecting waves in the ranges of 750 - 1100 nm, an angular kinematic mirror holder KCB1EC/M, a light diffuser with a diameter of 1 inch with a divergence angle of 20°, a biconcave lens with a diameter of 12.7 mm and a focal length of 15 mm, on both surfaces of which an antireflective coating is applied for the wavelength range of 650-1050 nm.

The housing of the video camera clamp and the housing of the laser clamp may contain channels for connection to each other and to the operating exoscope using pins.

The surgical exoscope is a video camera on a tripod with the ability to adjust focus, light exposure and zoom.

The implementation of the infrared radiation filter and optical polarizer with the ability to rotate as a single set of parts simplifies the design and increases the reliability of the system.

The inclusion of the specified parts in the laser clamp (a housing with the ability to attach to the side surface of the microscope objective, a laser diode, a Peltier element, an aspherical lens, two mirrors installed with the ability to adjust the redirection of laser radiation from the laser diode to the illumination zone, a light diffuser, a biconcave lens, an iris diaphragm with an adjustment ring with a scale and a rotating optics holder) ensures stable generation of speckle patterns with the ability to flexibly adjust the characteristics of laser radiation, while the proposed solution to include all important parts in a single closed housing provides protection from substances harmful to equipment located in the operating room and allows for the integration of the proposed system.

The implementation of a video camera holder and a laser holder with the ability to be fixed to each other and to the operating exoscope allows one to do without the use of a microscope, which increases the adaptability of the system.

The proposed invention is explained by diagrams and drawings.

Fig. 1 shows the proposed system for intraoperative assessment of blood flow, installed on an operating microscope, where: A is a video camera holder, B is a laser holder.

Fig. 2 shows a video camera clamp, where: B is a general diagram of the clamp, G is a sectional diagram of the clamp, in which: 1 is a polarizer,

2 - infrared filter, D - photo lock on which: 3 - screw for rotating the polarizer.

Fig. 3 shows a laser clamp, where: 4 is a holder of laser diodes and a Peltier element, 5 is a holder of an aspherical lens,

6 - tube, 7 - connecting pins, 8 - first mirror holder,

9 - iris diaphragm, 10 - rotating holder of the second mirror,

11 - parts of the laser lock housing.

Fig. 4 shows a diagram of the proposed system installed on an exoscope.

Fig. 5 shows an image of the surgical field obtained using the system proposed by the invention.

The proposed invention operates as follows.

Before the operation, the system is assembled and connected to the operating microscope or exoscope. The choice of visualization tool depends on the surgeons' preferences and the operating room equipment. After the system is assembled and turned on, it and the working area of the microscope or exoscope are covered with a disposable sterile film.

Neurosurgical access to the pathological focus (aneurysm, arteriovenous malformation, etc.) is performed. The brain matter and vessels located in the surgical manipulation zone fall into the field of view of the micro- or exoscope. Laser radiation emitted by the diode is dispersed and redirected to the surgical field. An infrared video camera records the image of the surgical field and transmits a sequence of video frames to a computer, where further processing of the registered signal occurs. The resulting images have the form of a "heat map", where intact brain zones and vessels are colored in one color (e.g. red), brain zones and vessels with impaired perfusion - in another color (e.g. blue).

The computer can be implemented as a separate portable computer, or it can be built into a microscope or exoscope as a single-board computer, the so-called embedded solution.

Thus, the proposed invention expands the diagnostic capabilities of assessing blood flow during neurosurgical interventions, is simple and easy to perform, does not require special skills from surgical personnel in the operating room, and allows for increased accuracy and expanded diagnostic capabilities.

List of references

1. Miller DR, Ashour R, Sullender CT, Dunn A (2021) Laser speckle contrast imaging for visualizing blood flow during cerebral aneurysm surgery: a comparison with indocyanine green angiography. medRxiv

2. Sdobnov A.Yu., Kalchenko V.V., Bykov A.V., Popov A.P., Molody G., Meglinsky I.V. Blood flow visualization by laser speckle-contrast measurements under non-ergodic conditions. Optics and Spectroscopy. 2020. Vol. 128. No. 6. P. 778-786.

Claims (4)

1. A system for intraoperative visualization of blood flow during neurosurgical interventions, including a laser, a video camera for receiving infrared radiation and transmitting a sequence of video frames to a computer, a laser clamp and a video camera clamp, characterized in that the video camera clamp includes a housing and contains an infrared radiation filter and an optical polarizer configured to rotate around the optical axis of the housing, the laser clamp includes a housing inside which a laser diode is located, a Peltier element, an aspherical lens, two mirrors installed with the possibility of adjustable redirection of laser radiation from the laser diode to the illumination zone, a light diffuser, a biconcave lens, an iris diaphragm with an adjustment ring with a scale and a rotating optics holder, wherein the housing of the video camera clamp is configured to be attached to the eyepiece of a microscope on one side and to the lens of a video camera on the other side, and the housing of the laser clamp is configured to be attached to the side surface of the lens of the microscope or the housing of the video camera clamp and the housing of the laser clamp are designed with the possibility of being fixed to each other and to the surgical exoscope. 2. The system according to claim 1, characterized in that the laser diode is made with a wavelength of 785 nm, a power of 300 mW, the aspherical lens is made with a focal length of 9.6 mm, on both surfaces of which an antireflective coating is applied for a wavelength range of 600-1050 nm, two mirrors are made with a diameter of 1 inch, reflecting waves in the range of 750-1100 nm, the rotating optics holder is made in the form of an angular kinematic mirror holder KCB1EC/M, the biconcave lens is made with a diameter of 12.7 mm with a focal length of 15 mm, on both surfaces of which an antireflective coating is applied for a wavelength range of 650-1050 nm. 3. The system according to item 1, characterized in that the housing of the video camera clamp and the housing of the laser clamp contain channels for connection with each other and with the operating exoscope using pins. 4. The system according to item 1, characterized in that the surgical exoscope is a stand designed with the ability to regulate the focus, light exposure and zoom of the video camera installed on it.