RU47203U1 - FIBER OPTICAL THERMOMETER - Google Patents

Abstract

The fiber optic thermometer contains a fiber optic sensor made of optical fiber with a thermosensitive element of silicon located at its end, connected to the optical fiber through a matching layer of silicon oxide. The sensor is located in the longitudinal groove of a metal rod placed in a metal tube, while the output end of the thermometer is made beveled.

Description

The invention relates to medicine, namely to the design of a fiber optic thermometer (BOT) for hyperthermic therapy in oncology.

For these purposes, sensors with a thermocouple are used. The sensor has the shape of a needle, which is introduced into the area of hyperthermic heating of the biological tissue by radiation of an Nd: YAG laser [1]. The disadvantages of temperature control with a thermocouple sensor include low measurement accuracy and the presence of live conductors that pose a potential danger to the patient.

As a prototype, the design of a fiber optic thermometer should be considered, including a fiber optic temperature sensor and a recording system [2]. The fiber optic sensor comprises an optical fiber with a silicon thermosensitive element located at its end. The sensor has a matching layer of silicon oxide, through which the thermally sensitive element is connected to the optical fiber. Temperature measurement is carried out at contact of a thermosensitive element with biological tissue. In this case, the thermally sensitive element must ensure reliable thermal contact with the surface of the biological tissue. In addition, due to the fragility of the design of the fiber-optic temperature sensor, introducing it into the volume of pathological biological tissue is problematic, therefore, it is unrealistic to ensure reliable thermal contact of such a measuring tool with the internal environment of the irradiated volume of biological tissue.

In the proposed design, this problem is solved. The fiber optic thermometer contains a fiber optic sensor made of optical fiber with a thermosensitive element of silicon located at its end, connected to the optical fiber through a matching layer of silicon oxide. The fiber-optic sensor is located in the longitudinal groove of a metal rod placed in a metal tube, while the output end of the thermometer is made beveled.

The technical result implemented in the proposed fiber-optic thermometer for hyperthermic therapy in oncology is the possibility of safe (both for the patient and the proposed technical design)

the introduction of a fiber-optic thermometer inside the volume of pathological biological tissue, as well as ensuring reliable thermal contact of such a measuring instrument with the internal environment of the volume of biological tissue.

The essence of the proposal is illustrated using figure 1, depicting a schematic diagram of a fiber optic thermometer.

The fiber optic thermometer has a metal rod 1 with a longitudinal groove 2, a metal tube 3, an optical fiber 4, a heat-sensitive element 5, a matching layer 6 and a beveled output end 7.

Fiber optic thermometer for hyperthermic therapy in oncology works as follows. A metal tube 3 containing a metal rod 1 in the longitudinal groove 2 of which is located a fiber-optic sensor 4-6, punctured the beveled end 7 of the pathological biological tissue to a depth corresponding to the temperature control point. Hyperthermic heating of a pathological biological tissue, for example, by a laser source leads to a change in the characteristics of the heat-sensitive element 5 and, with the help of the corresponding equipment, a change in temperature is recorded in the region of the end face 7.

Here is a specific example of a fiber optic thermometer.

As tube 3 (FIG. 1), a hollow tube of a medical instrument was used for puncture and sampling of biopsy material. The outer diameter of the tube is 2.0 mm, the inner 1.6 mm, the length of the metal part of the tube is 160 mm. A longitudinal groove 2 (with a depth and width of 450 microns) is milled on a metal rod (outer diameter about 1.5 mm, length 240 mm) from a set of tools for biopsy material sampling. Milling was performed, starting from a distance of 3-5 mm from the beveled (at an angle of 20 ° to the horizontal axis of the structure) surface of the end face of the fiber optic thermometer, to a length of 210 mm. A groove 2 contains a quartz-quartz optical fiber with a light guide core diameter of 100 microns. The protective sheath of the optical fiber is made of fluoroplastic. The heat-sensitive element 5 was a single crystal silicon wafer with a size of 100x100x20 microns ³ . The formation of a matching layer of silicon oxide occurs due to the oxidation of the silicon element at a temperature of 1100 ° С-1200 ° С when the latter is placed in an arc of an electric discharge for 10-15 minutes. The connection of the structure of the matching layer is a thermosensitive element with a highlander of the optical fiber is carried out by arc welding. The outer diameter of the fiber optic sensor was about 350 microns.

A fabricated sample of a fiber-optic thermometer provides temperature measurement in the range of 30-110 ° C with a measurement accuracy of ± 0.2 ° C.

The proposed fiber-optic thermometer can be used in hyperthermic therapy of cancer and surgical endoscopy.

Literature:

[1] P.J. Milne et al. Development of stereotactically guided laser interstitial thermotherapy of breast cancer: In situ measurement and analysis of the temperature fied in vivo adipose tissue, Lasers in Surgery and Medicine, 2000, vol 26, No. 1, p. 67-75.

[2] Utility Model Patent No. 31447, “Fiber Optic Temperature Sensor”. IPC G 01 K 11/12.

Claims (1)

Fiber optic thermometer containing a fiber optic sensor made of optical fiber with a thermosensitive element of silicon located at its end, connected to the optical fiber through a matching layer of silicon oxide, characterized in that the fiber optic sensor is located in the longitudinal groove of the metal rod placed in a metal tube, while the output end of the thermometer is made beveled.