RU208768U1 - DEVICE FOR SFINCTEROMANOMETRY IN LABORATORY ANIMALS - Google Patents

Abstract

The utility model relates to the field of experimental medicine, namely to coloproctology. The device for sphincteromanometry in laboratory animals measures the pulses, compression force and frequency of contractions of the formed neosphincter and sphincter of rats by placing a pressure difference transducer in the signal measurement area, while the sterile rectal balloon catheter 8 FR is supplied through the valve with the pressure required to create muscle resistance. rat sphincter and neosphincter strength. The pressure is then fixed in the required range using a visual assessment of the location of the sensor and the readings of the oscilloscope instrument. Thereafter, the ultra-precise electric relative pressure sensor converts the difference in sensor pressure, sphincter and neosphincter muscle strength, and atmospheric pressure into low power electrical signals that are fed to a signal amplifier. After that, the signals supplied by the sensor are read using a powerful, ultra-precise, low-noise electrical signal amplifier. Then the data is converted five times into electrical impulses in the required measurement range from 0.01 to 0.5 V and fed to the oscilloscope, shown on the oscilloscope display in the form of a graph, as well as in a digital display, then, based on the readings obtained in the digital display, it is estimated maximum compression and sensor expulsion dynamics. In the static state of the balloon catheter, the force of compression, the frequency of contractions of the anal sphincter are evaluated, and at the time of evacuation of the balloon catheter, the periods of tension and relaxation of the sphincter muscles, the force of contraction, and the frequency of contraction are evaluated in dynamics. The method simplifies measurements and improves the accuracy of diagnosing the state of the rectal sphincter in laboratory animals, including in dynamics, improving experimental studies of the functions of the rectum to study on such models the influence of various factors in the postoperative management of patients with rectal pathology, as well as the role of various therapeutic factors on the outcome of surgical or other treatment of patients, rehabilitation or prevention. 2 ill.

Description

L. et al., 2014;

J. et al., 2018; Li P. et al., 2020). Кроме того, в биологии, зоологии и ветеринарии есть необходимость регистрации и точного измерения тонуса мышц нижних отделов толстого кишечника, в частности, у крыс, что также требует создания новой измерительной аппаратуры соответствующего профиля (Морозов А.М. и др., 2019; Гирфанов А.И., Ежкова А.М., Ежков В.О., 2020; Антонов С.Д., 2020; Васильцова И.В., Бокова Т.И., Коваль Ю.И., 2020; Barriga-Rivera A., Vinuesa J.L., Lopez-Alonso M., 2015; Evers J., Jones J.F.X., O'Connell P.R., 2017; Hoey R.F., Hubscher С.H., 2020).The development of new devices that increase the efficiency of preclinical and other experimental studies on laboratory animals in medicine, including coloproctology, is very important in Russia and other countries (Yakovlev A.T. et al., 2017; Smirnova A.V., 2018 ; Chuchkova N. N. et al., 2019; Grinevich V. B. et al., 2020;

L. et al., 2014;

J. et al., 2018; Li P. et al., 2020). In addition, in biology, zoology and veterinary medicine, there is a need to register and accurately measure the muscle tone of the lower parts of the large intestine, in particular, in rats, which also requires the creation of new measuring equipment of the appropriate profile (Morozov A.M. et al., 2019; Girfanov A.I., Ezhkova A.M., Ezhkov V.O., 2020; Antonov S.D., 2020; Vasiltsova I.V., Bokova T.I., Koval Yu.I., 2020; Barriga-Rivera A., Vinuesa JL, Lopez-Alonso M., 2015; Evers J., Jones JFX, O'Connell PR, 2017; Hoey RF, Hubscher C.H., 2020).

Anorectal manometry, both in humans and other mammals, is a functional diagnostic study of the anorectal zone by manometry in order to obtain information about the tone of the anorectal muscle complex and the coordinated contractions of the rectum and anus sphincters. In the process of studying muscle tone, both in humans and laboratory animals, the following parameters and characteristics can be determined (Sysoev K.V., Samochernykh K.A., Khachatryan V.A., 2019; Kit O.I. et al. , 2020; Khvorostov I.N. et al., 2020; Scott S.M., Carrington E.V., 2020; Oliveira L.C.C., 2020):

1. Maximum and average compression pressure of the external anal sphincter

2. Asymmetry of sphincter contraction

3. Inhibitory rectoanal reflex

4. Vector volume

5. Sphincter length

6. Rectal pressure profile in 1 cm increments.

The use of catheters with a balloon for manometry allows you to determine (Yakovleva O.V., 2019; Kuzminov A.M. et al., 2019; Lee T.N. et al., 2020; Athanasakos E. et al., 2020):

1. The threshold of rectal sensitivity (in humans, the minimum volume required for the sensation of intestinal filling to appear is less than or equal to 25 ml);

2. The minimum volume to relax the internal anal sphincter (the volume at which the first urge to defecate occurs; normally 10-20 ml);

3. Threshold for persistent urge to defecate (volume required for persistent urge to occur; normally less than or equal to 220 ml);

4. Maximum tolerable volume (normally 110-280 ml).

The standards of medical care approved by the Russian Ministry of Health and Social Development determine the need to perform anorectal manometry in 100% of patients suffering from Hirschsprung's disease, diverticular bowel disease and megacolon. Four main devices are used for this: MSM S4402, Solar WPM, Solar URO and Gastrokan-SF. Anorectal and colonic catheters are also known, for example: balloon water perfusion catheter for anorectal manometry, multichannel water perfusion catheter for anorectal manometry. In addition, two types of catheters can be used in anorectal manometry: water-perfusion or solid-state probes. Solid-state pressure sensors are short-lived and expensive, which significantly limits their use (Kuzminov A.M. et al.; Yakovleva O.V., 2019; Shelygin Yu.A. et al., 2020; Di Chio T. et al., 2020; Basilisco G., Corsetti M., 2020; Leo CA et al., 2020).

By design, water-perfusion anorectal catheters can be balloon or standard. The design of balloon catheters differs from other types of catheters used, for example, in esophageal or antroduodenal manometry, in that a balloon is located at its end. Of the standard design catheters, 4 or 8-channel water-perfusion catheters are used with ports located radially at an angle of 45° to each other and 7 cm apart between them (Osadchuk A.M. et al., 2019; Athanasakos E. , Cleeve S., 2019; Bjorsum-Meyer T. et al., 2020).

The prototype of our utility model is the device described in the article by Barriga-Rivera A., Vinuesa JL, Lopez-Alonso M. "Anorectal manometry in Wistar rats with inexpensive setup: A physiological description of the mechanical activity)) ("Journal of Medical and Biological engineering). - 2015. - I. 35. - no. 2. - P. 242-248), which uses a laboratory setup for experimental anorectal manometry, consisting of a perfusion individual catheter, a signal acquisition and processing system, and a personal computer with software for displaying biosignals. Twenty Wistar rats, ten males and ten females, were anesthetized with a ketamine-xylazine preparation. The tone of the anorectal sphincter and rectosphincter reflex was measured. Under basic conditions, two frequency peaks were found, one at 0.015±0.007 Hz and the other at 0.363±0.057 Hz, corresponding to slow and ultra-slow pressure waves, re-assumed. The maximum resting pressure varied between 37.8 and 109.0 mmHg. Art. Anorectal relaxation induced by stimulation of the rectal wall decreased to 82.65±14.61%, from pressure level to stimulation. The total period of the relaxation wave was 10.22±2.91 s. The length of the catheter was 70 cm and the outer diameter was approximately 2 mm. Here, the inner and outer diameters were 0.2 and 1.0 mm, respectively, and were bonded together. A silicone insufflation balloon was placed at the tip of one of the lumen and was used to inflate the rectum. The insufflation time was short enough to be neglected. The other two lumens were perfused with distilled water and the balloon was filled with air. A constant water flow of 3 ml/h was maintained using a valve built into the pressure sensor. Distilled water was stored at 300 mm Hg. Art. in a plastic bag. The valve prevented high pressure transmission and maintained a constant flow through the catheter. Two holes with a diameter of approximately 0.1 mm were located at a distance of 10 and 15 mm from the center of the beam to record pressure changes. Pressure conversion for registration of pressure waves used disposable pressure transducers. The top of the instrument shows perfusion and a pressure recording setup that provides a constant flow. The lower part describes the signal of the conditioning unit, which is connected to the distal end of the catheter. The external player supplies power to the 10 VDC sensor with a sensor sensitivity of 5 lV/V/mmHg. Art., and the measurement range of this device is 300 mm Hg. Art., exceeding the pressure limits from -400 to 5000 mm Hg. The signal generated by the pressure sensor is an amplitude signal collected with a differential amplifier. The input impedance is 10 GX and the bandwidth is 3 and 0.3 kHz with a gain of 1009 and 10009 respectively. After conditioning, including low pass filtering to avoid aliasing, the signals were acquired with an A/D converter (Ni-USB6008, National Instruments, TX, USA) at 50 Hz with 12 bit resolution. The voltage range was -1.1 V , and thus the pressure resolution was 0.1 mmHg. The software used was LabView 8.5 (National Instruments, USA) with a developed graphical user interface for monitoring information during experiments. All signals were displayed simultaneously using a vertical screen to improve visual control. The software was designed so that more channels could be used to display any other biosignal, including the electrical activity of the anorectal sphincter.

The disadvantage of this solution is the lack of verification of a significant effect of measurements specifically for surgical models of the experiment using neosphincter in laboratory rats. In addition, the proposed utility model is more compact, portable, does not contain mercury, is easy to install, consists of more accessible components and does not require special software. Also, our device evaluates more than two indicators simultaneously in dynamics: tension, relaxation, period of inactivity, the sequence of these periods, the duration of periods, while the above prototype evaluates only two peak indicators: tension and relaxation, as well as time, while the proposed device reads data in any position, while analogues only in the position of the studied animals on the back. The proposed model refers to the most sparing methods for assessing the work of the rectum and neosphincter, because a soft balloon catheter is used, which provides tight contact with the intestinal wall and sphincter according to the principle of ellastography, and thus is also the most informative manometry.

An analogue of the proposed device is also patent WO 2012164127A1 "ANORECTAL MANOMETRY DEVICE" (Inventor: Manuel Lopez Alonso, Jose Antonio Cabo Valdes), describing an apparatus for anorectal manometry, containing: an anorectal probe equipped with a rectal balloon and a plurality of channels designed to record anorectal pressure patient, a data acquisition card configured to record analog signals from connected pressure sensors to channels for recording anorectal pressure and converting said signals into digital signals, as well as means for analyzing and presenting digital signals generated by the data acquisition card. In a preferred embodiment of the present invention, pressure relief perfusion holes are located at different distances from the rectal balloon in each channel. In this case, it is possible to record pressure data at various points of the rectum, obtaining additional information about the patient's condition with the help of a single introduction of the anorectal probe. Preferably, the perfusion holes are located at least 25 mm, 30 mm and 25 mm from the rectal balloon. In another embodiment of the invention, the analysis and presentation means comprises a programmable computer. This makes it possible to provide the device with greater configurability, which allows the user to change the conditions for analyzing the received data. In addition, the use of a personal computer allows the device to store received information corresponding to various tests performed on one or more patients, as well as their study, both in real time and after some time after receiving the data. In another embodiment of the invention, the analysis and presentation means comprises a monitor. This allows you to offer the possibility of visual representation of the received data, configuring the specified representation through analysis tools, which allows the user to be able to visualize the information necessary to develop a diagnosis. In another embodiment of the invention, the data acquisition card contains: a plurality of analog signal inputs connected to the anorectal pressure recording channels, at least one microcontroller configured to control the operation of the data acquisition card, at least one analog signal generation unit for connecting to the microcontroller input , at least one interface unit for data transmission, connected to the analysis and presentation environment, preferably configured in accordance with a communication protocol adapted to control the conversion of the output level of the microcontroller signals, and the specified output contains voltage levels recorded by the converters, and their translation from using the communication protocol being used. This gives the invention a means for translating and processing received data, which is small in size, while allowing access to said data through analysis and presentation. In another embodiment of the invention, the data acquisition board is connected to a clock that marks the execution time of the microcontroller's work program. This gives the invention a means by which they can be registered in such a way that it determines the exact time at which the tests are performed, as well as the time at which patient data is obtained. In one embodiment of the invention, the parsing and presenting means comprises a combination of hardware or software that implements a graphical environment that allows one or more programs to be executed, containing one or more of the following functions: communication with a data collection card, receiving information transmitted through a communication port , management and control of errors, operational presentation of the received data and autonomous study of the specified data.

The disadvantage of this solution is the lack of validation of the reliable effect of measurements specifically for surgical models of the experiment using the sphincter and neosphincter in laboratory rats. In addition, the proposed utility model is more compact, portable, easy to mount, consists of more accessible components and does not require special software. Also, our device evaluates several indicators simultaneously in dynamics: tension, relaxation, period of inactivity, the sequence of these periods, the duration of periods, while the above-described analogue evaluates only two peak indicators: tension and relaxation, as well as time, while the device reads the data in any position, while analogues are only in the position of the studied animals on the back. The proposed model refers to the most sparing methods for assessing the work of the rectum and neosphincter, because a soft balloon catheter is used, which ensures tight contact with the intestinal wall and sphincter according to the principle of elastography, and thus is an additionally more informative manometry.

), в котором применяется устройство для обнаружения заболеваний прямой кишки с использованием манометрии, имеющей множество датчиков давления, расположенных с определенными интервалами вдоль секции в произвольном месте в направлении длины трубки манометра, причем способ включает этапы: получение значений давления от каждого из множества датчиков давления в течение заранее установленного времени; получение трехмерного распределения давления, показывающего изменения значений давления в соответствии с местоположением и временем, с использованием времени, значений давления и местоположений, в которых датчики давления расположены в секции в произвольном месте; и вычисление в трехмерном распределении давления интеграла объема секции в интересующем месте, которое заранее определено в соответствии с заболеваниями. Этот повышает эффективность определения различных заболеваний, связанных с прямой кишкой и анусом, за счет использования значений давления определенных датчиков, относящихся к ректальной или анальной области, когда проводится манометрия. Устройство включает в себя измеритель импеданса, измеритель проводимости, измеритель трехмерного распределения и объема. В комплект поставки входят интегральный калькулятор, блок сравнения порогов, блок определения заболевания, блок классификации интервалов и блок установки процентных интервалов. Множество импедансных электродов расположены с заданными интервалами (например, интервалами 2 см) вдоль произвольного положения участка импедансного манометра в продольном направлении. Сечение произвольного положения означает участок частичной длины, в котором электрод установлен среди всей длины трубчатой части импедансного манометра. Значение импеданса получают отдельно от каждого импедансного электрода, но непрерывно в течение заданного времени. Изменение значения импеданса в каждом импедансном электроде со временем может быть известно, и изменение значения импеданса в соответствии с положением каждого импедансного электрода измеряется. Блок получения трехмерного распределения показывает изменение проводимости относительно положения и времени с использованием положения, времени и значения проводимости, когда каждый импедансный электрод расположен в произвольном положении секции, в которой установлен электрод. Положение установки импедансного электрода выражается в диапазоне от 0 до 30 см, имеет трехмерную форму поверхности. Каждый из электродов импеданса расположен с интервалом 2 см вдоль продольного направления импедансного манометра, значение проводимости для интервала между ними является точно детализированным. Блок вычисления интеграла объема вычисляет общее интегральное значение объема для трехмерного распределения проводимости. Вычисляется интегральное значение объема для всего трехмерного распределения проводимости, полученного в течение от 0 до 25 секунд для всего участка от 0 до 30 см.An analogue of the proposed utility model is another patent WO 2015142120A1 "METHOD FOR DETECTING DISEASES USING HIGH RESOLUTION MANOMETRY, AND APPARATUS THEREFOR" (Inventor:

), which uses a device for detecting diseases of the rectum using manometry, having a plurality of pressure sensors located at certain intervals along the section at an arbitrary location in the direction of the length of the manometer tube, and the method includes the steps of: obtaining pressure values from each of the plurality of pressure sensors in during a predetermined time; obtaining a three-dimensional pressure distribution showing changes in pressure values according to location and time using time, pressure values, and locations where pressure sensors are located in the section at an arbitrary location; and calculating, in a three-dimensional pressure distribution, the volume integral of the section at the location of interest, which is predetermined according to the diseases. This enhances the detection of various diseases associated with the rectum and anus by using the pressure values of certain sensors related to the rectal or anal area when manometry is performed. The device includes an impedance meter, a conductivity meter, a 3D distribution meter, and a volume meter. The package includes an integral calculator, a threshold comparison unit, a disease detection unit, an interval classification unit, and a percentage interval setting unit. A plurality of impedance electrodes are located at predetermined intervals (eg, 2 cm intervals) along an arbitrary position of the section of the impedance gauge in the longitudinal direction. An arbitrary position section means a section of partial length in which the electrode is installed among the entire length of the tubular part of the impedance manometer. The impedance value is obtained separately from each impedance electrode, but continuously for a given time. The change in the impedance value at each impedance electrode over time can be known, and the change in the impedance value according to the position of each impedance electrode is measured. The 3D distribution acquisition unit shows the change in conductance with respect to position and time using the position, time, and conductance value when each impedance electrode is located at an arbitrary position of the section in which the electrode is installed. The installation position of the impedance electrode is expressed in the range from 0 to 30 cm, has a three-dimensional surface shape. Each of the impedance electrodes is located at 2 cm intervals along the longitudinal direction of the impedance gauge, the conductivity value for the interval between them is finely detailed. The volume integral calculation block calculates the overall volume integral value for the three-dimensional conductivity distribution. The integral value of the volume is calculated for the entire three-dimensional distribution of conductivity obtained within 0 to 25 seconds for the entire area from 0 to 30 cm.

The disadvantage of this solution is the lack of verification of the reliable effect of measurements using the sphincter and neosphincter in laboratory rats. In addition, the utility model developed by us is more compact, portable, easy to mount, consists of more accessible components, does not require special software, evaluates simultaneously in dynamics more than two indicators: tension, relaxation, period of inactivity, the sequence of these periods, the duration of periods, in while the above prototype evaluates only two peak indicators: tension and relaxation, as well as time, while the device reads data in any position, while analogues only in the position of the studied animals on the back. The proposed model refers to the most sparing methods for assessing the work of the rectum and neosphincter, because a soft balloon catheter is used, which provides tight contact with the intestinal wall and sphincter according to the principle of elastography.

A fairly similar device is described in the domestic utility model RU185442U1 "SEGMENTAL SPHINCTEROMETER" (Patent holders: LLC "Scientific and Medical Firm MBN", Federal State Budgetary Institution "State Scientific Center for Coloproctology named after A.N. Ryzhykh" of the Ministry of Health of Russia), also used to diagnose the obturator apparatus of the rectum contains a housing and a segmental sensor installed in the housing, which allows you to simultaneously record pressure indicators from the segments of the obturator apparatus of the rectum, and the segmental sensor is made in the form of a cylinder with a rounded end, the inner part of the sensor consists of four sections that divide the sensor in the longitudinal direction into four mutually independent segments, separating elements are plastic plates in the cross section of the sensor, forming a cruciform figure, and in each of the segments there is a measuring element in the form of a silicone tube with one of the ends plugged, the other end of each of the four silicone new tubes is connected to the electronic module of the sphincterometer, and four pressure sensors are installed as part of the electronic module, each of the pressure sensors located in the electronic unit of the sphincterometer is connected to the segmental sensor using a silicone tube, and all measuring elements consisting of silicone tubes are filled water.

The disadvantage of this patent is the lack of verification of a reliable measurement effect specifically for surgical models of the experiment using the sphincter and neosphincter in laboratory rats. In addition, the proposed utility model is more compact, portable, easy to mount, consists of more accessible components and does not require special software. Also, our device evaluates more than two indicators simultaneously in dynamics: tension, relaxation, period of inactivity, the sequence of these periods, the duration of periods, while the above-described prototype evaluates only two peak indicators: tension and relaxation, as well as time, while the device reads data in any position, while analogues are only in the position of the studied animals on the back. The proposed model refers to the most sparing methods for assessing the work of the rectum and neosphincter, because a soft balloon catheter is used, which provides tight contact with the intestinal wall and sphincter according to the principle of elastography.

A close analogue is the useful model RU 55569U1 "SPINCTEROMETER" (Patentee: State Educational Institution of Higher Professional Education "Samara State Medical University of Roszdrav"), which contains a cylindrical body with an elastic cuff. The cavity formed by the cuff is connected by a tube with holes and to a tee, which is connected to a source of compressed medium and a recording device and is equipped with an exhaust valve. The sphincterometer can be made of a biologically and chemically inert polymeric material. The sphincterometer is used as follows - it is inserted into the rectal canal, from the pressure source create in the cavity 3 of the housing 1 initial pressure. The force of muscle compression and the change in pressure of the compressed medium are used to measure all the necessary measurement parameters on a recording device, namely: the tone of the anal sphincter, the maximum strength of the anal sphincter, the volitional effort of the sphincter. Using hot or cold water as a compressed medium, depending on the disease and the patient's condition, it is possible to treat the anal sphincter.

The disadvantage of this solution is the lack of validation of the reliable effect of measurements specifically for surgical models of the experiment using neosphincter and sphincter in laboratory rats. This device does not evaluate the duration of periods of relaxation and tension, their sequence and the physiological nature of the act of defecation. In addition, the proposed utility model is more compact, portable, easy to mount, consists of more accessible components and does not require special software. Also, our device evaluates more than two indicators simultaneously in dynamics: tension, relaxation, period of inactivity, the sequence of these periods, the duration of periods, while the above-described prototype evaluates only two peak indicators: tension and relaxation, as well as time, while the device reads data in any position, while analogues are only in the position of the studied animals on the back. The proposed model refers to the most sparing methods for assessing the work of the rectum and neosphincter, because a soft balloon catheter is used to ensure tight contact with the intestinal wall and sphincter.

A similar device with the same pathology is used in the invention RU 26399U1 "SPINCTEROMETER" (Patent holder: "State Institution Tver State Medical Academy"), where a sphincterometer is used, consisting of an ovoid with a metal rod bent at the free end in the form of a hook, and a steelyard with scale from 0 to 2 kg in divisions of 50 g. Inside a standard proctoscope, three ovoids with dimensions of 19 × 25 mm are freely placed, connected by a Mylar thread 5 cm long, and inside the distal ovoid there is an air supply channel with two cannulas along the edges, to which on one side an inflatable latex balloon is attached, on the other hand, a Riva-Roci apparatus is installed through the air supply line, and a metal rod 30 cm long with a hook-shaped end and a steelyard, consisting of a cylindrical body and a scale from 0 to 2, is soldered into the proximal ovoid.

The disadvantage of this solution is the lack of validation of the reliable effect of measurements specifically for surgical models of the experiment using the sphincter and neosphincter in laboratory rats. In addition, the proposed utility model evaluates more than two indicators simultaneously in dynamics: tension, relaxation, period of inactivity, the sequence of these periods, the duration of periods, while the prototype described above evaluates only two peak indicators: tension and relaxation, as well as time, at In this case, the device reads data in any position, while analogues only in the position of the studied animals on the back. The proposed model refers to the most sparing methods for assessing the work of the rectum and neosphincter, because a soft balloon catheter is used, which provides tight contact with the intestinal wall and sphincter according to the principle of elastography, and thus is also the most informative manometry.

Also, an analogue of a similar study of the neosphincter is the technique from method RU2719661C1 "METHOD OF CREATING AN EXPERIMENTAL MODEL OF POSTOPERATIVE ISCHEMIA OF NEORECTUM BY RECTAL STRETCH" (Patentee: I.M. Sechenov First Moscow State Medical University (Sechenov University)), in which it is used in laboratory animals weighing from 350 g, when a circular incision is also made in the skin and subcutaneous fat around the anus. A section of the rectum is isolated directly along the intestinal wall to the external anal sphincter with a length of at least 35 mm. A longitudinal incision of the wall of the rectum is carried out at the point corresponding to 12 o'clock to the middle of the selected section of the rectum, followed by the reduction of the intestine to the perineum with tension and the imposition of the first interrupted suture between the skin of the anus and the intestine at 12 o'clock. A longitudinal incision of the rectal wall is carried out at the point corresponding to 6 o'clock to the middle of the selected area, followed by the second interrupted suture between the skin of the anus and the intestine at 6 o'clock, with the formation of two flaps of the rectum with a length corresponding to half the length of the selected area of the rectum. The formed flaps are resected. A neoanus is created by applying interrupted sutures between the skin of the anus and the intestine along the entire circumference of the intestine. Get a model of ischemia neorectum on the third day after surgery.

The disadvantage of this method is that it describes only a method for examining the rectum in laboratory animals that is close in purpose, relevance and purpose, and there is no complete description of the neosphincter manometry device itself.

The utility model proposed by us is arranged and functions as follows.

After preparation, a Laborie Medical, 8 FR, deflated, sterile, 8 Fr sphincteromanometry rectal balloon catheter is inserted into the sphincter or neosphincter of the rat, after which it is inflated to muscle resistance. In the static state of the balloon catheter, the compression force and the frequency of contractions are evaluated. At the moment of evacuation of the balloon catheter, the periods of tension and relaxation of the sphincter muscles, the force of compression, and the frequency of contraction are evaluated in dynamics.

The silicone catheter has a size of 8 Fr, balloon volume 2.5 cm ³ , length 40 cm. 1-1.5 ml, winged Luer-Lock connectors provide ease of use and a secure connection.

Measurement of impulses, compression force and frequency of contractions of the formed neosphincter of rats is carried out according to the principle of placing a pressure difference transducer (PDT) in the signal measurement area. Through the valve (Pin) the pressure required to create resistance to the muscle force of the rat neosphincter is applied. The pressure is fixed in the required range using a visual assessment of the location of the PDT sensor and the readings of the DSO 112A oscilloscope. The Ips PE electrical ultra-precise relative pressure transducer converts the difference in PDT transducer pressure, neosphincter muscle force and atmospheric pressure into low power electrical signals that are fed to a signal amplifier. The signals from the IPS PE sensor are read by a powerful, ultra-precise, low-noise electrical signal amplifier AD820 and converted five times into electrical pulses in the required measurement range from 0.01 to 0.5 V and fed to the DSO 112A oscilloscope. Signals of such a duty cycle are clearly visible on the oscilloscope display in the form of a graph, as well as in a digital display. Based on the obtained readings in the digital display, the maximum compression, maximum relaxation, the dynamics of the transducer ejection, the duration of periods of relaxation and tension, and their sequence are evaluated.

The scheme of the device is shown in Fig. 1, where they are indicated by letters:

IPS PE - 5700 GP Relative pressure sensor;

AD820ANZ - Monopolar metal oxide field-effect transistor amplifier;

DSO 112 - Oscilloscope;

Power+5V from Li-ion, digital power supply and OUT+5V 1.OA;

PDT - differential pressure transmitter.

The pressure was measured using a special tool - a rectal sensor, which is an integral part of the device. The transducer is inserted into the anal sphincter of the animal under study. One measurement cycle lasts no more than 30 seconds. Changes in sphincter pressure are displayed on the display of the device in the form of a graph. The measurement results are stored in the instrument's memory. At the end of the study, the data are transferred to the memory of a personal computer. In the future, on a computer, you can view the measurement results on the screen in the form of graphs, tables and texts and analyze the results of the research.

An elastic balloon is inserted into the anal canal at a distance of 2 to 5 cm. Air is pumped with a pump and the indicators are evaluated.

The operation of the device is also shown in Fig. 2, where instrument measurement performance studies are indicated by letters and numbers:

(a) Dynamics of sphincter or neosphincter relaxation, (b) Statistical analysis of maximum sphincter or neosphincter contraction in comparison with the control group. One-way analysis of variance with Tukey's correction, Group 0 - control without surgery, group 1 - surgery without neuroticism, group 2 - surgery with neuroticism, group 3 - surgery with neuroticism and creation of a neurotrophin gradient. (b) Graphs show mean±SD, * - p<.05, ** - p<.01, *** - p<.001, **** - p<0001.

A study was made of the effectiveness of the use of the device in experimental medicine on the example of four groups of laboratory rats.

The experiment was carried out in the centralized vivarium of the First Moscow State Medical University. THEM. Sechenov. Experimental studies were carried out on animals: 24 male Wistar rats with an average weight of 350 g and an age of 4-6 months. The animals were kept under standard vivarium conditions with a day/night schedule 12/12, with free access to water and food. The maintenance and use of laboratory animals complied with the rules adopted at Sechenov University, the recommendations of the local ethical committee and national laws.

90 days after the neosphincter formation operation in rats, the neosphincter region was photographed, followed by an assessment of the neosphincter function.

As a result of a statistical study of a differentiated and dynamic measurement of the sphincter and neosphincter tone, it was shown that in experimental animals the maximum neosphincter tension was in the third group and amounted to 0.066 ± 0.005 V.

In the first group of experimental animals, which underwent plasty of the obturator apparatus of the rectum without direct neurotization of the muscle, the maximum tension of the neosphincter was 0.02±0.01 V.

In the second group of experimental animals, which underwent plasty of the obturator apparatus of the rectum with direct muscle neurotization without creating a neurotrophin gradient, the maximum value of the neosphincter voltage was 0.026 ± 0.0057 V.

Based on the data obtained from the dynamic assessment of the evacuation of the balloon catheter of the device, we, using this device, measured the mechanism of defecation in healthy rats and in groups of experimental animals. In healthy animals of the control group, during defecation, regular episodes of periodic tension and relaxation of the muscles of the rectal sphincter with a tendency to its complete relaxation are noted, which contributes to the evacuation of feces.

In rats of the third group, which underwent plasty of the obturator apparatus of the rectum with direct neurotization of the muscle with the creation of a gradient of neurotrophins, an absolutely identical picture was observed. The evacuation of the balloon catheter was also accompanied by regular episodes of tension and relaxation of the neosphincter muscles, with a trend towards complete relaxation of the neosphincter. The evacuation process did not differ in time from the control group.

In rats of the second group, which underwent rectal obturator plasty with direct muscle neurotization without creating a neurotrophin gradient, balloon catheter evacuation was also accompanied by regular episodes of muscle tension and relaxation with a tendency to complete relaxation. A significant difference from the third and control groups of experimental animals was a greater compression force and shorter periods of neosphincter relaxation, as well as a longer period of complete evacuation of the balloon catheter.

In rats of the first group, which underwent plasty of the obturator apparatus of the rectum without performing direct neurotization of the muscle, the appearance of a diametrically opposite mechanism for evacuating the balloon catheter was noted. A short period of relaxation of the neosphincter was accompanied by a sharp increase in its tone, with a tendency to increase without periods of relaxation, up to the complete evacuation of the balloon catheter.

The result of the study of the developed utility model showed that in the second and third groups of experimental animals, the normal physiology of the act of defecation was restored. And in the first group of rats, which underwent manometry after plastic surgery of the obturator apparatus of the rectum without direct neurotization of the muscle, a compensatory mechanism of fecal mass evacuation operates, diametrically opposite to the control group, accompanied by an increase in tone and the absence of periods of relaxation.

The model we developed can be used in experimental studies to study the influence of various factors in the postoperative management of patients with rectal pathology, as well as the role of various operational factors on the outcome of surgical treatment. Lethality when creating a model is 0%, reproducibility of the model is 100%.

Claims (1)

A device for sphincteromanometry in laboratory rats, characterized in that it is made with the ability to measure impulses, contraction force and frequency of contractions of the sphincter and neosphincter of rats in real time by placing a pressure difference transducer in the signal measurement area with feeding into a sterile rectal balloon catheter of 8 Fr size through pressure valve required to create resistance to the muscle strength of the sphincter and neosphincter of the rat, with the possibility of fixing the pressure in the required range using a visual assessment of the location of the pressure difference transducer and oscilloscope readings, followed by conversion of the pressure difference between the muscle strength of the sphincter and atmospheric pressure using an electrical ultra-precise relative sensor pressure into electrical signals, which are read by an ultra-precise electrical signal amplifier, are converted five times into electrical impulses in the required measurement range from 0.01 to 0.5 V and are displayed on the oscilloscope display in the form of a graph, as well as in digital form, with the possibility of estimating the maximum compression and dynamics of the transducer ejection, as well as the compression force and frequency of contractions of the anal sphincter in the static state of the balloon catheter, and at the time of evacuation of the balloon catheter in dynamics with the ability to assess periods of tension and relaxation of the sphincter and neosphincter muscles, the period of inactivity and the sequence of these periods, as well as the ability to measure the force of contraction and the frequency of muscle contraction.

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