RU2195972C2 - Electric stimulation device for treating gastroenteric tract - Google Patents

Abstract

FIELD: medical engineering. SUBSTANCE: device has hermetically sealed capsule having two cup-shaped electrodes one of which has suction openings and has connecting pipe for making connection to catheter tube. Hybrid integral circuit is mounted in the capsule comprising oscillator for producing stimulating pulses connected to output unit via frequency divider and to unit for measuring impedance via restricting resistor. The unit for measuring impedance has output connected via amplifier to output unit input and synchronization unit input which output is connected to control input of the oscillator for producing stimulating pulses. The output unit is connected to electrodes being also measuring electrodes of the unit for measuring impedance having electronic key for making connection to common power supply bus. EFFECT: enhanced effectiveness of treatment; avoided adverse side effects. 2 dwg

Description

 The present invention relates to the field of biomedical engineering, more specifically to electrical stimulating devices for the diagnosis and treatment of organs and tissues, and more specifically to the improvement of an autonomous electrical stimulator of the gastrointestinal tract (GIT).

 Known electrical stimulator probe of the gastrointestinal tract, made in the form of a sealed capsule containing two electrically isolated cup-shaped electrodes, one of which has aspiration openings and is equipped with a fitting for connection to a catheter tube, in which a hybrid integrated circuit including a generator is placed stimulating pulses, frequency divider, output device, electronic key and power source [1].

 We have taken this electrical stimulator as a prototype.

 The disadvantages of the electrical stimulator probe - prototype are as follows. It is known [2] that the rhythms of periodic motor activity of the gastrointestinal tract are different not only depending on the digestive tract, but also are a particular species feature of a person and, moreover, are determined by the mental state, environment, phases of food intake and starvation, etc., etc. The hybrid integrated circuit of the electro-stimulator probe works regardless of the characteristics of the stimulated object and the state of the digestive system. Stimulation occurs in advance given (some averaged over the entire gastrointestinal tract) parameters of the output signal. The lack of synchronization of stimulating impulses with the intrinsic muscle activity of various sections of the gastrointestinal tract causes asynchrony of the motor activity of the latter and leads to unpleasant and painful sensations in patients [3]. On the other hand, as was established in the same work, prolonged local exposure to stimulating impulses (more than 30 min) on any section of the intestine leads to inhibition of its motor activity and to a decrease in its evacuation function.

 The objective of the present invention is to eliminate side effects and increase the therapeutic effect by synchronizing and modulating stimulating pulses with the rhythm of their own muscle contractions of various sections of the gastrointestinal tract, without causing inhibition of the motility of the latter.

 This task is achieved in that the stimulating pulse generator is connected through a frequency divider to the output device and through a limiting resistor to an impedance measuring unit, the output of which through the amplifier is connected to the input of the output device and the input of the synchronization block, the output of which is connected to the control input of the stimulating pulse generator, wherein the output device is connected to the electrodes, which are also measuring electrodes of the impedance measuring unit, and connected to the electronic key, through which power source is connected to a common power bus.

 The electrical impedance of the gastrointestinal tract depends on the degree of contraction of the intestinal muscles. It is known that a low-frequency current (hundreds of hertz - units of kilohertz) passes mainly through the intercellular spaces and the resistance to this current will be determined by the size of the intercellular spaces [4]. With a decrease in the size of the intercellular spaces decrease - the resistance increases. That is, knowing the nature of the change in the impedance of various sections of the gastrointestinal tract and receiving an electrical signal proportional to this change, it is possible to synchronize stimulating pulses with the work of muscles of various sections of the gastrointestinal tract, modulating them in amplitude.

 The invention is illustrated by drawings.

 Figure 1 is a functional diagram of an electrical stimulator.

 Figure 2 - typical current diagrams of a stimulating series of pulses and a control signal.

In FIG. 1:
1 - generator of stimulating pulses;
2 - frequency divider;
3 - output device;
4 - impedance measurement unit;
5 - amplifier;
6 - block synchronization;
7 - electrodes;
8 - electronic key;
9 - power source;
R is a limiting resistor.

In FIG. 2:
Ist - some averaged series of current stimulating pulses;
Z is a typical signal from the output of the amplifier unit 5 (Fig. 1), proportional to the change in tissue impedance of a particular section of the gastrointestinal tract during its reduction;
I ^I st - current stimulus signal plots in the presence of muscle contractions.

 The output of the stimulating pulse generator 1 through a frequency divider 2 is connected to an output device 3, and through a limiting resistor R, to an impedance measuring unit 4, the output of which is connected to the input of amplifier 5. The output of amplifier 5 is connected to the input of output device 3 and to the input of synchronization unit 6 the output of which is connected to the control input of the stimulating pulse generator 1. The output of the output device 3 is connected to electrodes of the electric stimulator 7 connected to the impedance measuring unit 4 and to the electronic key 8. Power supply The company 9 is connected via an electronic key 8 to a common power bus.

 The electrical stimulator works as follows.

 When an electric stimulator enters the conducting medium of the gastrointestinal tract, the electronic key 8 closes and the power supply from the power supply 9 is supplied to the stimulating pulse generator 1, the impedance measuring unit 4 is simultaneously turned on and the impedance of the gastrointestinal tract is measured at the location of the electric stimulator probe at the frequency of the stimulating generator pulses 1, the signal from which to the impedance measuring unit 4 is supplied through the limiting resistor R (while the amplitude of the measuring signal, so as not to cause stimulation th tissue is much lower (by more than 2 orders of magnitude) the stimulation signal amplitude). The measuring electrodes of the impedance measuring unit 4 are the electrodes of the electrostimulator-probe 7. From the unit 4, the measured signal is supplied to the amplifier unit 5, which controls the output device 3 that generates a signal proportional to the value of the measured impedance value. At the same time, the signal from the amplifier 5 through the synchronization unit 6 is used to synchronize the operation of the generator of stimulating pulses 1 with the current phase of muscle contraction. In the absence of contraction of the muscle tissue of the gastrointestinal tract, the stimulating pulse generator 1 supplies the electrodes of the electrostimulator probe 7 with stimulating pulses averaged over the parameters [4], and then, when the contractions appear, it automatically switches to adaptive stimulation mode.

 Thus, the introduction of new distinctive signs into the gastrointestinal tract electrical stimulator made it possible to achieve a new positive result - increasing the therapeutic effect by synchronizing and modulating stimulating pulses with the rhythm of one’s own muscle contractions of various sections of the gastrointestinal tract, without causing depression of the motility of the latter.

LITERATURE
1. Glushchuk S.F. Autonomous stimulators-probes of the gastrointestinal tract and a system-integrated approach to their design: Abstract. dis .... cand. tech. Sciences: 05.11.17. - M., 1989.15 s.

 2. N.M. Lebedev. Digestive system biorhythms. - M.: Medicine, 1987 .-- 257 p.

 3. Popov O.S. Autonomous electrical stimulation of the gastrointestinal tract in surgery: dis .... cand. honey. sciences. Tomsk - 1988.224 s.

 4. Khachatryan A.P. Clinical and pathophysiological aspects of electrical impedancemetry: dis .... doc. honey. Sciences: M.00.16, 14.00.27. - Tomsk, 1992 .-- 52 p.

Claims (1)

 Gastrointestinal probe electrostimulator made in the form of a sealed capsule containing two cup-shaped electrodes electrically isolated from each other, one of which has aspiration openings and is equipped with a fitting for connection to a catheter tube, in which a hybrid integrated circuit including a stimulating generator is placed pulses, a frequency divider, an output device, an electronic switch and a power source, characterized in that the stimulating pulse generator is connected via a frequency divider to one device and through a limiting resistor with an impedance measuring unit, the output of which through an amplifier is connected to the input of the output device and the input of the synchronization unit, the output of which is connected to the control input of the stimulating pulse generator, while the output device is connected to electrodes, which are also measuring electrodes of the impedance measuring unit , and is connected to an electronic key through which the power source is connected to a common power bus.

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