DD265001A1 - CIRCUIT ARRANGEMENT FOR GLUCOSE MONITORING DURING THE DIALYSIS - Google Patents

Abstract

In the course of dialysis for patients suffering from diabetes mellitus, the blood glucose concentration is continuously or discontinuously monitored in such a way that blood is taken from the arterial branch of the dialysis stream in small amounts and firstly diluted in a mixing section with a buffer solution. The promotion takes over a pump. After passing through the mixing section, the measuring liquid passes through a GOD-glucose electrode and is brought into contact with the active reaction layer of the pO2 sensor. The electrical signal generated proportionally to the glucose concentration in the dismutated blood then passes into a pre-amplifier / optocoupler unit for measured value preprocessing and then into the main amplifier. The output signal of the main amplifier ultimately serves m. H. to carry a continuous detection of a logging device, to operate an A / D display and to sound an audible alarm when exceeding and falling below the predetermined limits of blood glucose concentration. Fig. 1 shows the overall arrangement best again.

Description

-2- 265 001 Presentation of the Invention

The technical problem which is solved by the invention.

The invention is based on the technical object of providing a simple and effective method of monitoring the glucose level and possibly regulating it to a normal level with the new arrangement, namely while the dialysis is being carried out.

Meri./nale of the invention According to the invention the problem is solved by the fact that the circulating in the artificial kidney blood of the arterial side to Received evaluation and fed by means of a suitable pump, a small amount of a mixing unit and there with a Buffer solution is diluted in a predetermined ratio. In a subsequent flow chamber, this will happen

prepared blood / buffer mixture with an active sensor surface in contact, wherein by diffusion of Glucoserr.molekülenin the reaction layer of the sensor one of the glucose concentration in the diluted blood piupurtionalos electrical signal is generated. The latter is also fed via a Vorverriärker / optocoupler unit to the amplifier, where it is A / D converted and digitally comes to the display.

The amplifier has a normal register unit (eg y-t-writer), after which one expediently one Warning device connects with critical conditions, eg. As a too low glucose concentration in the patient's blood, a

visual-acoustic warning signal initiates the possible intervention in good time.

At dun digital output of Vere'ärkors (tonη in addition, a control device angoscnlossen be the current Glucose concentration according to the given target function influenced by glucose and / or insulin infusions. The described continuous data acquisition can also be discontinuous on the basis of the Tasior query "the most recent Zeitrngime done. Ausfiihrungsbelsplel The Erf. ndung is unhand the block diagram of Figure 1 has been explained.

Figure 2: pre-amplifier / OptoUopplereinheit Figure 3: main amplifier

The blood is drawn from the arterial branch of the dialysis test of the artificial kidney KN continuously by means of a

safety requirements of the application class C corresponding pump P, the small amount with a

Buffer solution is fed to the mixing section MS for dilution. The dilution ratio depends on the

achievable linear measuring range ">> Dependence on the inserted glucose-permeable sensor membrane

Mixture MS, which for reasons of homogeneous mixing blood / buffer solution sufficiently long and advantageously

must be coiled, the mixture flows at the GOD-glucose electrode GE and the active reaction layer of

Sensor surface of the pGySensor SEN over and will accuse afterwards. That by the sensor SEN according to the Glucoseinzontration in dilute blood generated electrical signal is a preamplifier / optocoupler unit VO

fed, which operates separately from the mains-operated main amplifier HV.

The circuit of the v. G. Unit is shown in Fig. 2. Thereby, the voltage supply of the electrode GE and the Meßwertvorvera> processing is eaiisiert. The Huuptvorstärker HV connected thereto in the connection, which can be seen in its essential components in FIG. 3,

prepares the received signals on further, so that the Ausgangssignai, A / D-converted, comes to the display AN or as

Analog signal for logging PR is given and gogebenenfalls when exceeding or falling below the set Limits of Glucosekonzr.ntration the warning device WE is be'ätigt. Another Te "realized the main amplifier

a calibration routine for the electrode assembly.

The electrodes are designed and prepared as a GOD glucose electrode with pOj basic sensor. To the electrode body belongs a sealing Durchflußstück, "o that only the active surface of the electrode (cathode) via

the membrane is brought into contact with the measuring liquid.

The described continuous measured value recording also known discontinuously according to button inquiry or after

preceded by a time frame.

Claims (3)

255 255 Claims: 1. Circuit arrangement for glucose monitoring during dialysis, preferably by continuously from the arterial branch dos dialysis of the artificial kidney by means of a safety requirements sufficient pump, the low blood collection, characterized in that the blood sample with a buffer solution within the mixing section (MS) for dilution is mixed with the proviso that the respective linear measuring range is maintained depending on the glucose permeable sensor membrane used and then the homogeneous solution for the purpose of measured value at the GOD-glucose electrode (GE) and in particular the active reaction layer of the surface of the pO ₂ sensor ( SEN) is passed along with the aim that in the pO ₂ sensor (SEN) of the glucose concentration proportionally generated electrical signal further to the preamplifier / optocoupler unit (VO) for measured value preprocessing and then fed to the main amplifier (HV) is, where he converts the acquired signals A / D and either via the display (AN) digitally or analogous to the protocol device (PA) leaves for registration and optionally on exceeding or falling below the preselected glucose limits in the blood a warning device (WE) turns on, so that the normal value can be restored via a downstream control device. 2. Circuit arrangement according to item 1, characterized in that the measured value recording described can also be carried out discontinuously according to probe query or preset preset time and the main amplifier realizes a calibration routine for the electrode assembly. For this 3 pages drawings Field of application of the invention The invention relates to a circuit arrangement for glucose monitoring during dialysis for the discontinuous or continuous registration of the blood glucose level, wherein a comparison is made with the extremes of the blood glucose concentration and a downstream regulating unit ensures that a normal value is maintained. Typical applications are found not only in medical technology, but also among others. also in the chemical or pharmaceutical industry. Characteristic of the known state of the art According to DE-OS 2724543, a failure is provided for transcutaneous or subcutaneous, injury-free monitoring and determination of the glucose concentration in BI it, and the concentration determination is made by utilizing the absorption of radiant light in glucose-containing fluids. There is the disadvantage that no practically relevant measurements can be achieved in the measuring medium blood. A suitable COD-glucoso-electrode is therefore necessary. There is also according to DE-OS 2326265 a device for monitoring the blood glucose level in a living organism by an implanted fuel cell is used as the core piece for generating a glucose concentration of proportional signals. The disadvantage here is that analytical measurements are hardly rrsögür'i. US Pat. No. 4,573,968 describes a technical solution which approximates the invention and which essentially, but with significantly different means, influences the blood glucose concentration. However, the reliability of the reachable control room due to oversized sensor array analyzer output (control signal) is considered to be low. The measuring device operates only in the flow and ode with ion-selective Elektr. The latter is physiologically less suitable. GB-PS 1370943 proposes a monitoring system according to which the patient's condition is compared with an integrated signal with the reference signal and when overwriting or signing e ne warning device is actuated, so that a subsequent influence on critical states must begin , This type of comparison of the measured values requires apparatus-related / circuit-technically relatively high expenditure and is therefore not effective. Object of the invention The aim of the invention is that already critical during the dialysis z. ß. Hypoglycemic conditions in the patients are immediately recognized and such information about the K5he Glucosenivnaus is taken as the starting point for a controlled glucose infusion and / or insulin infusion, d. h., By comparison of the measured value with certain limits continuously or discontinuously influence on 'lie compliance with the normal level is taken and at the same time an alarm is triggered.