Yu.M. Rybin1, I.M. Ageev2, V.K. Novikov3

1,2 MAI (Moscow, Russia)

3 Research Institute of Emergency Medicine named after N.V. Sklifosovsky (Moscow, Russia)

In the intensive care unit of a hospital, surgical actions for insulin replacement therapy are often required for disorders in patients with carbohydrate metabolism of various etiologies. An insulin therapy apparatus operating in an automatic mode is best suited for solving such a problem. The long-term successful medical practice of using the prototype of the insulin therapy apparatus has confirmed the correctness of the selected technical solutions. The principal feature of the prototype is the algorithm of its operation, where the degree of disturbance of carbohydrate metabolism is assessed by the results of measuring the temperature difference between the thermal core of the body and the subcutaneous fatty tissue. The legitimacy of using this method for diagnosing disorders of carbohydrate metabolism in the patient's body is confirmed by the corresponding patent of the Russian Federation. At the same time, shortcomings of the prototype were identified, including: the need for frequent calibration of the readings of thermistors used as thermal sensors of the catheter; relatively low accuracy of measuring the absolute values of temperatures by temperature sensors and, as a consequence, low accuracy of measuring the values of the difference temperature; relatively high complexity of the instrument block, which leads to the expected high cost of the apparatus. The purpose of this work is to improve the apparatus in the direction of improving its operational parameters. For this, a hardware-software complex for insulin therapy has been developed, which automatically injects the necessary doses of insulin to the patient according to the results of non-invasive biometric measurements – the difference temperature between the nucleus of the body and the subcutaneous tissue. The design feature of the complex is the use of a standard sound card of a personal computer as a measurement data collection board, a reference signal source and a signal source that controls the insulin dispenser. The software part of the complex is based on the patented operation algorithm used in the prototype of the insulin therapy apparatus. A number of experiments were performed on the operating model of the complex, which confirmed its efficiency. The results of one of the experiments are given in the text of the article, from which it can be seen that the complex provides accurate dosing of insulin in accordance with the sign, magnitude and rate of change in the differential temperature. The hardware part of the complex includes a simple matching device that does not require tuning and scarce radioelements, a catheter with two thermistors and a standard insulin pump. The software part of the complex is implemented in the Python environment and can be installed on an ordinary personal computer. The technical solutions used make it possible to measure the patient's biometric parameters with high accuracy, to optimize the insulin injection algorithm, and to reduce the cost of the complex in the process of industrial production.

Rybin Yu.M., Ageev I.M., Novikov V.K. Hardware and software complex for insulin therapy. Biomedicine Radioengineering. 2021. V. 24. № 6. Р. 69−74. DOI: https://doi.org/10.18127/j15604136-202106-07 (In Russian)

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