Complicated medical device
We face both “complex” and “simple” products in the course of work. Let’s clarify what we mean by these concepts.
A “complex” product is:
– a product incorporating many elements, each of which requires a detailed description in the technical and operational documentation;
– highly engineered product;
– a product in compliance with international safety standards, possibly even widely distributed on the international market, but inconsistent with one or more national regulatory documents.
The first two items determining the “complexity” of the product are understandable. With regard to the third item, let’s consider at a specific example.
There is such a medical device as a blood and infusion solution heater.
Its appearance does not fall into the category of “complex” products in any way: a rather simple design, no other components except the device itself, as well as clear regulatory documentation.
Fig. 1 Standard view of the blood and infusion fluids heating device
However, this is a “complex” product. This is due to the established Rules for the Clinical Use of Donated Blood and its Components, approved by Order of the Ministry of Healthcare of the Russian Federation No. 183n dated 02.04.2013 (hereinafter the “Rules”).
These Rules stipulate that the temperature of transfused blood and its components should fall within the range of 36-37°С. In terms of the Russian legislation, an apparatus able to heat the fluid within the range of 33-42°does not comply with this regulatory document.
There is an international standard ASTM F2172 – 02(2011), which regulates the safe characteristics of blood heaters. All products sold on the territory of the North America and Europe should comply with this standard. A blood and infusion solution heater, in accordance with this standard, confirms its safety, but not for the Russian Federation.
For those unfamiliar with the blood heater operation, we provide a brief explanation. Blood is heated using a heating profile, which can have the form of a solid surface on to which the infusion line is being “rewound”, or the form of a hollow tube into which the infusion line is inserted. The fluid flows inside the infusion line at different flow rates as determined by the medical staff. The fluid’s temperature delivered to the patient depends on several factors:
– initial drug temperature;
– fluid flow rates along the line;
– environmental conditions (temperature and humidity of the room where the procedure is being performed);
– temperature measurement point.
By adjusting the heating temperature, we set the temperature at a point where the infusion line extends away from the heating profile. Depending on the distance, the fluid inside the line cools down to some extent until it reaches the patient. From the text of the Rules it logically follows that the device must have an alarm when the temperature of blood flow inside the line exceeds 37°C and drops down below 36°C. However, this requirement cannot be met, since in order for the blood to reach the patient within the required temperature range, it is necessary to set the heating temperature above 37° C, taking into account that in any case there will be a heat-free section of the line where the blood cools down. The device can control the temperature on the heating profile surface, but not at the point where the blood is infused directly into the patient.
As you can see, this is quite a nontrivial task. It is impossible to register this device in Russia without fundamental change in its heating characteristics and its alarm system.
Waiving part of the product’s functionality is one of the possible ways to avoid any major changes in the device’s operation, namely the blood heating feature, while maintaining the feature of heating the infusion solution. The point is that infusion solutions, apart from recommendations by the drug manufacturer and healthcare institutions, have no documents establishing strict limits on the heating temperature.
Thus, neither the compliance of the product with international standards, nor the extensive successful experience in using the product abroad, can serve as a good reason for registering this medical device.