In this research article, its author presents new results obtained as a result of the search work conducted by him, the search work conducted by the author of this article, dedicated to the reflection of such a topic as the representation of the most diverse philatelic materials, thematically dedicated to the image on them of such an important and popular, even today, medical instrument as a stethoscope. The text part of this research article is provided, as illustrations, with numerous screenshots of philatelic materials, with the presentation on their front/obverse, of images of a stethoscope, its various models and varieties, in the image, on them, of various plot drawings.

The study of any issues related to medicine and its most diverse aspects is always a relevant and in-demand process. This directly concerns the issue considered in this author's research article, thematically related to the practical use in everyday medical practice, both by doctors and nurses and midwives, of such an important medical instrument as a stethoscope.
Introduced into everyday medical practice by the French doctor and inventor, Rene Laennec, his full French name and surname - Laennec Rene Theophile Hyacinthe (1781-1826), in 1816-1819 [1], the stethoscope underwent significant changes and transformations and, in many ways, changed. But the principle of auscultation, the work of the respiratory system (breathing noises and wheezing, in the lungs and bronchi), the work of the heart (listening to heart murmurs and heart rhythm0, auscultation of sounds in the abdominal cavity, in a number of its pathological conditions, the use of a stethoscope in other situations (sapper work associated with demining) and other situations. In fairness, the author of this research work previously conducted research on the history of the creation of the stethoscope and the biography of Rene Laennec and, in 2023, even wrote an article about this, reflecting philatelic and numismatic, collection materials [2]. Also, there is a rather interesting article, authored by another researcher, about R. Laennec, as a supporter of the clinical diagnostic direction in medicine, and the stethoscope, in the reflection of collecting tools [1-3].
But, since the writing of these research articles, several years have passed, and new, not yet presented collection materials, including philatelic ones, on this issue have appeared, which required presentation. This was the motivating moment for conducting another, new study, and writing a completely new research article based on its results. 
Aim of study: 
The purpose of this research article is to present the results obtained from the research work conducted by the author in the study of the issue of the representation of images of such an important and popular instrument as a stethoscope and the plots associated with it in various means of philately, such as: postage stamps, artistic stamped envelopes, first day covers, postage blocks and postmarks of special cancellation.
Hypothesis of the study: 
During the preparation for this study, and the receipt of collectible philatelic materials for the subsequent writing of his research article, its author put forward a working hypothesis that in the means of world philately, as in other means of collecting, there may be a fairly large number of philatelic miniatures, which reflect various subjects, which depict both the stethoscope itself and its use by both doctors and nurses in the process of examining patients (auscultation of the lungs and heart, the process of measuring blood pressure).

In conducting this thematic research, its author actively used the method of literary-critical analysis on the problem under study. For this purpose, special collection sites and Internet pages of philatelists-collectors collecting postage stamps and envelopes were carefully studied, both on medical topics in general, and on obstetrics and gynecology in particular. All thematic philatelic materials found on the Internet were sorted, grouped, and also converted by the author of this research using a special computer program into their screenshot copies, both black and white and color. These screenshot copies were used by the author of the article, later, as thematic illustrations, accompanied in the text of the research article by brief, accompanying comments.

I would like to begin my presentation of new, discovered as a result of the research conducted by the author of this research article, collection materials, both philatelic and phaleristic, with a small philatelic selection of postage stamps from different countries of the world. On the front side (obverse) of these philatelic miniatures, there is an image of a stethoscope or scenes where it is actively used by doctors and/or nurses - both in the process of examination (auscultation) of both adult patients and children (in pediatric practice). The author of this research article, for convenience and better perception of the presented information, highlighted separate groups: the use of a phonendoscope in children, in pediatric practice in children, in pediatric practice, and in adult patients, both by doctors and nurses. Figure 1 shows a thematic selection dedicated to the image of only the stethoscope itself, sometimes on some general background [5-20, 56]. These are postage stamps of the Isle of Man (United Kingdom) - 2020, Japan (1958), Poland (2005, 2014), Canada, Liechtenstein, Djibouti (2022), Uruguay, Bangladesh (1972), Spain (2005), Thailand, USA, Brazil, Mexico (1978), United Arab Emirates (1974), Central African Republic (2014), Republic of Cuba (1970). This section contains 24 screenshot copies of postage stamps from different countries of the world.

 Figure 1: A selection of postage stamps with a stethoscope on them:
In plot figure 2, a small thematic selection of postage stamps is presented, dedicated to the use of a stethoscope in pediatric practice [21-63]. These are postage stamps of the following countries: Isle of Man, United Kingdom (2020), Germany (Third Reich) – 1944, Laos (1982), Rwanda (1963), Fiji (2002), South Africa (1997), India (2013, 2015), Kenya (2005), Dominica (1973), Republic of Guinea (1966, 1976), Cuba (1973), Israel (2011), Philippines (1953), Denmark (2014), Grenada, People's Republic of China (1960), Central African Republic (2016, 2023), New Caledonia (2001), Czechoslovakia (1952), North Korea (1976, 1980, 1988), United Kingdom, Libyan Jamahiriya (1986), Democratic Republic of the Congo (1981), Guinea-Bissau (2022), Dubai, Australia (1990), Tunisia (2010), USA (2005), Botswana (1985), Democratic Republic of the Congo (2001), Algeria (1983). Also presented are postal blocks of Germany, the Central African Republic, the Republic of Guinea and Spain, with an image of the use of a stethoscope in pediatric practice.
In addition, in the same figure 1, artistic stamped envelopes of the Republic of Cuba, the USA, the People's Republic of China, and Australia are presented, with an image of plot drawings, which show the use of a stethoscope in pediatrics [2,1,23-44]. In total, this section contains 52 philatelic materials dedicated to the use of a stethoscope in pediatrics