Trodden Lanes or New Paths: Ballisto- and Seismocardiography Till Now.

Ballisto- and seismocardiography (BCG/SCG) are methods of studying blood circulation and cardiac function by using the vibration measurements at the body surface, e.g. via accelerometers. The aim of this work is to show the current relevance of BCG/SCG for the target medical diagnostics. To reach this goal and to examine the relevance, an overall search for all BCG and SCG articles in the databases PubMed and IEEEXplore was first carried out ("ballistocardiography OR seismocardiography") for the years till 2019. The results of this literature study show, overall 425 papers for the years from 2003 till 2019, with BCG (317) as significantly stronger represented than SCG (120). The distribution of the included subjects shows that a smaller group (n<=10) of mostly healthy people is more common. Last but not least, we examined which sensors have been included in the articles since 2003, with the result that accelerometers, whether as self-developed prototypes or installed in smartphones, were used in slightly less than 50% of the articles found. The differences in the numbers of publications between BCG and SCG may also be due to the distinction's complexity between BCG, which is more intuitive, and SCG. Looking at the number and distribution of included subjects, it is noticeable that this is rather low and primarily healthy subjects are used. However, the publication increase indicates that we are at a threshold in this topic and actual benefit to medicine.