Search results

We retrieved a total of 381, 1279 and 1243 records from three databases (Pubmed, Web of Science (WOS), and IEEE) respectively (Fig. ​(Fig.9).9). Initially, we applied time filters due to the commencement of VCPM research in 2007, which resulted in a remaining total of 345, 1026, and 1139 records respectively. Subsequently, specific built-in filter tools of the three databases were employed: (1) Exclude 28 records with not full text filter in Pubmed; (2) After filtering out literature types that include review papers, unspecified material, books, abstracts only and letter, 730 papers remain in the search results of WOS; (3) Utilizing the filter of publication topics (patient monitoring, medical image processing, medical signal processing, cardiology, diseases, health care, biomedical optical imaging, telemedicine, medical signal detection or cardiovascular system) and 993 records remain in the search results of IEEE. Next, after eliminating the duplicates, there were 1943 items remaining. Finally, after screening by title, abstract or full text, studies conducted in laboratory settings or using radar sensors (e.g., MMW radar) were excluded. Only research papers related to clinical settings, digital medicine, telemedicine or healthcare were selected for final analysis, resulting in a total of 43 papers.

Flowchart for literature search and screening.