In the recent years, blockchain technology has gained significant attention in the healthcare sector. It has the potential to alleviate a wide variety of major difficulties in electronic health record systems. This study presents an elaborate overview of the existing research works on blockchain applications in the healthcare industry. This paper evaluates 144 articles that discuss the importance and limits of using blockchain technologies to improve healthcare operations. The objective is to demonstrate the technology’s potential uses and highlight the difficulties and possible sectors for future blockchain research in the healthcare domain. The paper starts with an extensive background study of blockchain and its features. Then, the paper focuses on providing an extensive literature review of the selected articles to highlight the current research themes in blockchain-based healthcare systems. After that, major application areas along with the solutions provided by blockchain in healthcare systems are pointed out. Finally, a discussion section provides insight into the limitations, challenges and future research directions.

This research aims to fill up the research gap in energy‐efficient transistor‐level wide word‐length carry circuit generator by using ripple carry (RC) and carry look‐ahead (CLA) method‐based hybrid 4‐bit carry generation process for wide word‐length carry‐select adder (CSLA). Compared to the existing 4‐bit CLA architectures, the proposed 4‐bit RC‐CLA method‐based hybrid 4‐bit carry generator showed performance improvement in terms of power and power delay product (PDP). Later, the 4‐bit carry architectures (existing and proposed) were used as a base to implement 16‐bit carry select adder (CSA) in order to investigate and compare the effect of using the proposed hybrid RC‐CLA based 4‐bit carry generator in large structures. Unlike 4‐bit operation, the proposed design displayed the best performance in power and PDP for 16‐bit CSA extension, which proves its effectiveness in wide word‐length adder structures.