Recent advancements in medical technology, especially micro- and nanoelectronic wearable technologies, now allow for the remote monitoring of patients at home or in nonclinical environments [1], thus improving healthcare outcomes while reducing cost and inconvenience [2]. Various types of sensors including electrodes, microphones, pressure sensors, optical sensors, temperature sensors and accelerometers are used to capture physiological data. Such devices typically have the be used frequently and/or over extended durations, thus putting a premium on small, wearable devices that can minimize inconvenience to the user. Attached to the wrist, chest, fingers, forehead or ankles, these devices gather important health data using non-invasive sensors [1]. Tractica forecasted that annual sales of wearable devices will increase from 118 million units in 2016 to 430 million units by 2022, representing a compound annual growth rate (CAGR) of 24.1%, and that growth in the next stage of the wearable device market will be driven by healthcare applications for smartwatches, fitness trackers, and body sensors [3]. Furthermore, a market research report recently forecasted that the global wearable technology market will grow at a CAGR of 17.66% from 2019 to 2024 [4].

Wearable Biosensors, generally a combination of wearable objects and biosensors, are attached to the surface of the body or embedded on clothes or on objects carried by person [5], [6]. One or more biosensors commonly are used in the wearable medical devices to monitor a variety of physiological data including temperature, blood pressure (BP), electrocardiogram (ECG), heart rate, blood oxygen saturation (SpO2), posture, and movement to access early diagnosis, and facilitate treatment and home rehabilitation [1], [7]. Recently, several novel biosensors have been developed including sensors that are enzyme-based, tissue-based, piezoelectric, and thermal biosensors, along with immunosensors and DNA biosensors. These new devices display high sensitivity while offering additional advantages including operational simplicity, low cost, potential automation, and miniaturization [8].

Sheikh and Sheikh [9] used patent analysis to depict the Fisher-Pry projections or S-curves of the emerging biosensor technologies under consideration and forecasting their growth. They found that blood biosensors reached their technology maturity midpoint in 2009 with the midpoints of saliva and breath biosensors lagging by 8 and 14 years respectively. Fatimi [10] introduced what has been innovated and patented concerning cellulose-based biosensors between 2010 and 2020. A total of 241 patent documents related to cellulose-based biosensors were found and based on patent classifications, most patents and inventions were intended for chemical analysis of biological materials and testing. However, these studies only addressed the technology classification and technology life circle of specific biosensors, rather than the whole progress and advancement of technology, functions and applications of wearable biosensor in health.

Technology-driven technology roadmaps (TRM), one of the most widely used methods to support strategic technology management for emerging technologies. TRM method helps organizations plan their technologies strategies by describing the evolution of inventions, technologies, and products. Furthermore, patents record the nature of the invention, the direction of technological development and R&D activities, and promote the spreading of knowledge and innovation. Therefore, patent documents are a rich source of technological and commercial intelligence and can be used to anticipate development trends for biosensor technologies. An TRM framework with timeline is proposed to identify both promising technologies and potential products in the domain of biosensor using patent-based analysis.

This study can make several important contributions. First, this study contributed to the current understanding of whole picture and progress of technologies and functions in the domain of wearable biosensors. Furthermore, biochemical (T2), and electroencephalography (T5) are identified and expected to play a significant role over the coming decade in improving the current healthcare infrastructure, and enhancing the democratization of information and allocation of medical resources. Finally, this patent-based TRM can be systematically applied by patent holders, application operators, and equipment manufacturers for seeking to develop a technology-driven strategy in emerging industry domains. The findings systematically identify critical potential technologies and products which should be of interest to biosensor patent holders, application operators, and equipment manufacturers.