*2.3.1.1.6 Biosensors in artificial limbs (prostheses)*

The potential of prostheses to restore human skin's sensory capabilities would provide users of mechanical limbs with a more natural feeling [78]. The use of a pressure sensor on an artificial hand, for example, might change the amount of force applied by the fingers when gripping objects. This could protect the object from falling due to an underapplied force or breaking due to an overapplied force. A system with sensors

for electromyography, temperature, and strain incorporated into stimulation electrodes was developed [79], and its practical use for prosthesis control with sensory input as well as electrical muscle stimulation was reported [80].

#### *2.3.2 Regenerative medicine*

Biosensors serve as a control platform for other technologies, allowing for realtime monitoring of system behavior for improved efficiency. Biosensing technologies are used in regenerative medicine for a variety of purposes, including biomanufacturing (for example, product release requirements), organ-on-a-chip technologies, and therapeutic efficacy indicators.

#### *2.3.2.1 Application of biosensors in regenerative medicine*

#### *2.3.2.1.1 Biomanufacturing*

Biomanufacturing is a relatively recent industrial strategy to produce economically relevant biological goods such as human tissues by leveraging biological systems. Industrial-scale bioproducts are made using additive manufacturing techniques such as 3D printing and other biofabrication technologies **Figure 13** [81]. shows DNA biosensing with 3D printing technology.

Biomanufacturing facilities may also use altered cells to manufacture chemical or molecular products, as well as mass culture cells for organ fabrication. Biomanufacturing may be used in a variety of industries, including healthcare, food production, and even agriculture. Controlling the quality and condition of the biological structure is crucial for producing trustworthy goods, and biosensing technologies can help with this. Electrochemical enzyme-based biosensors, for example, have been utilized to monitor metabolites in cell culture medium in real time [81].

#### *2.3.2.1.2 Organ-on-a-chip technologies*

Using microfluidic technology and organoids, organ-on-a-chip technologies have opened up a new biomedical research field. Organoids are tiny cell clusters of a certain tissue type that can mimic the behavior of regular tissues and organs more accurately. Organ-on-a-chip technology is utilized for a variety of purposes, including evaluating the response of organoids to medications and other external stimuli [83]. The use of biosensors for real-time monitoring of the behavior of microtissues and organoids has progressed the technique significantly. Damage to cardiac organoids was monitored using a new microfluidic aptamer-based electrochemical biosensor **Figure 14** [84]. shows the use of biosensors to develop organs-on-a-chip technology.

#### *2.3.2.1.3 As indicators for therapeutic efficacy*

Given that most outcomes are observed visually (e.g. a regenerated tissue or a healed wound) or functionally (e.g. improved sensory ability), biosensors for detecting the efficacy of regenerative medicine-related therapies remain relatively unexplored. Biosensors, on the other hand, may play an increasingly essential role in therapeutic evaluation in the future. For example, with glucose sensors, patients undergoing treatment can make use of biosensors to self-monitor the efficacy of the

**Figure 13.** *DNA biosensing with 3D printing technology [82].*

#### **Figure 14.**

*Diagram showing the use of biosensors in organ-on-a-chip integration [85].*

treatment (for instance, the presence of the required growth factors in their bloodstream after undergoing treatment).

Also, biosensors that monitor stem cell differentiation status before transplantation for therapeutic purposes can be made with nanotechnology [86]. Small cellular surface proteins and neurotransmitters, for example, can be measured to validate the differentiation of stem cells into dopamine-producing brain cells before their implantation into Parkinson's disease patients [87].

Future applications of biosensing can be seen in the monitoring of regenerative medicine therapies in patients, such as biosynthesized tissue preparation and posttreatment self-monitoring. With the advancement of technology and stem cell-related applications, physicians and patients will be able to use biosensors in new ways.

*Recent Advances in Biosensing in Tissue Engineering and Regenerative Medicine DOI: http://dx.doi.org/10.5772/intechopen.104922*

#### *2.3.3 Mobile health (mHealth)*

The pathbreaking spread of mobile technologies together with innovative application advancements has brought up deliberate attempts to address health-related matters using mobile devices. This has led to the evolution of a new pathway of electronic health (eHealth), known as mHealth. According to the International Telecommunication Union, there are about 5 billion mobile phone subscriptions in the world, with over 85% of the world's population now covered by a commercial wireless signal [88]. Mobile phones have penetrated most low-income countries more than other infrastructures such as paved roads and electricity. The increasing quality of these networks which involves providing higher speeds of data transmission alongside cheaper and more powerful handsets is transforming the way health services and information are accessed, delivered, and managed. With increased accessibility comes a greater possibility of personalization and adoption in healthcare delivery [89].

The term "mobile" in mHealth connotes a sense of freedom and flexibility to function anywhere and at any time [90]. There is no one generally accepted definition for the term – mobile health, and how it is defined keeps changing with time, and as you move from one field to the other. However, World Health Organization Global Observatory for eHealth (WHO, GOe) has defined mHealth as a subdivision of eHealth (electronic health). This subdivision is referred to as medical and public health practice supported by mobile devices. The mobile devices include the following:


mHealth capitalizes on a mobile phone's core utility of voice and short messaging service (SMS) as well as more complex functionalities and applications including general packet radio service (GPRS), third- and fourth-generation mobile telecommunications (3G and 4G systems), a global positioning system (GPS), and Bluetooth technology [89].

On the other hand, [91] it has described mHealth as wireless devices and sensors (which include mobile phones) which are meant to be carried or accessed by an individual throughout regular activities that are performed daily. This definition tells us that an important component of mHealth is the sensor that can monitor and measure physiological data; hence, the sensors can be used for various applications including monitoring and measuring physiological data in mHealth.

#### *2.3.3.1 Application of biosensors in mHealth*

There are many types of biosensors employed in mHealth for telecare. For biosensors to fit into mobile devices, they have to be of high quality and miniaturized, and consume low power. This has been better achieved through innovation in materials and instrumentation [92–95]. As biosensors gain more and more attachments with smart devices for mHealth, they become necessary for researchers to design

biosensors with suitable functionalities and specifications to work flawlessly with accompanying hardware and software [96].

Two features will remain immutable with mHealth devices: a sensing technology for sensing health parameters and processing software to transform the sensor data into useful information. Hence, biosensors will remain invaluable components of mHealth. In designing a biosensor for mHealth, the biosensor can be built as a distinct microfluidic chip to communicate with the smartphone via wired or wireless connectivity. Alternatively, the biosensing chip with computing features can be incorporated directly into the design of smartphones, and this will eliminate additional hardware, thereby improving portability and possibly bringing about overall cost reduction [97].

Regarding smartphone-based mHealth, recent smartphones lack some key health sensor modalities. An integrated smartphone biosensor has limitations in the types of health data it can collect. Yet, the presence of connectivity technology such as USB, Bluetooth, and WiFi that enable them to interface with a large number of external biosensors to expand their range of signal acquisition is a great advantage. In mHealth, data processing can either be local processing (on the smartphone or a standalone biosensing accessory) or server processing (taking place on the cloud or on a nearby computer that communicates with the smartphone or a standalone biosensing accessory) [97].

Smartphones are not very suitable for data processing that requires high computing power as they may take a long time to process the data into useful information. However, smartphones can take advantage of their built-in connectivity features to transfer sensor data to a more powerful server. After the processing is completed, the server can transmit the results back to the smartphone to be accessible to the user.
