*4.2.2 Connected health objects*

A connected object is an object that is connected to the Internet, capable of sending information in real time and interacting with its environment. A connected object is based on three essential things:


A connected object has two main functions:


Examples of connected objects:

The weight is displayed directly on the scale and can also be displayed on the Smartphone via Bluetooth or Wi-Fi. The latter allows the saving and synchronization of measurements with a weight curve and also the transfer of data to a health professional (doctor/nutritionist).

Connected watches and bracelets placed around the wrist to record activity according to the sensors they contain (heart rate, GPS, accelerometer etc.). The recorded data is communicated to the Smartphone.

Connected mattresses, contain sleep and environmental sensors that collects and sends data to your Smartphone in order to determine your ideal sleeping temperature [29].

#### *4.2.3 Connectivity and the internet of things*

The Internet of Things is the set of objects connected to the Internet that generate data through specific sensors. What they have in common is that they are physical objects and transmit digital information as well as computations, remotely, through an application, often directed from a mobile device (phone, tablet, and computer) [24].

This allows data to be collected, sent and stored over a network without requiring human-to-human or human-to-computer interaction [30].

The application of the IoTconcept in the field of medicine and surgery has great potential. For example, the connection to various external sensors for diagnosis, monitoring and follow-up is a promising technological advance. The data collected from these different sensors constitute a valuable database that will be of great help during treatment. Communication between doctor and patient also takes on another dimension with these new modes of connectivity, making access to care easier.

Connected objects for medical purposes make it possible to monitor the patient's condition more frequently, more accurately and, therefore, better.

#### *4.2.4 Connectivity and artificial intelligence*

Artificial intelligence is a set of theories and techniques used to create machines capable of simulating human intelligence.

#### *Smartphone and Surgery, Reality or Gadget? DOI: http://dx.doi.org/10.5772/intechopen.98889*

AI is applied to any activity that involves data collection, followed by decision making and taking action, the cycle repeating itself ad infinitum.

Use of AI in the medical field seems to be highly promising and the potential applications are endless. A medical device could, in theory, use the sum of the experiences of all medical images, of all surgeries if this data could be formatted and collected. It is through self-learning from real-life results that AI is becoming more and more powerful [24].

AI has been applied in various health fields including cancer research, cardiology, diabetes, mental health, etc.

#### **4.3 Smartphone cameras**

Smart phones are equipped with increasingly sophisticated cameras whose performance is equal to or better than that of professional cameras [31]. Some smart phones are equipped with high resolution cameras, even 4 K resolution, or threedimensional cameras. Some professional films have been completely recorded by smart phones. Others have won awards [32].

The integration of microscopes into smart phones to visualize bio-components such as blood cells and micro-organisms has improved over time to the nanoscale level where nano particles, viruses and DNA can now be detected [33].

Smart phones may offer a viable solution for early diagnosis of skin diseases, specifically for remote screening and long-term monitoring of skin lesions [34].

#### *4.3.1 The Smartphone's sensors*

The Smartphone is equipped with a multitude of sensors:


#### *4.3.1.1 Internal sensors of the smartphone*

Smart phones embody a series of integrated sensors that allow them to interact with the outside world (movement, light, magnetic field …): thus turning it into a real pocket laboratory.

In recent years, there has been a growing interest in the use of motion sensors embedded in smart phones such as accelerometers, gyroscopes and magnetometers, as well as location sensors such as GPS for real-time monitoring of physiological constants and activities of daily living.

#### *4.3.1.2 External sensors*

Nowadays, it is possible to attach several complementary electronic devices to the Smartphone, converting it into a multi diagnostic system depending on the nature of the attached device [35].

These technological solutions appear to be particularly cost-effective and attractive in resource-limited settings where access to diagnostics and care is not always possible.

Currently, many body organs can be monitored via smart phones.

For example, ultrasound probes can be directly connected to the Smartphone and seem to be a very interesting prospect for the future. Different probes are

already available on the market for vascular, soft tissue, lung, abdominal and pelvic examination, FAST ultrasound… [36].

These handheld ultrasound probes have high diagnostic accuracy, sensitivity and specificity for basic anatomy and pathology and can be an acceptable and reproducible diagnostic tool with great potential for future applications particularly in low resource countries to increase access to ultrasound [37].

These connected objects can collect, store, process and transfer data or perform specific actions according to the information received. They carry out measurements in real time and can provide information on many parameters affecting health: weight, body temperature, pulse, blood pressure, breathing rate, heart rate, blood sugar level, sleep quality, etc. At the end of the object's connection is a computer or a Smartphone, a doctor or a call centre, a coaching centre, etc. aiming to create an alert system: any change in one of the parameters transmitted abruptly or reaching a previously set critical value prompts an intervention, special monitoring, advice or recommendations [24].

#### *4.3.1.3 Biosensors*

Biosensors are measuring instruments that integrate a biological element (enzyme, antibody, plant or animal cell, DNA fragment, lipid, etc.) and a physical transducer (electrode, optical fiber, etc.). The aim of biosensors is to detect characteristic markers of disease at an early stage in order to improve patient care. There are many potential applications. The most famous biosensor is the one used to analyze blood sugar levels in patients with diabetes [38].

The Smartphone is now a miniaturized computer system, to which several kinds of biosensors can be connected. A phone application can detect several biological agents using the data transmitted by the biosensor.

Currently, much work has focused on miniaturizing biosensors and bioelectronic devices, such as micro fabricated transducers and compact readout instruments, to achieve state-of-the-art, easy and reproducible real-time detection [33].

#### **5. The smartphone in clinical evaluation and preoperative examination**

We propose here the main applications of the Smartphone in preoperative care.

#### **5.1 Cardiovascular analysis**

Measurements of heart rate, blood pressure and even continuous monitoring have become possible [39].

One study compared finger-measured BP, using the OptiBP Smartphone application based on a pulse wave analysis algorithm, with BP measured via an arterial catheter. The difference in BP (mean ± standard deviation) between the two methods was within the norm. This may therefore become a valuable tool for detecting hypertension in various settings, such as pre-anesthetic assessment especially in low income countries [39].

A Chinese study done in 2021 proposed a new method of measuring heart rate variability using the Smartphone rear camera as a sensor. The fingertip video signals of 24 students were acquired using the rear camera of an HTC M8d Smartphone. ECG signals were recorded simultaneously as a reference. The results were comparable [40].

Some Smartphone-connected watches can perform a single-lead electrocardiogram (ECG) and detect atrial fibrillation. The clinical accuracy of the waveforms

*Smartphone and Surgery, Reality or Gadget? DOI: http://dx.doi.org/10.5772/intechopen.98889*

of these single-lead ECGs is still lower than a 12-lead ECG. But there is evidence, for example, that the Apple watch produces accurate ECGs in healthy adults with moderate to high agreement of baseline ECG intervals [41].

A study evaluating the efficacy of Cardio-Rhythm was conducted in 1013 patients with T2DM and hypertension: Atrial fibrillation was diagnosed in 28 patients (2.76%). The diagnostic sensitivity of CardioRhythm was 92.9% and was higher than that of a clinical score algorithm Alive Corautomated Algorithm (71.4%) [42].

#### **5.2 Respiratory status**

Smart phones can monitor and transmit arterial oxygen saturation (SpO2) data. The validity and reliability of a Smartphone oximeter has been validated by several studies [39, 43].

## **5.3 Measurement of hemoglobin level**

• Non-invasive Hb measurement: HemaApp.

The HemaApp is an application to detect the hemoglobin level in the blood by color analysis using the HemaApp camera flash. By passing the light from the phone's camera flash through the patient's finger, HemaApp analyses the color of the patient's blood to estimate hemoglobin levels.

The FDA has approved it in the US as a non-invasive hemoglobin measurement tool [44].

• External sensors connected to the Smartphone to measure hemoglobin levels:

Automated external sensors linked to the Smartphone are able to quantitatively measure, without chemical reactions, the concentration of hemoglobin ([Hb]) in whole blood samples [45].

#### **5.4 Measuring blood glucose**

The conventional method of measuring blood glucose requires several pieces of equipment such as a glucometer, a test strip, a needle, an alcohol swab and gloves. This method of measurement is uncomfortable for the patient, especially if several measurements have to be performed every day.

To make the measurement more convenient and less invasive, researchers have developed a method based on colorimetric and electrochemical techniques to determine the glucose level using a Smartphone. This is called photo-plethysmography (PPG), a non-invasive, low-cost technique that measures the volumetric variation of blood in the arteries.

The principle of the proposed non-invasive technique is to record a short video (20 s–50 s) of the subject's fingertip using a commercial Smartphone camera. This video is then converted into images containing RGB channel information of different wavelengths. Because the wavelengths of the transmitted light (red, blue and green) are different, each penetrates the tissue differently: Red light has a longer wavelength than green or blue, and therefore penetrates deeper into the tissue. By integrating this image data (RGB channel), a PPG signal is generated from the recorded video.

Using these PPG signals acquired from the Smartphone and the corresponding glucose levels acquired with a glucose meter, linear regression models for glucose

level prediction are created, allowing each PPG measurement to be assigned a blood glucose level. (Blood Glucose Level Regression for Smartphone PPG Signals Using Machine Learning Tanvir).

#### **5.5 Hyperbilirubinemia**

Other applications have been developed to detect hyperbilirubinemia based on the degree of absorption of the blue light emitted by the Smartphone flash. The image of the skin taken with this flash is compared to a color spectrum to classify it as icteric or non-icteric skin. The results are comparable to modern transcutaneous bilirubinometers [46].

#### **5.6 Examples of connected medical devices**

Several connected medical devices have been marketed in recent years such as stethoscopes, blood pressure monitors, ECGs, etc. [29].

The company EKO introduced on the market one of the first connected smart stethoscopes, capable of detecting heart murmurs with a sensitivity and specificity of 87% [47, 48].

There are many connected ECGs available on the market. Thanks to their connectivity with a Smartphone, sharing recordings is now easy between patients and doctors [49]. The principle consists in placing two fingers of each hand on the device and the result is displayed directly on the Smartphone.

Several studies have shown that these connected ECGs are capable of detecting atrial fibrillation in the ambulatory setting [50].
