Sensors For Vital Signs Monitoring

Vital signs, such as heart rate and respiration rate, are useful to health monitoring because they can provide important physiological insights for medical diagnosis and well-being management. Most traditional methods for measuring vital signs require a person to wear biomedical devices, such as a capnometer, a pulse oximeter, or an electrocardiogram sensor. These contact-based technologies are inconvenient, cumbersome, and uncomfortable to use. There is a compelling need for technologies that enable contact-free, easily deployable, and long-term monitoring of vital signs for healthcare. Contactless Vital Signs Monitoring presents a systematic and in-depth review on the principles, methodologies, and opportunities of using different wavelengths of an electromagnetic spectrum to measure vital signs from the human face and body contactlessly. The volume brings together pioneering researchers active in the field to report the latest progress made, in an intensive and structured way. It also presents various healthcare applications using camera and radio frequency-based monitoring, from clinical care to home care, to sport training and automotive, such as patient/neonatal monitoring in intensive care units, general wards, emergency department triage, MR/CT cardiac and respiratory gating, sleep centers, baby/elderly care, fitness cardio training, driver monitoring in automotive settings, and more. This book will be an important educational source for biomedical researchers, AI healthcare researchers, computer vision researchers, wireless-sensing researchers, doctors/clinicians, physicians/psychologists, and medical equipment manufacturers. Includes various contactless vital signs monitoring techniques, such as optical-based, radar-based, WiFi-based, RFID-based, and acoustic-based methods. Presents a thorough introduction to the measurement principles, methodologies, healthcare applications, hardware set-ups, and systems for contactless measurement of vital signs using camera or RF sensors. Presents the opportunities for the fusion of camera and RF sensors for contactless vital signs monitoring and healthcare.

Sensor technology for monitoring vital signs is an important topic for various service applications, such as entertainment and personalization platforms and Internet of Things (IoT) systems, as well as traditional medical purposes, such as disease indication judgments and predictions. Vital signs for monitoring include respiration and heart rates, body temperature, blood pressure, oxygen saturation, electrocardiogram, blood glucose concentration, brain waves, etc. Gait and walking length can also be regarded as vital signs because they can indirectly indicate human activity and status. Sensing technologies include contact sensors such as electrocardiogram (ECG), electroencephalogram (EEG), photoplethysmogram (PPG), non-contact sensors such as ballistocardiography (BCG), and invasive/non-invasive sensors for diagnoses of variations in blood characteristics or body fluids. Radar, vision, and infrared sensors can also be useful technologies for detecting vital signs from the movement of humans or organs. Signal processing, extraction, and analysis techniques are important in industrial applications along with hardware implementation techniques. Battery management and wireless power transmission technologies, the design and optimization of low-power circuits, and systems for continuous monitoring and data collection/transmission should also be considered with sensor technologies. In addition, machine-learning-based diagnostic technology can be used for extracting meaningful information from continuous monitoring data.

This book provides a broad survey of the field of biochips, including fundamentals of microelectronics and biomaterials interaction with various, living tissues, as well as numerous, diverse applications. Although a wide variety of biochips will be described, there will be a focus on those at the brain-machine interface. Analysis is included of the relationship between different categories of biochips and their interactions with the body and coverage includes wireless remote control of biochips and arrays of microelectrodes, based on new biomaterials.

Through the use of enhanced sensitivity sensors and carefully matched electronics, Active Signal Technologies, under contract with MRMC, developed and tested a portable Vital Signs Monitor (VSM). The purpose of the VSM is to monitor the condition of casualties at the point of injury and display the two principal vital signs of pulse rate and breathing rate and an additional temperature display that provides an indication of surface temperature. The sensors are contained in a band that is attached to the neck--a site selected in order to avoid the necessity of tearing the casualty's clothing for sensor placement. One sensor rests on the carotid and the other over the larynx. Once in place, the sensor's signals are conditioned and digitized by suitable electronics to count pulse rate, breathing rate, and temperature. The system was tested successfully on patients at the University of Maryland Shock Trauma Center and on pilots at the National Guard Armory at the Aberdeen Proving Grounds. It performed well with an occasional low reading from persons with very faint breathing signals. The next system literation can include isolating all signals from any ambient noise or motion.

The book introduces flexible and stretchable wearable electronic systems and covers in detail the technologies and materials required for healthcare and medical applications. A team of excellent authors gives an overview of currently available flexible devices and thoroughly describes their physical mechanisms that enable sensing human conditions. In dedicated chapters, crucial components needed to realize flexible and wearable devices are discussed which include transistors and sensors and deal with memory, data handling and display. Additionally, suitable power sources based on photovoltaics, thermoelectric energy and supercapacitors are reviewed. A special chapter treats implantable flexible sensors for neural recording. The book editor concludes with a perspective on this rapidly developing field which is expected to have a great impact on healthcare in the 21st century.

As diverse as tomorrow’s society constituent groups may be, they will share the common requirements that their life should become safer and healthier, offering higher levels of effectiveness, communication and personal freedom. The key common part to all potential solutions fulfilling these requirements is wearable embedded systems, with longer periods of autonomy, offering wider functionality, more communication possibilities and increased computational power. As electronic and information systems on the human body, their role is to collect relevant physiological information, and to interface between humans and local and/or global information systems. Within this context, there is an increasing need for applications in diverse fields, from health to rescue to sport and even remote activities in space, to have real-time access to vital signs and other behavioral parameters for personalized healthcare, rescue operation planning, etc. This book’s coverage will span all scientific and technological areas that define wearable monitoring systems, including sensors, signal processing, energy, system integration, communications, and user interfaces. Six case studies will be used to illustrate the principles and practices introduced.

For remote registration of vital signs, non-invasiveness is attractive. The possibility of acute loss of consciousness threatens the lives of employees such as soldiers, fire fighters, police officers, and law enforcement personnel, who perform duties at hazardous or remote conditions. The brain cells die within three minutes after occurrence of hypoxia in cerebrospinal fluid. Consequently, acute occurrence of cardiac or pulmonary system failure reduces an employee's likelihood of surviving due to the lack of ability for communication and the lack of ability for emergency calls. In the case of severe injury, a medic's response time becomes a crucial parameter for increasing a person's likelihood of survival. Continuous monitoring of vital signs therefore assists medics and employees by reducing response time to severe accidents. For detection of vital signs; electrocardiography, capnometry and pulse oximetry are being widely used as the golden standard for extraction of vital signs such as heart rate, respiration rate and blood oxygenation. But, these sensors require motionless attachment to specific areas of the body. The fact that employees are constantly in motion and sometimes covered by protection shields introduces difficulty concerning the continuous obtaining of vital signs. In this dissertation, we studied feasibility of replacing Electrocardiography by Photoplethysmography on mechanically flexible sensors. Three major studies were performed. First, we developed an algorithm for the detection of respiration rate from Photoplethysmography. During this study, a fast respond CO2 sensor was also modulated to detect respiration rate, and both methods were compared to respiration effort transducer. Second, we assessed the feasibility of fabricating PPG sensors on plastic polymers. During this study, we designed and integrated a novel PPG device, using inkjet-printing technology. At last, we developed a computationally inexpensive algorithm for the extraction of heart rate variability (HRV) from the morphology of PPG. Results were compared to HRV from commercial ECG and the performance of the device was evaluated respectively.

Ambient Sensor based vital sign monitoring has been emerging and more attractive in the field of health care. Market study shows that there is a need for continuous monitoring of vital signs. A set of ambient vital sign monitoring sensors are studied in thesis. Pyroelectric infrared (PIR) sensor is used for non-contact based resting heart rate estimation. This infrared system monitors and records the chest motion of a subject using the analog output signal of the PIR sensor. The analog output signal represents the composite motion due to inhaleexhale process with magnitude much larger than the minute vibrations of heartbeat. Since the acceleration of the heart activity is much faster than breathing the second derivative of the PIR sensor signal monitoring the chest of the subject is used to estimate the resting heart rate. This new system provides a low cost and an effective way to estimate the resting heart rate, which is an important biological marker. Ballistocardiogram (BCG) technique is used for non-invasive vital sign measurement system. Polyvinylidene flouride (PVDF) and Electromechnical film (EMFi) sensor are used for non-intrusive based vital sign monitoring. Respiration rate is estimated based on the inhale and exhale breathing force exerted on the sensors. Data is collected from various subjects and the results are validated to the industry standard sensors. A total of 30 subjects (5 females) are recruited. The age group of subjects lies between 20 and 55 years old. During the experiment subjects were wearing their own outfits. The experiment was conducted in a standard lab environment. Prior to the experiment an institutional review board (IRB) approval is obtained from human research protection program (HRPP).