Wearable Pressure Sensors for Pulse Wave Monitoring

Abstract

Furthermore, by 2030 this number is expected to rise steadily to 23.6 million. [2] Despite such high mortality rates, most CVD, [3,4] including arteriosclerosis, [5,6] diabetes, [7][8][9][10] myocardial infarction, [11,12] coronary heart disease, [13,14] and hypertension, [15][16][17][18] can be prevented and treated through early diagnosis and long-term monitoring of physiological signaling. Conventional health systems suffer from deficiencies in wearability, wireless technology, lifespan, and stability to maintain a long-term collection of clinical-grade individual health metrics for accurate diagnosis. [19][20][21] As such, promoting the utility of Internet of Things (IoT)-enabled technology in personalized healthcare is still significantly impeded by the need for costeffective and wearing-comfort biomedical devices to continuously provide real-time patient-generated health data. Over the past several decades, significant advances in wearable pressure sensors have been observed, allowing them to noninvasively and continuously detect human physiological and pathological signals. [22][23][24][25][26][27][28][29][30][31][32][33][34][35] These biomedical metrics can then be used to evaluate cardiovascular conditions, providing a personalized health care system with better health outcomes, increased user-friendliness, greater quality, and cost-effectiveness that are essential to reducing CVD incidence and mortality. [36][37][38][39] Pulse waves are prominent component of human physiological signaling and involve abundant human-health information that can reveal individual conditions, including heart problems (such as arrhythmia), blood pressure, vascular aging, exercise, medication, and sleep status. [40][41][42][43][44][45] Although physical symptoms are often elusively observed in their early stages, they can be diagnosed through subtle pulsewave changes. Preventive action of CVDs can be taken by differentiating the variance of pulse waveforms with consideration of participants' age, gender, weight, and daily diet. [46][47][48][49] Traditional Chinese medicine (TCM) has proposed empirical approaches to analyze human physical state from pulse waves, rendering pulse wave surveillance unavoidable for TCM. [50,51] TCM is unable to continuously monitor pulse waves, limiting the accuracy of the assessment results. As such, empirical diagnostic methods may profoundly depend on the experiences of the practitioner, the emotions of the participant, and the external environment, resulting in the administration of distorted or problematic treatment. [52] Additionally, the diagnostic results among practitioners are Cardiovascular diseases remain the leading cause of death worldwide. The rapid development of flexible sensing technologies and wearable pressure sensors have attracted keen research interest and have been widely used for longterm and real-time cardiovascular status monitoring. Owing to compelling characteristics, including light weight, wearing comfort, and high sensitivity to pulse pressures, physiological pulse ...

Mechanical Sensors for Cardiovascular Monitoring: From Battery-Powered to Self-Powered

“…For all of these sensors, the active sensing component changes in response to strain or pressure, resulting in a change in resistance, capacitance, or induced charge, which further changes the electrical signal output for sensing. Resistive and capacitive sensors require an external power source for sensing, whereas piezoelectric and triboelectric sensors can convert pressure or strain directly into an electrical signal for self-powered sensing [ 22 ]. Generally, macro-/micro-/nanostructural design on the surface of these sensing materials can increase the effective contact area and force perception ability, thereby improving the sensitivity of the sensor and enabling it to sensitively detect weak external pressure changes [ 12 , 14 , 23 , 24 , 25 , 34 , 35 ].…”

“…These limitations present significant challenges in identifying detailed information about the physiological form carried by the pulse waveform signal. In contrast, mechanical methods can obtain information directly, reflecting the pressure waves in the vasculature by attaching a pressure or strain sensor to the surface of the vascular system or the skin close to the arteries [ 21 , 22 ]. Moreover, they are relatively more energy efficient and typically operated in the nanowatt to microwatt range.…”

A Deep‐Learning‐Assisted On‐Mask Sensor Network for Adaptive Respiratory Monitoring

“…The working principle of the textile sensor for respiratory monitoring is the combination of the triboelectric effect and electrostatic induction that converts breathing pressure into electricity. [17,22,[42][43][44][45] A cross section of the textile sensor is schematically shown in Figure 3a-I. With the breathing pressure, the two yarns contact each other and equivalent electrification with opposite polarities is generated on the surface of PVDF and epoxy.…”

Soft Iontronic Capacitive Sensor for Beat‐to‐Beat Blood Pressure Measurements

“…[11][12][13][14][15] Compared to other pressure sensors that used piezoresistance, [16][17][18][19][20] optics, [21][22][23] piezoelectricity, [24][25][26][27][28] triboelectricity, [29][30][31][32] and magnetoelasticity, [33,34] CPSs were known for their good dynamic response. [35] Despite having high sensitivities, recent pressure sensors that used variable conductance hydrogel or transistor configuration required constant supply of power for operation and therefore, not ideal for wearable applications that require sustained operation and are used for long-term vital signal monitoring. [36,37] However, existing CPS designs were limited in sensitivity, response time, detection range, and anti-noise interference.…”