Seismocardiography (SCG) is a measure of chest vibration associated with heartbeats. While skin soft electronic tattoos (e‐tattoos) have been widely reported for electrocardiogram (ECG) sensing, wearable SCG sensors are still based on either rigid accelerometers or non‐stretchable piezoelectric membranes. This work reports an ultrathin and stretchable SCG sensing e‐tattoo based on the filamentary serpentine mesh of 28‐µm‐thick piezoelectric polymer, polyvinylidene fluoride (PVDF). 3D digital image correlation (DIC) is used to map chest vibration to identify the best location to mount the e‐tattoo and to investigate the effects of substrate stiffness. As piezoelectric sensors easily suffer from motion artifacts, motion artifacts are effectively reduced by performing subtraction between a pair of identical SCG tattoos placed adjacent to each other. Integrating the soft SCG sensor with a pair of soft gold electrodes on a single e‐tattoo platform forms a soft electro‐mechano‐acoustic cardiovascular (EMAC) sensing tattoo, which can perform synchronous ECG and SCG measurements and extract various cardiac time intervals including systolic time interval (STI). Using the EMAC tattoo, strong correlations between STI and the systolic/diastolic blood pressures, are found, which may provide a simple way to estimate blood pressure continuously and noninvasively using one chest‐mounted e‐tattoo.

telemedicine, mobile health, prosthetics, athletic training, human-machine interface (HMI) and so on. From "skin-like" electronics (a.k.a. e-skins) [1] to "epidermal electronics" (a.k.a. e-tattoos), [2] people are hopeful that the emerging flexible/ stretchable electronics technologies will disrupt the wearable industry. Specifically, e-tattoos are ultrathin, ultrasoft membranes that can well conform to the skin to monitor a variety of biomarkers including electrophysiology, [3] mechanoacoustic signals, [4] skin temperature, [5] skin hydration, [6] skin stiffness, [7] blood pressure, [8] blood oxygen saturation, [9] and even sweat analytes. [10] Wireless communication enabled by near field communication (NFC) [9a,11] and Bluetooth [12] have also been demonstrated in a few recent e-tattoos. However, which biomarker to measure is highly personal and may vary from time to time for the same individual. Moreover, different biomarkers should be measured at different locations using different types of sensors and read-out circuits. Even if one can build a multimodal e-tattoo, excessive recordings not personalized to the user may cause unnecessary power and bandwidth consumption, which is a major concern for wireless wearables. Although it is possible to build specific e-tattoos for specific sensing tasks, it would be a big waste of the wireless transmission and read-out circuits if the whole e-tattoo has to be disposed after just one use.Herein, we propose a possible remedy for all the aforementioned challenges-the modular and reconfigurable e-tattoos, where layers of distinct functionalities (e.g., NFC layer, analog front end (AFE) layer, electrode layer, etc.) can be pre-fabricated as building blocks that can be picked and assembled into customized e-tattoos and can also be swapped out to form new e-tattoos. Electrical connections between the layers can be achieved through aligned vias. Compared with existing monolayer, fully pre-defined e-tattoos, the newly proposed modular and reconfigurable e-tattoos would have the following appealing advantages. First, the multilayer stack can effectively shrink the footprint of the e-tattoo on the skin, especially when numerous components and complex circuits are needed for signal read-out and wireless transmission. Second, when the measurement is done, only the passive electrode/sensor layer that has been in direct contact with the skin needs to be peeled off from the e-tattoo and disposed. As a result, the leftover NFC In the past few years, ultrathin and ultrasoft epidermal electronics (a.k.a. e-tattoos) emerged as the next-generation wearables for telemedicine, mobile health, performance tracking, human-machine interface (HMI), and so on. However, it is not possible to build an all-purpose e-tattoo that can accommodate such a wide range of applications. Thus, the design, fabrication, and validation of modular and reconfigurable wireless e-tattoos for personalized sensing are reported. Such e-tattoos feature a multilayer stack of stretchable layers of distinct function...

In article number 1900290 , Nanshu Lu and co‐workers create a noninvasive, ultrathin, and stretchable e‐tattoo capable of electro‐mechano‐acoustic cardiovascular (EMAC) sensing to synchronously measure electrocardiogram (ECG) and seismocardiogram (SCG), which can be used to extract various cardiac time intervals and infer systolic and diastolic blood pressure beat‐to‐beat. A 3D digital image correlation (DIC) method is applied to map human chest displacement to determine the best location for e‐tattoo attachment.

High-resolution microendoscopy (HRME) is a low-cost strategy to acquire images of intact tissue with subcellular resolution at frame rates ranging from 11 to 18 fps. Current HRME imaging strategies are limited by the small microendoscope field of view (∼0.5 mm2); multiple images must be acquired and reliably registered to assess large regions of clinical interest. Image mosaics have been assembled from co-registered frames of video acquired as a microendoscope is slowly moved across the tissue surface, but the slow frame rate of previous HRME systems made this approach impractical for acquiring quality mosaicked images from large regions of interest. Here, we present a novel video mosaicking microendoscope incorporating a high frame rate CMOS sensor and optical probe holder to enable high-speed, high quality interrogation of large tissue regions of interest. Microendoscopy videos acquired at >90 fps are assembled into an image mosaic. We assessed registration accuracy and image sharpness across the mosaic for images acquired with a handheld probe over a range of translational speeds. This high frame rate video mosaicking microendoscope enables in vivo probe translation at >15 millimeters per second while preserving high image quality and accurate mosaicking, increasing the size of the region of interest that can be interrogated at high resolution from 0.5 mm2 to >30 mm2. Real-time deployment of this high-frame rate system is demonstrated in vivo and source code made publicly available.

. Significance Despite recent advances in multimodal optical imaging, oral imaging systems often do not provide real-time actionable guidance to the clinician who is making biopsy and treatment decisions. Aim We demonstrate a low-cost, portable active biopsy guidance system (ABGS) that uses multimodal optical imaging with deep learning to directly project cancer risk and biopsy guidance maps onto oral mucosa in real time. Approach Cancer risk maps are generated based on widefield autofluorescence images and projected onto the at-risk tissue using a digital light projector. Microendoscopy images are obtained from at-risk areas, and multimodal image data are used to calculate a biopsy guidance map, which is projected onto tissue. Results Representative patient examples highlight clinically actionable visualizations provided in real time during an imaging procedure. Results show multimodal imaging with cancer risk and biopsy guidance map projection offers a versatile, quantitative, and precise tool to guide biopsy site selection and improve early detection of oral cancers. Conclusions The ABGS provides direct visible guidance to identify early lesions and locate appropriate sites to biopsy within those lesions. This represents an opportunity to translate multimodal imaging into real-time clinically actionable visualizations to help improve patient outcomes.