Biotechnologies toward Mitigating, Curing, and Ultimately Preventing Edema through Compression Therapy

Wearable Sensors for Remote Health Monitoring: Potential Applications for Early Diagnosis of Covid-19

Wearable sensors are emerging as a new technology to detect physiological and biochemical markers for remote health monitoring. By measuring vital signs such as respiratory rate, body temperature, and blood oxygen level, wearable sensors offer tremendous potential for the noninvasive and early diagnosis of numerous diseases such as Covid-19. Over the past decade, significant progress has been made to develop wearable sensors with high sensitivity, accuracy, flexibility, and stretchability, bringing to reality a new paradigm of remote health monitoring. In this review paper, the latest advances in wearable sensor systems that can measure vital signs at an accuracy level matching those of point-of-care tests are presented. In particular, the focus of this review is placed on wearable sensors for measuring respiratory behavior, body temperature, and blood oxygen level, which are identified as the critical signals for diagnosing and monitoring Covid-19. Various designs based on different materials and working mechanisms are summarized. This review is concluded by identifying the remaining challenges and future opportunities for this emerging field.

Advanced Design and Manufacture of Mechanoactive Materials Inspired by Skin, Bones, and Skin-on-Bones

Life is mechanobiological. Natural living materials exhibit remarkable, emergent and smart properties under mechanical loading. Such materials are classified as mechanoactive, in contrast to electroactive polymers and materials that exhibit advanced properties when subjected to electrical stimulation. Cutting edge, multiscale imaging technologies have proven enabling for the elucidation of molecular to meso-scale structure and function of natural mechanoactive materials. Using Microscopy-Aided Design And ManufacturE, (MADAME) this perspective article describes mechanoactive properties of natural materials including skin-on-bones (periosteum) and bone itself. In so doing, it demonstrates the principle to emulate natural smart properties using recursive logic, the basis of many computer algorithms, and to design and manufacture mechanoactive materials and products using advanced manufacturing methods that also incorporate principles of recursive logic. In sum, the MADAME approach translates physically the computer science paradigm of recursion by implementing Jacquard textile methods, which themselves form a historical basis for computing machines, together with additive manufacturing methods including multidimensional printing, stereolithography, laser sintering, etc. These integrated methods provide a foundation and translational pathway for scaled-up manufacture of disruptive mechanoactive materials that will find use in fields as varied as medicine, safety, transport and sports, for internal (implants) and external (wearables) applications.

Compression therapy in lymphedema: Between past and recent scientific data

Aim

To extrapolate and discuss the scientific data on compression in lymphedema treatment, so to review old and innovative concepts about pressure, stiffness and other interplaying factors related to its efficacy and comfort.

Material and methods

Narrative review based on search in Medline/Google Scholar through key-words related to compression in lymphedema.

Results

Currently available literature lacks relevant details about data on protocol, devices, techniques, interface pressure, stiffness, as well as biases are represented by the different descriptions to present the outcomes. More recent evidence from adjustable wrap devices and elastic garments question the need for high pressure (especially for the upper limb) and stiffness in lymphedema treatment.

Conclusions

At present time a very strong compression pressure exerted by material with high stiffness seem to be questionable in lymphedema treatment. A low pressure provides the best outcomes in arm lymphedema, while a pressure in the range of 40–60 mm Hg seems to provide higher efficacy in lower limb lymphedema, provided it is maintained overtime. A high stiffness seems to be unnecessary to treat chronic edema. Future clinical trials, including proper description of treatment methodology and adequate investigating instrumental tools, are awaited to possibly corroborate the conclusive outcomes of our review.

Ultrasensitive and Stretchable Strain Sensors Based on Mazelike Vertical Graphene Network

Here, we report a new type of strain sensors consisting of vertical graphene nanosheets (VGNs) with mazelike network, sandwiched between poly(dimethylsiloxane) (PDMS) substrates. The new sensors outperform most graphene thin-film-based sensors reported previously and show an outstanding combination of high stretchability of ∼120%, excellent linearity over the entire detection range, and high sensitivity with a gauge factor of ∼32.6. The sensitivity can be tuned by controlling the thickness of VGNs, with sensors consisting of thicker VGNs showing higher sensitivity but slightly lower stretchability (the maximum gauge factor is ∼88.4 with a maximum detection strain of ∼55%). Detailed microscopic examinations reveal that the ultrahigh sensitivity stems from the formation of microcracks initiated in the buffer layer. These microcracks are bridged by strings of graphene/PDMS, enabling the conductive network to continue to function up to a strain level significantly higher than that of previously reported graphene thin-film-based sensors. Furthermore, the present sensors have been found to be insensitive to temperatures and various liquids, including water and 0.1 mol L^-1 sodium chloride solution (similar to the sweat on human skin). Demonstrations are presented to highlight the new sensors' potential as wearable devices for human motion detection and pressure distribution measurement.