In Situ and Intraoperative Detection of the Ureter Injury Using a Highly Sensitive Piezoresistive Sensor with a Tunable Porous Structure

Abstract

Iatrogenic ureteral injury, as a commonly encountered problem in gynecologic, colorectal, and pelvic surgeries, is known to be difficult to detect in situ and in real-time. Consequently, this injury may be left untreated, thereby leading to serious complications such as infections, renal failure, or even death. Here, highperformance tubular porous pressure sensors were proposed to identify the ureter in situ intraoperatively. The electrical conductivity, mechanical compressibility, and sensor sensitivity can be tuned by changing the pore structure of porous conductive composites. A low percolation threshold of 0.33 vol % was achieved due to the segregated conductive network by pores. Pores also lead to a low effective Young's modulus and high compressibility of the composites and thus result in a high sensitivity of 448.2 kPa −1 of sensors, which is consistent with the results of COMSOL simulation. Self-mounted on the tip of forceps, the sensors can monitor tube pressures with different frequencies and amplitudes, as demonstrated using an artificial pump system. The sensors can also differentiate ureter pulses from aorta pulses of a Bama minipig in situ and in real-time. This work provides a facile, cost-effective, and nondestructive method to identify the ureter intraoperatively, which cannot be effectively achieved by traditional methods.

Wireless Rehabilitation Training Sensor Arrays Made with Hot Screen-Imprinted Conductive Hydrogels with a Low Percolation Threshold

“…In general, piezoresistive sensors responding to different pressures rely on two principal factors: (1) the resistance change of the pressure-sensitive materials and (2) the change of contact resistance between the microstructures of pressure-sensitive materials and the electrodes. 36 Recently, various sophisticated microstructures, including the micropyramid structure, 37 the micropillar structure, 38 the interlocked structure, 39 the porous structure, 40 and so on, have been used to enhance the sensitivity of piezoresistive sensors. These microstructures can provide more contact area and increase the change rate of contact resistance.…”

A Novel Hollow Graphene/Polydimethylsiloxane Composite for Pressure Sensors with High Sensitivity and Superhydrophobicity

“…26−28 Generally, the pore size and pore shape introduced through chemical foaming and natural mold are not controllable and tunable, and the regular porous structure prepared through the hard template often contains complicated processes and toxic reagents. 29,30 Notably, both the micropatterned surface and the hybrid porous micro- structure play important roles in improving the sensing performance. The common way of combining multiple microstructures by introducing a micropatterned surface on the internal porous material helps to further achieve highperformance sensors.…”

“…The hierarchical design of the micropattern helps to broaden the linear range for a high sensitivity since the irregular microstructures can provide additional conducting paths as well as increase the contact area under pressure. − For example, the sensor based on the skin-inspired hierarchical structure endows the sensor with a linear range of 30 kPa, and a binary hierarchical structure enables the sensor sensing for a wide range to 120 kPa with a sensitivity of 17.5 kPa –1 . In addition to surface micropatterned structures, introducing a porous active layer can also decrease the modulus of the materials and permit more three-dimensional microstructure design of the active layer. − Generally, the pore size and pore shape introduced through chemical foaming and natural mold are not controllable and tunable, and the regular porous structure prepared through the hard template often contains complicated processes and toxic reagents. , Notably, both the micropatterned surface and the hybrid porous microstructure play important roles in improving the sensing performance. The common way of combining multiple microstructures by introducing a micropatterned surface on the internal porous material helps to further achieve high-performance sensors. , For example, Zhao fabricated a pressure sensor based on a hybrid structure through a one-step microwave irradiation process, showing a high sensitivity of 611.85 kPa –1 .…”

Flexible pressure sensors via engineering microstructures for wearable human-machine interaction and health monitoring applications

“…Copyright 2019, American Chemical Society(Wang et al, 2021b). Copyright 2021, Elsevier Ltd(Wang et al, 2021d). Copyright 2021, American Chemical Society(Zhao et al, 2020).…”