Nonuniform Deformation of Cell Structures Owing to Plastic Stress Wave Propagation

In cell structures, unlike in dense bodies, nonuniform deformation occurs from the impact end, even at velocities in the order of tens to hundreds of meters per second. In this study, we experimentally examine the nonuniform deformation mechanism of cell structures. They prepared two kinds of specimens: nickel foam (Ni foam) and silicone-rubber-filled nickel foam (Ni/silicone foam). As a dynamic and impact test method (compression velocity of 20 m/s or more), we used a dynamic and impact load-measuring apparatus with opposite load cells to evaluate the loads on both ends of the specimen in one test. At compression velocities of 20 m/s or less, no nonuniform deformations were observed in the Ni foam and the Ni/silicone foam, and the loads on the impact and the fixed ends achieved force equilibrium. The Ni foam showed no change with an increasing strain rate, and the Ni/silicone foam showed a strong strain rate dependence of the flow stress. At a compression velocity of approximately 26 m/s, the loads differed at the two ends of the Ni/silicone foam, and we observed nonuniform deformation from the impact end. The results of the visualization of the load and deformation behavior obtained from both ends of the specimen revealed that the velocity of the plastic stress wave and the length of the specimens are important for nonuniform deformation.

Effect of Silicone Inlaid Materials on Reinforcing Compressive Strength of Weft-Knitted Spacer Fabric for Cushioning Applications

Spacer fabrics are commonly used as cushioning materials. They can be reinforced by using a knitting method to inlay materials into the connective layer which reinforces the structure of the fabric. The compression properties of three samples that were fabricated by inlaying three different types of silicone-based elastic tubes and one sample without inlaid material have been investigated. The mechanical properties of the elastic tubes were evaluated and their relationship to the compression properties of the inlaid spacer fabrics was analysed. The compression behaviour of the spacer fabrics at an initial compressive strain of 10% is not affected by the presence of the inlaid tubes. The Young’s modulus of the inlaid tubes shows a correlation with fabric compression. Amongst the inlaid fabric samples, the spacer fabric inlaid with highly elastic silicone foam tubes can absorb more compression energy, while that inlaid with silicone tubes of higher tensile strength has higher compressive stiffness.

Effect of Self-Adhesive Soft Silicone Foam Dressing Combined with Clustered Nursing Strategy on Prevent Pressure Injury in Patients after Pancreaticoduodenal Surgery

Background and purpose: Pancreaticoduodenectomy is a kind of abdominal surgery with large trauma, complicated operation and high incidence of postoperative complications especially for elderly patients. Pressure injury is one of its common complications. This study explored the preventive effect of self-adhesive soft silicone foam dressing combined with clustered nursing strategy on patients with pressure injury after pancreaticoduodenal surgery. Methods: From November 2018 to November 2020,120 elderly patients who underwent pancreaticoduodenectomy in the Department of Hepatobiliary Surgery of Hunan Provincial People’s Hospital were selected and randomly divided into a control group and an observation group. The control group was treated with routine care, and the observation group was treated with self-adhesive soft silicone foam dressing combined with clustered care. The pressure injury risk score, pressure injury incidence rate, skin complication rate, psychological concern score, and sense of trust score, comfort score, physiological problem score and nursing satisfaction score were compared between the two groups. Results: Compared with the control group, the pressure injury risk score, pressure injury incidence rate, and skin complications incidence rate of the observation group were lower (P < 0.05), while the psychological concern score, trust score, comfort score, the scores of physiological problems and nursing satisfaction were higher (P < 0.05). Conclusion: Self-adhesive soft silicone foam dressing combined with clustered nursing strategy can reduce the risk score and incidence of pressure injury in elderly patients after pancreaticoduodenal surgery, reduce the occurrence of complications, and improve nursing comfort and satisfaction. It is worthy of promotion

Use of multilayer silicone foam dressings as adjuvant therapy to prevent pressure injuries

Despite progress in the prevention of pressure injuries (PIs), they remain a challenging public health problem because of their frequency and morbidity. Protection of the skin by multilayer silicone foam dressings may be an adjuvant measure to prevent PIs in high-risk patients. Despite the available clinical data and published recommendations on this measure, caregivers face difficulties in identifying patients who would benefit from this adjuvant measure. The objective of this work was to define the profiles of high-risk patients who would benefit optimally from this measure in combination with basic preventive procedures. This consensual expert opinion was drawn up using two methods: the Nominal Group Technique with eight medical and paramedical experts, and the Delphi process with 16 experts. The bases for this expert consensual opinion were a formal search and analysis of the published literature regarding evidence on the prevention of PIs using multilayer silicone foam dressings. The consensual expert opinion reported here addresses five proposals mostly intended to define patients who would benefit from the use of a multilayer silicone foam dressing (≥4 layers) to prevent PIs (sacrum and heels).

Electroplating and Ablative Laser Structuring of Elastomer Composites for Stretchable Multi-Layer and Multi-Material Electronic and Sensor Systems

In this work we present the concept of electroplated conductive elastomers and ablative multi-layer and multi-material laser-assisted manufacturing to enable a largely automated, computer-aided manufacturing process of stretchable electronics and sensors. Therefore, the layers (conductive and non-conductive elastomers as well as metal layers for contacting) are first coated over the entire surface (doctor blade coating and electroplating) and then selectively removed with a CO2 or a fiber laser. These steps are repeated several times to achieve a multi-layer-structured design. Is it not only possible to adjust and improve the work previously carried out manually, but also completely new concepts such as fine through-plating between the layers to enable much more compact structures become possible. In addition, metallized areas allow the direct soldering of electronic components and thus a direct connection between conventional and stretchable electronics. As an exemplary application, we have used the process for manufacturing a thin and surface solderable pressure sensor with a silicone foam dielectric and a stretchable circuit board.

A soft silicone foam dressing that aids healing and comfort in oncology care

Maintaining skin integrity plays a key role in the ongoing care and comfort of patients at the end of life. Unfortunately, patients receiving cancer treatments are at higher risk of altered skin integrity. Cancer treatments involve multiple modalities, all of which impair wound healing. Excess exudate can be distressing to patients, resulting in catastrophic damage to the wound bed and surrounding skin, reducing quality of life and increasing the need for specialist services. This article describes the use of the Kliniderm foam silicone range of dressings, in combination with best practice, in the treatment of wounds in the oncology setting. The case study evidence presented indicates that this range of dressings is useful in the management of radiotherapy and oncology wounds. It had a positive effect on the exudate level, wound-association pain and the peri-wound skin in these patients, aiding the management of the wound bed.

Pressure ulcer prevention dressing design and biomechanical efficacy

The objective of this educational article is to explain in non-technical terms how the engineering considerations in the design of prophylactic dressings for pressure ulcer (PU, also known as pressure injury) prevention eventually determine the associated clinical and cost-benefit outcomes. The article specifically describes a bioengineering algorithm for quantitative evaluation of the biomechanical efficacy of different prophylactic dressing designs, which is exemplified for two fundamentally different dressing technologies, one based on superabsorbent cellulose core versus the conventional silicone-foam dressing design. A set of three biomechanical indices is described and employed for the above comparative evaluation, namely, the protective efficacy index, the protective endurance and the prophylactic trade-off design parameter. It is demonstrated that the dressing with the superabsorbent cellulose core is at least as good as silicone-foams but, importantly, provides a good balance between its protective performance in its ‘new’ condition, as opposed to its ‘used’ condition, i.e., after being exposed to moisture. Most notably, we show that preventative dressings are never equal in their performances; the underlying structure and the dressing ingredients together determine the extent of the delivered tissue protection and its durability.