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We devised a surgical tape that prevents skin tears while maintaining adhesive strength. Under the assumption that microscopic damage to the skin is reflected in pain felt on the skin, we statistically analyzed skin pain when the tape was peeled off to show the skin protection effect of the mesh on the new tape. This tape has a three-layer structure consisting of a tape substrate, adhesive, and mesh. When the tape is applied to the skin, a mesh is located between the adhesive and the skin. The adhesive contacts the skin through the mesh holes and fixes the substrate to the skin; it does not come into contact with the skin at the mesh body; therefore, the adhesive-skin contact area is reduced. In this experiment, we used surgical tape with and without mesh. At 8 hours after the application of each tape to the forearm of five adult males, it was removed. All tapes were peeled off while maintaining an angle of approximately 120° between the skin and tape substrate. For the tape with mesh, the tape substrate was peeled off in two ways: peeling off the substrate together with the mesh and peeling off the substrate, leaving the mesh on the skin. A perception and pain quantification analyzer (Pain Vision™) was used to quantify pain. The data were compared and examined statistically (Friedman's test and Wilcoxon's coded rank test). The least pain was experienced while peeling off the tape substrate, leaving the mesh on the skin. There was a significant difference in pain levels among the three tape removal methods. There was also a significant difference between the two peeling methods in the experimental group. The skin protection effect of the mesh reduced pain when the surgical tape was removed. [ABSTRACT FROM AUTHOR]

The authors have been teaching conceptual design courses to graduate schools and adult groups. Despite the instructors’ encouragement to refine a design to a level that clarifies the elemental functional requirement for each part element, the students often lump elemental functional requirements into higher level functions. The resulting Design Record Graph shows a functional requirement with multiple arcs extending to the corresponding nodes in the design parameter space. When such a design maps to a Design Matrix in Axiomatic Design, the matrix turns into a rectangular one with non-diagonal elements. Instead of just speaking to the students that they will face difficulty when it comes to producing prototypes, the authors developed a metric that quantifies the level of detail of a design so the students, often driven to gain higher numerical scores, will naturally spend efforts to refine their designs to levels that are ready for building prototypes. We call this metric Level of Readiness Index, i.e., LOR Index.

This paper proposes “Value Axiom” that states “The larger the sum of Customer Attribute values, the better the design.” A customer evaluates a design with the sum of the value produced by each Customer Attribute, expressing it with a monetary value such as Japanese yen. A designer can hardly estimate and express a perfect set of Customer Attributes at the early stage of a design. The designer writes down the design equation to visualize the entire design, and improves the sets of Design Parameters and Functional Requirements using the Independence Axiom and Information Axiom, and at the same time, it is also important to review the values of Customer Attributes using the Value Axiom.

The authors have students draw Functional Requirement (FR) – Design Parameter (DP) charts for their free subject design assignments before teaching them Axiomatic Design (AD) in detail. The students cannot list all important FRs and DPs even with Zigzag thinking between FR and DP from higher level to lower; then, they tend to list FRs chronologically like flowcharts and DPs spatially like bill of material. The strategy, however, often results in different counts of FRs and DPs and a number of interferences among them. When this happens, we lead the students to carry out the thinking processes of functional integration of FRs and physical integration of DPs so they can reach a regular matrix for the design equation. Once regularization is reached, the students can apply independence axiom to improve their designs.

Designers spend much efforts in defining their products and systems, planning how they work during normal operation. Design assisting tools like Design Matrices in Axiomatic Design (AD) or Design Record Graphs (DRG) are available to the designer in search for ways to improve their work. Majority of accidents, however, take place during irregular operations like maintenance when interlocks are often bypassed and automatic processing are switched to manual. System safety is then in the hands of human operators. A number of past AD studies have addressed safety in products and systems, however, design parameters (DPs) have been physical parts or structures. This paper shows assignment of human actions, like, “reading the quantity display,” “making judgement,” or “pressing a control button,” as DPs in axiomatic design. Such human DPs play important roles during maintenance, nevertheless, designers often leave out safety evaluation of their designs in this maintenance mode. When a human DP fails to meet its functional requirement (FR), the product often faces failure and the system often heads into an accident. Identifying human DPs in products or systems thus alerts maintenance phase workers about actions that are critical for safety. Most accidents take place with excessive dependence on human DP of memory.