How to use human pose estimation to measure the hand-arm motion in craft application with no influence on the natural user behavior

The interaction between human and machine plays an important role in the design and optimization of human-machine systems. This interaction is characterized by human motion using the technical system. Especially in the field of hand and power tool applications, the motion capture should be performed under the real working condition and without influencing the user. There are already motion tracking systems that allow capturing the motion during the interaction, but there is no mobile motion capture system that allows an individual analysis of the user for biomechanical analysis in the normal work process without influencing him. Therefore, requirements for a motion capture system are derived and a system is presented that meets these requirements. This system consists of two cameras and is based on the pose estimation algorithm OpenPose. The comparison of the presented system and the state-of-the-art system Xsens is performed and based on the measured elbow angle and the wrist position. The results show a very good correspondence between the curve characteristic of the elbow angle and the wrist position of both systems. However, inexplicable values shifting at two different levels still occur, which need to be investigated further. Overall, the presented system shows great potential in terms of mobility and flexibility of the presented system with some weaknesses in the data processing and efficiency. By addressing these weaknesses, the presented system can be used in the analysis and optimization of human-machine systems

User-centered design of power tools: a generic process for evaluation of usability aspects [Die Nutzerzentrierte Produktentwicklung von Power-Tools: Ein generischer Prozess zur Untersuchung von Usability-Aspekten]

User-centered design focuses on the individual needs of the product users. The aim is to adjust the design of the product according to the requirements of the user and application. Existing methods for evaluation of the perceived usability are often limited to one specific aspect, and it requires a high effort to transfer the respective method to other aspects. A generic process for the evaluation of the perceived usability is missing. This paper presents the generic Usability Study Evaluation Process (USE-Process) that helps product designers to identify and evaluate usability aspects relevant to the suitability of the usage of a product. The process is divided into three sections: 1. A structured field study to identify the relevant usability aspects; 2. A generic study design for the subjective evaluation of usability aspects under objective and reproducible conditions; 3. The use of measurement tools that help to quantify the results of the subjective evaluation. The generic applicability of the process is shown by the example of the evaluation of cordless screwdrivers; several usability aspects were identified, clustered, and evaluated by using subjective evaluation methods and measurement techniques

Probabilistic seismic hazard estimation in low-seismicity regions considering non-Poissonian seismic occurrence

Geophysical Journal International, v. 164, n. 3, p. 543-550, 2006. http://dx.doi.org/10.1111/j.1365-246X.2006.02863.xInternational audienc

Stable T-bet(+)GATA-3(+) Th1/Th2 hybrid cells arise in vivo, can develop directly from naive precursors, and limit immunopathologic inflammation.

Differentiated T helper (Th) cell lineages are thought to emerge from alternative cell fate decisions. However, recent studies indicated that differentiated Th cells can adopt mixed phenotypes during secondary immunological challenges. Here we show that natural primary immune responses against parasites generate bifunctional Th1 and Th2 hybrid cells that co-express the lineage-specifying transcription factors T-bet and GATA-3 and co-produce Th1 and Th2 cytokines. The integration of Th1-promoting interferon (IFN)-γ and interleukin (IL)-12 signals together with Th2-favoring IL-4 signals commits naive Th cells directly and homogeneously to the hybrid Th1/2 phenotype. Specifically, IFN-γ signals are essential for T-bet(+)GATA-3(+) cells to develop in vitro and in vivo by breaking the dominance of IL-4 over IL-12 signals. The hybrid Th1/2 phenotype is stably maintained in memory cells in vivo for months. It resists reprogramming into classic Th1 or Th2 cells by Th1- or Th2-promoting stimuli, which rather induce quantitative modulations of the combined Th1 and Th2 programs without abolishing either. The hybrid phenotype is associated with intermediate manifestations of both Th1 and Th2 cell properties. Consistently, hybrid Th1/2 cells support inflammatory type-1 and type-2 immune responses but cause less immunopathology than Th1 and Th2 cells, respectively. Thus, we propose the self-limitation of effector T cells based on the stable cell-intrinsic balance of two opposing differentiation programs as a novel concept of how the immune system can prevent excessive inflammation

Induction of T-bet and IFN-γ in the presence of IL-4 critically depends on IFN-γ signaling.

<p>(A) WT C57BL/6 mice or the indicated gene-deficient mice were infected with <i>H. polygyrus</i>. On d 20 of infection, CD4⁺ T cells from spleens were analyzed for T-bet and GATA-3 expression (<i>n</i> = 6–7 mice/group). The frequencies of T-bet⁺GATA-3⁺ hybrid Th1/2 cells among activated CD4⁺CD44⁺ T cells are shown. (B) The frequencies of T-bet⁺GATA-3⁺ hybrid Th1/2 cells among activated CD4⁺CD44⁺ T cells as shown in (A) in the indicated organs were normalized to the mean of the wild-type group. Data are representative of two independent experiments. (C) FACS-sorted naive CD4⁺CD62L^hiCD44^loCD25⁻CXCR3⁻Gr-1⁻ Th cells from C57BL/6 or <i>Ifngr^−/−</i> mice were activated with anti-CD3/anti-CD28 in the presence of the indicated cytokines and cytokine-blocking antibodies. T-bet and GATA-3 expression was analyzed on d 5 (upper row). Inserted numbers indicate geometric mean indices. Cytokine expression was analyzed upon PMA/ionomycin restimulation on d 5 (lower row). Numbers indicate frequencies. Data are representative of two independent experiments.</p

Simultaneous commitment of naive T cells to the Th1 and Th2 differentiation programs.

<p>(A–E) FACS-sorted naive CD4⁺CD62L^hiCD44^loCD25⁻CXCR3⁻Gr-1⁻ LCMV-TCR^tg Th cells were activated with APCs and GP_61–80 peptide in the presence of the indicated cytokines and cytokine-blocking antibodies. (A) T-bet and GATA-3 expression is shown in naive cells (top row) or on d 5 of culture (middle row). Geometric mean indices are indicated. Cytokine expression upon PMA/ionomycin restimulation is shown on d 5 of culture (lower row). Numbers indicate frequencies. Data are representative of five independent experiments. (B) Geometric mean indices ± SD of T-bet and GATA-3 stainings versus isotype control stainings on d 5 of culture are depicted as normalization to Th1 cells for T-bet or to Th2 cells for GATA-3. Data are pooled from five independent experiments. (C) Cytokine expression was analyzed after PMA/ionomycin restimulation on d 5 of culture. Mean frequencies ± SD of cytokine⁺ cells are shown. Data are pooled from five independent experiments. (D) Expression of the indicated cytokine and chemokine receptors (upper row) and transcription factors (lower row) was analyzed on d 5 of culture. Tfh cells were obtained from spleens of WT C57BL/6 mice and identified as CD4⁺CXCR5⁺PD-1⁺ cells. Numbers indicate geometric means. Data are representative of two independent experiments. (E) On d 2 of culture, levels of phosphorylated (upper row) and total (lower row) STAT proteins were determined. Numbers indicate geometric mean indices. Data are representative of two independent experiments. (F) Naive Th cells from WT Balb/c mice were cultured with anti-CD3/anti-CD28 in the presence of polarizing cytokines and cyokine-blocking antibodies to induce Th1, Th2, and hybrid Th1/2 cells. T-bet and GATA-3 expression was analyzed in a kinetic fashion and plotted as geometric mean indices. Data are representative of three independent experiments.</p