Design of Semirigid Wearable Devices Based on Skin Strain Analysis.

Nowadays, both usability and comfort play a key role in the development of medical and wearable products. When designing any device that is in contact with the human body, the mechanical behavior of the embraced soft tissue must be known. The unavoidable displacement of the soft tissue during motion may lead to discomfort and, thus, the removal of the wearable product. This paper presents a new methodology to design and test a wearable device based on the measurement of the dynamic skin strain field. Furthermore, from this field, the anatomical lines with minimum strain (lines of nonextension (LoNEs)) are calculated to design the structural parts of the wearable device. With this new criterion, the resulting product is not only optimized to reduce the friction in skin-device interface, but fully personalized to the patient's morphology and motion. The methodology is applied to the design of an ankle-foot wearable orthosis for subjects with ankle dorsiflexors muscles weakness due to nervous system disorders. The results confirm that the use of LoNEs may benefit the design of products with a high interaction with the skin.

Ergonomic assessment of a new hand tool design for laparoscopic surgery based on surgeons' muscular activity.

Laparoscopic surgery techniques are customarily used in non-invasive procedures. That said traditional surgical instruments and devices used by surgeons suffer from certain ergonomic deficiencies that may lead to physical complaints in upper limbs and back and general discomfort that may, in turn, affect the surgeon's skills during surgery. A novel design of the laparoscopic gripper handle is presented and compared with one of the most used instruments in this field in an attempt to overcome this problem. The assessment of the ergonomic feature of the novel design was performed by using time-frequency analysis of the surface electromyography (sEMG) signal during dynamic activities. Singular Spectrum Analysis (SSA) was used to decompose the sEMG signal and extract the median frequency of each muscle to assess muscle fatigue. The results reveal that using the proposed ergonomic grip reduces the mean values of the muscle activity during each of the proposed tasks. The novel design also improves the ease of use in laparoscopic surgery as it minimises high-pressure contact areas, reduces large amplitude movements and promotes a neutral position of the hand, wrist and forearm. Furthermore, the SSA method for time-frequency analysis provides a powerful tool to analyse a prescribed activity in ergonomic terms. The proposed methodology to assess muscle activity during surgery activities may be useful in the selection of surgical instruments when programming extended procedures, as it provides an additional selection criterion based on the surgeon's biomechanics and the proposed activity.

Adrenal function in different subgroups of septic shock patients.

BACKGROUND: Relative adrenal insufficiency (RAI) is a common complication during septic shock and may be more frequent in specific subgroups. The main objectives of this study were to determine the adrenal function and the RAI incidence in different subgroups of septic shock patients considering: main admission categories (medical, elective or emergency surgery); source of infection; nosocomial or community-acquired infections; gender, age <65 years or >65 years; and the presence or absence of neurological diseases, acute respiratory distress syndrome (ARDS) and bacteremia. METHODS: Prospective study in a medical-surgical ICU, including adults with septic shock, from May 2002 to May 2005. All patients had total serum cortisol measured at baseline and 60 min after a high-dose ACTH test within the first 96 h of shock onset. RAI was defined as a serum cortisol increment after ACTH test (Deltamax(249)) <90 microg/l. RESULTS: One hundred and two subjects were enrolled, and the overall RAI incidence was 22.5%. Patients with ARDS before ACTH test or bacteremia showed lower Deltamax(249) values than patients with ARDS after ACTH test (96 vs. 153 microg/l, P=0.02) or without bacteremia (140 vs. 175 microg/l, P=0.04). Multivariate regression analysis revealed that female gender, development of ARDS before ACTH test, and bacteremia were associated with greater RAI incidence. There was no difference in RAI incidence considering neurological diseases, age, type and source of infection and the main admission categories. CONCLUSIONS: Female gender, bacteremia and early-onset ARDS were variables independently associated with greater RAI incidence in septic shock patients. There was no difference in the RAI incidence concerning other subgroups.

A Quantitative Analysis of Cold Water for Human Consumption in Hospitals in Spain.

An estimation of the water used for human consumption in hospitals is essential to determine possible savings and to fix criteria to improve the design of new water consumption models. The present work reports on cold water for human consumption (CWHC) in hospitals in Spain and determines the possible savings. In the period of 2005-2012, 80 Eco-Management and Audit Schemes (EMAS) from 20 hospitals were analysed. The results conclude that the average annual consumption of CWHC is 1.59 m(3)/m(2) (with a standard deviation of 0.48 m(3)/m(2)), 195.85 m(3)/bed (standard deviation 70.07 m(3)/bed), or 53.69 m(3)/worker (standard deviation 16.64 m(3)/worker). The results demonstrate the possibility of saving 5,600,000 m(3) of water per year. Assuming the cost of water as approximately 1.22 €/m(3), annual savings are estimated as 6,832,000 €. Furthermore, 2,912 MWh of energy could be saved, and the emission of 22,400 annual tonnes of CO2 into the atmosphere could be avoided.

Long-term thalidomide use in refractory cutaneous lesions of lupus erythematosus: a 65 series of Brazilian patients.

Thalidomide has been reported as efficacious in refractory cutaneous lupus erythematosus (LE). The most fearful side-effects are teratogenicity and neuropathy. We reported clinical efficacy of long-term low-dose use of thalidomide in 65 patients with LE, emphasizing the prevalence of adverse effects, especially of neuropathy and its related factors. Data obtained from medical records included age, sex, disease duration, and the presence of diagnostic criteria for systemic lupus erythematosus (SLE), the extent and activity of cutaneous lesions and previous treatments. Sixty-three patients (98.9%) presented complete or partial improvement with thalidomide therapy. Drowsiness occurred in 50 patients (77%). Twenty-eight patients (43.2%) presented neuropathy symptoms. Nerve conduction studies were done in 21 (75%) of them and were abnormal in 12 (57%). With the interruption of thalidomide, 24 (82.5%) had complete or partial improvement of neuropathy symptoms and 23 (82%) of them had cutaneous relapse. There were no significant differences between those who developed or not neuropathy in treatment duration, age, total dose and systemic versus cutaneous LE. In conclusion, thalidomide can be used in refractory cutaneous LE with great efficacy and relative security. Controlled studies with schemes with lower doses or intermittent usage or alternative drugs are wanted to reduce the burden of cutaneous morbidity of lupus erythematosus.

Stimulation of early eosinophil progenitors by a heat stable alveolar macrophage product from ovalbumin-sensitized and non-sensitized guinea pigs.

BACKGROUND: Alveolar macrophages (AM) may participate in brochopulmonary hyper-reactivity by secreting cytokines that recruit mature eosinophils, or induce eosinophil production from recruited circulating progenitors. OBJECTIVE: To define whether AM products can contribute to lung eosinophil production in immunized guinea pigs (GP), by analysing the effect of AM culture supernatants (AM-SN) on in vitro eosinophilopoiesis. METHODS: Liquid and semi-solid bone marrow (BM) cultures were seeded with SN from 95% pure AM exposed to LPS. RESULTS: AM-SN increased very significantly the long-term viability, cell proliferation and eosinophil production in liquid culture and supported formation of eosinophil-bearing mixed colonies, by acting on progenitors depleted of mature eosinophils. The effect on eosinophil production was not duplicated by natural or recombinant sources of GM-CSF (which nevertheless supported GM colony formation by GP BM), not by rhIL-8 (which was active on GP cells) and was not due to residual LPS. FPLC separation of active AM SN yielded a peak of apparent m.w. 43 kDa, active on both liquid and semi-solid cultures. The active moiety was heat- and trypsin-resistant. Neutralizing monoclonal antibodies to hGM-CSF, mGM-CSF, hIL-3 and mIL-3 failed to deplete the activity in AM-SN. Ovalbumin immunization induced its production by AM even without LPS challenge. CONCLUSIONS: The lack of T lymphocytes among factor-producing AM, the properties of the active material, the inability of GM-CSF to reproduce these effects, and the failure of MoAbs to GM-CSF and to IL-3 to neutralize the activity indicate it is not due to the major eosinopoietic factors GM-CSF, IL-3 or IL-5.