A local sensor for joint temperature and velocity measurements in turbulent flows.

We present the principle for a micro-sensor aimed at measuring local correlations of turbulent velocity and temperature. The operating principle is versatile and can be adapted for various types of flow. It is based on a micro-machined cantilever, on the tip of which a platinum resistor is patterned. The deflection of the cantilever yields an estimate for the local velocity, and the impedance of the platinum yields an estimate for the local temperature. The velocity measurement is tested in two turbulent jets: one with air at room temperature which allows us to compare with well-known calibrated reference anemometers, and another one in the GReC jet at CERN with cryogenic gaseous helium which allows a much larger range of resolved turbulent scales. The recording of temperature fluctuations is tested in the Barrel of Ilmenau which provides a controlled turbulent thermal flow in air. Measurements in the wake of a heated or cooled cylinder demonstrate the capability of the sensor to display the cross correlation between temperature and velocity correctly.

Air versus ground transport of patients with acute myocardial infarction: experience in a rural-based helicopter medical service.

AIMS: Primary prehospital Helicopter Emergency Medical Service (HEMS) interventions may play a role in timely reperfusion therapy for patients with ST-segment elevation myocardial infarction (STEMI). We designed a prospective study involving patients with acute myocardial infarction aimed at the evaluation of the potential benefit of such primary HEMS interventions as compared with classical Emergency Medical Services ground transport. METHODS AND RESULTS: This prospective study was conducted from 1 July 2007 to 15 June 2012. Successive patients with STEMI eligible for percutaneous coronary intervention were included. Simulated ground-based access times were computed using a digital cartographic program, allowing the estimation of healthcare system delay from call to admission to the catheterization laboratory.During the study period, 4485 patients benefited from HEMS activations. Of these patients, 342 (8%) suffering from STEMI were transferred for primary percutaneous coronary intervention. The median primary response time was 11 min (interquartile range: 8-14 min) using the helicopter and 32 min (25-44 min) using road transport. The median transport time was 12 min (9-15 min) using HEMS and 50 min (36-56 min) by road. The median system delay using HEMS was 52 min (45-60 min), whereas this time was 110 min (95-126 min) by road. Finally, the system delay median gain was 60 min (47-72 min). CONCLUSION: Using HEMS in a rural region allows STEMI patients to benefit from appropriate rescue care with delays similar to those seen in urban settings.