Stabilized dried blood spot collection

During the collection phase of the dried blood spot method, practitioners need to ensure that there is no smearing of the blood sample on the filter paper or else readings from it will be invalid. This can be difficult to accomplish in the field if there is relative motion between the site of blood discharge on the finger and the filter paper. In this article, a gyroscope stabilization method is introduced and demonstrated to provide consistent and improved dried blood spot collection within a circular guide region notwithstanding the presence of rocking.     

A wearable system for pre-impact fall detection

Unique features of body segment kinematics in falls and activities of daily living (ADL) are applied to make automatic detection of a fall in its descending phase, prior to impact, possible. Fall-related injuries can thus be prevented or reduced by deploying fall impact reduction systems, such as an inflatable airbag for hip protection, before the impact. In this application, the authors propose the following hypothesis: “Thigh segments normally do not exceed a certain threshold angle to the side and forward directions in ADL, whereas this abnormal behavior occurs during a fall activity”. Torso and thigh wearable inertial sensors (3D accelerometer and 2D gyroscope) are used and the whole system is based on a body area network (BAN) for the comfort of the wearer during a long term application. The hypothesis was validated in an experiment with 21 young healthy volunteers performing both normal ADL and fall activities. Results show that falls could be detected with an average lead-time of 700 ms before the impact occurs, with no false alarms (100% specificity), a sensitivity of 95.2%. This is the longest lead-time achieved so far in pre-impact fall detection.     

A neural basis for gyroscopic force measurement in the halteres of <Emphasis Type="Italic">Holorusia</Emphasis>

Dipteran flight requires rapid acquisition of mechanosensory information provided by modified hindwings known as halteres. Halteres experience torques resulting from Coriolis forces that arise during body rotations. Although biomechanical and behavioral data indicate that halteres detect Coriolis forces, there are scant data regarding neural encoding of these or any other forces. Coriolis forces arise on the haltere as it oscillates in one plane while rotating in another, and occur at oscillation frequency and twice the oscillation frequency. Using single-fiber recordings of haltere primary afferent responses to mechanical stimuli, we show that spike rate increases linearly with stimulation frequency up to 150 Hz, much higher than twice the natural oscillation frequency of 40 Hz. Furthermore, spike-timing precision is extremely high throughout the frequency range tested. These characteristics indicate that afferents respond with high speed and high precision, neural features that are useful for detecting Coriolis forces. Additionally, we found that neurons respond preferentially to specific stimulus directions, with most responding more strongly to stimulation in the orthogonal plane. Directional sensitivity, coupled with precise, high-speed encoding, suggests that haltere afferents are capable of providing information about forces occurring at the haltere base, including Coriolis forces.