Investigation of Subjective User Experiences of Applied Passive Compression on Varying Upper Body Locations

Strategically-applied compression on the body has been shown to elicit positive affect by creating feelings of calmness/relaxation. Although compression-based therapies are widely used in Occupational Therapy as a clinical intervention, current compression garment solutions suffer from various functional and usability issues and the spatial distribution between different commercially-available solutions vary widely. Currently, little is known about the specific location(s), intensity, and duration of pressure on the body that should be targeted in order to improve physical or mental well-being. With the hopes of contributing to more empirically-based compression garment designs in the future, this work reports a pilot investigation of the subjective user experiences when compression is applied on varying body locations.

Raising the pressure: Hemodynamic effects of splanchnic nerve stimulation

A number of cardiovascular and neurological diseases are characterized by a dysregulation of intravascular volume distribution. The veins and arteries of the visceral organs form the so-called splanchnic vascular compartment and are the largest reservoir for intravascular blood. The blood localized in the splanchnic compartment can be mobilized in and out of the compartment via passive compression or active neurohormonal recruitment. We studied the hemodynamic effects of splanchnic nerve stimulation during five cases of irreversible electroporation (IRE) in patients with pancreatic cancer. In IRE, repeated bursts of high-voltage electrical fields are applied to visceral beds for >1 min, which induces rapid increase in blood pressure, heart rate, and cardiac output. We present the first analysis into the hemodynamic changes with splanchnic nerve stimulation and explore potential mechanisms of the hyperdynamic state. Our analysis presents the first human report of splanchnic nerve stimulation to induce hypertension and volume redistribution, introducing the splanchnic nerves as a key component of cardiovascular regulation. NEW & NOTEWORTHY Our case series provides the first detailed description of human hemodynamic effects with splanchnic nerve stimulation. Splanchnic nerve stimulation results in profound hemodynamic alteration with rapid onset of hypertension and blood mobilization.

Passive compression technique applied to UWB beamforming and imaging architectures

Recent works have demonstrated the feasibility of microwave imaging using compressive techniques, exempting the use of active delay lines, phase shifters, or moving parts to achieve beamforming. With this method, waves are coded in a passive way by a compressive device to reduce the complexity of the transmitter and/or receiver chains of the telecommunication and radar systems requiring beamsteering. Such a technique is based on the exploitation of the frequency diversity, implying that a reduction of the compressive device's volume imposes a diminution of the number of driven antennas. In this paper, the improvement brought by simultaneous excitations of the compressive device is presented. Adapting a new mathematical formulation, it is shown that M inputs can send independent waveforms allowing the beamsteering of an N-elements antenna array, while maintaining N > M.

Effects of Lymphangion Subdivision in a Numerical Model of a Lymphatic Vessel

We have recently reported development of a lumped-parameter model for several lymphangions in series [1]. The model provides for both active smooth muscle contraction (intrinsic pumping) and passive compression of the lymphatic by external tissues (extrinsic pumping). The valves which define the lymphangions vary their resistance sigmoidally, having a high (low) resistance for an adverse (favorable) pressure difference. With no refractory period between sinusoidal active tension episodes, maximum pumping efficiency was reached when each lymphangion contracted 135° after that immediately upstream; simultaneous contraction (corresponding to the situation of extrinsic pumping) was especially inefficient.