324 results about "I e ratio" patented technology

A method for calibrating a pulse oximeter device and an apparatus incorporating the method and a system for utilizing the method. The method is based on modeling light propagation in tissue at two wavelengths, typically, one in the red and one in the infrared range of the spectrum. A formula is derived relating the arterial oxygen saturation to a ratio R commonly measured by standard pulse oximeters. A specific parameter is identified and utilized in the calibration of the oximeter. This parameter is formulated in terms of the DC signals measured by the pulse oximeter at the two wavelengths. An empirical method for estimating this parameter based on experimental data is also described.

A device and a method for measuring body fluid-related metrics using spectrophotometry to facilitate therapeutic interventions aimed at restoring body fluid balance. The specific body fluid-related metrics include the absolute volume fraction of water in the extravascular and intravascular tissue compartments, as well as the shifts of water between these two compartments. The absolute volume fraction of water is determined using algorithms where received radiation measured at two or more wavelengths are combined to form either a single ratio, a sum of ratios or ratio of ratios of the form log[R(λ1) / R(λ2)] in which the received radiation in the numerator depends primarily on the absorbance of water and the received radiation in the denominator depends primarily on the absorbance of water and the sum of the absorbances of non-heme proteins, lipids and water in tissue. The difference between the fraction of water in the intravascular fluid volume (“IFV”) and extravascular fluid volume (“EFV”) compartments are also determined using a differential method that takes advantage of the observation that pulsations caused by expansion of blood vessels in the skin as the heart beats produce changes in the received radiation at a particular wavelength that are proportional to the difference between the effective absorption of light in the blood and the surrounding tissue. This difference, integrated over time, provides a measure of the quantity of the fluid that shifts into and out of the capillaries. A mechanism for mechanically inducing a pulse is built into the device to improve the reliability of measurements of IFV−EFV under weak-pulse conditions.

A stent and method of its use, the stent in its expanded configuration, exhibiting varying outward radial force along its length. In use, the expanded stent is of a tapered configuration which provides greater force in vessel regions requiring greater force and less force in regions requiring less. In particular the stent is useful in the ostium regions and at areas of bifurcation in vessels. Varying force over the length of the stent is achieved by varying the number of elements, the density of elements, the thickness of the elements making up the stent body, and maintaining a substantially metal to artery ratio in the expanded stent over its length.

Apparatus and method detect a detection cluster that is associated with a neurological event, such as a seizure, of a nervous system disorder and update therapy parameters that are associated with a treatment therapy. The occurrence of the detection cluster is detected when the maximal ratio exceeds an intensity threshold. If the maximal ratio drops below the intensity threshold for a time interval that is less than a time threshold and subsequently rises above the intensity threshold, the subsequent time duration is considered as being associated with the detection cluster rather than being associated with a different detection cluster. Consequently, treatment of the nervous system disorder during the corresponding time period is in accordance with one detection cluster. Treatment therapy may be provided by providing electrical stimulation, drug infusion or a combination. Therapy parameters may be updated for each mth successive group of applications of the treatment therapy or for each nth detection cluster.

A golf club head has a ratio of a head mass to a head volume equal to or grater than 3 g / cm2, and a face portion that includes an impact surface is configured by a member made from an aluminum alloy having a maximum tensile strength equal to or greater than 600 MPa. The aluminum alloy is made by using a rapid quenching method. The golf club head can improve the carry distance and the flight direction characteristics of a hit golf ball compared with a conventional golf club head.

A golf ball comprising a core having an outer surface and a geometric center and being formed from a substantially homogenous formulation throughout; intermediate layer; and a cover layer; wherein the surface and center have a hardness, the hardness of the surface being substantially the same as or lower than the hardness of the center, and wherein a ratio of antioxidant to initiator used in said formulation is greater than about 0.40 when normalized to 100% activity.

An inhaler for producing an inhalable aerosol of a powdered medicament includes an aerosolizing device in the form of a vortex chamber 1. The vortex chamber 1 has a tangential inlet port 3 and an axial port 2. The ratio of the diameter of the vortex chamber 1 to the diameter of the exit port 2 is between 4 and 12. The length of the exit port 2 is less than its diameter. The cross-section of the inlet port 3 is rectangular and is defined at the bottom and at the radially outermost edge by the walls of the vortex chamber 1. The cross-sectional area of the inlet conduit 7, which supplies the medicament in a gas flow to the inlet port 3, decreases in the direction towards the vortex chamber 1. The inlet conduit 7 may be curved. The inhaler is capable of repeatably producing an aerosol of a medicament with a high proportion of particles in the range 1 to 3 microns, while using a 20 relatively small amount of energy.

A microwave hyperthermia apparatus that can be inserted into the body which includes a hollow central tube for the insertion of radioactive therapy sources. The use of a coaxial transmission line impedance transformation along the insertable portion of the coaxial cable enables a reduction in the characteristic impedance by increasing the outer diameter of the inner coaxial conductor so that the center conductor can be a metal tube. If the ratio of the outer coaxial conductor diameter vs. the inner coaxial conductor is decreased, the characteristic impedance of the transmission line is lowered. This enables the inner conductor diameter to increase sufficiently to make the central hollow opening large enough to receive standard radioactive sources therein. This provides for a good impedance match that improves microwave energy efficiency while at the same time permitting a large hollow center opening. The combination of the microwave antenna device and brachytherapy sources provides for enhanced effectiveness when the two treatments are delivered simultaneously or in close time proximity to each other.