Optix LP

Ablacor Medical Corporation

Automated Medical Instruments, Inc.

Howard E Guthermann

Martin J Sklar

Howard Ring

Myron J Block

Lester Sodickson

Michael Misner

An apparatus and method for performing cardiac ablations employs a catheter comprising an anchoring device and an ablating device to perform the ablations to electrically isolate the pulmonary veins and left atrium from surrounding atrial tissue. The anchor can comprise a balloon-type device, a stent-like device, a strut-like device, a spring-strut-like device, an umbrella-like device, a mushroom-like device, or other device that allows the catheter to maintain a position with respect to target tissue. The ablator can comprise a balloon ablator, an umbrella ablator, a pinwheel ablator, an umbrella ablator incorporating a cinch mechanism, a mushroom balloon ablator and a segmented balloon or pinwheel ablator. The anchor and ablator can also comprise a combination mushroom balloon anchor section and mushroom balloon ablator section. The anchor and ablator can include electrodes for measuring a conductance therebetween when in deployed position, so as to determine the effectiveness of the ablation.

Anchored cardiac ablation catheter

A non-invasive detection method for glucose and other constituents of interest in a sample is described. The apparatus and methods of the invention provide an analog of color perception of human vision, preferably in the near infrared region, replacing the spectrophotometers used in other non-invasive near infrared detection methods. A plurality of detection units are used, each covering a broad region of the detected spectrum, paralleling color perception and colorimetry. In some circumstances, a neural net is used for analysis, allowing the system to learn. Analyte concentrations in scattering mediums can be obtained by calibrating the results with in vitro measurements.

Measurement of an analyte concentration in a scattering medium

The absence of a defined optical pathlength for in vivo measurements creates problems for the noninvasive measurement of analyte concentration. These problems can be reduced by combining measurements made at several wavelengths and using the fact that normal renal function causes the concentration of water in whole blood to be tightly controlled. Hence, the concentration of water in arterial blood can serve as a useful internal standard for such measurements. The measurements are then procured so as to remove the dependency of concentration on path length traversed by the illuminating radiation and on the scattering properties of the volume through which the illuminating radiation propagates. Using this method, one can create improved calibration for measurements of absorbing constituents in arterial blood and thereby provide absolute concentration measurements of constituents such as hemoglobin and glucose in arterial blood.

Method for improving calibration of an instrument for non-invasively measuring constituents in arterial blood

A method of improving the accuracy and reproducibility of non-invasive measurements of a concentration of a constituent of interest carried in a body part has been developed. The method relies on elevating the body part during the measurement cycle so that the body part is maintained above the heart during the measurement cycle. Measurements of the constituent during an arterial pulse leads to improved intra-run and run-to-tun determinations.

Method of improving reproducibility of non-invasive measurements

The invention relates to the enhancement of the signal-to-background ratio of a non-invasive measurement of the concentration of a blood constituent at a measurement site by applying an external pressure at a location near the measurement site. In one embodiment, sufficient pressure is applied proximate to a measurement site to stop blood flow. The pressure is then suddenly relased, thereby generating a blood bolus passing through the site. By illuminating the measurement site before and during the passage of the blood bolus and observing the interaction of the input radiation with the measurement site, the concentration of a blood constituent can be measured. In another embodiment, the venous pulse is occluded by applying a pressure midway between systolic and diastolic pressure. By illuminating the measurement site in the absence of a venous pulse, the signal-to-background ration can be enhanced and the concentration of a blood constituent can be measured.

Methods of enhancing optical signals by mechanical manipulation in non-invasive testing

The present invention provides a generally applicable apparatus and method for achieving measurements of a constituent in a sample. This is achieved by employing a detection means having a plurality of detectors responsive to radiation in a selected region of the spectrum, e.g., the infrared. In most embodiments, at least two of the detectors provide broad wavelength bandpass. If narrow bandpass sources or detectors are used, the information generated is processed in a manner similar to broadband information. The broad bandpass response of the detectors can be contrasted with the approach of classical spectrophotometry, in which the spectral response of the detectors is designed to be as narrow as feasible, and substantially narrower than the spectral features of the constituent or constituents of interest. The data is processed such that the contributions of known background constituents and scattering is eliminated prior to further processing, thereby yielding a better result in high background situations. The use of intensity processing rather than absorbance processing also allows the method and apparatus to be used in a variety of non-ideal situations.

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Newton, MA, United States of America

Howard E Guthermann