Pressure applicator devices particularly useful for non-invasive detection of medical conditions

Abstract

A probe for application to a body part particularly a finger of a patient to detect a change in the physical condition of the patient includes a housing defining a compartment closed at one end and open at the opposite end for receiving the distal end of the patient's finger and means consituted of a medium wholly self-contained within the probe for applying a static pressure field substantially uniformly around the distal end of the patient's finger, of a predetermined magnitude sufficient to substantially prevent distention of the venous vasculature, uncontrolled venous backflow, and retrognade shockwave propagation into the distal end, and to partially unload the wall tension of, but not to occlude, the arteries in the distal end when at heart level or below. A sensor senses changes in the distal end of the patient's finger related to changes in arterial blood volume therein.

Description

FIELD AND BACKGROUND OF THE INVENTION[0001] The present invention relates to pressure applicator devices for applying a predetermined static pressure to a body part of a patient. The invention is particularly useful as a probe for application to a digit (i.e., a finger or toe) of a patient for the non-invasive detection of certain medical conditions in accordance with the method described in our PCT Application PCT / IL97 / 00249; and the invention is therefore described below especially with respect to such applications.[0002] Our Application PCT / IL97 / 00249 (WO98 / 04182, published Feb. 5, 1998) discloses methods and apparatus for the non-invasive detection of a change in a physiological condition of a patient by monitoring changes in the peripheral arterial tone as manifested by changes in the arterial blood volume in a terminal extremity of a body part, preferably a digit (finger or toe) of the patient. The method and apparatus are described in that application particularly for detecti...

AI Technical Summary

Benefits of technology

[0004] An object of the present invention is to provide a device particularly useful as a probe in the method and apparatus of the above-cited PCT Application but of a simplified or improved construction as compared to the devices described therein. Another object is to provide a probe which does not restrict the mobility of the patient.

[0008] According to further features in the latter described embodiments, the pressurizing means further includes an outer resilient membrane attached to the housing externally thereof and defining therewith an outer chamber communicating with the inner chamber via openings in the housing for enlarging the effective volume of the inner chamber such as to cause the inner membrane to apply substantially the same static pressure around the distal end of the patient's body part despite changes in volume therein.

[0011] As will be described more particularly below, the present invention enables probes to be constructed with the static pressurizing means wholly self-contained within the probe housing, thereby greatly simplifying the construction of the probe as well as reducing restrictions on the mobility of the patient using such a probe. However, the invention may also be implemented in a two-section probe wherein one section includes a first housing attached to the body part and defining a part of the static pressurizing means, and the second section includes a second housing having another part of the static pressurizing means in fluid connection to the first section, the sensor being located within the second section.

Problems solved by technology

However, utilizing such remotely-located pressure sources complicates the construction of the apparatus and also restricts the mobility of the patient.

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