# US 8,147,428 B2 · Device and method for quantifying edema > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,147,428 B2 - Document ID: US8147428B2 - Status: Granted - Kind: B2 - Application number: 11/107,302 - Filed: 2005-04-15 - Published: 2006-02-09 - Granted: 2012-04-03 - Earliest claimed: 2004-04-16 - Assignees: University of Massachusetts; Worcester Polytechnic Institute - Inventors: Kristen L. Billiar; Raymond M. Dunn - Web page: https://patentgrep.com/patent/US8147428B2 ## CPC - A61B 5/0053: {by applying pressure, e.g. compression, indentation, palpation, grasping, gauging} - A61B 5/442: {Evaluating skin mechanical properties, e.g. elasticity, hardness, texture, wrinkle assessment} - A61B 5/4878: {Evaluating oedema} - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) ## Abstract The preferred embodiments of the present invention are directed at a device that provides a reliable, accurate and quantifiable measure of a patient's edema. The device improves on the current method of digital manipulation by evaluating the pitting phenomena in a user-independent manner. The output of the device allows a physician to categorize edema into at least ten different levels of severity. The systems of the present invention provides the ability to distinguish between tissues of varying viscosity. ## Claims ### Claim 1 A method of measuring edema comprising: contacting a region of skin tissue of an arm or leg of a patient with a displacement member the region of tissue including edematous tissue; applying pressure to the region of skin tissue to displace the region of tissue a distance to a displaced position with the displacement member; releasing the pressure applied with the displacement member to the region of skin tissue; subsequently measuring a displacement of the region of tissue with the displacement member and a sensor that measures a displacement of the displacement member over a time during which the region of tissue relaxes from the displaced position; and displaying a quantitative value from the measured displacement with a display device, the measured displacement indicating a level of edema. ### Claim 2 (depends on 1) The method of claim 1 further comprising using the displacement member, a light source and a sensor, the light source and sensor determining a position of the displacement member. ### Claim 3 (depends on 2) The method of claim 2 further comprising using a housing on which the displacement member, light source and sensor are mounted. ### Claim 4 (depends on 1) The method of claim 1 further comprising measuring a time for return of the tissue to half the distance of the displaced position. ### Claim 5 (depends on 1) The method of claim 1 wherein the steps of contacting the region of tissue further comprises contacting a region of skin of the patient with the displacement member, displacing the region of skin with the displacement member and holding the displacement member at the displaced position for a selected period of time prior to the releasing step and subsequently measuring the relaxation of the skin from the displaced position. ### Claim 6 (depends on 1) The method of claim 1 further comprising treating the region of edematous tissue by compressing the region of tissue for a period of time. ### Claim 7 (depends on 1) The method of claim 1 further comprising recording the displacement of tissue as a function of time after the release of pressure. ### Claim 8 (depends on 1) The method of claim 1 further comprising using a housing, the housing and the displacement member undergoing relative movement from a first position to a second position. ### Claim 9 (depends on 1) The method of claim 1 further comprising comparing measured displacement data with stored data. ### Claim 10 (depends on 1) The method of claim 1 further comprising holding a housing on which the displacement member is mounted, and processing displacement data with a processor in the housing. ### Claim 11 (depends on 1) The method of claim 1 wherein the sensor comprises an LVDT such that the method further comprises using the LVDT to measure the displacement of the displacement member. ### Claim 12 (depends on 1) The method of claim 1 further comprising processing an output signal from the sensor with an amplification and filter circuit. ### Claim 13 (depends on 1) The method of claim 1 wherein the sensor and displacement member are mounted in a housing with a battery. ### Claim 14 A method for measuring edema in an arm or leg of patient comprising: contacting a region of tissue on the arm or the leg of a patient with a displacement member, the region of tissue including edematous tissue; applying pressure to the region of tissue to displace the region of tissue a selected distance to a displaced position with the displacement member; releasing the pressure applied with the displacement member to the region of interest; subsequently measuring a displacement of the region of tissue from the displaced position with the displacement member and a sensor that measures a displacement of the displacement member over a period of time during relaxation of the edematous tissue from the displaced position; and displaying a quantitative value from the measured displacement with a display device, the measured displacement indicating a level of edema. ### Claim 15 (depends on 14) The method of claim 14 further comprising using a housing, the displacement member being movably attached to the housing. ### Claim 16 (depends on 14) The method of claim 14 further comprising measuring tissue swelling in the arm or leg of the patient. ### Claim 17 (depends on 14) The method of claim 14 further comprising treating the patient by compressing the region of tissue for a period of time and subsequently remeasuring edema in the region of tissue of the patient. ### Claim 18 (depends on 14) The method of claim 14 further comprising using a battery mounted within a housing to provide power to the sensor for measuring patient edema in the arm or the leg of the patient, the displacement member being mounted to the housing.