# US 12,109,036 B2 · Devices and methods to measure gastric residual volume > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,109,036 B2 - Document ID: US12109036B2 - Status: Granted - Kind: B2 - Application number: 17/675,903 - Filed: 2022-02-18 - Published: 2022-06-02 - Granted: 2024-10-08 - Earliest claimed: 2014-02-06 - Assignees: Gravitas Medical, Inc. - Applicants: Gravitas Medical, Inc. - Inventors: Daniel R. Burnett; Marcie Hamilton; Evan S. Luxon; Alexander Vergara; Saheel Sutaria - Web page: https://patentgrep.com/patent/US12109036B2 ## CPC - A61B 5/4238: {stomach} - A23L 33/30: {Dietetic or nutritional methods, e.g. for losing weight (A23L33/10 takes precedence)} - A23L 35/00: Foods or foodstuffs not provided for in groups A23L5/00 - A23L33/00; Preparation or treatment thereof (preservation thereof A23B) - A61B 1/2736: {Gastroscopes} - A61B 5/01: Measuring temperature of body parts {; Diagnostic temperature sensing, e.g. for malignant or inflamed tissue} (clinical contact thermometers G01K13/20) - A61B 5/036: {by means introduced into body tracts (A61B5/032 and A61B5/035 take precedence)} - A61B 5/1073: {Measuring volume, e.g. of limbs} - A61B 5/14507: {specially adapted for measuring characteristics of body fluids other than blood (devices for taking samples of body liquids A61B10/0045)} - A61B 5/14532: {for measuring glucose, e.g. by tissue impedance measurement} - A61B 5/14539: {for measuring pH} - A61B 5/14546: {for measuring analytes not otherwise provided for, e.g. ions, cytochromes} - A61B 5/4848: {Monitoring or testing the effects of treatment, e.g. of medication} - A61B 5/486: {Biofeedback (using electroencephalography [EEG] A61B5/375)} - A61B 5/6847: {mounted on an invasive device} - A61B 5/6852: {Catheters} - A61B 5/6865: {Access ports} - A61B 5/6871: {Stomach} - A61B 5/742: {using visual displays (displays for heart-related electrical signals, e.g. ECG, A61B5/339)} - A61J 15/008: {Sensor means, e.g. for sensing reflux, acidity or pressure (sensors for diagnostic purposes A61B5/00; sensors for inflation control A61M25/1018)} - A61B 2562/0204: Acoustic sensors - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) - A23L: FOODS, FOODSTUFFS OR NON-ALCOHOLIC BEVERAGES, NOT OTHERWISE PROVIDED FOR; PREPARATION OR TREATMENT THEREOF (preservation thereof A23B) - A61J: CONTAINERS SPECIALLY ADAPTED FOR MEDICAL OR PHARMACEUTICAL PURPOSES; DEVICES OR METHODS SPECIALLY ADAPTED FOR BRINGING PHARMACEUTICAL PRODUCTS INTO PARTICULAR PHYSICAL OR ADMINISTERING FORMS; DEVICES FOR ADMINISTERING FOOD OR MEDICINES ORALLY; BABY COMFORTERS; DEVICES FOR RECEIVING SPITTLE ## Abstract Devices and methods to measure gastric residual volume (GRV) are described where at least one additive component (a GRV indicator) may be dispersed in a body lumen such as a stomach. The GRV indicator may changes a physical (chemical, electrical, thermal, mechanical, optical, etc.) characteristic within the stomach by a measureable degree. This degree of change and/or the rate of return to the previous state, may be used to determine the GRV of a patient. The determined GRV can also be used to automatically or semi-automatically control the patient's feeding rate and/or volume and/or frequency to adequately nourish the patient but avoid complications. The physical characteristic(s) may also be used to detect that the feeding catheter or tube is in the correct location (ie stomach vs lung or esophagus. ## Claims ### Claim 1 An apparatus for determining a gastric residual volume (GRV), comprising: an elongate body having a length; one or more GRV sensors positioned along the elongate body, wherein the one or more GRV sensors are configured to measure a change in a GRV parameter when positioned within a body lumen of a subject; one or more placement sensors positioned along the elongate body, wherein the one or more placement sensors are configured to measure a change in a first physiological parameter and in a second physiological parameter when positioned within the body lumen, wherein the first and second physiological parameters comprise conductivity or impedance, and temperature; and a controller in communication with the one or more GRV sensors and the one or more placement sensors, wherein the controller is configured to determine a GRV based on the change in the GRV parameter, and wherein the controller is further configured to confirm a location of the elongate body within the subject during use based upon the change in the physiological parameter. ### Claim 2 (depends on 1) The apparatus of claim 1 further comprising a medium having one or more GRV indicators for introduction into the body lumen. ### Claim 3 (depends on 1) The apparatus of claim 1 wherein the controller is configured to determine the change in the GRV parameter or the first or second physiological parameter during positioning of the elongate body within the subject. ### Claim 4 (depends on 1) The apparatus of claim 1 wherein the controller is configured to determine the change in the GRV parameter or the first or second physiological parameter continuously. ### Claim 5 (depends on 1) The apparatus of claim 1 wherein the controller is configured to determine the change in the GRV parameter and the first or second physiological parameter continuously. ### Claim 6 (depends on 1) The apparatus of claim 1 wherein the one or more GRV sensors and the one or more placement sensors are the same. ### Claim 7 (depends on 6) The apparatus of claim 6 wherein the one or more GRV sensors and the one or more placement sensors are configured to sense impedance or conductivity. ### Claim 8 (depends on 1) The apparatus of claim 1 wherein at least one of the GRV sensors and the one or more placement sensors are different from one another. ### Claim 9 (depends on 1) The apparatus of claim 1 wherein the elongate body defines at least one lumen therethrough. ### Claim 10 (depends on 9) The apparatus of claim 9 wherein a medium having one or more GRV indicators is in fluid communication through the at least one lumen. ### Claim 11 (depends on 9) The apparatus of claim 9 wherein the one or more GRV sensors are positioned within the at least one lumen. ### Claim 12 (depends on 11) The apparatus of claim 11 wherein the controller is configured to measure an initial baseline GRV parameter from the one or more GRV sensors. ### Claim 13 (depends on 1) The apparatus of claim 1 wherein the one or more GRV sensors are positioned along an external surface of the elongate body. ### Claim 14 (depends on 13) The apparatus of claim 13 wherein the one or more GRV sensors are embedded along the external surface of the elongate body in a smooth transition. ### Claim 15 (depends on 1) The apparatus of claim 1 further comprising a restrictor in communication with the elongate body, wherein the restrictor is configured to control a flow of a medium through the elongate body. ### Claim 16 (depends on 15) The apparatus of claim 15 wherein the restrictor is configured to be controlled via the controller through a feedback loop. ### Claim 17 (depends on 16) The apparatus of claim 16 wherein the feedback loop comprises an upper cutoff limit. ### Claim 18 (depends on 16) The apparatus of claim 16 wherein the feedback loop comprises a lower cutoff limit. ### Claim 19 (depends on 16) The apparatus of claim 16 wherein the flow of medium is controlled based upon the GRV. ### Claim 20 (depends on 15) The apparatus of claim 15 wherein the controller is configured to meter the flow of the medium into boluses. ### Claim 21 (depends on 15) The apparatus of claim 15 wherein the controller is configured to meter the flow of the medium into a continuous flow. ### Claim 22 (depends on 15) The apparatus of claim 15 wherein the controller is configured to control a content of the medium. ### Claim 23 (depends on 1) The apparatus of claim 1 further comprising an inflatable balloon positioned along the elongate body and in communication with the controller. ### Claim 24 A method of determining a gastric residual volume (GRV) in a body lumen, comprising: measuring a change in a first physiological parameter and in a second physiological parameter within the body lumen via one or more placement sensors positioned along an elongate body, wherein the first and second physiological parameters comprise conductivity or impedance, and temperature; confirming a location of the elongate body within the body lumen based upon the change in the first or second physiological parameter; sensing a GRV parameter from a medium having one or more GRV indicators within the body lumen via one or more GRV sensors positioned along the elongate body; monitoring the one or more GRV indicators for a change in the GRV parameter; and determining a GRV of the body lumen based on the change in the GRV parameter. ### Claim 25 (depends on 24) The method of claim 24 further comprising introducing the medium having the one or more GRV indicators through the elongate body and into the body lumen prior to sensing the GRV parameter. ### Claim 26 (depends on 24) The method of claim 24 wherein monitoring the one or more GRV indicators comprises monitoring for the change in the GRV parameter or the first or second physiological parameter while positioning the elongate body within the body lumen. ### Claim 27 (depends on 24) The method of claim 24 wherein monitoring the one or more GRV indicators comprises monitoring for the change in the GRV parameter or the first or second physiological parameter continuously. ### Claim 28 (depends on 24) The method of claim 24 wherein monitoring the one or more GRV indicators comprises monitoring for the change in the GRV parameter and the first or second physiological parameter continuously. ### Claim 29 (depends on 24) The method of claim 24 wherein sensing the GRV parameter further comprises sensing the GRV parameter or the first or second physiological parameter. ### Claim 30 (depends on 29) The method of claim 29 wherein sensing the GRV parameter or the physiological parameter comprises sensing for impedance or conductivity. ### Claim 31 (depends on 24) The method of claim 24 wherein the one or more placement sensors and the GRV sensors are the same. ### Claim 32 (depends on 24) The method of claim 24 wherein sensing the GRV parameter comprises sensing via the one or more GRV sensors positioned within the elongate body. ### Claim 33 (depends on 32) The method of claim 32 further comprising measuring an initial baseline GRV parameter from the one or more GRV sensors. ### Claim 34 (depends on 24) The method of claim 24 wherein the one or more GRV sensors are positioned along an external surface of the elongate body. ### Claim 35 (depends on 34) The method of claim 34 wherein the one or more GRV sensors are embedded along the external surface of the elongate body in a smooth transition. ### Claim 36 (depends on 25) The method of claim 25 wherein introducing the medium comprises controlling a flow of the medium through the elongate body via a restrictor in communication with the elongate body. ### Claim 37 (depends on 36) The method of claim 36 wherein controlling the flow of the medium comprises controlling the restrictor through a feedback loop via a controller. ### Claim 38 (depends on 37) The method of claim 37 wherein the feedback loop comprises an upper cutoff limit. ### Claim 39 (depends on 37) The method of claim 37 wherein the feedback loop comprises a lower cutoff limit. ### Claim 40 (depends on 37) The method of claim 37 wherein the flow of medium is controlled based upon the GRV. ### Claim 41 (depends on 25) The method of claim 25 wherein introducing the medium comprises metering the flow of the medium into boluses. ### Claim 42 (depends on 25) The method of claim 25 wherein introducing the medium comprises metering the flow of the medium into a continuous flow. ### Claim 43 (depends on 25) The method of claim 25 wherein introducing the medium comprises controlling a content of the medium. ### Claim 44 (depends on 24) The method of claim 24 wherein the elongate body further comprises an inflatable balloon positioned along the elongate body.