# US 11,076,811 B1 · Calibration of a wearable medical device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,076,811 B1 - Document ID: US11076811B1 - Status: Granted - Kind: B1 - Application number: 16/994,165 - Filed: 2020-08-14 - Granted: 2021-08-03 - Earliest claimed: 2014-04-09 - Assignees: Tula Health, Inc. - Applicants: Tula Health, Inc. - Inventors: Devin Warner Miller; David Rich Miller; Jeffrey Michael Lee - Web page: https://patentgrep.com/patent/US11076811B1 ## CPC - A61B 5/7221: {Determining signal validity, reliability or quality (preventing, reducing or removing noise induced by motion artefacts A61B5/7207; noise originating from a therapeutic or surgical apparatus A61B5/7217)} - A61B 5/0002: {Remote monitoring of patients using telemetry, e.g. transmission of vital signals via a communication network (endoradiosondes A61B5/07)} - A61B 5/02438: {with portable devices, e.g. worn by the patient} - A61B 5/0295: using plethysmography, i.e. measuring the variations in the volume of a body part as modified by the circulation of blood therethrough, e.g. impedance plethysmography - A61B 5/0535: Impedance plethysmography (for measuring blood flow A61B5/0295) - A61B 5/1495: Calibrating or testing of in-vivo probes - A61B 5/4875: {Hydration status, fluid retention of the body} - A61B 5/681: {Wristwatch-type devices} - A61B 5/7207: {of noise induced by motion artifacts} - A61B 5/02007: {Evaluating blood vessel condition, e.g. elasticity, compliance} - A61B 5/0536: Impedance imaging, e.g. by tomography - A61B 5/0537: Measuring body composition by impedance, e.g. tissue hydration or fat content - A61B 5/117: Identification of persons (methods or arrangements for recognising patterns, e.g. fingerprints, G06F18/00, G06V40/00; identification of persons by analysing their voice or speech G10L17/00) - A61B 5/14517: {for sweat} - A61B 5/14532: {for measuring glucose, e.g. by tissue impedance measurement} - A61B 5/14535: {for measuring haematocrit} - A61B 5/14542: {for measuring blood gases (A61B5/14551 takes precedence)} - A61B 5/6807: {Footwear} - A61B 5/6814: {Head} - A61B 5/6823: {Trunk, e.g., chest, back, abdomen, hip} - A61B 5/6824: {Arm or wrist} - A61B 5/6829: {Foot or ankle} - A61B 5/684: {Indicating the position of the sensor on the body} - A61B 5/7246: {using correlation, e.g. template matching or determination of similarity} - A61B 5/7267: {involving training the classification device} - A61B 5/7275: {Determining trends in physiological measurement data; Predicting development of a medical condition based on physiological measurements, e.g. determining a risk factor} - A61B 5/7296: {for compensation of signal variation due to stress unintentionally induced in the patient, e.g. due to the stress of the medical environment or examination} - A61B 2560/0238: Means for recording calibration data - A61B 2560/0252: using ambient temperature - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) ## Abstract A technology for a wearable medical device for monitoring medical parameters. Medical measurement data can be received at the wearable medical device from a medical measurement sensor attached to the wearable medical device or a medical measurement sensor in communication with the wearable medical device. A calibration coefficient can be determined for calibrating the wearable medical device based on the medical measurement data. The wearable medical device can be calibrated based on the calibration coefficient. ## Claims ### Claim 1 A system, comprising: a first medical device that is wearable by a user, the first medical device comprising a first sensor that is configured to take a first measurement of a first physiological parameter of the user; a second medical device comprising a second sensor that is configured to take a second measurement of a second physiological parameter of the user, wherein: the second measurement is different from the first measurement; the first measurement does not measure the second physiological parameter; and the first physiological parameter and the second physiological parameter change as a third physiological parameter changes; and a processing device communicatively coupled to the first medical device and the second medical device, the processing device configured to: collect first measurement data from the first sensor; collect second measurement data from the second sensor; determine an orthogonal data point or an orthogonal data set between the first measurement data and the second measurement data, wherein an orthogonal data point or an orthogonal data set corresponds to: the first measurement data being indicative of the third physiological parameter; and the second measurement data being indicative of the third physiological parameter; and determine the third physiological parameter using the first sensor of the first medical device or the second sensor of the second medical device, wherein: the first measurement data is correlated with the third physiological parameter by the orthogonal data point or the orthogonal data set; and the orthogonal data point or the orthogonal data set enables the first medical device to indirectly measure, by the first sensor, the third physiological parameter by directly measuring the first physiological parameter. ### Claim 2 (depends on 1) The system of claim 1, wherein: the first sensor acquires the first measurement data by non-invasive measurement; or the second sensor acquires the second measurement data by invasive measurement. ### Claim 3 (depends on 1) The system of claim 1, wherein the processing device is configured to determine the third physiological parameter using the first sensor of the first medical device in response to the orthogonal data point or the orthogonal data set having a threshold degree of orthogonality. ### Claim 4 (depends on 1) The system of claim 1, wherein: the first sensor takes the first measurement continuously; and the second sensor takes the second measurement non-continuously, periodically, or when manually prompted by the user. ### Claim 5 (depends on 4) The system of claim 4, wherein the processing device is further configured to determine an error rate for the first measurement taken continuously. ### Claim 6 (depends on 5) The system of claim 5, wherein the processing device is further configured to recursively calibrate the first medical device based on the error rate. ### Claim 7 (depends on 1) The system of claim 1, wherein: the orthogonal data point or the orthogonal data set comprises a first measurement of the first measurement data and a second measurement of the second measurement data; and the first measurement and the second measurement are taken from the user approximately contemporaneously. ### Claim 8 (depends on 1) The system of claim 1, wherein the processing device is configured to determine the third physiological parameter using the first sensor of the first medical device in response to a current measurement value of the third physiological parameter exceeding a standard deviation of a baseline measurement value for the third physiological parameter. ### Claim 9 (depends on 1) The system of claim 1, wherein the orthogonal data point or the orthogonal data set is determined using a multivariate analysis or a regression analysis. ### Claim 10 A device, comprising: a first sensor that is configured to take a first measurement of a first physiological parameter of a user; and a processing device coupled to the first sensor and communicatively coupled to a medical device, the processing device configured to: collect first measurement data from the first sensor; receive second measurement data from the medical device, wherein: the medical device is configured to take a second measurement of a second physiological parameter, the second measurement being different from the first measurement; the second measurement does not measure the first physiological parameter; and the first physiological parameter and the second physiological parameter change as a third physiological parameter changes; determine an orthogonal data point or an orthogonal data set between the first measurement data and the second measurement data, wherein the orthogonal data point or the orthogonal data set corresponds to: the first measurement data being indicative of the third physiological parameter; and the second measurement data being indicative of the third physiological parameter; and determine the third physiological parameter by correlating the third physiological parameter with the orthogonal data point or the orthogonal data set. ### Claim 11 (depends on 10) The device of claim 10, further comprising an environmental sensor, wherein the processing device is further configured to: receive, from the environmental sensor, environmental data on an environmental condition of an environment of the user, wherein the third physiological parameter is influenced by the environment of the user; and determine the third physiological parameter based on the environmental data and: the orthogonal data point; or the orthogonal data set. ### Claim 12 (depends on 10) The device of claim 10, wherein the processing device is further configured to: receive information regarding a unique physiological characteristic of the user, wherein the third physiological parameter is influenced by the unique physiological characteristic of the user; and determine the third physiological parameter based on the unique physiological characteristic and: the orthogonal data point; or the orthogonal data set. ### Claim 13 (depends on 10) The device of claim 10, wherein the processing device is further configured to: receive third measurement data that: corresponds to the first physiological parameter; and is crowd-sourced from a set of other users; receive fourth measurement data that: corresponds to the second physiological parameter; and is crowd-sourced from the set of other users; determine an orthogonality between: the third measurement data and the second measurement data; the fourth measurement data and the first measurement data; or the third measurement data and the fourth measurement data; and calibrate the first sensor based on the orthogonality. ### Claim 14 (depends on 10) The device of claim 10, wherein the processing device is further configured to forecast a future value for the third physiological parameter based on the orthogonal data point or the orthogonal data set. ### Claim 15 A method, comprising: receiving, at a processing device, first measurement data from a wearable medical device, wherein: the first measurement data directly corresponds to a first physiological parameter; and the first measurement data does not correspond to a second physiological parameter; receiving, at the processing device, second measurement data from a separate medical device that is separate from the wearable medical device, wherein: the second measurement data directly corresponds to the second physiological parameter; and the second measurement data does not correspond to the first physiological parameter, determining, by the processing device, orthogonal data between the first measurement data and the second measurement data; and determining, by the processing device, a third physiological parameter based on the orthogonal data. ### Claim 16 (depends on 15) The method of claim 15, further comprising: determining, by the processing device, an error rate for the first measurement data; and determining, by the processing device and based on the error rate, a recalibration rate for the wearable medical device. ### Claim 17 (depends on 15) The method of claim 15, wherein: the first measurement data comprises a first measurement; the second measurement data comprises a second measurement; the first measurement and the second measurement are taken from a user of the wearable medical device approximately contemporaneously; and the first measurement and the second measurement are orthogonal and form at least a part of the orthogonal data. ### Claim 18 (depends on 15) The method of claim 15, further comprising receiving, at the processing device, information corresponding to a habit of a user of the wearable medical device, wherein determining the third physiological parameter includes correlating the information corresponding to the habit of the user with the orthogonal data. ### Claim 19 (depends on 15) The method of claim 15, further comprising setting, by the processing device, a baseline measurement for the third physiological parameter based on the orthogonal data. ### Claim 20 (depends on 15) The method of claim 15, further comprising: receiving, at the processing device, a first value for the third physiological parameter from the wearable medical device; receiving, at the processing device, a second value for the third physiological parameter from the separate medical device; determining, by the processing device, whether the first value matches the second value; and in response to the first value not matching the second value, calibrating, by the processing device, the orthogonal data using the first value and the second value.