# US 12,004,870 B2 · Physiological feedback systems and methods

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- Number: US 12,004,870 B2
- Document ID: US12004870B2
- Status: Granted
- Kind: B2
- Application number: 17/200,690
- Filed: 2021-03-12
- Published: 2021-08-12
- Granted: 2024-06-11
- Earliest claimed: 2017-04-21
- Assignees: Physio-Control, Inc.
- Applicants: Physio-Control, Inc.
- Inventors: Robert G. Walker; Fred W. Chapman
- Web page: https://patentgrep.com/patent/US12004870B2

## CPC

- A61B 5/486: {Biofeedback (using electroencephalography [EEG] A61B5/375)}
- A61B 5/0836: {Measuring rate of CO2 production}
- A61B 5/14551: {for measuring blood gases}
- A61B 5/4836: {Diagnosis combined with treatment in closed-loop systems or methods (A61B5/0036 takes precedence)}
- A61H 31/004: {Heart stimulation}
- A61H 31/005: {with feedback for the user}
- A61B 5/0002: {Remote monitoring of patients using telemetry, e.g. transmission of vital signals via a communication network (endoradiosondes A61B5/07)}
- A61B 5/0205: Simultaneously evaluating both cardiovascular conditions and different types of body conditions, e.g. heart and respiratory condition
- A61B 5/085: Measuring impedance of respiratory organs or lung elasticity
- 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 5/742: {using visual displays (displays for heart-related electrical signals, e.g. ECG, A61B5/339)}
- A61H 2201/501: connected to external computer devices or networks
- A61H 2230/045: used as a control parameter for the apparatus
- A61H 2230/065: used as a control parameter for the apparatus
- A61N 1/36521: {the parameter being derived from measurement of an electrical impedance}
- A61N 1/37: Monitoring; Protecting
- A61N 1/3904: {External heart defibrillators [EHD]}
- A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D)
- A61H: PHYSICAL THERAPY APPARATUS, e.g. DEVICES FOR LOCATING OR STIMULATING REFLEX POINTS IN THE BODY; ARTIFICIAL RESPIRATION; MASSAGE; BATHING DEVICES FOR SPECIAL THERAPEUTIC OR HYGIENIC PURPOSES OR SPECIFIC PARTS OF THE BODY (electrotherapy, magnetotherapy, radiation therapy or ultrasound therapy A61N)
- A61N: ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY (measurement of bioelectric currents A61B; surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body A61B18/00; anaesthetic apparatus in general A61M; incandescent lamps H01K; infrared radiators for heating H05B)

## Abstract

The disclosed physiological feedback systems and methods assist with assessing, monitoring and/or treating a patient experiencing a cardiac arrest event. The systems and methods receive multiple inputs and are continuous and/or iterative during a treatment session to provide physiological state trends of the patient. An index of the physiological state of the patient can be derived and confounders, and/or their effects, can be identified, and/or removed, from the index. Additionally, the systems and methods can assist with determining ischemic injury in a patient based on cerebral tissue oxygenation and/or other physiological data.

## Claims

### Claim 1

A medical device comprising:
an airway sensor configured to detect a level of carbon dioxide expelled from an airway of an individual;
an oximetry sensor configured to detect a blood oxygenation level of the individual; and
a processor configured to:
determine a threshold based on the level of carbon dioxide expelled from the airway of the individual;
determine that the blood oxygenation level of the individual exceeds the threshold; and
determine that the patient has experienced return of spontaneous circulation (ROSC) based on determining that the blood oxygenation level of the individual exceeds the threshold.

### Claim 2 (depends on 1)

The medical device of claim 1, wherein the oximetry sensor comprises a regional tissue oxygenation (rSO2) sensor.

### Claim 3 (depends on 1)

The medical device of claim 1, further comprising:
a screen configured to visually output an indication of the ROSC; and
a speaker configured to audibly output the indication of the ROSC.

### Claim 4

A medical device comprising:
a first sensor configured to detect a first physiological parameter indicating a hemodynamic adequacy of an individual, the first physiological parameter being correlated with a confounder;
a second sensor configured to detect a second physiological parameter indicating the hemodynamic adequacy of the individual, the second physiological parameter being non-correlated with the confounder; and
a processor configured to:
determine, based on the first physiological parameter, a threshold;
compare the second physiological parameter to the threshold; and
based on the comparison of the second physiological parameter to the threshold, determine a condition of the individual, wherein the condition comprises a return of spontaneous circulation (ROSC) of the individual, an effectiveness of cardiopulmonary resuscitation (CPR) performed on the individual, or a risk of cardiac re-arrest of the individual.

### Claim 5 (depends on 4)

The medical device of claim 4, wherein the first physiological parameter or the second physiological parameter comprises carbon dioxide expelled from an airway of an individual.

### Claim 6 (depends on 4)

The medical device of claim 4, wherein the first physiological parameter or the second physiological parameter comprises a blood oxygenation level of the individual.

### Claim 7 (depends on 6)

The medical device of claim 6, wherein the first sensor or the second sensor comprises a regional tissue oxygenation (rSO2) sensor configured to detect the blood oxygenation level of the individual.

### Claim 8 (depends on 4)

The medical device of claim 4, wherein the confounder comprises a medication administered to the individual or a treatment administered to the individual.

### Claim 9 (depends on 4)

The medical device of claim 4, further comprising:
a display configured to visually output an indication of the condition.

### Claim 10 (depends on 4)

The medical device of claim 4, further comprising:
a speaker configured to audibly output the indication of the condition.

### Claim 11 (depends on 4)

The medical device of claim 4, further comprising:
a transmitter configured to transmit an indication of the condition of the individual to an external device.

### Claim 12

A device comprising:
a processor; and
memory storing instructions that, when executed by the processor, cause the processor to perform operations comprising:
determining a threshold based on a first physiological parameter indicative of a hemodynamic adequacy of an individual, the first physiological parameter being correlated with a confounder;
comparing the threshold to a second physiological parameter indicative of the hemodynamic adequacy of the individual, the second physiological parameter being non-correlated with the confounder; and
based on the comparison of the second physiological comparison to the threshold, determine whether the individual is experiencing return of spontaneous circulation (ROSC).

### Claim 13 (depends on 12)

The device of claim 12, further comprising:
a receiver configured to receive data indicative of the first physiological parameter or the second physiological parameter.

### Claim 14 (depends on 12)

The device of claim 12, wherein the first physiological parameter or the second physiological parameter comprises carbon dioxide expelled from an airway of an individual.

### Claim 15 (depends on 12)

The device of claim 12, wherein the first physiological parameter or the second physiological parameter comprises a blood oxygenation level of the individual.

### Claim 16 (depends on 12)

The device of claim 12, wherein the confounder comprises a medication administered to the individual or a treatment administered to the individual.

### Claim 17 (depends on 12)

The device of claim 12, further comprising:
a display configured to visually output an indication of whether the individual is experiencing ROSC; or
a speaker configured to audibly output the indication of the individual is experiencing ROSC.

### Claim 18 (depends on 12)

The device of claim 12, wherein the operations further comprise:
based on the comparison of the second physiological comparison to the threshold, determining an effectiveness of cardiopulmonary resuscitation (CPR) performed on the individual.

### Claim 19 (depends on 18)

The device of claim 18, further comprising:
a transmitter configured to transmit, to an external device, a signal based on whether the individual is experiencing ROSC or the effectiveness of the CPR performed on the individual.

### Claim 20 (depends on 19)

The device of claim 19, wherein the external device comprises a mechanical CPR device.