WO2019152246A1

WO2019152246A1 - Apparatus, systems, and methods for pulse monitoring

Info

Publication number: WO2019152246A1
Application number: PCT/US2019/014845
Authority: WO
Inventors: Robert MORA
Original assignee: The Board Of Regents Of The University Of Texas System
Priority date: 2018-01-30
Filing date: 2019-01-23
Publication date: 2019-08-08

Abstract

Apparatus and methods for detecting and monitoring a pulse in a human subject. Exemplary embodiments include a plurality of sensors distributed over an area of a flexible member that can be coupled to the human subject via an adhesive.

Description

DESCRIPTION

APPARATUS, SYSTEMS, AND METHODS FOR PULSE MONITORING

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the priority benefit of United States provisional application number 62/623,879, filed January 30, 2018, the entire contents of which is incorporated herein by reference.

BACKGROUND

Over 140 million people visit the emergency room annually in the U.S.¹ In 2001, septicemia (blood poisoning/infection) and cardiac conditions were the top reasons for admission among adults 45 year and older.² In 2016, the national incidence of cardiac arrest was 350,000 in out-of-hospital settings and over 200,000 within hospitals.³ Patients who are suffering from acute myocardial infarction (commonly referred to as a “heart attack”) and those in septic shock have lengthened stays in emergency departments and require more intense cardiac monitoring than has been done in the past.⁴

The guidelines for cardiopulmonary resuscitation (CPR) specify that arrest should be determined by detection of a pulse in a major artery within ten seconds and standard practice is the detection of pulse by placing the fingers on the area over the artery.⁵ Studies have suggested that trained medical personnel were able to determine pulselessness manually only 55% of the time.⁶ Additionally, continued pulse checks require manual detection by one or more medical staff, tying up limited and valuable personnel in a time-critical situation. A more reliable, automatic method to monitor the pulse without manual intervention would provide a more timely medical response and allow personnel to focus on other critical tasks.

There are devices on the market to help medical professionals find a pulse and monitor cardiac output. Physicians can choose from catheters, esophageal Doppler probes, impedance cardiography (which uses electrical conductivity through the skin), or transcutaneous Doppler ultrasound.⁴ Catheters and esophageal probes require time intensive placement procedures that are not feasible in an emergency situation. Impedance cardiography, which is part of standard hospital vital sign monitoring equipment, is based on electrical signals detected through the skin by adhesive leads. However, patients suffering cardiac arrest can have Pulseless Electrical Activity (PEA) and show a heart rhythm on an electrocardiogram that should produce a pulse, but one is not present.⁷ Therefore, this type of monitoring is not conclusive in cardiac arrest situations.

The global market for ambulance and emergency medical services equipment was $5.9 billion in 2013, and is expected to rise to $6.8 billion in 2018.¹¹ The cardiac and respiratory sub-segment is expected to increase from $2.4 billion in 2013 to $2.7 billion in 2018.^11,12 One current transcutaneous Doppler ultrasound that is available for pulse detection requires operation by a trained medical professional. It uses a pencil shaped probe that is very limited in its detection area and easily moved out of alignment with the blood vessel. Maintaining proper Airway, Breathing, and Circulation (ABC) is the foundation of Emergency Medicine. When a“coding” patient is presented to the emergency room and resuscitation is performed, the fundamental question is whether or not the patient has a pulse. Successful resuscitation constitutes establishing Return of Spontaneous Circulation (ROSC) and, therefore, a pulse. Current modalities for pulse detection include: Palpation; expensive bedside ultrasound machines; and, cumbersome pencil-probes attached to Doppler boxes. Research has shown that medical professionals only detect pulselessness correctly 55% of the time. The small surface area of a current pen’s sensor requires continuous, precise placement that is inefficient and cumbersome to use. Other devices also have shortcomings. For example, bedside ultrasound machines are costly for both the hospital and patient. In addition, cardiac electrical monitoring systems do not always accurately determine pulselessness due to Pulseless Electrical Activity (PEA), and ten percent of all in-hospital deaths result from PEA. One common technological issue is that current pulse-detection methods require inefficiently occupying essential personnel. SUMMARY

Embodiments of the disclosed invention include an apparatus and a method for reliably monitoring a pulse through Doppler flow detection, rather than electrical signals, in a non-responsive patient. Exemplary embodiments of the present disclosure can be used during resuscitation events by trained medical professionals. Thus, such embodiments could be incorporated into the standard equipment available in emergency rooms, intensive care units and ambulances. It is estimated that each ER or ICU would have one unit available within the department for use during a non-responsive“code” event. Using this assumption, there are almost 90,000 facilities/vehicles that could be purchasers of a more reliable pulse detection method, as shown in Table 1.

Table 1: ER, ICU and Ambulances in the US

Exemplary embodiments include an adhesive strip covered with Doppler ultrasound sensors. In exemplary embodiments, the adhesive strip would be placed over a major pulse point (e.g. carotid or femoral artery) of a patient for auditory monitoring of the pulse. In certain embodiments, the adhesive strip connects to a Doppler instrument for signal generation, return signal detection and auditory output.

Exemplary embodiments of the present disclosure include a noninvasive transcutaneous Doppler ultrasound. Instead of using an external probe (usually in the shape of a pen) with a single Doppler sensor at the end, exemplary embodiments use an adhesive strip with several Doppler sensors that cover a larger area. This would benefit the physician several ways. For example, it would allow a user to operate unattended and free up medical personnel to perform other critical tasks while still actively monitoring the pulse activity. This can free-up essential personnel to participate in other aspects of the“code” process, who would otherwise be palpating or probing for a pulse. In addition, multiple sensors applied over a larger area would provide a constant and consistent signal even during movement associated with resuscitation efforts. The greater surface area of the sensors can increase accuracy of pulse detection, thereby potentially improving patient survivability. Furthermore, the adhesive strip can provide secure attachment that can be used on any major pulse location. Accordingly, exemplary embodiments can provide continual, long-term pulse monitoring.

Exemplary embodiments could primarily be used by trained medical professionals during resuscitation events in Emergency Departments, ICU’s, and ambulances. There are almost 90,000 facilities/vehicles in the United States that could be prospective purchasers of exemplary embodiments of the device, sometimes referred to by the inventors as“The Pulse-Strip.” In 2013, the global market for ambulance and EMS equipment was $5.9 billion and is expected to rise to $6.8 billion by 2018. The cardiac and respiratory medical device sub-segment is expected to have a market of $2.7 billion by 2018. With presentation to the American Heart Association (AHA), the Pulse- Strip could become a standard of care.

BRIEF DESCRIPTION OF THE DRAWINGS

The following drawings form part of the present specification and are included to further demonstrate certain aspects of the present disclosure. Various embodiments may be better understood by reference to one of these drawings in combination with the detailed description of specific embodiments presented herein.

FIG. 1 shows a view of an embodiment of an apparatus for pulse monitoring according to the present disclosure during use in a first location.

FIG. 2 shows the embodiment of FIG. 1 during use in a second location.

FIG. 3 shows a view of particular components of the embodiment of FIG. 1. DETAILED DESCRIPTION

Referring now to FIGS. 1-3, an apparatus 100 comprises a flexible planar member 110 with a plurality of ultrasonic sensors 120, an ultrasonic flow detector 130 and a cable 140 coupling ultrasonic sensors 120 and ultrasonic flow detector 130. Flexible planar member 110 comprises an adhesive side 115 that may be used to couple flexible planar member 110 and ultrasonic sensors 120 to a human subject 150. Flexible planar member 110 may be formed from a cloth, plastic or any suitable material capable of being coupled to the skin surface of a human subject.

An overview of apparatus 100 and its operation will now be provided, followed by more detailed discussion of various aspects. For purposes of clarity, not all components are labeled with reference numbers in every figure.

As shown in FIG. 1, flexible planar member 110 is coupled to a femoral artery region 152. In FIG. 2, flexible planar member 110 is coupled to a carotid artery region 154. With flexible planar member 110 coupled to human subject 150 in either femoral artery region 152 or carotid artery region 154 (or any suitable region in which a pulse can be detected), ultrasonic sensors 120 can detect a pulse in human subject 150.

In certain embodiments, ultrasonic sensors 120 may be configured as Doppler sensors and ultrasonic flow detector 130 may be configured as a Doppler flow detector. Ultrasonic sensors 120 can detect a signal (including for example, an auditory signal) indicating a pulse of blood flow in patient 150. The signal can be transmitted to ultrasonic flow detector 130 via cable 140, which can provide confirmation (e.g., a visual or audible alert) that a pulse has been detected or that a change in pulse status has occurred (e.g. a pulse that was previously detected is no longer detected, or a pulse is detected where one had previously note been detected).

Apparatus 100 provides significant advantages over typical existing techniques for detecting a pulse in a subject. For example, the inclusion of a plurality of ultrasonic sensors 120 over the surface area of flexible planar member 110 can provide more reliable detection of a pulse in human subject 150. Because there are multiple sensors distributed over a wide area, a user is not required to place a single sensor directly over an artery in order to detect a pulse of a subject as in typical existing techniques. This can reduce the amount of time needed to detect a pulse. In addition, a user can apply flexible planar member 110 to human subject 150 and then be freed to perform other tasks without having to maintain manually maintain contact between a sensor (e.g. a typical ultrasonic pen or the user’s finger) and human subject by physically holding the sensor to the subject. In certain embodiments ultrasonic sensors 120 and ultrasonic flow detector 120 may be electronically coupled via other coupling mechanisms, including for example, a wireless communication system.

In the preceding discussion, the term“coupled” is defined as connected, although not necessarily directly, and not necessarily mechanically. Thus, one element may be directly, mechanically coupled to another, as is the case with the purge port 4 of the pumping diaphragm 24. An element may also be indirectly, fluidly coupled to another, as is the case (during operation) of the base plate 17 and the pumping membrane flange 3.

The use of the word“a” or“an” when used in conjunction with the term “comprising” in the claims and/or the specification may mean“one,” but it is also consistent with the meaning of “one or more” or“at least one.” The terms“about”, “approximately” or“substantially” mean, in general, the stated value plus or minus 5%. The use of the term“or” in the claims is used to mean“and/or” unless explicitly indicated to refer to alternatives only or the alternative are mutually exclusive, although the disclosure supports a definition that refers to only alternatives and“and/or.” The terms“comprise” (and any form of comprise, such as“comprises” and

“comprising”),“have” (and any form of have, such as“has” and“having”),“include” (and any form of include, such as“includes” and“including”) and“contain” (and any form of contain, such as“contains” and“containing”) are open-ended linking verbs. As a result, a method or device that“comprises,”“has,”“includes” or“contains” one or more acts or elements, possesses those one or more acts or elements, but is not limited to possessing only those one or more elements. Likewise, an act in a method or an element of a device that“comprises,”“has,”“includes” or“contains” one or more features, possesses those one or more features, but is not limited to possessing only those one or more features. Furthermore, a device or structure that is configured in a certain way is configured in at least that way, but may also be configured in ways that are not listed. All of the apparatus, systems and/or methods disclosed and claimed herein can be made and executed without undue experimentation in light of the present disclosure. While these apparatus, systems and methods have been described in terms of particular embodiments, it will be apparent to those of ordinary skill in the art that variations may be applied to the apparatus, systems and/or methods without departing from the scope of this disclosure. All such similar substitutes and modifications apparent to those of ordinary skill in the art are deemed to be within the scope of this disclosure, as defined by the appended claims.

REFERENCES:

The contents of the following references are incorporated in their entirety by reference herein:

1. U.S. Patent 6575914

2. U.S. Patent Publication 20100076315

3. U.S. Patent Publication 20110015527

4. U.S. Patent Publication 20120065479

5. U.S. Patent Publication 20120184854

6. U.S. Patent Publication 20140058267

7. U.S. Patent Publication 20150351703

8. U.S. Patent Publication 20170105700

9. U.S. Patent Publication 20170143309

10. FastStats - Emergency Department Visits. (2017).

11. Weiss, A. J., Wier, L. M., Stocks, C. & Blanchard, J. Overview of Emergency Department Visits in the United States, 2011.

doi:https://www.ncbi.nlm.nih.gov/books/NBK235856/ (2014).

12. Cardiac Arrest Statistics,

http://cpr.heart.org/AHAECC/CPRAndECC/General/UCM_477263_Cardiac- Arrest-Statistics.jsp> (2017).

13. Interrater reliability of cardiac output measurements by transcutaneous Doppler ultrasound: implications for noninvasive hemodynamic monitoring in the ED - ScienceDirect. doi:l0.l0l6/j.ajem.2006.05.0l2 (2017).

14. Part 5: Adult Basic Life Support and Cardiopulmonary Resuscitation Quality“ ECC Guidelines, <https://eccguidelines.heart.org/index.php/circulation/cpr-ecc- guidelines-2/part-5-adult-basic-life-support-and-cardiopulmonary-resuscitation- quality/> (2017).

15. Schonberger, R. B. et al. Handheld Doppler to Improve Pulse Checks during Resuscitation of Putative Pulseless Electrical Activity Arrest. Anesthesiology:

The Journal of the American Society of Anesthesiologists 120, 1042-1045, doi : 10.1097/ ALN.0000000000000106 (2017).

16. Pulseless Electrical Activity: Background, Etiology, Epidemiology,

<https://emedicine.medscape.com/article/l6l080-overview> (2017).

17. National ED Inventory - US, <http://www.emnet-usa.org/nedi/USA.htm> (2017). SCCM I Critical Care Statistics,

<http://www.sccm.org/Comniunications/Pages/CriticalCareStats.aspx> (2017). NASEMSO Survey Provides Snapshot of EMS Industry,

<http://www.jems.com/articles/20l 1/1 l/nasemso-survey-provides-snapshot-ems- ind.html> (2017).

ReportBuyer. Ambulance and Emergency Equipment: Global Markets,

<https://www.prnewswire.com/news-releases/ambulance-and-emergency- equipment-global-markets-3000l20l7.html> (2017).

Owens, P. L. et al. Emergency department care in the United States: a profile of national data sources. Ann Emerg Med 56, 150-165,

doi : 10.1016/j . annemergmed.2009.11.022 (2010).

Claims

1. An apparatus comprising:

a flexible planar member comprising an adhesive side;

a plurality of ultrasonic sensors coupled to the flexible planar member, wherein the plurality of ultrasonic sensors are configured to detect a pulse in a human subject; an ultrasonic flow detector; and

a coupling mechanism coupling the plurality of ultrasonic sensors to the ultrasonic flow detector.

2. The apparatus of claim 1 wherein:

the plurality of ultrasonic sensors comprise Doppler sensors; and

the ultrasonic flow detector is a Doppler flow detector.

3. The apparatus of claim 1 wherein the flexible planar member comprises a fabric material.

4. The apparatus of claim 1 wherein the flexible planar member comprises a flexible plastic material.

5. The apparatus of claim 1 wherein the coupling mechanism is a cable.

6. The apparatus of claim 1 wherein the coupling mechanism is a wireless communication system.

7. The apparatus of claim 1 wherein the ultrasonic flow detector is configured to provide confirmation that a pulse has been detected.

8. The apparatus of claim 1 wherein the ultrasonic flow detector is configured to provide a visual alert to a change in a pulse status.

9. The apparatus of claim 1 wherein the ultrasonic flow detector is configured to provide an audible alert to a change in a pulse status.

10. A method of detecting a pulse in a human subject, the method comprising:

placing a flexible planar member at a location on the human subject, wherein the flexible planar member comprises an adhesive side;

coupling the flexible planar member to the first location via the adhesive side;

detecting an auditory signal via a plurality of ultrasonic sensors coupled to the flexible planar member, wherein the auditory signal indicates a pulse in the human subject; and

transmitting the auditory signal to an ultrasonic flow detector.

11. The method of claim 10 wherein the location on the human subject is a femoral artery region.

12. The method of claim 10 wherein the location on the human subject is a carotid artery region.

13. The method of claim 10 wherein:

the plurality of ultrasonic sensors comprise Doppler sensors; and

the ultrasonic flow detector is a Doppler flow detector.

14. The method of claim 10 wherein the flexible planar member comprises a fabric material.

15. The method of claim 10 wherein the flexible planar member comprises a flexible plastic material.

16. The method of claim 10 wherein the coupling mechanism is a cable.

17. The method of claim 10 wherein the coupling mechanism is a wireless communication system.

18. The method of claim 10 wherein the ultrasonic flow detector is configured to provide confirmation that a pulse has been detected.

19. The method of claim 10 wherein the ultrasonic flow detector is configured to provide a visual alert to a change in a pulse status.

20. The method of claim 10 wherein the ultrasonic flow detector is configured to provide an audible alert to a change in a pulse status.