Patent Description:
Resuscitation treatments for patients suffering from cardiac arrest generally include clearing and opening the patient's airway, providing rescue breathing for the patient, and applying chest compressions to provide blood flow to the victim's heart, brain and other vital organs. If the patient has a shockable heart rhythm, resuscitation also may include defibrillation therapy. Such treatment may include basic life support (BLS), which involves initial assessment; airway maintenance; expired air ventilation (rescue breathing); and chest compression. When all these elements are combined, the term cardiopulmonary resuscitation (CPR) is used. Relatively untrained rescuers, such as laypeople, may provide BLS, while trained rescuers such as physicians or emergency medical technicians (EMTs) may provide advanced life support (ALS), which may additionally involve, among other things, cardiac monitoring, intravenous cannulation (IV), intraosseous (IO) access and intraosseous infusion, surgical cricothyrotomy, needle cricothyrotomy, and advanced medication administration through parental and enteral routes.

Ventilation in various instances may involve rescue breathing, or more commonly, bag or bag-valve-mask ventilation for ALS, which involves placing a mask in a seal over a patient's face and forcing air into the patient's lungs by repeatedly compressing and expanding a flexible device that is attached to the mask. Such ventilation may be performed in time-wise coordination with chest compressions and with defibrillation shocks delivered by a defibrillator, such as a portable defibrillator in the form of an automatic external defibrillator (AED) or other types of defibrillators. The chest compression can be automatically coordinated by the defibrillator, such as by the provision of an accelerometer positioned relative to the defibrillator electrodes on a patient's chest so that the accelerometer can be used to provide a rescuer with feedback if they are compressing too hard or too soft, and too fast or too slow, as compared to set standards and protocols. <CIT> discloses a self-inflating resuscitation system formed from a self-inflating resuscitation bag and an exhalation indicator. In particular, the self-inflating resuscitation bag provides an exhalation indicator, which may be an audio or visual indicator, or both.

Patent document <CIT> is hereby acknowledged.

This document describes systems that may be used to monitor a caregiver's provision of ventilation to a medical patient. We also disclose a ventilation monitor that is placed in or on a ventilation assembly in the form of a ventilation bag and mask. The ventilation monitor may include a ventilation sensor for sensing a direction of ventilation (inhalation or exhalation of the patient) and may also include a sensor for sensing the volume of the patient's ventilation. The ventilation may include a transceiver for sending to an external unit such as a defibrillator or computing tablet a signal that indicates the occurrence of ventilation or respiration events (e.g., a signal for each exhalation, each inhalation, or both, or data otherwise representing a rate or volume of respiration in the patient). The external unit may then provide feedback to a rescuer, either directly or through the ventilation monitor, such as by providing a ventilation metronome (i.e., a sound that plays each time a rescuer is to provide ventilation) or by spoken feedback, such as feedback telling the provider of ventilation that they are providing too much or too little ventilation, or that they are going too fast or too slow.

The particular feedback may be directed to the particular patient and may be coordinated with other feedback given to a rescuer or rescuers. For example, the feedback may be coordinated with feedback for chest compressions so as to ensure that the provision of ventilation and of chest compressions stays synchronized. To prevent interference between the two feedback signals, the tones or other indications for chest compressions may be of one type (e.g., a beep or other hard sound that begins and ends crisply) and those for ventilation may be another (e.g., a whooshing or other soft noise that evokes the sound of breathing). Also, the feedback may be delivered wirelessly to headsets that are worn by each member of a rescue crew, where one headset delivers chest compression feedback and the other delivers ventilation feedback. The feedback may also be customized to the patient. For example, a rescuer may be asked a number of questions about the patient and the patient's condition, and the answers to the questions may affect the manner in which the rescuers are instructed to perform the rescue. Also, electronic medical record (EMR) data and dispatch information about the patient may also be accessed for similar reasons. For example, a victim who has suffered a traumatic brain injury will need tightly controlled ventilation, so that feedback prompting in such situations (e.g., when the criticality of proper ventilation or other operations on the victim) may be more overt to a rescuer (e.g., audible feedback may be louder, more insistent, or require rescuer confirmation) so as to assure that the rescuer focuses on appropriate ventilation technique.

According to an aspect, the present disclosure is a medical ventilation monitoring system as defined in claim <NUM>. The system comprises a patient ventilation unit defining an airflow path, the unit arranged so that when the unit is applied to a patient, the airflow path is in fluid communication with the patient's airway; an airflow sensor positioned in the air flow path to sense the presence of ventilation airflow to or from the patient; and an external unit arranged to receive from the airflow sensor a signal that indicates the occurrence of ventilation or respiration events and to use the data to provide feedback to a rescuer regarding proper administration of ventilation wherein said feedback is provided by one or both of: a visual indication at the airflow sensor or loudspeakers mounted with the airflow sensor. The ventilation unit can comprise a mask that seals to and fits over a lower portion of the patient's face, and can further include a flexible bag connected to provide ventilation air through the air flow path.

In some aspects, the airflow sensor comprises a differential pressure sensor. Also, the wireless transmitter can comprise a Bluetooth wireless transmitter. The system can also include a defibrillator having a wireless transceiver configured to communicate with the wireless transmitter so as to provide feedback to a rescuer in the vicinity of the wireless transmitter. The feedback can also comprise feedback that communicates to the rescuer an appropriate rate for providing ventilation to the patient. Moreover, the system can also include a portable computing device configured to receive inputs about a patient encounter from a medical caregiver, and programmed to generate a treatment regimen and to transmit data for implementing the treatment regimen.

In yet other aspects, the portable computing device is further programmed to transmit the data for implementing the treatment regimen to the patient ventilation unit, and can be further programmed to transmit a first portion of the data for implementing the treatment regimen to the patient ventilation unit, and a second portion of the data for implementing the treatment regimen to a portable defibrillator. Also, the portable computing device can be configured to receive input regarding a current condition of the patient, and to provide feedback to a rescuer based on one or more parameters that reflect the current condition of the patient. In addition, the rescuer input device can be programmed to receive input regarding a current condition of a patient by posing one or more questions to the rescuer about the patient, and to use answers to the one or more questions to determine an appropriate treatment regimen for the patient. The portable computing device can also be further programmed and arranged to upload information about the patient wirelessly to a central server system for sharing up the uploaded information to caregivers at a central medical facility. The system can further include a visual feedback mechanism for providing information to a rescuer regarding delivery of ventilation comprising a plurality of lights arranged to indicate, based on which lights of the plurality of lights are activated, whether excessive ventilation, too little ventilation, or an appropriate amount of ventilation is being provided to the victim.

The system can further comprise an activation structure that, when selected, causes the ventilation monitoring device to attempt to establish a data connection with a wireless computing device. The activation structure can itself comprise a switch that is accessible from an exterior part of the ventilation monitoring device. Also, the activation structure can comprise a switch that is not accessible to a user of the device, and is activated by an action of the ventilation monitoring device being brought into proximity with a ventilation providing component. Moreover, the system can include a feedback mechanism for annunciating feedback instructions to a user of the device. The feedback mechanism can also comprise an LED light that blinks to indicate a proper ventilation rate for the person in need of assisted ventilation. The feedback mechanism can also comprise a speaker for creating an audible signal to indicate a proper ventilation rate for the person in need of assisted ventilation. In addition, the device can be further arranged to provide feedback regarding ventilation volume to be provided to the person via the speaker.

In certain aspects, the device housing is arranged to provide an airtight interface with components of an assisted ventilation assembly. The device housing can also be arranged to fit between an air bag and a face mask of an assisted ventilation assembly. The airflow sensor itself can comprise a differential pressure sensor.

In some aspects, the revised treatment protocol differs from any published protocol for treating a patient. Also, the initial and revised treatment protocols can define chest compression and ventilation rates for the person in need of emergency assistance. Moreover, the initial treatment protocol can follow a published protocol, and the revised treatment protocol can fail to follows the published protocol.

We also disclose an unclaimed medical ventilation monitoring system, comprising: a patient ventilation unit providing an airflow path and arranged so that when the unit is applied to a patient, the airflow path is in fluid communication with the patient's airway; an airflow sensor positioned in the airflow path to sense the presence of ventilation airflow to or from the patient; and an external unit arranged to receive from the airflow sensor a signal that indicates the occurrence of ventilation or respiration events and to use the data to provide feedback to a rescuer regarding proper administration of ventilation; wherein the external unit is configured to: provide an initial treatment protocol for providing care to the patient comprising applying ventilation at an initial ventilation rate and at an initial ventilation volume; receive data regarding one or more patient parameters; and provide a revised treatment protocol comprising applying ventilation at an updated ventilation volume different from the initial ventilation volume, or at an updated ventilation rate different from the initial ventilation rate, the revised treatment protocol being based at least in part on information from the airflow sensor and the received one or more patient parameters. Optionally, the feedback comprises feedback that communicates to the rescuer an appropriate rate and/or volume for providing ventilation to the patient. Optionally, the patient ventilation unit comprises a mask that seals to and fits over a lower portion of the patient's face. Optionally, the patient ventilation unit further includes a flexible bag connected to provide ventilation air through the air flow path. Optionally, the airflow sensor comprises a differential pressure sensor. Optionally, the patient ventilation unit comprises a wireless transmitter, optionally a Bluetooth transmitter, for communicating with the external unit. Optionally, the external unit is a defibrillator having a wireless transceiver configured to communicate with the wireless transceiver of the patient ventilation unit so as to provide feedback to a rescuer in the vicinity of the wireless transmitter of the patient ventilation unit. Optionally, the external unit is a portable computing device configured to receive inputs about a patient encounter from a medical caregiver, and programmed to generate a treatment regimen and to transmit data for implementing the treatment regimen. Optionally, the portable computing device is further programmed to transmit the data for implementing the treatment regimen to the patient ventilation unit. Optionally, the portable computing device is further programmed to transmit a first portion of the data for implementing the treatment regimen to the patient ventilation unit, and a second portion of the data for implementing the treatment regimen to a portable defibrillator. Optionally, the portable computing device is configured to receive input regarding a current condition of the patient, and to provide feedback to a rescuer based on one or more parameters that reflect the current condition of the patient. Optionally, the system further comprises a rescuer input device programmed to receive input regarding a current condition of a patient by posing one or more questions to the rescuer about the patient, and to use answers to the one or more questions to determine an appropriate treatment regimen for the patient. Optionally, the portable computing device is further programmed and arranged to upload information about the patient wirelessly to a central server system for sharing up the uploaded information to caregivers at a central medical facility. Optionally, the system further comprises a feedback mechanism for providing information to a rescuer regarding delivery of ventilation, the feedback mechanism comprising at least one of: a plurality of lights arranged to indicate, based on which lights of the plurality of lights are activated, whether excessive ventilation, too little ventilation, or an appropriate amount of ventilation is being provided to the victim; a ventilation timer providing information about respiratory rate or elapsed time between ventilation events; a speaker for annunciating feedback instructions to a user of the device; an LED light that blinks to indicate a proper ventilation rate for the person in need of assisted ventilation; and a speaker for creating an audible signal to indicate a proper ventilation rate and/or volume for the person in need of assisted ventilation. Optionally the system further comprises an activation structure that, when selected, causes the ventilation monitoring device to attempt to establish a data connection with a wireless computing device.

This document describes mechanisms by which various devices can interact in a life-saving situation to improve the care that a victim (which should be understood to be a person in need of CPR, ventilation, or related care that is typically provided by an emergency medical technician or physician, but may also be provided by lay responders in certain situations) receives in such a situation. In particular, this document describes a system in which a patient ventilation sensor communicates with one or more other portable medical devices so that a ventilation rate, and perhaps a ventilation volume, may be analyzed, and a provider of care to the victim may be instructed in how best to ventilate the victim. The instructions may be coordinated with instructions for giving chest compressions to the victim and for defibrillating the victim. As one example, instructions regarding how fast, and when, to provide chest compressions and ventilation may be provided in a properly coordinated manner. Also, as a battery charges for a defibrillation pulse, such timing may be adjusted so that chest compressions and ventilation are finished as the defibrillator reaches a fully charged state, so that a defibrillation pulse may be delivered immediately upon the unit becoming charged. Also, the charging rate of the unit may be changed based on the location that rescuers are currently at in a protocol, so that the charging can occur at a rate that the device is ready at the proper point, and the device may be charged more slowly than it might otherwise be charged, thus conserving battery power in the device.

<FIG> shows a system <NUM> for responding to an emergency medical condition. In general, system <NUM> includes various portable devices for monitoring on-site care given to a victim of an emergency situation, such as a victim <NUM> suffering from sudden cardiac arrest or a victim <NUM> at the scene of a traffic accident. The various devices may be provided by emergency medical technicians who arrive at the scene and who provide care for the victim <NUM>, such as emergency medical technician <NUM>. In this example, the emergency medical technician <NUM> has deployed several devices and is providing care to the victim <NUM>. Although not shown, one or more other emergency medical technicians may be assisting and working in coordination with emergency medical technician <NUM> according to a defined protocol and training.

The emergency medical technician <NUM> in this example is interacting with a computing device in the form of a touchscreen tablet <NUM>. The tablet <NUM> may include a graphical display by which to report information to the emergency medical technician <NUM>, and may have an input mechanism such as a keyboard or a touchscreen by which the emergency medical technician <NUM> may enter data into the system <NUM>. The tablet <NUM> may also include a wireless transceiver for communicating with a wireless network, such as a <NUM> or <NUM> chipset that permits long distance communication over cellular data networks, and further through the internet.

Separately, a portable defibrillator <NUM> is shown in a deployed state and is connected to the victim <NUM>. In this example, electrodes <NUM> have been applied to the bare chest of the victim <NUM> and have been connected to the defibrillator <NUM>, so that electrical shocking pulses may be provided to the electrodes in an effort to defibrillate the victim <NUM>. The defibrillator <NUM> may take a variety of forms, such as the ZOLL MEDICAL R Series, E Series, or M Series defibrillators.

The assembly for the electrodes <NUM> includes a center portion at which an accelerometer assembly <NUM> is mounted. The accelerometer assembly <NUM> may include a housing inside which is mounted an accelerometer sensor configuration. The accelerometer assembly <NUM> may be positioned in a location where a rescuer is to place the palms of their hands when performing cardio pulmonary resuscitation (CPR) on the victim <NUM>. As a result, the accelerometer assembly <NUM> may move with the victim's <NUM> chest and the rescuer's hands, and acceleration of such movement may be double-integrated to identify a vertical displacement of such motion.

The defibrillator <NUM> may, in response to receiving such information from the accelerometer assembly <NUM>, provide feedback in a conventional and known manner to a rescuer, such as emergency medical technician <NUM>. For example, the defibrillator <NUM> may generate a metronome to pace such a user in providing chest compressions. In addition, or alternatively, the defibrillator <NUM> may provide verbal instructions to the rescuer, such as by telling the rescuer that they are providing compressions too quickly or too slowly, or are pushing too hard or too soft, so as to encourage the rescuer to change their technique to bring it more in line with proper protocol - where the proper protocol may be a protocol generated by the system, but that is inconsistent with any published protocols.

The defibrillator <NUM> may communicate through a short range wireless data connection with the tablet <NUM>, such as using BLUETOOTH technology. The defibrillator <NUM> can provide to the tablet <NUM> status information, such as information received through the electrode assembly <NUM>, including ECG information for the victim <NUM>. Also, the defibrillator <NUM> can send information about the performance of chest compressions, such as depth and rate information for the chest compressions. The tablet <NUM> may display such information (and also other information, such as information from the defibrillator regarding ETCO2 and SPO2) graphically for the emergency medical technician <NUM>, and may also receive inputs from the emergency medical technician <NUM> to control the operation of the various mechanisms at an emergency site. For example, the emergency medical technician <NUM> may use the tablet <NUM> to change the manner in which the defibrillator <NUM> operates, such as by changing a charging voltage for the defibrillator <NUM>.

Another electronic mechanism, in the form of a ventilation bag <NUM> is shown sealed around the mouth of the victim <NUM>. The ventilation bag <NUM> may, for the most part, take a familiar form, and may include a flexible body structure that a rescuer may squeeze periodically to provide ventilation on the victim <NUM> when the victim <NUM> is not breathing sufficiently on his or her own.

Provided with the ventilation bag <NUM> is an airflow sensor <NUM>. The airflow sensor <NUM> is located in a neck of the ventilation bag <NUM> near the mouthpiece or mask of the ventilation bag <NUM>. The airflow sensor <NUM> may be configured to monitor the flow of air into and out of the patient's mouth, so as to identify a rate at which ventilation is occurring with the victim. In addition, in certain implementations, the airflow sensor <NUM> may be arranged to monitor a volume of airflow into and out of the victim <NUM>.

In this example, the airflow sensor <NUM> is joined to a short-range wireless data transmitter or transceiver, such as a mechanism communicating via BLUETOOTH technology. As such, the airflow sensor <NUM> may communicate with the tablet <NUM> in a manner similar to the communication of the defibrillator <NUM> with the tablet <NUM>. For example, the airflow sensor <NUM> may report information that enables the computation of a rate of ventilation, and in some circumstances a volume of ventilation, provided to the patient. The tablet <NUM>, for example, may determine an appropriate provision of ventilation and compare it to the determine provision, and may provide feedback for a rescuer, either directly such as by showing the feedback on a screen of the tablet <NUM> or playing the feedback through an audio system of the tablet <NUM>, or indirectly, by causing defibrillator <NUM> or airflow sensor <NUM> to provide such feedback. For example, defibrillator <NUM> or airflow sensor <NUM> may provide a metronome or verbal feedback telling a rescuer to squeeze the ventilation bag <NUM> harder or softer, or faster or slower. Also, the system <NUM> may provide the rescuer was an audible cue each time that the bag is to be squeezed and ventilation is to be provided to the victim <NUM>.

Such feedback may occur in a variety of manners. In the present embodiment, the feedback is provided by one or both of: a visual indication at the airflow sensor or loudspeakers mounted with the airflow sensor <NUM>. However, in other unclaimed examples, the feedback may be played on built-in loudspeakers mounted in any of tablet <NUM>, defibrillator <NUM>, or airflow sensor <NUM>. Visual notifications may be provided on any combination of such units. Also, feedback may be provided to wireless headsets (or other form of personal device, such as a smartphone or similar device that each rescuer may use to obtain information and to enter data, and which may communicate wirelessly over a general network (e.g., WiFi or <NUM>/<NUM>) or a small area network (e.g., BLUETOOTH) that are worn by each rescuer, and two channels of communication may be maintained, so that each rescuer receives instructions specific to their role, where one may have a role of operating the defibrillator <NUM>, and the other may have the role of operating the ventilation bag <NUM>. In this manner, the two rescuers may avoid being accidentally prompted, distracted, or confused by instructions that are not relevant to them.

A central server system <NUM> may communicate with the tablet <NUM> or other devices at the rescue scene over a wireless network and a network <NUM>, which may include portions of the Internet (where data may be appropriately encrypted to protect privacy). The central server system <NUM> may be part of a larger system for a healthcare organization in which medical records are kept for various patients in the system. Information about the victim <NUM> may then be associated with an identification number or other identifier, and stored by the central server system <NUM> for later access. Where an identity of the victim <NUM> can be determined, the information may be stored with a pre-existing electronic medical record (EMR) for that victim <NUM>. When the identity of the victim <NUM> cannot be determined, the information may be stored with a temporary identification number or identifier, which may be tied in the system to the particular rescue crew so that it may be conveniently located by other users of the system.

The information that is stored may be relevant information needed to determine the current status of the victim <NUM> and the care that has been provided to the victim <NUM> up to a certain point in time. For example, vital signs of the victim <NUM> may be constantly updated at the central server system <NUM> as additional information is received from the tablet <NUM>. Also, ECG data for the victim <NUM> may be uploaded to the central server system <NUM>. Moreover, information about drugs provided to the victim may be stored. In addition, information from a dispatch center may also be stored on a central server system and accessed by various users such as rescuers. For example, a time at which a call came in may be stored, and rescuers (either manually or automatically through their portable computing devices) can use that time to determine a protocol for treating the patient (e.g., ventilation or chest compression needs may change depending on how long the victim has been in need of treatment).

Other users may then access the data in the central server system <NUM>. For example, as shown here, an emergency room physician <NUM> is operating his or her own tablet <NUM> that communicates wirelessly, such as over a cellular data network. The physician <NUM> may have been notified that victim <NUM> will be arriving at the emergency room, and, in preparation, may be getting up-to-speed regarding the condition of the victim <NUM>, and determining a best course of action to take as soon as the victim <NUM> arrives at the emergency room. As such, the physician <NUM> may review the data from central server system <NUM>. In addition, the physician <NUM> may communicate by text, verbally, or in other manners with emergency medical technician <NUM>. In doing so, the physician <NUM> may ask questions of the emergency medical technician <NUM> so that the physician <NUM> is better prepared when the victim <NUM> arrives at the emergency room. The physician <NUM> may also provide input to the emergency medical technician <NUM>, such as by describing care that the emergency medical technician <NUM> should provide to the victim <NUM>, such as in an ambulance on the way to the emergency room, so that emergency room personnel do not have to spend time performing such actions. Also, physicians could see aspects of a currently-operating protocol on the system, and could act to override the protocol, with or without the rescuers needing to know that such a change in the protocol has been made (e.g., their devices will just start instructing them according to the parameters for the manually revised protocol).

Where the published protocol is organized in a flowchart form, the flowchart may be displayed to a rescuer or a physician, and such user may drag portions of the flowchart to reorder the protocol. Alternatively, the user could tap a block in the flowchart in order to have parameters for that block displayed, so that the user can change such parameters (e.g., ventilation volume or time between ventilations). Data describing such an edited protocol may then be saved with other information about an incident so that later users may review it, and a user may save reordered protocols so that they can be employed more easily and quickly in the future.

In this manner, the system <NUM> permits various portable electronic devices to communicate with each other so as to coordinate care that is provided to a victim <NUM>. Each such device may sense information about the care provided to the victim <NUM>, and/or may provide instructions or may store data about such care. As a result, the system <NUM> may provide improved care for the victim <NUM> by better integrating and coordinating each form of the care that the victim <NUM> receives. The victim <NUM> made thus receive improved care and an improved chance of obtaining a positive outcome from an event.

In certain instances, a condition of a victim that is used to generate a protocol for treatment of the victim may be based on on-site observations made by a rescuer, by information in an EMR for the victim, or both. For example, a determination from an EMR that a victim is taking a particular drug may result in a change in protocol for ventilation rate. Likewise, an observation by a rescuer that the victim has suffered a head injury on site may also affect the protocol for ventilation rate. The two factors may also be considered together to determine yet a more refined ventilation rate for which a rescuer will be instructed to provide to the victim.

Thus, in operation, a two-person rescue team may arrive at a scene. One member of the team may set up and attach a defibrillator, and do the same with a ventilation bag assembly. The other member may begin an examination of the victim and enter information obtained from the examination into a portable computing device such as a general tablet computer (e.g., an iPad or netbook). In some situations, the second rescuer may be able to verbally interview the victim, at least initially, so as to determine whether the victim is lucid, what drugs the victim may be taking, and the like. The second rescuer could also make visual observations (e.g., types of trauma to the victim) and record those in the computing device. Moreover, one of the rescuers may obtain vital sign information for the victim, and such information may be entered manually into the computing device or automatically, such as through wireless links from a blood pressure cuff, or other relevant medical device.

The computing device, using all of the entered information, may then generate a protocol for treating the victim. Such a generating may occur by selecting from among a plurality of available protocols by plugging the observations into a protocol selector. The generation may also be more dynamic, and may depends on a series of heuristics that use the observations as inputs, and generate a protocol (which may be made up of one or more sub-protocols) as an output. Moreover, a lookup table may be consulted, where the table may define correlations between particular observed patient conditions or physical parameters, and a particular feature of a treatment protocol.

The computing device may also submit the observation information over a network such as the internet, and a protocol may be generated by a central computer server system and then automatically downloaded to, and implemented by, the portable computing device. Such an approach may have the benefit of being able to easily update and modify protocol-generation rules.

The computing device may then receive information about the performance by the rescuers, such as from wired or wireless transmitters on a defibrillator, an assisted ventilation unit, or other medical device (e.g., blood pressure reader). The computing device may provide feedback or coaching when the performance falls out of line with a defined protocol, or may provide feedback to maintain the performance in line with the protocol. Also, the computing device may update the protocol as care is being provided to the victim. For example, the rate of required ventilation or chest compressions may change as a function of time. Also, if one of the rescuers attaches an oxygen source to a ventilation assembly (as sensed, e.g., by a switch where the connection occurs, by a manual rescuer input to the system, or by sensors in the assisted ventilation system), the rate of required ventilation may change. Other changes in the patient condition, such as changes in measured levels of ETCO2 or SpO2, can lead to the computing device generating a revised protocol and providing feedback to the rescuers so that they adapt to the revised protocol (sometimes without consciously knowing that the protocol has been revised).

<FIG> shows an example of an airflow sensor <NUM> used with a ventilation bag assembly <NUM>, which may be used to ventilate a patient or victim of an accident. In this example, the airflow sensor <NUM> is mounted as an integral part of the ventilation bag assembly <NUM>. The assembly <NUM> includes a face mask <NUM> which is formed from a flexible material that is configured to produce a tight seal around the periphery of a victim's mouth so that air provided by the assembly <NUM> may be forced into the victim's airway, and thus the victim may be properly ventilated.

The force for ventilating the patient is provided by compression of a ventilation bag body <NUM>, which itself may be made of a flexible material that is sized and shaped so that the rescuer may place his or her hands around the body <NUM> and squeeze to force ventilation air into a victim. A reservoir attached to the body <NUM> may serve as an area for mixing of gases to be introduced, in a familiar manner. An oxygen supply line <NUM> is also provided and connected to the body <NUM>, so that supplemental oxygen may be conveniently provided to a victim by way of the ventilation bag assembly <NUM>.

A neck <NUM> extends from the body <NUM> and forms a right angle for purposes of permitting the assembly <NUM> to be held in a comfortable position relative to a victim's face when the mask <NUM> is sealed to the face. The neck <NUM> is a tube having a round cross-section that defines an airflow path in its interior portion, so that air may flow out of the body <NUM>. Through the neck <NUM>, and into the mask <NUM>. Attached between the neck <NUM> and the mask <NUM> is the airflow sensor <NUM>. The airflow sensor <NUM> may itself define an interior passage that is matched to an exterior diameter of an extension of the neck <NUM> and an extension of the mask <NUM>. As a result, the airflow sensor <NUM> may be friction fit over such extensions, allowing the airflow sensor <NUM> to be added conveniently to a system that is not designed initially to have an airflow sensor, such as airflow sensor <NUM>.

The airflow sensor <NUM> may operate in various known manners to detect and measure the presence of airflow in or out of a victim, and in certain implementations, to measure a volume of airflow in or out of the victim. For example, the airflow sensor <NUM> may include a differential pressure sensor that is attached to a venturi mechanism in an airflow path inside sensor <NUM>. A differential pressure sensor may also be provided in coordination with a beam that substantially bisects an air flow path inside sensor <NUM>. Taps from the differential pressure sensor may extend from discrete sides of the beam, so that the presence and volume of airflow may be determined by the difference in pressure measured between the taps. The beam may be positioned and shaped so as to provide more accurate readings, in known manners.

The sensor <NUM> may include an activation button <NUM> that, when pressed, causes the sensor <NUM> to activate and to begin attempting to communicate with other medical devices in its vicinity. The sensor <NUM>, for example, may communicate using BLUETOOTH technology and may establish a connection with another device through standard BLUETOOTH handshaking mechanisms. Once the wireless connection is made, the device <NUM> may determine how frequently to send updates to another medical device, and may begin sending such updates. In certain implementations, the sensor <NUM> may also receive input from such other devices, such as input for providing a rescuer with instruction in the performance of rescue operations.

Although shown externally in the figure for manual activation, the button <NUM> may be mounted internally to sensor <NUM>, such that it is activated as soon as neck <NUM> is inserted into sensor <NUM>. The button <NUM> may instead be represented by a magnetic switch that is automatically activated when the sensor <NUM> is assembled with the neck <NUM> or the mask <NUM>. The sensor <NUM> may also be activated in other relevant manners such as by a mercury switch, motion detector, or other appropriate mechanism.

An LED light <NUM> is shown connected to the sensor <NUM> and may be used to provide feedback to a user of the sensor <NUM>. For example, the LED light <NUM> may blink each time ventilation is to be provided to a victim, so as to provide visual orientation for a rescuer. In this example, the LED light <NUM> is shown at the end of an elongated flexible strip, so as to position the LED light <NUM> at a location that is more likely to be seen by a rescuer, and less likely to be blocked visually by the body <NUM> of ventilation bag assembly <NUM>. The LED light <NUM> can also be mounted directly in the body of sensor <NUM> in appropriate circumstances.

In other implementations, multiple modes of feedback may be provided (e.g., both rate and volume). In such a situation, a first LED, which may backlight a letter "R" for rate, and another may backlight a letter "V" for volume, and/or a pair of LEDs may be located on opposed sides of the letter, with lighting of an LED behind the letter indicating that the rate or volume being applied by the rescuer, respectively, is correct. The LEDs to the side of the letter may be lit alternatively, depending on whether the rescuer is being prompted to increase or decrease their rate or volume of ventilation.

The assembly <NUM> thus enables the performance of ventilation on a victim to be monitored and feedback to be provided to a rescuer. Such feedback may be provided from a computing device that takes into account various parameters of the victim's medical history and/or current medical condition, and coordinates the activities of the various medical devices that are treating the victim at one time.

Other sensors, not shown here, may also be used with a monitoring and feedback system. For example, airway gas detectors may be used, including to determine a level of oxygen that is being provided to a patient through a mask. In addition, differential absorption characteristics of CO2 in red and infrared (IR) wavelengths may also be measured. Also, trans-thoracic impedance may be measured in order to determine, for example, when problems with an intubation have occurred (e.g., the tube becomes dislodged from bouncing on stairs or in an ambulance). Checks for intubation tube status can also be linked to the air flow sensor, so that the checks are begun when ventilation of the victim begins. The various coordinated sensors may also be used, in certain instances, to move a procedure outside of a standard protocol, or to follow a protocol that has been designed to be more flexible and responsive to patient needs than are typical protocols that depend on the limited capabilities of one or two caregivers.

Also, sensors other than airflow sensors may be used to determine a ventilation rate. For example, a strain sensor may be provided on the bag of a ventilation assembly, and may be used to determine how frequently the bag is being squeezed, and by extension the rate of assisted ventilation being provided to a victim.

3A is a flowchart of a process for providing feedback to a caregiver who is operating a ventilation bag or similar structure. In general, the process involves deploying various medical devices at the scene of an emergency and causing the devices to coordinate their operations so as to improve the care that is given to a victim at the scene.

The process begins a box <NUM>, where electrodes for a defibrillator are applied to a victim and the defibrillator is powered up. Such action may occur soon after rescuers, who may be lay rescuers using an AED or emergency medical technicians using an advanced defibrillator, arrive on a scene and recognize that a victim is in need of defibrillation.

At box <NUM>, a ventilation bag is attached to the victim and an airflow sensor associated with the bag is activated. In one example, a second emergency medical technician may be assigned this task and may recognize that the victim's airway is patent and is not in need of incubation at the moment, and may deploy the ventilation bag to begin providing forced ventilation to the victim.

At box <NUM>, a communication link is established between the bag airflow sensor and a feedback unit, which may be in the form of a tablet, like tablet <NUM> in <FIG>, or a defibrillator like defibrillator <NUM> in <FIG>. The communication may occur automatically upon activating the two communicating components, such as by instigating an automatic BLUETOOTH or WiFi connection in a familiar manner.

At box <NUM>, ventilation data is received from the ventilation bag airflow sensor. The ventilation data may simply include time stamped indicators of the start or end of inhalation and/or exhalation for the victim. The data may also include information about the length of inhalation or exhalation, and the volume of air moved by the victim or for the victim. Such information may be passed from the airflow sensor to a computing component such as tablet <NUM>. The data may then be compared against a protocol for providing ventilation, and determinations may be made with respect to whether the ventilation is being properly or improperly applied relative to that protocol. Also, coordination of the ventilation with other actions being taken on the victim (e.g., chest compressions) may also be performed via a device such as tablet <NUM>.

Upon the device making such determinations, it may provide feedback to the rescuer in applying ventilation, as shown at box <NUM>. For example, the tablet <NUM> may provide visual or audible feedback to guide a rescuer regarding when and with how much force to squeeze a ventilation bag. The tablet <NUM> may also communicate data to another device, such as a defibrillator or back to the airflow sensor, and that receiving device may provide the feedback to the caregiver. In addition, information may be provided to a headset or other personal interface worn by the particular rescuer, which may enable feedback provided to one rescuer to be separated from feedback provided to the other rescuer, so that the rescuers are less likely to become confused with the feedback. In addition, other communications may occur through such headsets, such as communications between cooperating caregivers, and communications from a dispatch center or from a central physician such as an emergency room physician who is tracking the progress of the team of the EMTs, or providing input to such a team.

The feedback provided may follow a set protocol that does not differ from victim to victim, or may be customized for he particular victim. For example, the rate and volume of ventilation to provide a victim may depend on how long the victim has been suffering from a current condition. Thus, a rescuer may try to ascertain how long the victim has been down, or a time stamp from the time at which an emergency was called in may be used as a proxy. Also, various states of the victim may be relevant to the rate and volume of ventilation to be provided to the victim, including:.

At box <NUM>, the system reports the victim's condition to rescuers and may also report the condition of the victim to central caregivers, such as physicians or other staff in an emergency room where the victim will be taken. Such reporting may include providing ECG readout information, vital signs, and other relevant information needed by the immediate (e.g., EMT's) or secondary (e.g., ER Physicians) caregivers.

At box <NUM>, incident report data is saved, such as by sending the data from one or more of the portable medical devices at a scene to a central electronic medical record system. The data may be gathered initially at one device such as tablet <NUM>, and may then be forwarded to the central system. The incident report data may include information regarding drugs and other treatments provided to the patient, and other information that may be relevant to downstream caregivers, such as emergency room physicians.

In this manner, and using this example process, information relating to various aspects of care given to a victim at the scene of an accident may be collected, and treatment of the patient may be coordinated, including by coordinating the provision of chest compressions, defibrillation shocks, and ventilation to the patient.

4A is a swim lane diagram of a process by which various parameters can be used to provide feedback to one or more medical rescuers. In general, the process is similar to that shown in FIG. 3A, though particular example structures are shown in this figure as performing certain steps in the process. The particular steps that are carried out by each structure or device can be changed as is appropriate, and other steps may be added, steps may be rearranged or modified, or steps may be removed from the process.

The process begins at boxes <NUM> and <NUM>, where a tablet and defibrillator are powered up at the site of an emergency. Such powering may simply involve deploying them from emergency vehicles and activating power switches on each such device. At boxes <NUM> and <NUM>, a wireless communication connection is established between the tablet and the defibrillator for the transfer of data between the two devices while care is being provided to a victim at the emergency scene.

At box <NUM>, victim information is entered into the tablet (though at least some of the information may also have been previously entered by a dispatcher, and that information may auto-populate on the device). Such information may include a name or alphanumeric ID number of the victim, as a mechanism for retrieving electronic medical record information about the victim. Such information may also include information about the current condition of the victim. For example, a caregiver may record whether the victim has suffered head trauma, whether the victim is bleeding, has broken bones, approximately age and gender of the victim, and other information that may be relative to the care to be given to the victim. Such information may be entered on a touchscreen display, including by selecting input values from a menuing system (including a system that performs a question-and-answer interview session with a rescuer), or could also be provided by a spoken input to the tablet.

Where an identifier for a victim, such as a name of the victim is provided, the tablet may attempt to access records in a central system, as shown by box <NUM>. Where the tablet has provided appropriate credentials, such as identifier and password of an emergency medical technician, the central system may transmit medical record information about the victim, at box <NUM>, back to the tablet. Upon receiving additional information about the victim, the tablet may establish a protocol for treatment of the victim, and may begin carrying out the protocol by instructing rescuers at the scene. For example, the condition of the victim, the victim's age, the victim's medical history, and the victim's size, may all be relevant to the manner in which chest compressions, defibrillation shocks, and ventilation are provided to the victim. The protocol established by the tablet may take into account each relevant factor in developing a plan of treatment.

While the system is obtaining data and developing a plan, a caregiver at the site may be connecting and positioning electrodes on the victim's chest (box <NUM>), and the same caregiver or another caregiver may be applying a ventilator (box <NUM>) on the victim.

The caregivers may then begin executing the protocol, such as by applying chest compressions and ventilation to the victim. At boxes <NUM> and <NUM>, the defibrillator provides received rescue data to the tablet, such as by transmitting information regarding the victim's ECG and also the manner in which chest compressions have been applied to the victim, and the ventilator or ventilation sensor may provide information about ventilator events. Such information may include, for example, the frequency with which ventilation is being applied, and also the volume of ventilation air being provided.

At box <NUM>, the tablet compares the received inputs to the appropriate protocol, which may be a static protocol or may be a dynamic protocol that changes as treatment of the victim continues. Where the inputs do not match the protocol so that corrective action by the caregivers is required, the tablet may provide instructions (box <NUM>) to the caregivers. For example, the tablet may transmit information to the defibrillator, and the defibrillator may be caused to announce instructions to a provider of chest compressions, such as having a speaker on the defibrillator state those instructions (box <NUM>). The tablet may also send data to the ventilator, causing the ventilator to announce instructions to another caregiver (box <NUM>), either visually or audibly.

At boxes <NUM> and <NUM>, respectively, the caregiver providing chest compressions and operating the defibrillator may follow the received instructions, and a caregiver operating the ventilating device may follow the other appropriate instructions. At boxes <NUM> and <NUM>, respectively, the defibrillator and the ventilator may record the performance of the particular caregiver in response to the instructions. Such performance data may be stored and transmitted back to the tablet at boxes <NUM> and <NUM>. The data may indicate whether the relevant caregivers have altered their actions sufficiently to place their activities back within the protocol ranges. Also, the protocol may change over time, such as by calling for a certain period of chest compressions followed by the provision of electric shock to the patient for defibrillation. Thus, the tablet, at box <NUM> may change the instructions that it provides so as to match the changes in the protocol.

At box <NUM>, the tablet receives and processes the patient data. The process may then loop back to box <NUM> and until treatment of the victim is completed. Changes may be made to the protocol as treatment continues also, such as by recognizing that the patient has been without a normal heart rhythm for particular time, and adjusting the timing and sequencing of care given to the victim based on such a determination.

At box <NUM>, data is transmitted for the patient's record to the central system. Such data may be provided consistently throughout provision of care, such as by providing ECG and vital signs data that may be reviewed in real time by a central emergency room physician who accesses the central system. The data may also be provided when the care is complete, such as may be recognized by the powering down of the tablet, defibrillator, or ventilator, so that the medical devices may be returned to an ambulance or other vehicle in which the patient is transported to an emergency room. Also, the tablet may invoke additional dialogue with one of the caregivers on such a trip, so as to complete the patient record before the caregivers move to another project.

At box <NUM>, the central system processes, stores, and forwards, relevant data regarding the victim. For example, the treatment information, such as drugs that may have been given to the patient through intravenous tubes, may be recorded and added to the victim's medical record. In addition, a billing system may be notified, and appropriate fees may be applied to a victim's account in such a system. Moreover, a snapshot of relevant data from the treatment may be provided in advance to an emergency room team at a hospital where the patient has been taken. Then, at box <NUM>, the relevant data is received at the emergency room, so that the emergency room team can review it when providing further treatment for the patient.

<FIG> shows exemplary information, e.g., a ventilation timer <NUM>, displayed on a display device to a rescuer during the administration of ventilation to a patient. The ventilation timer <NUM> provides information to the rescuer to help the rescuer control the rate of ventilation provided to the patient. The ventilation timer <NUM> can include a bar <NUM> (or other shape) that that fills as time elapses between breaths. The bar <NUM> can include scaling information (e.g., tick marks on the graph) that provide information about the elapsed time <NUM> and/or ventilation rate <NUM>. The elapsed time <NUM> provides an indication of the amount of time that has passed since the last ventilation event and the respiration rate <NUM> provides the number of breaths per minute (e.g., <NUM> seconds between breaths=<NUM> breaths/minute).

The information displayed on the ventilation timer <NUM> is based on ventilation related data received from a device that detects when a ventilation has been delivered (e.g., a flow meter, capnography, thoracic impedance). The ventilation related information is used by a computer to provide an input indicating when to re-start the timer such that the elapsed time can be determined.

In some examples, the information presented on the ventilation timer <NUM> can be color coded or otherwise supplemented by a visual indicator of ranges that indicate adequate ventilation versus sub-optimal ventilation. In one example, the color of the bar <NUM> in the ventilation timer can change based on the adequacy of the ventilation. For example, the bar could be colored green when proper ventilation is being provided and yellow or red when the ventilation falls outside the desired range of respiration rates. Additionally, in some examples, an indication of whether the user should increase or decrease the rate of respiration could be provided. Additionally, in some examples, an indication of the optimal elapsed time/ventilation rate could be provided such as by overlaying a line or other indicator at the desired level so the rescuer can attempt to have the bar <NUM> match the displayed optimal timing indicator.

In some additional examples, the information presented in the ventilation timer <NUM> can be color coded or otherwise supplemented by other visual indicator based on the nature of the underlying condition being treated, e.g. respiratory distress vs cardiac arrest vs TBI. Additionally, the range that is indicated as an optimal or an acceptable respiration rate can change based on information from one or more physiologic monitoring sensors and estimate from those sensor(s) of the underlying status of the patient's cardiopulmonary status. Such physiologic monitoring can be based, for example on information about EtCO<NUM> (e.g., the partial pressure or maximal concentration of carbon dioxide, CO<NUM> at the end of an exhaled breath, which is expressed as a percentage of CO<NUM> or mmHg) and/or information about oxygen saturation from a pulse oximeter, a medical device that indirectly monitors the oxygen saturation of a patient's blood. Such physiologic monitoring can also include information from a tissue CO<NUM> sensor that can be used to calculate the blood oxygen concentration, for example, based on the ventilation/perfusion ratio (or V/Q ratio) which provides a measurement used to assess the efficiency and adequacy of the matching of the amount air reaching the alveoli to the amount of blood reaching the alveoli (sometimes reported as the VQ mismatch which is used to express when the ventilation and the perfusion of a gas exchanging unit are not matched).

<FIG> shows exemplary information displayed during the administration of ventilation and CPR compressions to a patient. The system automatically switches the information presented based on whether chest compressions are detected and whether appropriate ventilation is detected. For example, CO2 or depth of chest compressions may be displayed (e.g., a CO2 waveform <NUM> is displayed in FIG. 8B) during CPR administration and upon detection of the cessation of chest compressions the waveform can be switched to display and SpO2 or pulse waveform (not shown).

A portion <NUM> of the display can include ventilation information such as a ventilation timer (e.g., as described above in relation to <FIG>) providing information about respiratory rate associated with the elapsed time between ventilations.

Another portion <NUM> of the display can include information about the CPR such as depth <NUM>, rate <NUM> and perfusion performance indicator (PPI) <NUM>. The PPI <NUM> is a shape (e.g., a diamond) with the amount of fill in the shape differing to provide feedback about both the rate and depth of the compressions. When CPR is being performed adequately, for example, at a rate of about <NUM> compressions/minute (CPM) with the depth of each compression greater than <NUM> inches, the entire indicator will be filled. As the rate and/or depth decreases below acceptable limits, the amount of fill lessens. The PPI <NUM> provides a visual indication of the quality of the CPR such that the rescuer can aim to keep the PPI <NUM> completely filled.

<FIG> is a schematic diagram of a computer system <NUM>. The system <NUM> can be used for the operations described in association with any of the computer-implement methods described previously, according to one implementation. The system <NUM> is intended to include various forms of digital computers, such as laptops, desktops, workstations, personal digital assistants, servers, blade servers, mainframes, and other appropriate computers. The system <NUM> can also include mobile devices, such as personal digital assistants, cellular telephones, smartphones, and other similar computing devices. Additionally the system can include portable storage media, such as, Universal Serial Bus (USB) flash drives. For example, the USB flash drives may store operating systems and other applications. The USB flash drives can include input/output components, such as a wireless transmitter or USB connector that may be inserted into a USB port of another computing device.

The system <NUM> includes a processor <NUM>, a memory <NUM>, a storage device <NUM>, and an input/output device <NUM>. Each of the components <NUM>, <NUM>, <NUM>, and <NUM> are interconnected using a system bus <NUM>. The processor <NUM> is capable of processing instructions for execution within the system <NUM>. The processor may be designed using any of a number of architectures. For example, the processor <NUM> may be a CISC (Complex Instruction Set Computers) processor, a RISC (Reduced Instruction Set Computer) processor, or a MISC (Minimal Instruction Set Computer) processor.

In one implementation, the processor <NUM> is a single-threaded processor. In another implementation, the processor <NUM> is a multi-threaded processor. The processor <NUM> is capable of processing instructions stored in the memory <NUM> or on the storage device <NUM> to display graphical information for a user interface on the input/output device <NUM>.

The features described can be implemented in digital electronic circuitry, or in computer hardware, firmware, software, or in combinations of them. The apparatus can be implemented in a computer program product tangibly embodied in an information carrier, e.g., in a machine-readable storage device for execution by a programmable processor; and method steps can be performed by a programmable processor executing a program of instructions to perform functions of the described implementations by operating on input data and generating output. The described features can be implemented advantageously in one or more computer programs that are executable on a programmable system including at least one programmable processor coupled to receive data and instructions from, and to transmit data and instructions to, a data storage system, at least one input device, and at least one output device. A computer program is a set of instructions that can be used, directly or indirectly, in a computer to perform a certain activity or bring about a certain result.

Examples of communication networks include a local area network ("LAN"), a wide area network ("WAN"), peer-to-peer networks (having ad-hoc or static members), grid computing infrastructures, and the Internet.

Claim 1:
A medical ventilation monitoring system comprising:
a patient ventilation unit (<NUM>) defining an airflow path, the unit arranged so that when the unit is applied to a patient (<NUM>), the airflow path is in fluid communication with the patient's airway;
an airflow sensor (<NUM>, <NUM>) positioned in the air flow path to sense the presence of ventilation airflow to or from the patient; and
an external unit (<NUM>) arranged to receive from the airflow sensor (<NUM>, <NUM>) a signal that indicates the occurrence of ventilation or respiration events and to use the data to provide feedback to a rescuer regarding proper administration of ventilation,
wherein said feedback is provided by a visual indication at the airflow sensor.