HK1053433B - Bio-mask with integral sensors - Google Patents

Description

Bio-mask with integral sensor

Technical Field

The present invention relates to a breathing mask equipped with a sensor for detecting sleep apnea and respiratory disorders of a patient for use in anesthesia or ventilation.

Background

A mask for applying a forced pressure to a patient suffering from apneas or other respiratory disorders is disclosed in patent 5243971. These masks form a seal that prevents air in the mask from leaking out of the junction of the mask and the face. Other types of masks for delivering gas to a patient are also commonly used.

The flow of gas supplied to the patient is measured in patent 5503146 by measuring the flow of gas already supplied to the patient with a metering sensor in the supply air connected to the mask, or in patent 5131399 by measuring the breathing of the patient with a strap wrapped around the chest of the patient.

Some devices, such as that of patent 5507716, provide sensors in combination with a sleep mask that covers the eyes of the patient. However, there is no disclosure of a sensor provided in a respiratory mask to detect or study a breathing disorder of a patient.

Currently, if the patient is to be closely monitored, multiple electrodes or sensors are applied to the patient separately and wired to a recording device. The use of such monitoring devices is hampered by the plurality of sensors and the resulting tangled wires. Sensors that provide useful information include electroencephalography (EEG), Electromyography (EMG), Electrooculogram (EOG), Electrocardiogram (ECG), Pulse Transit Time (PTT), airflow sensors, temperature sensors, microphones, oximetry, blood pressure sensors, pulse sensors, patient movement, posture, light, activity sensors, mask leaks detected by polyvinylidene fluoride- (PVD) or piezoelectric (Piezo), mask pressure, eye movement, and other elements that gather data about the patient or its environment.

This is inconvenient for patients and nurses who have to attach a series of different devices to patients in order to monitor a number of different parameters simultaneously. It is therefore desirable to provide a single device that facilitates the measurement of multiple parameters.

Disclosure of Invention

The present invention relates to the provision of sensors in a respiratory mask to facilitate patient monitoring. The mask has a soft pliable seal material around its periphery that contacts the patient's face to form a secure seal therebetween. The sensor may be recessed in a soft pliable seal material placed on the surface to contact the user's face when the mask is placed on the user's face. The wiring of the sensor may be located inside a soft, easily deformable sealing material which insulates the wires from damage during use of the mask. A number of sensors may be assembled within the mask. The sensors may be placed on the periphery or other portion of the mask without contacting the skin. The sensors may also be placed in a band or cap associated with the mask or other device used with the mask.

The patient and caregiver monitoring for sleep disorders, breathing disorders or anesthesia is easier and more convenient because all sensors need to be placed in a mask that is easily and quickly worn on the patient, with all wiring connecting the sensors being integral with the mask and routed through a single plug.

Types of sensors on or in the mask, straps or headgear connected to the mask include, but are not limited to, oximetry sensors, patient position sensors, eye movement sensors, leak detection sensors, EEG, EMG, EOG, ECG, PTT, microphones, pulse, blood pressure, oxygen saturation, temperature, movement sensors, position sensors, light sensors, leak detection sensors, and gas delivery sensors.

The connector of the external air source conveyed to the mask is connected to the mask through an air nozzle. The power connector and the data output cable are connected into the cable connected with the mask through the plug. In addition, a battery in the mask and telemetry devices in the mask may provide power and transmit data to the microprocessor or computer. For ease of portability, the microprocessor may be mounted on a mask or carried by the patient. Likewise, the gas cylinder may be attached to the mask and carried by the patient so that the patient may be moved while the mask is worn.

Unique uses of the bio-mask include the ability to employ anesthesia level monitoring while administering anesthetic gas to a subject. The ability to monitor a patient without a biological mask while administering anesthetic gas to the patient provides information on the biofeedback function of the subject directly and in response to the level of anesthesia. The biological mask may be employed to determine the sleep state of the subject by applying standard sleep staging metrics, such as metrics of R & K rules and/or the application of diagnostic techniques to analyze the number of EEG signals, such as bispectrum Analysis (Bispectral Analysis). The present invention is unique in that such analysis can be performed with minimal invasiveness to the respiratory mask of the person being treated.

The R & K rules refer to the "handbook of standardized terms, techniques and scoring system for the sleep stages of the treated persons" written in 1968 by Rechtschuffen and Anothony Kales, which is incorporated herein by reference.

The present invention is directed to monitoring a patient.

It is an object of the present invention to provide data needed to assist in the treatment of a patient.

It is an object of the present invention to provide a sensor for monitoring a patient wearing a respiratory mask or a combination thereof.

It is an object of the present invention to regulate the flow of gas to a patient based on data obtained by monitoring the patient.

The present invention is directed to diagnosing a patient based on data obtained from monitoring the patient.

The object of the invention is to apply all sensors needed for the examination of a patient conveniently and quickly.

According to the present invention, there is provided a mask for monitoring a patient during gas delivery, comprising: a body having an inner surface and an outer surface and a periphery for contacting a patient's face; at least one sensor located in a surface or periphery of the body to sense at least one parameter indicative of a condition of the patient; a wire connected to the at least one sensor to transmit data from the at least one sensor; an element for transmitting data from the at least one sensor; an element for transferring power to and from the at least one sensor; and a hose connector on the mask for connecting to a hose to deliver gas to the mask.

Other objects, advantages and novel features of the invention will become apparent from the following detailed description of the invention when considered in conjunction with the drawings.

Drawings

Fig. 1 is a schematic illustration of the sensor area on the inner surface of a soft pliable material on the periphery of a respiratory mask.

Fig. 2 is a view of sensors and wiring within a soft pliable material on the periphery of a respiratory mask.

Fig. 3 is a side view of sensors and wiring within a soft pliable material on the periphery of a respiratory mask.

Fig. 4 is a side view of a strap attached to a mask having a sensor embedded in the strap and mask.

Fig. 5 is a schematic diagram of the sensor area on the periphery of a respiratory mask.

FIG. 6 is a schematic diagram of sensors on the inner surface of a respiratory mask.

Fig. 7 is a side view of a mask with sensors located on the surface of the mask.

Detailed Description

Fig. 1 shows the interior of a mask 10, which mask 10 includes a peripheral surface 12 that contacts the face of a patient. The peripheral surface 12 has a plurality of regions 20. Each region 20 has a sensor 25 in a recess 29 for sensing a parameter or other data of the patient to be monitored, such as a gas leak. Other sensors 26 are provided on the mask 10, but not in contact with the patient's skin. These sensors 26 sense patient data or related data such as ambient light, gas pressure in the mask or ambient temperature. The mask 10 has a gas connection 14 and a mask interface connector 16, the gas connection 14 being for connection of a hose 32 to supply gas to the mask 10, the mask interface connector 16 being plugged by a cable 30 to provide power and data transfer.

In some embodiments of the present invention, sensor 25 does not require an external power source because sensors such as thermal and light sensitive sensors generate current.

The mask peripheral surface 12 is preferably made of a soft, pliable material such as silicone rubber that forms a good sealing contact with the patient's face to prevent gas leakage. The material should be soft and pliable enough to conform to the contours of the face. The peripheral face preferably has a recess 29 into which the sensor 25 is inserted so that the sensor remains in contact with the patient's skin when the mask is pressed against the patient's face.

As shown in fig. 3, the sensors or electrodes 25 attached to the mask 10 are preferably made of a rubber compound 28 such as silicon or other food grade type rubber, the rubber compound 28 embedding carbon or other conductive material for electrical contact with the skin in the mask. As shown in fig. 2, the recess 29 is sufficiently spaced to accommodate an electrical connection to the conductor 27, the conductor 27 being embedded in a soft pliable material beneath the peripheral surface 12. Thus preventing the wires 27 from being damaged to form electrical insulation. The sensor 25 is preferably inserted into the conductor 27 or printed circuit within the recess 29. The leads 27 are preferably located on printed circuits embedded in the mask or fine wires embedded in the mask and connect the sensor 25 to the mask interface connector 16.

Fig. 5 shows that a conductive material 40, such as carbon embedded with silicon, located on the surface of region 20 may be used on the surface of the periphery 12 of mask 10 in isolation region 20 to conduct electrical surface energy from the patient's face. The conductive material 40 is preferably activated in the presence of moisture when in contact with the skin to increase its conductivity. The conductive material 40 may be applied to all electrodes 25 in contact in all regions 20. Alternatively, the electrodes 25 may be in direct contact with the patient's face. The electrodes may also be located within a soft pliable material on the periphery 12 of the mask 10.

Figure 4 shows a side view of the mask 10 and straps 35 used to secure the mask in place on the patient. The strap 35 has the sensor 25 connected to a lead 27, the lead 27 connecting the sensor to the mask interface connector 16 and the cable 30 for communicating data to a computer or other instrument. The sensors 25 in the belt 35 may be electroencephalographic (EEG) sensors for measuring brain waves. The strap 35 may be replaced by a cap having a sensor therein. In addition, the chin strap 37 may be provided with a sensor 25.

Fig. 5 shows an embodiment of the type of sensor 25 used in region 20 around the periphery of mask 10. Physiological signals generated by the patient's skin potential are detected by sensors in the area 20 around the periphery 12 of the mask 10. Conductive electrode paste 40 may be used to improve the electrical contact between the sensor 25 and the skin surface. Conductive gel 40 can help reduce the impedance between the face and the electrical output produced by sensor 25 in region 20. The conductive paste 40 also helps prevent gas leakage.

The following describes the sensor and its function as an embodiment of the mask sensor arrangement. Many other types and arrangements of sensors are possible.

Region 50 is the eye current map (EOG) from the eye movement reference electrical signal obtained above the bridge of the nose.

The region 51 is an EOG for detecting an eye movement electric signal inside the left eye, and the region 61 is designed for an eye movement electric signal inside the right eye. The eye movement data is related to the level of sleep, e.g. fast eye movement REM indicates a deep sleep state and dreaming.

Region 52 is designed for EOG to detect eye movement electrical signals outside the left eye and region 62 is designed for eye movement electrical signals outside the right eye.

Area 53 is designed for Electromyography (EMG) to detect electrical signals generated by muscle contraction in the upper left chin. Region 63 corresponds to the upper right chin. Regions 54 and 64 correspond to the lower left and lower right chin, respectively. The magnitude of the chin signal is proportional to the patient's state of relaxation and subsequent sleep.

Zone 55 is the EMG of the upper left lip, displaying information about sleep state. It is proportional to the relaxation and sleep states of the patient. Zone 65 is the EMG of the upper right lip.

Zone 56 is the EMG of the left nasal inner mask, which also provides a signal of lip movement and is proportional to the relaxation and sleep states of the patient. Likewise, zone 66 is the EMG of the right nasal inner mask.

The areas 57 and 67 are for the oral left and oral right external masks EMG signal, which is also proportional to the patient's relaxed and sleep states.

Region 70 is the pressure sensor port for air flow determination.

A microphone 80 on the mask detects the patient's breathing or snoring sounds.

Fig. 6 shows an embodiment in which two sensors 58 and 68 are used to detect the electrocardiogram ECG of a patient. This data is also used to monitor the patient. The patient's cardiac function provides a lot of useful data about the patient's condition. Pulse Transfer Time (PTT) is the time it takes to transfer an ECG pulse from the heart to a sensor such as a sensor placed on the head, finger tip or ear. The PTT sensor may be placed in the mask in connection with the mask. PTT measurements are used to determine patient arousal and changes in qualified blood pressure.

A heat sensitive sensor 81 is used on the inner surface of the mask to detect nasal breathing. A heat sensitive sensor 82 is used on the outer surface of the mask to detect mouth breathing. The thermal sensitivity of sensors 81 and 82 on the face of mask 10 facing the nose or mouth indicates whether the patient is breathing through his nose or mouth. The thermal sensors 81, 82 may alternatively be placed on the inside of the mask 10, on the outside of the mask 10 or inside the material of the mask 10 to detect breathing. The thermal sensors 81, 82 may be thermistor materials, thermocouple materials, or any other temperature sensitive material. The thermal sensors 81, 82 may be covered on the mask interior, on the mask exterior or in the mask. The heat sensors 81, 82 detect heat in proportion to the amount of breathing.

Detecting mouth breathing is important because undetected or partially undetected mouth breathing affects the integrity of respiratory monitoring of the patient's breathing gas and thus compromises the desired gas delivery to the patient. It is important to detect mouth breathing, which aids in the diagnosis of abnormal breathing during sleep. In addition, control of mask nasal ventilation is achieved by mouth breathing.

The pressure sensor 84 measures the pressure inside the mask to indicate whether positive pressure exists inside the mask and the magnitude of the pressure. A decrease in pressure indicates the occurrence of a leak.

The surface reflection oximetry sensor 85 inside the mask detects the patient's pulse rate and oxygen saturation.

A surface blood pressure sensor 90 on the periphery 12 of the mask 10 in contact with the patient may be used to monitor the patient's blood pressure.

The thermistor 91 on the periphery 12 of the mask 10 that is in contact with the patient can be used to monitor the temperature of the patient.

A patient recirculation gas detection system having a sensor 95 located on the interior surface of the mask detects the amount of gas exhaled by the patient remaining in the mask 10. A high level of exhaled gas in the mask means that the mask is not completely blown clean and can be troublesome if not enough fresh gas is delivered.

A patient return gas generation detector 97 in the mask hose connector 14 detects the amount of exhaled gas in the mask that is being delivered with fresh gas.

Fig. 7 shows a thermally sensitive sensor 83 such as a thermistor or thermocouple on the inside or outside of the mask near the periphery 12. These sensors may be affixed to a thermally conductive material 92 around the periphery of the mask 10. Additionally, a thermally conductive material may be on a portion of the periphery. The heat sensitive material may be on the inner surface of the mask 10, on the outer surface of the mask 10, or embedded within the mask material. Detection of temperature changes by the thermal sensor 83 or the thermal sensor 83 on the thermally conductive material 92 is related to mask leakage around the periphery. The heat sensitive material may be a heat sensitive material on the mask interior, on the mask exterior, or on the mask periphery in the mask. The thermally sensitive material may be a temperature sensitive battery, a thermocouple, or any other thermally sensitive material.

Gas leakage from the mask 10 can cause temperature changes associated with the thermally conductive material 92 and the sensor 83 and allow the health care professional to monitor the leak in real time or after the mask leaks. In some cases, gas delivery to the patient is critical and can save lives, and in other cases, leak incidents can aid in the diagnosis of the patient. The aid is administered in the form of an alarm to the health care professional informing them that the delivered gas is leaking, which can affect patient handling and patient diagnostic status. In other cases, gas leak detection may enable a gas delivery system to automatically compensate for gas leaks.

A light sensitive resistor 86 on the outer surface of the mask 10 indicates the ambient light condition of the patient.

The posture sensor 87 displays the posture or activity of the patient. For example, these sensors show whether the patient is lying and stationary. Such a sensor may be a moving ball passing through the switch contacts or a mercury sensor switch.

The body movement sensor 88 may be a PVD or piezoelectric material or micro-mechanism for detecting the range or speed of patient body movement in order to determine a wake-up or rest condition.

All of the above sensors may transmit data via telemetry rather than cable 30.

All of the above-described collected data may be useful for various purposes of monitoring a patient, including sleep observation, anesthesia, or sleep apnea.

The collected data may be converted into a series of data streams such that a single line connects all of the sensors. The sensor may provide data to regulate the delivery of gas to the patient.

The signal may be amplified and filtered to adjust for signal source conditions that bring the signal close to optimum noise and signal performance.

An electrical bias to a sensor such as a patient position sensor, a thermally conductive area, a microphone, or a light dependent resistor may be applied.

The computer may process the data or simply store data generated by the monitoring sensors in the mask or in straps attached to the mask. The monitored data may be used to diagnose the patient, provide feedback to an instrument secured to the patient, increase or decrease the gas supplied to the patient, or perform other functions.

An example of EEG data control in a bio-feedback application, where the patient has a nasal exhaust such as a ventilator, the air delivery to the patient may be Continuous Positive Air Pressure (CPAP), bi-positive air pressure (BIPAP), Variable Positive Air Pressure (VPAP), sleep connected positive air pressure (SPAP), EEG electrodes providing one of the important signals whether the patient is asleep or not. Gas is only applied to the mask when the patient is considered asleep. This function is more sophisticated, sensitive to patient comfort, and more economically feasible than the delayed tilt system used in some exhaust systems.

In an exhaust device using a delayed incline, the user sets the time of the system to distribute the delivery of the gas pressure in an incline to the patient so that the gas application does not have too much disturbing effect on the user and adversely affect his sleep.

Prior to application of the supplemental nasal discharge, sensors in the mask 10 are preferably able to determine when the patient is actually asleep. Premature application of pressure may prevent the patient from falling asleep due to the discomfort of the additional positive pressure.

The mask 10 can be made as a sterile disposable device for medical use that reduces the cost of handling by eliminating the need for sterile handling of a new patient and providing a more sterile process than a reusable mask.

Obviously, many modifications and variations of the present invention are possible in light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.

Claims (36)

1. A mask for monitoring a patient during gas delivery, comprising:

a body having an inner surface and an outer surface and a periphery for contacting a patient's face;

at least one sensor located in a surface or periphery of the body to sense at least one parameter indicative of a condition of the patient;

a wire connected to the at least one sensor to transmit data from the at least one sensor;

an element for transmitting data from the at least one sensor;

an element for transferring power to and from the at least one sensor; and

the hose connector is used to connect a hose to deliver gas to the mask.

2. The mask of claim 1, wherein the component for communicating data comprises a mask interface connector for connecting wires in the mask to a cable.

3. The mask of claim 1, wherein the means for transferring power to operate the sensor comprises an interface connector connecting a power supply lead with a lead in the mask.

4. The mask of claim 1, wherein the means for transferring power to operate the sensor comprises a battery connected to a lead in the mask to transfer power to the sensor, and the means for communicating data comprises a telemetry device.

5. The mask of claim 1, wherein the sensors on the mask are selected from the group consisting of EEG, EMG, EOG, ECG, PTT, temperature, superficial blood pressure, pulse, blood oxygen content, light, respiratory rate, respiratory volume, airflow, nasal airflow, oral airflow, posture, activity sensors, mask leaks, mask pressure, eye movement, microphones, gas pressure, patient recirculated air detection, and patient movement.

6. The mask of claim 1, wherein at least one sensor in the periphery of the mask is in contact with the patient's skin to measure the parameter.

7. The mask of claim 6 wherein the mask periphery has a soft pliable material for contacting the patient's face.

8. The mask of claim 7 wherein the periphery has at least one recess with a sensor disposed therein for contacting the patient's skin.

9. The mask of claim 8, wherein wires in the pliable material connect to at least one sensor for power and data connections.

10. The mask of claim 9, wherein the carbon embedded rubber material provides electrical contact between the sensor in the soft pliable material and the patient's skin.

11. The mask of claim 1, further comprising at least one strap connected to the body to secure the mask in place on the patient's head.

12. The mask of claim 11, wherein the at least one strap has at least one second sensor associated with the element for communicating data.

13. The mask of claim 1, further comprising a cap attached to the mask to hold the mask in place.

14. The mask of claim 1, further comprising an attached cap for securing the mask in place, the cap having at least one second sensor attached to the cap that is connected to the leads in the mask.

15. The mask of claim 11, wherein the strap comprises a chin strap.

16. The mask of claim 15, further comprising at least one second sensor on chin straps for measuring chin EMG.

17. The mask of claim 11, said at least one strap assembled as a head strap having at least one second sensor for measuring EEG.

18. The mask of claim 13 wherein said cap includes at least one second sensor that measures EEG.

19. The mask of claim 11, wherein the at least one strap comprises an ear strap having an oxygen saturation sensor associated with the ear of the patient.

20. The mask of claim 1, wherein the at least one sensor is a thermal sensor located on a portion of the mask body to detect temperature changes on the portion of the mask body.

21. The mask of claim 20, wherein at least a portion of the mask body comprises a thermally sensitive material to which the at least one thermal sensor is thermally coupled.

22. The mask of claim 1, wherein at least a portion of the mask body includes a heat sensitive material proximate the patient's nose to detect temperature changes indicative of nasal breathing.

23. The mask of claim 1, wherein at least a portion of the mask body includes a heat sensitive material proximate the patient's mouth to detect temperature changes.

24. The mask of claim 1, wherein at least a portion of the mask body includes a thermo-sensitive material to detect a temperature change of the leak detection.

25. The mask of claim 21, wherein the heat sensitive material comprises a thermistor.

26. The mask of claim 21, wherein the heat sensitive material comprises a thermocouple.

27. The face mask of claim 21, wherein the heat sensitive material is included in a coating on the face mask.

28. The mask of claim 21, wherein the heat sensitive material is included in an interior surface portion of the mask body.

29. The mask of claim 21, wherein the thermo-sensitive material is included in an exterior surface portion of the mask body.

30. The mask of claim 20, wherein at least a portion of the mask body comprises a heat sensitive material.

31. The mask of claim 1, wherein at least one sensor is a thermal sensor located on a mask periphery to detect temperature changes on the mask periphery.

32. The mask of claim 20, wherein the mask periphery comprises a thermally sensitive material to which the at least one thermal sensor is thermally coupled.

33. The mask of claim 1, wherein the mask periphery includes a heat sensitive material proximate the patient's nose to detect temperature changes indicative of nasal breathing.

34. The mask of claim 1, wherein the mask periphery includes a heat sensitive material proximate the patient's mouth to detect temperature changes.

35. The mask of claim 1, wherein a portion of the periphery of the mask includes a thermo-sensitive material to detect temperature changes of leak detection.

36. The mask of claim 20, wherein the mask periphery comprises a heat sensitive material.