US20060264762A1 - PC-based physiologic monitor and system for resolving apnea episodes during sedation - Google Patents

Abstract

An anesthesia delivery and monitoring system for use during outpatient surgery performed under sedation level anesthesia that includes a ventilatory system, a system for supplying sedation anesthesia, a respiratory sensor adapted to detect a respiration parameter of such a patient, and a system for supplying a timed back-up breath to such a patient through the ventilatory system. The timed back-up breaths are supplied in response to the respiration parameter falling outside a preset threshold and at a positive pressure exceeding a base operating pressure of the respiratory system. The system for supplying sedation anesthesia is an intravenous supply system for anesthesia, a ventilatory system coupled to the patient, a needle and syringe, or any combination thereof. The respiratory system includes a PC-based physiologic monitor with user modified feedback control signal.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS
• This application claims priority under 35 U.S.C. § 119(e) from provisional U.S. patent application No. 60/665,919 filed Mar. 28, 2005 the contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
• 1. Field of the Invention
• The present invention relates to resolving apnea episodes during sedentary anesthesia, and, in particular, to the use of a ventilator system that delivers timed back-up breaths to patients during sedentary anesthesia, and to a PC-based physiologic monitor used in such a system.
• 2. Description of the Related Art
• During surgery and other procedures in which the patient undergoes a light plane of anesthesia, also called sedation level anesthesia or sedentary anesthesia, the patent is given anesthesia, but an artificial airway and mechanical ventilation is not utilized, which is a procedure done during a more major surgery using a general anesthesia. Because the airway is not protected and breathing is not assisted, the patient under sedation level anesthesia can experience obstructive apneas, as well as, hypoventilation and central apneas. Patients are also known to accidentally drift from a light plane of anesthesia to a deep plane. When this occurs, patients are known to experience obstructive apneas, hypopneas, hypoventilation, and central apneas.
• It has been previously proposed to apply continuous positive airway pressure (CPAP) respiratory therapy to certain patients during certain levels of anesthesia to maintain the patency of the airway. Furthermore, it has been proposed to apply a bi-level pressure support therapy, in which the pressure of the flow of gas delivered to the patient varies with the patient's respiratory cycle, to certain patients during certain levels of anesthesia to maintain the patency of the airway and to ensure that the patient receives a desired tidal volume. These systems represent active additional respiratory therapies that are applied to certain patients without regard to whether the patient is actually in need of the therapy. That is, some patients are being given a CPAP or bi-level therapy even though that patient may not be experiencing apneas or hypopneas. There is a need in the art to provide a ventilatory system that is responsive to sensed patient conditions, particularly in sedentary anesthesia applications, and to provide such a system without requiring the use of complicated and costly anesthesia machines used by hospitals during general anesthesia.
SUMMARY OF THE INVENTION
• Accordingly, it is an object of the present invention to provide a monitor system that overcomes the shortcomings of conventional techniques for monitoring a patient, especially during sedation level anesthesia. This object is achieved, according to one embodiment of the present invention, by providing a personal computer (PC) based physiologic monitor system that includes a personal computer having a display and an input/output port for attachment to an external device. The PC based system also includes a physiologic sensor coupled to the personal computer through the input/output port so that a modified output of the physiologic sensor is graphically displayed on the display. A controller, a portion of which is disposed in the personal computer, modifies the output of the physiologic sensor and provides a feedback control signal for modifying the output of the physiologic sensor.
• It is a further object of the present invention to provide a ventilatory system for use during outpatient surgery performed under sedation level anesthesia that overcomes the shortcomings of conventional pressure support systems used in this environment. This object is achieved, according to one embodiment of the present invention, by providing a ventilatory system for use during outpatient surgery performed under sedation level anesthesia that includes a pressure/flow generating system adapted to be coupled to a patient, a system for supplying sedation anesthesia to such a patient, a sensor coupled to such a patient and adapted to detect a respiration parameter of such a patient, and a controller. The controller receives the output from the sensor and controls the pressure/flow generating system so as to provide a timed back-up breath to such a patient based on the output from the sensor. The timed back-up breath is supplied in response to the respiration parameter falling outside a preset threshold, and is supplied at a positive pressure exceeding a base operating pressure of the pressure/flow generating system.
• These and other objects, features, and characteristics of the present invention, as well as the methods of operation and functions of the related elements of structure and the combination of parts and economies of manufacture, will become more apparent upon consideration of the following description and the appended claims with reference to the accompanying drawings, all of which form a part of this specification, wherein like reference numerals designate corresponding parts in the various figures. It is to be expressly understood, however, that the drawings are for the purpose of illustration and description only and are not intended as a definition of the limits of the invention. As used in the specification and in the claims, the singular form of “a”, an and “the” include plural referents unless the context clearly dictates otherwise.
BRIEF DESCRIPTION OF THE DRAWINGS
• FIG. 1 is a schematic view of a first embodiment of a anesthesia delivery and monitoring system for use during outpatient surgery performed under sedation level anesthesia according to the principles of the present invention;
• FIG. 2 is a schematic view of a second embodiment of a anesthesia delivery and monitoring system for use during outpatient surgery performed under sedation level anesthesia according to the principles of the present invention;
• FIG. 3 is a schematic representation of the output pressure of the anesthesia delivery and monitoring system of the present invention and the patient's tidal volume displayed over a period of time;
• FIG. 4 is a schematic representation of a control system for the physiologic sensor according to the principles of the present invention;
• FIGS. 5A-5E are schematic views of various physiologic displays for the PC based physiologic sensors according to the principles of the present invention; and
• FIG. 6 is a flow chart illustrating a method of monitoring a subject's physiologic parameters on a personal computer according to the principles of the present invention.
DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS
• FIG. 1 is a schematic representation of a first embodiment of a anesthesia delivery andmonitoring system10 for use during outpatient surgery performed under sedation level anesthesia according to the principles of the present invention. As noted above, sedation level anesthesia refers to a level of anesthesia below general anesthesia, where apatient12 is intended to be maintained in what is known as a light plane of anesthesia. This is common in many outpatient surgeries. The specific types of anesthesia utilized are well known in the art and are applied in a number of common techniques. Three common systems for supplying sedation anesthesia topatient12 include: (1) an intravenous supply system for anesthesia, which is such as shown inFIG. 1; (2) an anesthesia/ventilatory system coupled to the patient, such as shown inFIG. 2, and (3) a needle and syringe injection (not shown). In the intravenous supply system ofFIG. 1, the sedentary aesthesia is provided in an appropriate solution in an IVbag14, which is mounted on aconventional stand16. As noted above, a needle and syringe could also be used to supply intravenous sedentary anesthesia topatient12 through simple, periodic injections.
• Anesthesia delivery andmonitoring system10 of the present invention includes a ventilatory system coupled to a patient. Specifically, the ventilatory system includes a controlled pressure/flow generator20, which is typically a blower having a respiratory gas intake and power supply (not shown) and a respiratory gas output, coupled to thepatient12 through aconduit22 and apatient interface device24.Patient interface device24 is any conventional device that communicates a flow of gas fromconduit22 to an airway of a patient, such as a nasal mask, nasal/oral mask, nasal canula, or other respiratory patient coupling. Becauseconduit22 is a single-limb conduit,patient interface device24,conduit22, or both includes anexhaust vent26 for exhausting gas, such as a patient's exhaled breath, from the system to the ambient atmosphere, as generally known in the art. The present invention contemplates that the exhaust vent can be any suitable type of vent of expelling gas from the system to the atmosphere,conduit22 can be any suitable conduit, such as a flexible hose, and pressure/flow generator20 is any device capable of producing a flow of gas.
• Anesthesia delivery andmonitoring system10 includes asensor28 coupled topatient12 and adapted to detect a respiration parameter of the patient. InFIG. 1,sensor28 is attached topatient12 throughconduit22. In this configuration,sensor28 may be a pressure sensor or flow sensor for detecting the respiration parameters of the patient.Sensor28 could be placed onmask24, atvent26, onblower motor20, or any combination thereof, and obtain signals indicative of the patient's respiration parameters.Sensor28 may be placed directly on thepatient12 as well. The specific type and the location of the sensor can vary, provided that the sensor provides an output indicative of the patient's respiration parameters, i.e., at least the time of and preferably an indication of how much respiratory flow or volume the patient is receiving with each breath.
• In anesthesia delivery andmonitoring system10, pressure/flow generator20 andsensor28 are coupled to a central controller that is in the form of a lap-top computer30. In the illustrated exemplary embodiment,sensor28 is coupled tocomputer30 through anamplifier32 to prove a meaningful signal tocomputer30. Of course,amplifier32 can be built into the sensor or the computer. The coupling betweenamplifier32 andcomputer30, shown aslink34, may be a hardwire connection or a wireless connection. In a similar fashion, the coupling betweenblower motor20 andcomputer30, shown aslink36, may be a hardwire connection or a wireless connection. Wherelinks34 are hardwire connections, it is preferred that they couple to conventional existing ports oflaptop computer30.
• Anesthesia delivery andmonitoring system10 includes other physiologic sensors coupled topatient12. Specifically, apulse oximeter sensor40 is attached to the patient and coupled to the computer through anamplifier42 andlink44. The link betweenamplifier42 andcomputer30, shown discussed above, may also be a hardwire connection or a wireless connection. The addition of physiologic sensors, such assensors28 and40, allows the computer to be a physiologic monitor graphically displaying the sensed parameters of the patient, as will be described in detail hereinafter. The sensors for this physiologic monitor are not limited to respiratory, pulse and blood oxygenation, as shown inFIGS. 1 and 2, but may further include a blood pressure sensor, a blood flow sensor, a blood glucose sensor, a blood cholesterol sensor, a heart sound sensor, an EMG sensor, an EEG sensor, an EKG sensor, an EOG sensor, a blood perfusion sensor, a temperature sensor, a blood gas sensor, a motion sensor, a strain gauge, a body position sensor, a limb motion sensor, and any combinations thereof.
• Anesthesia delivery andmonitoring system10′ ofFIG. 2 is similar tosystem10 ofFIG. 1 except thatsystem10′ includes a system for supplying sedation anesthesia topatient12. Inhaled anesthesia agents are used in the embodiment ofFIG. 2, which are supplied to pressure/flow generator20 through ananesthesia gas supply50 and aninput conduit52. When using inhaled agents for anesthesia, the ventilatory system cannot vent to the room, or it could adversely affect the caregivers. Therefore, a closed (dual limb) system is created wherevent26 is replaced with a one way T orY coupling53 and aexpiratory limb54 that carries the gas to a CO₂/anesthesia scrubber56 that vents harmless material or returns the scrubbed respiratory gases to input52 throughtubing58.
• In the illustrated embodiment, a source ofoxygen60 is coupled to inputconduit52 throughtubing62 to supply oxygen to the closed system. Anoxygen sensor64 may be coupled to input conduit52 (or elsewhere on the closed system) and coupled tocontroller30 through alink66. The link between sensor64 (which may have an amplifier) andcomputer30, may be a hardwire connection or a wireless connection. As a closed respiratory system, it is sometimes desirable to track the oxygen level received by the patient.
• The operation of anesthesia delivery andmonitoring systems10 and10′ are used in the present invention in that the ventilatory portion of the system provides a system for supplying a timed back-up breath to the patient. More specifically, the timed back-up breaths are supplied in response to the respiration parameter falling outside a preset threshold. As noted above, timed back-up breaths, within the meaning of this disclosure, refer to the supplying of positive pressure to the airway of the patient to assist the patient's breathing. This is done in response to a sensed failure of the patient's actual breathing over a given period of time.
• Referring toFIG. 3, line P represents the output pressure of pressure/flow generator20 over time, and line Q represents the measured tidal volume of the patient's respiration over time. The normal operating pressure of the pressure/flow generator can be found intime segments70,72,74, and76, and this may be zero. Alternatively, the standard operating pressure of pressure/flow generator20 may be slightly positive to flush out CO₂from the patient circuit, e.g., not enough to assist the patient in breathing. As can be seen in the figure by referring to line Q,time periods70,72, and74 demonstrate normal tidal volumes for the patient's respiration, i.e., the patient is breathing in a satisfactory manner. Note that line Q is derived from the readings ofsensor28.
• Time period76, however, illustrates a situation in which satisfactory breath has not been taken by the patient. During this time interval, the patient is considered to be experiencing an apnea or hypopnea. In response to the event occurring inperiod76, a back-up breath is supplied to the patient inperiod78 by the pressure/flow generator. Specifically, in delivering the timed back-up breath, pressure/flow generator20 supplies respiratory gases to the patient at a positive pressure (as shown at line P in period78) exceeding the normal operating pressure of pressure/flow generator20 of the respiratory system at all other times. This can be done using any conventional pressure/flow control techniques, such by changing the operating speed of the blower in the pressure/flow generator or by manipulating a pressure/flow control valve in the pressure/flow generator. The preset limit that triggers the back-up breath, need not be “time without a breath”, the limit could be an indication of tidal volume, or a combination of any respiratory parameter set points, as desired. Further, it is expected that this limit may be varied by theoperator using computer30. The system may provide only one timed back-up breath then return to monitoring the patient's respiratory parameters, or may provide multiple breaths, as desired by the operator.
• Pressure/flow generator20 is effectively off (or at a low pressure) before any episode or event. In an exemplary embodiment, pressure/flow generator20 returns to this standard operating pressure after an event (with one, two, or other preset number of back-up breaths having been supplied to the patient). Consequently, the ventilator portion of the anesthesia delivery and monitoring system is a passive, back up ventilatory system that assists the patient's respiration only as required.
• Computer30 in the present invention serves as an inexpensive, user controlled, physiologic monitor that graphically displays the sensed parameters ofpatient12. In an exemplary embodiment of the present invention, each desired physiologic sensor, such as thesensors28,40, and64 discussed above, are coupled to a standard input/output port of computer30 (including wireless inputs). As shown inFIG. 4, each sensor (generically shown as80) is coupled through an external amplifier (generically shown as82) through a link that allows aninput signal84 from the sensor to the computer and afeedback control signal86 from acontroller90 withincomputer30 toamplifier82. The feedback control signal controls the modification of the output of the physiologic sensor. Auser input device92, such as a keyboard and/or mouse, allows the user to set and modifyfeedback control signal86 to control the modification of the output ofphysiologic sensor80, such asrespiratory sensor28.
• Closed loopfeedback control signal86 controls or drives at least one of a drive current, a drive voltage, a signal gain, a high pass filter point cutoff, a band pass filter range, or a low pass filter point cutoff for modifying the output ofsensor80. Closed loopfeedback control signal86 set by the user gives the user great flexibility in using the desiredsensors80. In clinical use, thesensors80 will likely have automatic or default settings. In research applications, the desired setting may vary greatly and the present physiologic monitoring system provides a simple, inexpensive tool to the researcher for adjusting these settings.
• The physiologic monitoring portion of anesthesia delivery andmonitoring system10 and10′ includes adisplay94 oncomputer30 to display the output or the modified output ofsensors80.Controller90 identifies each of the sensors that are coupled to the personal computer and sizes a respective display area for each modified output. As shown inFIGS. 5A-5E, a display area of a given modified output associated with onesensor80 will vary depending upon the specific sensors coupled to thepersonal computer30. Specifically,FIG. 5A illustrates an exemplary display area for the output of asensor80 when onesensor80 is attached tocomputer30.FIG. 5B illustrates exemplary display areas for the output of twosensors80 when twosensors80 are attached to thecomputer30.FIG. 5C shows exemplary display areas of threesensors80.FIG. 5D shows exemplary display areas when foursensors80 are attached to the computer, andFIG. 5E shows exemplary display areas for sixsensors80.
• The display areas inFIGS. 5A-5E are described above as exemplary display areas for several reasons. First, the present invention contemplates providing the user the ability to adjust the size of any window displayed (even electing to eliminate a given display) in a manner familiar to the Windows® operating system. Once the user sets a given display arrangement for a given set of sensors, that display will be the designated display format for those collections of sensors (unless the operator elects to go back to the default settings or the change the display again). Further, the present invention contemplates providing the user with the ability to select an alternative series of displays using any conventional selecting technique, such as via a pull down menu. For example, where there are six sensors attached to the system, the user may elect to display the output of two of the sensors on a first screen (FIG. 5B), the output of three of the sensors on a second screen (FIG. 5C), and the final sensor output on a third screen (FIG. 5A), with the user clicking to toggle or cycle between the given screens. This user defined set up would then become the display setting for this collection of sensors.
• As shown inFIG. 6, in usingcomputer30 as a physiologic monitor, thefirst step100 is attachingphysiologic sensors80 to the patient and to the computer, as noted above. Then, instep102, the user inputs the parameters for the feedback control signals86 for each sensor80 (or uses the defaults). Atstep104, the output of each of thephysiologic sensors80 is modified by the respectivefeedback control signal86. With all of the sensors attached,controller90 identifies, atstep106, the sensors that are actually attached to the computer to thereby size the output display areas on the display. Finally,computer30, instep108, graphically displays a modified output each of the physiologic sensors on the respective display area ofdisplay94.
• Although the invention has been described in detail for the purpose of illustration based on what is currently considered to be the most practical and preferred embodiments, it is to be understood that such detail is solely for that purpose and that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover modifications and equivalent arrangements that are within the spirit and scope of the appended claims.
Definition of Terms Used in the Specification
• The following is a listing of the terms used in the above specification. This listing is intended to supplement and not replace the definition of the terms given above, as understood by those skilled in the art based on the context in which they are presented, but may serve to help clarify the intended meaning of each.
• A personal computer within the meaning of this specification is a computer with its own operating system and of software intended for a variety of operations by the user. Examples of personal computers include those commonly referred to as a desk-top computer, a laptop computer, a workstation, or a notebook computer. A personal computer does not include a processor or CPU imbedded within a dedicated piece of equipment.
• A physiologic sensor within the meaning of this specification is a sensor that measures a parameter related to a physical characteristic of a living subject, such as a human. The types of physiologic sensors include, for example, blood pressure sensors, blood flow sensors, blood glucose sensors, blood cholesterol sensors, heart sound sensors, EMG sensors, EEG sensors, EKG sensors, EOG sensors, pulse sensors, oxygenation sensors, blood perfusion sensors, respiration sensors (both pressure, flow and rate), temperature sensors, additional blood gas sensors (such as nitrogen partial pressure, carbon dioxide partial pressure, carbon monoxide partial pressure, oxygen partial pressure, and pH level), motion sensors, strain gauges, body position sensors, limb motion sensors and the like. The term respiratory sensors is a subset of physiologic sensors and refers to those sensors measuring physical parameters of a subject indicative of respiration of the subject.
• The input/output ports of a personal computer refer to the communications links through which the personal computers send and receive information, which generally include serial ports, parallel ports, wireless links or connectors (such as WI-FL and Bluetooth), and universal serial bus (UBS) ports. In addition, some laptops have expansion slots for PCMCIA standard adaptor cards (Type I and Type II) that also form input/output ports.
• The terms sedation anesthesia or sedation level anesthesia within the meaning of this specification refers to a level of a anesthesia below general anesthesia in which a patient is intended to be able to respond to physical stimulus and maintain an airway, also known as a light plane of anesthesia. General anesthesia corresponds to a level of sedation in which a patient does not respond to physical stimulus and, as a result, cannot maintain an airway and breath on their own, also known as a deep plane of anesthesia. These definitions follow the American Society of Anesthesiologists (ASA) definitions.
• The term timed back-up breaths within the meaning of this specification refers to the supplying of, through a ventilatory system coupled to the patient, positive pressure assist to a patients breathing in response to a sensed failure of the patient's actual breathing over time or a reduction of the patient's respiratory flow or volume below a given threshold.
• The term respiratory gases, within the meaning of this specification, are gases to be breathed by the patient. This includes untreated air, air supplemented with increased oxygen or treated with other medicaments, oxygen, and other gases and combination of gases used for conventional respiratory treatment and care.

Claims (24)

1. A personal computer based physiologic monitor system comprising:

a personal computer having a display and an input/output port for attachment to an external device;

a physiologic sensor coupled to the personal computer through the input/output port, wherein a modified output of the physiologic sensor is graphically displayed on the display; and

a controller for the physiologic sensor, wherein the controller is adapted to modify the output of the physiologic sensor, and wherein at least a portion of the controller is disposed in the personal computer and provides a feedback control signal for modifying the output of the physiologic sensor.

2. The physiologic monitor system ofclaim 1, wherein the portion of the controller disposed in the personal computer forms a closed loop feedback control that drives at least one of a drive current, a drive voltage, a signal gain, a high pass filter point cutoff, a band pass filter range, or a low pass filter point cutoff for modifying the output of the physiologic sensor.

3. The physiologic monitor system ofclaim 2, wherein the portion of the controller disposed in the personal computer includes a user input device to allow a user to set and modify the feedback control signal for controlling the modification of the output of each physiologic sensor.

4. The physiologic monitor system ofclaim 1, wherein the physiologic sensor is selected from the group consisting of a blood pressure sensor, a blood flow sensor, a blood glucose sensor, a blood cholesterol sensor, a heart sound sensor, an EMG sensor, an EEG sensor, an EKG sensor, an EOG sensor, a pulse sensor, an oxygenation sensor, a blood perfusion sensor, a respiration flow sensor, a respiration rate sensor, a respiration pressure sensor, a temperature sensor, a blood gas sensor, a motion sensor, a strain gauge, a body position sensor, a limb motion sensor, and any combinations thereof.

5. The physiologic monitor system ofclaim 1, wherein the personal computer is a laptop or a notebook computer.

6. The physiologic monitor system ofclaim 1, wherein a plurality of physiologic sensors are coupled to the personal computer.

7. The physiologic monitor system ofclaim 6, wherein the personal computer includes a plurality of input/output ports, and wherein each physiologic sensor is coupled to the personal computer through a distinct one of the plurality of input/output ports.

8. The physiologic monitor system ofclaim 7, wherein the modified output of each physiologic sensor in the plurality of physiologic sensors is simultaneously displayed in a viewable format on the display.

9. The physiologic monitor system ofclaim 6, wherein the portion of the controller disposed in the personal computer is adapted to identify each physiologic sensor that is coupled to the personal computer and to size a respective display area for each modified output, whereby a size of a display area for a given modified output associated with a sensor varies depending upon the specific physiologic sensors coupled to the personal computer.

10. The physiologic monitor system ofclaim 1, wherein the physiologic sensor is adapted to be coupled to a patient, the system further comprising:

means for supplying sedation anesthesia to such a patient; and

means for supplying a timed back-up breath to such a patient, wherein the timed back-up breath is supplied in response to a respiration parameter falling outside a preset threshold.

11. The physiologic monitor system ofclaim 10, wherein the means for supplying sedation anesthesia includes an intravenous supply system, a ventilatory system coupled to an airway of such a patient, or both.

12. A ventilatory system for use during outpatient surgery performed under sedation level anesthesia comprising:

a pressure/flow generating system adapted to be coupled to a patient;

means for supplying sedation anesthesia to such a patient;

a sensor coupled to such a patient and adapted to detect a respiration parameter of such a patient; and

a controller that receives an output from the sensor and controls the pressure/flow generating system so as to provide a timed back-up breath to such a patient based on the output from the sensor, wherein the timed back-up breath is supplied in response to the respiration parameter falling outside a preset threshold, and wherein the timed back-up breath is supplied at a positive pressure exceeding a base operating pressure of the pressure/flow generating system.

13. The ventilatory system ofclaim 12, wherein the means for supplying sedation anesthesia includes an intravenous supply system for anesthesia to such a patient.

14. A method of monitoring a subject's physiologic parameters on a personal computer comprising the steps of:

attaching a physiologic sensor to the personal computer through an input/output port thereof;

graphically displaying a modified output of the physiologic sensor on the display of the personal computer; and

modifying the output of the physiologic sensor by providing a feedback control signal from the personal computer that controls the modification of the output of the physiologic sensor.

15. The monitoring method ofclaim 14, wherein the step of modifying the output of the sensor forms a closed loop feedback control adapted to drive at least one of a drive current, a drive voltage, a signal gain, a high pass filter point cutoff, a band pass filter range, or low pass filter point cutoff.

16. The monitoring method ofclaim 15, further including the step of inputting by the user on the personal computer to set the feedback control signal to control the modification of the output of each physiologic sensor.

17. The monitoring method ofclaim 14, further including the step of selecting the sensor from the group consisting of a blood pressure sensor, a blood flow sensor, a blood glucose sensor, a blood cholesterol sensor, a heart sound sensor, an EMG sensor, an EEG sensor, an EKG sensors, an EOG sensor, a pulse sensor, an oxygenation sensor, a blood perfusion sensor, a respiration flow sensor, a respiration rate sensor, a respiration pressure sensor, a temperature sensor, a blood gas sensor, a motion sensor, a strain gauge, a body position sensor, a limb motion sensor and a combination thereof.

18. The monitoring method ofclaim 14, further including the step of coupling a plurality of physiologic sensors to the personal computer, wherein each physiologic sensor in the plurality of physiologic sensors is coupled to the personal computer through a distinct one of a plurality of input/output ports of the personal computer.

19. The monitoring method ofclaim 18, wherein during the graphical displaying step, the modified output of each physiologic sensor in the plurality of physiologic sensors is simultaneously displayed in a viewable format on the display of the personal computer, and wherein the display area of a given modified output of a sensor on the display varies depending upon the specific physiologic sensors coupled to the personal computer.

20. The monitoring method ofclaim 14, further comprising the steps of

supplying sedation anesthesia to a patient; and

supplying a timed back-up breath to such a patient, wherein the timed back-up breath is supplied in response to a respiration parameters falling outside a preset threshold.

21. The monitoring method ofclaim 20, wherein the step of supplying sedation anesthesia includes delivering an anesthesia intravenously, delivering an anesthesia via an airway of such a patient, or both.

22. A ventilatory method for a patient comprising the steps of:

supplying a flow of gas to an airway of a patient;

coupling a respiratory sensor to such a patient to detect a respiration parameter of such a patient; and

supplying a timed back-up breath to such a patient through the system used for supplying the flow of gas, wherein the timed back-up breath is supplied in response to the detected respiration parameters falling outside a preset threshold, and wherein the timed back-up breath is supplied at a positive pressure exceeding a base operating pressure of the system used for supplying the flow of gas gases.

23. The method ofclaim 22, wherein the step of supplying a flow of gas is only operated during the supply of timed back-up breaths.

24. The method ofclaim 22, further including the steps of calculating a total volume for each patient breath, and supplying the timed back-up breath responsive to the total calculated volume of at least one breath is outside a preset threshold.

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