Method and apparatus for monitoring cardiovascular condition of patient with sleep disordered breathing

Related application

This application claims the benefit of US Provisional Application No. 60 / 557,846 filed March 31, 2004.

The present invention relates to methods and devices for treating and monitoring sleep apnea (SDB) in patients suffering from heart disease, or monitoring cardiovascular status in SDB patients.

"Sleep apnea" is generally a respiratory interruption symptom that occurs during sleep. The most common form of sleep apnea is obstructive sleep apnea (OSA). The OSA affects about 20 million Americans, similar to asthma and diabetes. Less than 10% of people with OSA are diagnosed, but only a few are treated. Intermittent snoring of loud voices, apnea, and decreased breathing are characteristic of OSA. Because the symptoms of sleep apnea manifest as a result of precursors, SDB has become a common term used to describe any disease state that reveals apnea and / or hypoventilation during sleep. I came. Apnea and hypoventilation interfere with gas exchange, disrupt sleep, and frequently cause oxygen desaturation. In severe cases, patients may experience these oxygen desaturation and awakenings from sleep hundreds of times each night.

The most common treatment for SDB is continuous positive airway pressure (CPAP). The use of nasal CPAP to treat OSA was invented by Sullivan and disclosed in US Pat. No. 4,944,310. Briefly, CPAP treatment is generally 4-20H₂It acts as an airway pneumatic sprint by applying positive pressure in the O range. Air is supplied to the airways by a motor-driven blower, which is coupled to a nose (or nose and / or mouth) mask in close contact with the patient's face via an air supply hose. A more elaborate form of CPAP treatment may be provided by a biphasic ventilator, a proportionally assisted ventilator, a servo-controlled ventilator. Such devices are generally used by patients essentially daily, before and during sleep.

For example, OSA nasal CPAP treatment may involve the use of an AUTOSET T device commercially available from ResMed or an automated blower such as AUTOSET SPIRIT . Examples of suitable nasal CPAP masks are the MIRAGE nasal mask and the MIRAGE full surface mask, also commercially available from ResMed. The AUTOSET T device continuously monitors the condition of the patient's airways, determines the appropriate pressure to treat the patient, and increases or decreases that pressure as needed. Alternatively, biphasic pressure is applied to the patient, as in the case of the VPAP II device marketed by ResMed. AUTOSET T device and VPAP The principles behind the operation of II devices are described in US Pat. No. 5,704,345. The entire disclosure of US Pat. No. 5,704,345 is incorporated herein by reference. Other forms of pressurization are also available. For example, pressure is supplied according to a smooth pressure waveform template and continuous phase variables to provide comfortable pressure support that is nearly synchronized with the patient's respiratory cycle. This device is the subject of US Pat. No. 6,532,957 and is incorporated herein by reference in its entirety.

In May 2000, a study in the New England Journal of Medicine pointed out a meaningful relationship between hypertension and SDB, which is independent of other related risk factors. Hypertension as a disease has been estimated to afflict more than 25% of people over the age of 44. If left untreated, it can lead to heart disease such as heart attack, stroke, coronary artery disease, and heart failure. Collectively, heart disease (CVD) is now considered a major cause of death and a disability in modern society. Studies show that more than 60% of stroke patients, 50% of heart failure patients, 35% of hypertensive patients, and more than 30% of coronary artery disease patients have SDB.

In general, CVD is a disease that affects the correct functioning of the heart and blood vessels. In addition to cerebrovascular disease (cerebral infarction), other serious CVDs include myocardial infarction (heart attack), congestive heart failure (CHF), and transient ischemic attack (TIA), to name a few. ), Includes peripheral vascular disease. Overall, it is estimated that about 17 million people die from CVD each year. Early diagnosis and treatment of CVD can be a major factor in reducing CVD-related mortality.

CPAP devices have traditionally been used for the treatment of SDB in CVD patients. In one such device, one form of pressure treatment has been directed to the treatment of heart failure and Cheyne-Stokes respiration. In a device called AUTOSET CS provided by ResMed, pressure support is altered in synchronization with the patient's respiration to counteract the ups and downs of patient respiration that are characteristic of Cheyne-Stokes respiration. This device is the subject of US Pat. No. 6,532,959 and is incorporated herein by reference in its entirety.

CPAP treatment has also been recognized as a beneficial treatment for stroke, as disclosed by Farrell et al. In US Pat. No. 6,336,454. The use of CPAP treats patients with cerebral infarction by improving arterial oxygen levels and reducing arterial carbon dioxide levels, as well as improving automatic regulation of blood pressure, cardiac output, and ventilation, for example. Improving morbidity (mortality), such as the rate and degree of recovery of vital signs, and stabilizing patients in the acute phase are expected benefits.

U.S. Pat. No. 5,794,615 also teaches a system that includes methods and devices for treating congestive heart failure. This system involves adding a separate and independent gain to the flow rate of pressurized gas supplied to the patient throughout the expiratory and inspiratory stages of the respiratory cycle. Pressure support is disclosed as reducing the preload and afterload of the heart.

In short, there are numerous devices used to treat SDB in patients with heart disease. However, despite the recognition of the need for early treatment or diagnosis of CVD patients, and despite the lack of a complete understanding of how these diseases work, CVD patients or potential CVD patients. In the lives of SDB patients who may be patients, there is little practice in taking advantage of the patient information monitoring capabilities of such CPAP devices to take advantage of the substantial presence of these CPAP devices. In short, there is a need to track or monitor patient information that facilitates early treatment and diagnosis of CVD and understanding of SDB.

<p> An object of the present invention is to provide a method and an apparatus for treating a respiratory disease in a patient with or expected to have heart disease.</p><p> A further objective is to provide methods and devices that assist in the management or monitoring of the cardiovascular status of such patients and assist in the diagnosis or treatment of related diseases.</p><p> Other objects will be apparent to those skilled in the art by the description of the invention described herein.</p>

<p> In one aspect of the invention is provided a device comprising a sleep apnea treatment unit and a unit for monitoring a patient for signs of heart disease.</p><p> The present invention provides methods and devices useful for patients with or expected to have heart disease with sleep apnea. Preferably, the device can provide positive airway pressure at a therapeutic level for the treatment of sleep apnea. The device can be configured with one or more protocols that may be utilized in performing such pressurization procedures. Over the course of one or more sessions of such treatment, the device suffers from sleep apnea, hypoventilation, partial obstruction, snoring, pressure vs. time, flow vs. time, leakage, etc. for subsequent analysis. It may be configured to detect and record related events.</p><p> The device also includes, for example, blood pressure, heart rate, oxygen measurement data, electrocardiogram data, Holter analysis results (including, for example, arrhythmia, heart rate, and fluctuation summary), body mass index (including height and weight data), left. Ventricular ejection fraction (LVEF), 6-minute walking data, type B sodium diuretic peptide (BNP), cardiac output data, VO₂Max Data, New York Heart Association Class (NYHA), ACC / AHA Heart Failure Stage, Quality of Life Related Data (eg Epworth Sleep Scale, Berlin Questionnaire, Minnesota Heart Failure Life Questionnaire, Kansas City Cardiomyopathy Questionnaire) Etc.), peripheral arterial tone (PAT) and critical neurohormone levels (eg, catecholamine levels) are configured to detect or facilitate and accept additional information about the patient's cardiovascular status as input.</p><p> Such data may be recorded or entered in the device continuously or periodically in relation to time. Using such data in the device, the association between cardiovascular information and events related to sleep apnea can be observed or produced on a common tom scale, thereby occurring almost or substantially in common. Changes can be observed or tracked. Such data may be retrieved from or viewed on the device for the purpose of monitoring or diagnosing the patient's SDB and / or potential CVD, or accessed remotely by a physician or clinician. May be done.</p><p> Another aspect of the invention is a combination of products, services and business channels for caring for patients with SDB and CVD.</p><p> Other aspects of the invention are described in the detailed description below.</p>

<figref num="1">The apparatus according to the present invention is shown.</figref><figref num="2">It is a flowchart of the method of monitoring the cardiovascular information of a patient.</figref><figref num="3">It is a flowchart which shows the business path which concerns on aspect of this invention.</figref><figref num="4">It is a flowchart which shows the business path which concerns on aspect of this invention.</figref>

With reference to FIG. 1, the present invention relates to a pressure supply device including a servo-controlled blower 2, a mask 6, and an air supply line 8 for connecting between the blower 2 and the mask 6. .. Exhaust gas is discharged through the exhaust hole 13. In some cases, flow sensor 4f and / or pressure sensor 4p may be utilized. In this case, in order to obtain the flow rate signal F (t), the mask flow rate is measured using a respiratory flow rate diagram and a differential pressure transducer or similar device, and the pressure signal P_maskMask pressure is measured with a pressure tap using a pressure transducer to obtain (t). The pressure sensor 4f and the flow rate sensor 4p are shown only symbolically in FIG. It goes without saying that those skilled in the art can understand how to measure the flow rate and pressure. Flow rate F (t) signal and pressure P_mask(t) The signal is sent to the controller or microprocessor 15, thereby the pressure request signal P._request(t) is obtained. Alternatively, as disclosed in US Pat. Nos. 5,740,795, 6,332,463 or 6,237,593, the current and / or speed of the motor supplied to the motor is monitored without the above-mentioned flow rate sensor or pressure sensor. By doing so, the flow rate signal f (t) and the pressure signal P_mask(t) may be evaluated or calculated for the blower motor. In some cases, the blower motor speed may be kept substantially constant and the pressure in the mask by controlling the operation of the servo valve which can variably divert / discharge or supply the air flow to the mask. May be changed.

The controller 15 or processor is configured to perform the methods described in detail herein and may also include integrated chips, memory and / or other instruction or data storage media. For example, a program instruction with a control method may be encoded by an integrated chip in the memory of the device, or such instruction may be loaded as software. With such a controller, for many different pressure treatment treatments, simply adjusting the pressure supply equation used to set the speed of the blower or to manipulate the discharge with the release valve. The device can be used for.

The device also preferably includes a communication port or module 10, a wireless communication transceiver and / or a network card for communicating with another device or computer, such as a portable display or control device 12. In addition, the device may include additional interfaces 16 for connecting to additional diagnostic or patient information gathering devices. For example, the diagnostic unit may optionally include a pulse oximeter 20, a respiratory movement sensor 22 such as a chest band, an EEG &amp; ECG24, an EOG25, and / or an electrode 28 for detecting cardiac rhythm. The oximeter may optionally be included in the main blower housing. There is a sensing tube 14 that connects the blower's main housing to the mask, which allows the device to sense the oxygen concentration and pressure level in the mask 6. In some cases, automatic PCO to feed the input data signal to microprocessor 16.₂Measuring device 21 or PCO₂Other non-invasive blood gas monitors / devices for measuring, eg, devices as taught in US Pat. No. 5,630,413, which is incorporated herein by reference in its disclosure, may be connected. If other automated measuring devices are involved in measuring other cardiovascular related information from the patient, the other automated measuring devices may be included with the diagnostic unit. In this case, the device, for example, communicates / receives such information from its own display (eg LCD screen) and input device (eg keypad or button), or blood pressure monitor, heart rate monitor, oxygen measurement. Monitor, ECG device, ECG event monitor, Holter electrocardiogram, automatic tape measure, automatic weight scale, treadmill device, blood analysis device, cardiac output analysis device, VO₂It may be configured to communicate / receive via a telemetry communication link or other communication link from a Max data device or peripheral arterial tone evaluation device. One of ordinary skill in the art can recognize the type of information that can be generated by such a device.

Other optional input and / or output devices 22 may be included to display the output signal and input the input signal for the microprocessor 16. Various suitable input and output devices such as keypads, display screens and other alternatives are known in the art.

Although the device is generally described as a single unit, it goes without saying that a combination of devices and / or computers connected by any available communication method may be used to achieve the object of the present invention. No. For example, the device can be connected to various mobile terminals such as the PalmPilot via wireless communication, or may be connected to a network for transmission between devices. With such a device or system, the physician can remotely monitor, analyze or record, for example, the patient's condition or data history. For example, the remote device may send or read any desired cardiovascular information or other information to or from the device. Such information may be transmitted from the device to a database of one or more patients. It is also possible to remotely monitor and modify the treatment program performed on the patient. If patient data is transmitted over an open network, the data may be encrypted for the purpose of patient confidentiality.

(Pressure treatment protocol) As shown in step 42 of the flowchart of FIG. 2, the device incorporates various pressurization treatment protocols that may be used to treat the patient's condition. For example, in one mode, the device provides a substantially constant pressure, which may be a therapeutic pressure, throughout the respiratory cycle, or changes to such a pressure set to treat the SDB. In another mode, the device supplies the mask with high pressure over the inspiratory portion of the respiratory cycle, the so-called IPAP (inspiratory positive airway pressure), and over the expiratory portion of the respiratory cycle, the so-called EPAP (expiratory positive airway pressure). Supply low pressure to the mask. Alternatively, the treatment supplied by the device can change smoothly with the patient's breathing to provide a smooth pressure waveform. For example, the device calculates a continuous phase variable to help synchronize with the patient's respiratory cycle and to calculate the pressure to be delivered according to the pressure waveform template. The supply of such pressure is disclosed in US Pat. No. 6,532,957. Alternatively, the pressure may be supplied in proportion to the patient's respiratory flow rate.

In yet other forms, the pressure support may be altered in synchronization with the patient's respiration to resist the increasing and decreasing changes in the patient's respiration that are characteristic of Cheyne-Stokes respiration. The methodology for such treatment is disclosed in US Pat. No. 6,532,959.

In some cases, the therapeutic pressure level of the above protocol may be preset by the physician, or may be adjusted automatically, as disclosed in US Pat. No. 5,704,345 (Berthon-Jones), or , Apnea (obstructive or central), hypoventilation, partial obstruction, snoring and other SDB-related events may be set by automatic detection. For example, the IPAP or EPAP level may be adjusted by automatic determination to find the minimum pressure required to prevent or reduce blockage. Other alternative methods of varying the therapeutic level of pressure for treatment of the patient and detecting SDB events may be utilized, and such methods are known in the art.

Accurate determination of respiratory flow is important when performing these procedures. Therefore, the determined flow rate of air to the patient may be adjusted to take into account the effects of leakage. To this end, even if the leaked air flow rate is determined using methods as taught in US Pat. No. 6,152,129 (Berthon-Jones), which is incorporated herein by reference in its entirety. Good. In addition, the leaked data may be recorded over time or stored in the device. Other known methods for determining leaks may be used by the device.

Other forms of pressure treatment are known to those of skill in the art and may be performed by the device.

(Monitoring information related to sleep apnea) Preferably, the device detects and records SDB events or relevant information or indices over time, eg, central apnea, obstructive apnea, hypoventilation, partial obstruction (eg, flow flattening), or Efficacy tracking is performed by tracking or detecting snoring. This is shown in step 44 of FIG. Similarly, pressure and / or flow vs. time data may be recorded for analysis. In doing so, the device preferably performs compliance tracking in which mask time-on and time-off are recorded with SDB-related events for statistical overview and statistical assessment. Methods for detecting and recording such information are known in the art and may be practiced as described in US Pat. No. 6,704,345.

For example, the device may record the AHI (Apnea Hypopnea Index) over time or over a specific period of time, eg, every session, every day, every hour. In one embodiment of the present invention, the AHI scoring system may be implemented as follows. (i) Apnea is recorded if the moving average ventilation for at least 10 consecutive seconds falls below 25% of the recent mean ventilation (time constant = 100s). (ii) If the 8-second moving average for 10 consecutive seconds falls below 50% of the recent mean ventilation but does not fall below 25%, respiratory depression is recorded.

Similarly, the device determines the index by comparing central apnea with obstructive apnea, as disclosed in US Pat. No. 6,832,609, which is incorporated herein by reference in its entirety. You may.

These events may be recorded with the time they occur or may be added to the total over a specific time period. Those skilled in the art can detect sleep apnea information such as hypopnea or apnea and recognize other methods or variants for determining AHI over time or within a period of time.

(Monitoring cardiovascular status) As mentioned above, and as shown in step 40 of FIG. 2, the device is configured to receive information related to cardiovascular information in the patient. Therefore, the device of the present invention preferably includes an input device for continuously or periodically receiving or recording such information based on the patient's condition, which is preferably shown in FIG. Such information may be associated with changes over time in sleep apnea-related information, as shown in step 46 of. Embodiments of the invention may include an automated measuring device capable of generating signals associated with automatically determined cardiovascular information for the processor of the device. Alternatively, the device may be used before and / or periodically, for example monthly, after 3 or 6 months, or after some other period that may be based on the use of the device (eg, the 30th night of use). After), it may be pre-programmed to prompt for such information or to inquire about such information on the display or from other remote devices, whereby such information is separate. It may be measured or determined by the user and may be entered by the user on a keyboard or other data entry device. For cardiovascular-related questions, queries may be pre-programmed into the device, allowing the patient to enter a more appropriate response depending on the prompting by the device.

In one embodiment, the apparatus of the present invention includes an automatic blood pressure monitoring device that continuously or periodically monitors or measures blood pressure and may record such information, for example, overnight summary-to-time. You may. Alternatively, the device may prompt for input of such information on the display and on the keypad without providing such an automatic device. Such information may then be illustrated on a comparable or similar timescale, either alone or in connection with the sleep apnea-related information or event of AHI et al., whereby relevant changes are observed. Or may be noticed.

In one embodiment, the device may continuously or periodically monitor and record heart rate and / or detailed echocardiographic data. Such information may be detected by filtering cardiogenic flow from respiratory flow signals as disclosed in US Pat. No. 5,704,345, or by other available heart rate detectors. You may. By recording such information alone or as sleep apnea information over time on a similar time scale, changes in heart rate can be observed, or changes in heart rate can be associated with changes in sleep apnea. It may be useful for tracking the patient's condition.

Similarly, various embodiments of the device may optionally include oxygen measurement data, blood glucose data, blood pressure data, electrocardiogram data, Holter analysis results (including, for example, arrhythmia, heart rate and / or fluctuation summary), body mass index. , Height / weight data, left ventricular ejection fraction (LVEF), 6-minute walking data, type B sodium diuretic peptide (BNP), cardiac output data, VO₂Max Data, New York Heart Association Class (NYHA), ACC / AHA Heart Failure Stage, Quality of Life Related Data (eg Epworth Drowsiness Scale, Berlin Questionnaire, Minnesota Heart Failure Life Questionnaire and / or Kansas City Cardiomyopathy Questionnaire) Further cardiovascular information including (including), peripheral arterial tone (PAT) and critical neurohormone levels (eg, catecholamine levels) may be measured, facilitated, and / or recorded / monitored.

Depending on the patient using the device, some or all of the cardiovascular information may be monitored by the device. In this case, the device may be configured to monitor all of this information, but the physician will select the device to select one or more features in a particular patient that will be monitored later during its use. It can be set in advance. In one embodiment, the device is pre-programmed with relevant sets or groups of data selected from cardiovascular information appropriate for a particular cardiovascular patient. By selecting a particular patient type, the device will monitor the appropriate cardiovascular information from the relevant set or group of monitored data without monitoring unnecessary cardiovascular information in the particular patient. Can be automatically configured. For example, hypertensive patients may be monitored for blood pressure, heart rate, body mass index, heart failure patients may be monitored for LVEF, heart rate, cardiac output data, and diabetics may be monitored for blood glucose. Etc. may be monitored. One of ordinary skill in the art can understand which cardiovascular information is preferably associated with different types of cardiovascular patients.

If such cardiovascular information collection is managed by a pressurization treatment device, eg, on a nightly or weekly basis, and it is relevant to a particular information collection, the physician or clinician will be referred to by step 48 in Figure 2. Substantial sources of information may be accessed on a regular basis for research or analysis, as indicated. Preferably, the cardiovascular and SDB information may be transmitted to the physician periodically and remotely, or may be accessed directly through a display on the device. In this way, the physician can respond to and observe the changing cardiovascular condition of the patient with minimal direct management or practice. In some cases, the device may trigger an alarm or send a message, or for a user, clinician or physician, either directly by the device or remotely, eg, via a secure electronic network to a database. To issue a warning, thresholds can be programmed for comparison with recorded cardiovascular information. For example, a warning or alarm may be issued if the recorded or detected heart rate is below an acceptable level. Similarly, the device may automatically issue warnings, alarms or messages when changes in body weight, arrhythmia, blood pressure, blood glucose, cardiac fluctuations, ECG data, etc. are recorded, as well as additional cardiovascular. Control of the device may be changed manually or automatically so that the information can be monitored, for example by changing the treatment protocol or changing the set of monitored cardiovascular information. For example, if changes in hypertension-related monitoring data indicate that the patient's cardiovascular condition is deteriorating, the device can monitor hypertension-related cardiovascular information from monitoring congestive heart failure-related cardiovascular information. You may switch to. Similarly, the device treatment protocol may switch from a standard biphasic protocol to a protocol that delivers servo-controlled pressure changes intended to reduce the increase and decrease changes associated with Cheyne-Stokes respiration. ..

Patient monitoring is an important aspect of the management of heart disease. In embodiments of the present invention, long-term use of a nasal CPAP device (almost every night for the rest of the patient's life) can be exploited to monitor the patient for many years. Therefore, it is hoped that early detection can improve patient outcomes.

Although the present invention has been described with various alternative embodiments and features, it goes without saying that these embodiments and features are merely exemplary of the principles of the invention. Other modifications can be made without departing from the ideas and scope of the invention, as will be appreciated by those skilled in the art. Cardiovascular-related treatments or diagnostic devices have been implemented to query or measure SDB-related information, for example, to detect SDBs or to determine the relationship between a patient's cardiovascular status and SDBs. You may. For example, a Holter ECG or cardiac event monitor may be configured or programmed to make SDB queries to a patient. Therefore, in one embodiment, the device may ask the user the following questions. 1. Do you snore? 2. Are you extremely tired all day long? 3. Do you feel short of breath and wake up during the night? 4. Have you ever talked about stopping breathing while you sleep? 5. Do you have a history of high blood pressure?

Clinicians or others to undertake sleep diagnostic studies to access the potential for SDB if, for example, two or more of these questions are answered yes in response to user input to the device. The device may record, transmit, or issue a warning to the user or physician to consider referrals to the physician. In more complex embodiments, a more detailed evaluation of SDB-related information may be performed by the device. For example, the following may be prompted. Gender: (male or female) Age group: 18-39 40-59 60-79 80+ Height: (feet, inches) Weight: (pounds) 1. Do you snore on a regular basis? 2. Do you get extremely drowsy during the day? 3. Do you feel short of breath and wake up during the night? 4. Have you ever been told that you are holding your breath while you sleep? 5. Do you wake up after waking up from an overnight sleep without being able to rejuvenate? 6. Do you have a history of high blood pressure? 7. Does the patient's BMI exceed 30?

The number of positive responses may be counted by the device to generate an SDB index, which may be reported to the patient with a warning or other message. Alternatively, the SDB index may be compared to one or more thresholds, and the degree of need to perform additional SDB studies may be included in the message or warning to the physician or user. For example, if the enumerated number is 1 or 0, the message reveals that it is unlikely that the patient has an SDB status or needs to continue sleep studies. If the number counted is higher, for example four or more, it is more serious or urgent, suggesting that there is a high or very high likelihood of SDB and the need for a sufficient SDB assessment. Warning message may be issued. Such data may be combined with other sleep apnea data recorded by the device, such as AHI, if the device is configured to record such data, and may also be combined with a physician or It may be included in a message or warning to the user.

Similarly, other cardiovascular related treatment or diagnostic devices such as blood pressure monitors, cardiac output monitors, oxygen measurement monitors, Holter electrocardiograms, other ECG or cardiac event monitors, automatic tape measures, automatic scale devices, treadmill devices, etc. Blood analysis device, cardiac output analysis device, VO₂Max data devices, peripheral arterial tone devices, etc. may be configured or programmed to evaluate the patient's SDB-related information.

Needless to say, clinicians interested in SDB and clinicians also interested in cardiovascular and other diseases are usually uncrosstalked and engaged in their respective other disciplines. Data collected during SDB treatment can be regressed over many years. This data may be excavated and used by clinicians interested in other diseases without even relating such data to events related to the patient's SDB. Even today, the data is not generally available. Our invention makes the data collected over a long period of time (at least several months) during the treatment of SDB available to clinicians treating one or more other diseases suffering from a patient. Is to do so. By accumulating such data, it is expected that even some of the costs associated with the treatment of SDB can be regained (clinicians study data related to hospitals, insurance companies, and patient illnesses. Including other institutions interested in doing).

(Business route) 3 and 4 show the business route according to the present invention. Such a route can be adopted by institutions caring for patients with SBD and CVD using the equipment shown in Figure 1. The route identifies the steps to be taken and the appropriate reinverse code. The route can be programmed into a portable computer such as the PALM PILOT portable computer, which allows the physician to quickly reference the appropriate code and to a highly skilled physician (eg, a cardiologist). You can entrust the task to the staff.

For example, in FIG. 3, in the first step, as described above, an inquiry programmed into the portable computer is made to the heart patient. Positive results from the inquiry, for example, Holter and Riinba prompt the device to propose the attendant-free sleep studies using over performs instruction code 95806,93230. After the sleep study, the results are input to the computer. High AHI from sleep studies indicates the possible presence of obstructive sleep apnea (OSA) or central sleep apnea (CSA). Patients with OSA may be treated with an automatic airway positive pressure (APAP) device such as ResMed's AUTOSET SPIRIT. Alternatively, patients with CSA may be treated with ResMed's VPAP III ST / A device or with adaptive servo ventilation as provided by ResMed's AutoSet CS2 device.

In one branch of the flow chart, the decision process involves OSA screening or oxygen measurement with a device such as ResMed's APNEA LINK.

Although the present invention has been described for several forms, it goes without saying that these forms are merely exemplary of the present invention. Other modifications can be made without departing from the ideas and scope of the invention, as will be appreciated by those skilled in the art.

2 ... blower, 6 ... mask, 8 ... air supply line, 15 ... controller or microprocessor, 20 ... pulse oximeter, 22 ... respiratory movement sensor.