A) TECHNICAL FIELD
[0001] The present invention generally relates to patent monitoring system (PMS) and particularly relates to alarm indication systems. The present invention more particularly relates to visual indication systems for the patient alarms and the auto frozen cascade waveform in PMS,
B) BACKGROUND OF THE INVENTION
[0002] The medical electronics has offered many types of electromechanical medical equipments to the mankind to monitor the health and the physical fitness of a patient or a normal healthy person. These medical equipments measure the electrocardiography. Electroencephalography, heart rate, cardiac output, blood pressure, percentage of oxygenated blood, respiration rate and the amount of carbon dioxide in the inhaled and the exhaled air etc. These types of electro-medical monitors are known as "vital sign parameter bed side monitor" or "Patient Monitoring System (PMS)".
[0003] The PMS acquires the measured physiological parameter of the patient through the several monitors attached to the patient and displays the measured parameter on a screen in a waveform format or numerically. A patient monitor acquires and processes the physiological data from the patient through the monitors. The processed result is displayed on the screen. The PMS gives audio and visual alarms, when the measured physiological parameter is above an upper threshold value or below a lower threshold value. In addition to the output of the alarms, the waveform display of the particular parameter for which the alarm is generated is automatically freezed.

[0004] The PMS acquires the ECG from the patient and displays on the screen in a waveform format. The ECG cascade waveform is provided in most of the patient monitors to display delayed waveform of the real-time and to freeze the waveform automatically during the generation of alarms or when the user invokes the freeze option.
[0005] When an ECG related alarm is generated, the cascade waveform is freezed automatically to display the waveform during that particular alarm condition. The freezed waveform is useful for the doctor in diagnosis. This will not unfreeze until the acknowledgement (ACK) key or UNFREEZE key is pressed by the user. Even if the alarm disappears, the cascade waveform will not be unfreezed.
[0006] There are some cases in which the freezed waveform may be misleading and may result in wrong diagnosis. For example in one case, the cascade waveform is freezed automatically and an alarm display is given, when an alarm has occurred. Eater on. the alarm display indicating the cause of the alarm is disappeared after the recovery of the alarm but the cascade waveform is continue to be displayed in freeze mode. In another condition, when two alarms are generated before the acknowledgement of the first alarm, the cascade waveform is freezed automatically due to the first alarm, while the cause of the second alarm is displayed in the alarm display window thereby misleading the doctor to false diagnosis.
[0007] The currently available PMS does not have a facility to indicate the cause of the freezed waveform display when several alarms have occurred or the alarm condition is

disappeared after some time. Hence there is a need to provide a system to display the cause for the alarm along with the freezed cascade waveform to enable the doctor to diagnose an alarm condition or critical condition of a patient efficiently.
C) OBJECTS OF THE INVENTION
[0008] The primary object of the present invention is to develop a system to provide a visual indication for the cause of an alarm which resulted in the freezing of displayed cascade waveform along with the display of the cascade wave form in freeze condition.
[0009] Yet another object of the present invention is to develop a system to provide a visual indication for the cause of an alarm which resulted in the freezing of displayed cascade waveform provide visual indication to avoid mismatch arising between frozen waveform and displayed alarm at any given time in a patient monitoring system.
[0010] These and other objects and advantages of the present invention will become readily apparent from the following detailed description taken in conjunction with the accompanying drawings.
D) SUMMARY OF THE INVENTION
[0011] The various embodiments of the present invention provide visual indication system and method for the PMS to display the cause of the alarm for which the cascade wave form is auto freezed along with the display of the freezed waveform. According to one embodiment of the invention, the controller is activated to display the cause of the

alarm in text format below the displayed cascade waveform in freezed condition, when the cascade wave form is freezed automatically due to the generation of an alarm. The controller is provided with an algorithm to process the signal received from the patient to detect an alarm condition. When an alarm condition is detected, the controller activates a display driver to freeze the displayed cascade waveform on the screen and to displav a text indicating the cause of the alarm below the displayed cascade wave form in the freeze condition.
[0012] According to another embodiment of the present invention, the ECG signal received from a patient is analyzed to detect an alarm condition. When an alarm condition is detected, the speaker and the LED alarm indicator are switched off and the cascade waveform displayed on the screen is freezed automatically. Then a text message indicating the cause of the alarm condition and the cascade freeze condition is displayed below the displayed cascade waveform in freeze condition. Afterwards the speaker and the LED alarm indicator are switched on to display the alarm condition.
[0013] Thus the visual indication system provides a text message for each patient related alarm which resulted in auto-freezing of the displayed cascade waveform thereby avoiding the mismatch between the cascade waveform in auto freeze condition and the recent alarm condition.

E) BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The other objects, features and advantages will occur to those skilled in the art from the following description of the preferred embodiment and the accompanying drawings in which:
[0015] FIG. 1 shows the block diagram of a patient monitoring system provided with a visual indication system for the alarm according to the present invention.
[0016] FIG.2 shows a flow chart illustrating the operation of a visual alarm indication system for alarms in a patient monitoring system according to present invention.
[0017] FIG.3 shows a patient monitor with an arrow and text message displayed below the frozen waveform according to present invention.
[0018] Although specific features of the present invention are shown in some drawings and not in others. This is done for convenience only as each feature may be combined with any or all of the other features in accordance with the present invention.
F) DETAILED DESCRIPTION OF THE INVENTION
[0019] In the following detailed description, reference is made to the accompanying drawings that form a part hereof, and in which the specific embodiments that may be practiced is shown by way of illustration. These embodiments are described in sufficient detail to enable those skilled in the art to practice the embodiments and it is to be

understood that the logical, mechanical and other changes may be made without departing from the scope of the embodiments. The following detailed description is therefore not to be taken in a limiting sense.
[0020] The various embodiments of the present invention provide visual indication system and method for the PMS to display the cause of the alarm for which the cascade wave form is auto freezed along with the display of the freezed waveform. According to one embodiment of the invention, the controller is activated to display the cause of the alarm in text format below the displayed cascade waveform in freezed condition, when the cascade wave form is freezed automatically due to the generation of an alarm, fhe controller is provided with an algorithm to process the signal received from the patient to detect an alarm condition. When an alarm condition is detected, the controller activates a display driver to freeze the displayed cascade waveform on the screen and to display a text indicating the cause of the alarm below the displayed cascade wave form in the freeze condition.
[0021] According to another embodiment of the present invention, the ECG signal received from a patient is analyzed to detect an alarm condition. When an alarm condition is detected, the speaker and the LED alarm indicator are switched off and the cascade waveform displayed on the screen is freezed automatically. Then a text message indicating the cause of the alarm condition and the cascade freeze condition is displayed below the displayed cascade waveform in freeze condition. Afterwards the speaker and the LED alarm indicator are switched on to display the alarm condition.

[0022] Thus the visual indication system provides a text message for each patient related alarm which resulted in auto-freezing of the displayed cascade waveform thereby-avoiding the mismatch between the cascade waveform in auto freeze condition and the recent alarm condition.
[0023] FIG.l shows the block diagram of a patient monitoring system provided with a visual indication system for alarms and for cascade waveform displayed in freezed condition according to one embodiment of the present invention. With respect to FIG.l, the filter block 1 i removes any undesired noise signals in the RCG signals received from the patient to improve the signal to noise ratio. The output of the signal from the filter block 11 is passed into an analog to digital converter 12 to convert the received filter output signal into digital signal. The digital output signal is fed to a controller 13. The controller 13 processes the input digital signal using an algorithm to detect an alarm condition. After detecting an alarm condition, the controller 13 switches off the speaker 16 and the LED indicator 15. The controller 13 further activates a display driver to freeze the displayed cascade waveform and to display a text message below the freezed cascade waveform to indicate the cause for the alarm generated on a TFT display device 14. Then the speaker 13 and the LED indicator 15 are activated to output the alarm condition to the user. The Alarms are indicated to the user by the audio tones output through the speaker 16. The alarm is indicated to the user visually through the blinking/flashing of LED 15. Further a text message is displayed below the cascade waveform in freezed condition to indicate the cause of the alarm and the cascade waveform displayed in freeze condition to enable the doctor to diagnose the patient

condition easily and efficiently. A key board 17 is provided to enable the user to set the alarm conditions in the controller 13.
[0024] When there is any ECG related alarm, the cascade waveform is freezed automatically to display the waveform during the alarm generated period to enable the doctor to study the waveform to identify the cause for the alarm condition to diagnose a patient condition. The freezed cascade waveform is unfreezed only when the user presses the ACK key or the UNFREEZE key. This is for the doctor to under stand the alarms conditions generated during his absence. In the mean time when a new alarm is generated and the freezed cascade wave form is not un-freezed. the cause for the new alarm is displayed on a window used for normally displaying alarm condition in the monitor, while the cause for the old alarm is displayed below the displayed waveform thereby avoiding the mismatch between frozen waveform and displayed alarm. Thus the present invention displays text message to indicate the cause of the corresponding alarm which resulted in auto-freeze condition to help the doctor in diagnosing the critical conditions of a patient easily and efficiently.
[0025] FIG.2 shows a flow chart illustrating the operation of a visual alarm indication system for alarms in a patient monitoring system according to present invention. With respect to FIG.2, the ECG signal is received from an ECG attached to a patient (21). The received ECG signal from the patient is analyzed to detect an alarm condition (22). When an alarm condition is detected, the speaker and the LED alarm indicator are switched off (23) and the cascade waveform displayed on the screen is freezed automatically (24). Then a text message indicating the cause of the alarm condition and the cascade freeze

condition is displayed below the displayed cascade waveform in freeze condition (25). Afterwards the speaker and the LED alarm indicator are switched on to display the alarm condition (26).
[0026] FIG.3 shows the front view of the display screen in the patient monitor provided with a visual indication for showing the cause of the alarm generated and the freezed cascade waveform. The cascade waveform 31 is displayed in a freeze condition when an alarm is generated. A text message 32 is displayed below the frozen waveform to indicate the cause of the alarm. When a new alarm is generated and the old alarm is not acknowledged, the alarm condition for the old alarm is indicated by the text 32 displayed below the freezed cascade wave form while the cause for the new alarm is displayed in the alarm indication window 33 provided in the monitor thereby preventing the mismatch between the displayed cascade waveform and the alarm condition shown in the alarm display window to help the doctor to diagnose the condition of the patient easily, efficiently and effectively. As shown in FIG.3, a TACHY message with an arrow towards its left side 32 is displayed to show the cause of the cascade waveform in auto-freeze condition. The arrow indicates whether it a high alarm or low alarm.
G) ADVANTAGES OF THE INVENTION
[0027] The various embodiments of the present invention provide a patient monitor with visual indication for the cause of the alarm generated and the cascade waveform displayed in freezed condition. It provides a text message below the displayed cascade waveform to enable the doctor to understand the alarm condition to improve the

diagnostic efficiency. Thus the visual indication system provides a text message for each patient related alarm which resulted in auto-freezing of the displayed cascade waveform thereby avoiding the mismatch between the cascade waveform in auto freeze condition and the recent alarm condition.
[0028] Although the invention is described with various specific embodiments, h will be obvious for a person skilled in the art to practice the invention with modifications. However, all such modifications are deemed to be within the scope of the claims.
[0029] It is also to be understood that the following claims are intended to cover all of the generic and specific features of the present invention described herein and all the statements of the scope of the invention which as a matter of language might be said to fall there between.

CLAIMS
What is claimed is:
1. A visual indication system for alarm in patent monitoring system connected to an
electrocardiogram (ECG) which is attached to a patient, the system comprising:
a controller connected to ECG monitor to receive ECG data and to process the received ECG data to detect an alarm condition to display a cascade waveform data in a frozen condition and to display the cause for alarm condition below the displayed cascade waveform data.
2. The system according to a claim 1, wherein the controller executes an algorithm
to display the cause for the alarm generated and the cascade waveform displayed
in the freezed condition.
3. The system according to claim 1. the controller displays a text message beiow the
displayed cascade waveform data in freezed condition to indicate the cause of the
alarm.
4. The system according to claim 1, wherein the controller displays the text message until the displayed wave form is defreezed.
5. The system according to claim 1, wherein the controller displays the text message until the alarm is acknowledged.