Title of Invention

TRANSDUCER DETECTION METHOD AND SYSTEM FOR IBP MONITOR

Abstract

The various embodiments of the present invention provide a system and method for detecting the presence of transducers in an IBP monitor. The system has a current sensing circuit to measure the excitation voltage drawn by the transducers upon connection. A comparator collates the measured value with a reference voltage level to detect the presence of a transducer. A microcontroller receives the detection signal from the comparator to output a message to the user to indicate the detection result.

Full Text

A) TECHNICAL FIELD [0001] The present invention generally relates to a patient monitoring system such as Invasive Blood pressure monitor and more particularly relates to a sensor device for the IBP monitor to detect the disconnection of transducer with the IBP monitor. B) BACKGROUND OF THE INVENTION [0002] The Blood Pressure (strictly speaking: vascular pressure) refers to the force exerted by circulating blood on the walls of blood vessels and constitutes one of the principal vital signs. The pressure of the circulating blood decreases as the blood moves through Arteries, arterioles, capillaries and veins. The term blood pressure generally refers to arterial pressure, i.e., the pressure in the larger arteries, arteries being the blood vessels which:take blood away from the heart. The Arterial pressure is most commonly measured via a sphygmomanometer, which uses the height of a column of mercury to reflect the circulating pressure. Although many modem vascular pressure devices no longer use mercury, vascular pressure values are still universally reported in millimeters of mercury (mmHg). [0003] The systolic arterial pressure is defined as the peak pressure in the arteries, which occurs near the beginning of the cardiac cycle. The diastolic arterial pressure is the lowest pressure (at the resting phase of the cardiac cycle). The average pressure throughout the cardiac cycle is reported as mean arterial pressure. The pulse pressure reflects the difference between the maximum and minimum pressures measured. The Arterial pressures can be measured invasively by penetrating the skin and measuring ^ inside the blood vessels) or non-invasively. [0004] The non-invasive auscultatory and oscillometric measurements are simpler and quicker than invasive measurements. They require less expertise in fitting, have virtually no complications arid are less unpleasant and painful for the patient. However, non-invasive measures may yield somewhat lower accuracy and small systematic differences in numerical results. Non-invasive measurement methods are more commonly used for routine examinations and monitoring. [0005] The auscultatory method uses a stethoscope and a sphygmomanometer. This comprises an inflatable cuff placed around the upper arm at roughly the same vertical height as the heart, attached to a mercury or aneroid manometer. The mercury ■I i! manometer, considered to be the goldstandard measurement technique for arterial ii pressure measurement, measures the height of a column of mercury, giving an absolute result without need for calibration, and consequently not subject to the errors and drift of calibration whichfaffect other methods. The use of mercury manometers is often required in clinical trials and for the clinical measurement of hypertension in i high risk patients, including firegnant women. [0006] A cuif of appropriate size is fitted and inflated manually by repeatedly squeezing a rubber bulb until the artery is completely occluded. Listening with the stethoscope to the brachial'artery at the elbow, the examiner slowly releases the pressure in the cuff When blood just starts to flow in the artery, the turbulent flow creates a "whooshing" or pounding (first Korotkoff sound). The pressure at which this .1 I '^ sound is first heard is the systolic blood pressure. The cuff pressure is further released i until no sound can be heard (fifth Korotkoff sound), at the diastolic arterial pressure. ' Sometimes, the pressure is palpated (felt by hand) to get an estimate before auscultation. [0007] The Oscillometric methods are sometimes used in the long-term measurement and sometimes in general practice. The equipment is functionally similar to that of the il auscultatory method, but with an electronic pressure sensor (transducer) fitted in to detect the blood pressure, instead of using the stethoscope and the expert's ear. In practice, the pressure sensor is a calibrated electronic device with a numerical readout of blood pressure. To maintain accuracy, calibration must be checked periodically, unlike the inherently accurate mercury manometer. In most cases the cuff is inflated and released by an electrically operated pump and valve, which may be fitted on the I! wnst (elevated to heart height), although the upper arm is preferred. They vary widely i in accuracy, and should be checked at specified intervals and if necessary recalibrated. [0008] The Oscillometric measurement requires less skill than the auscultatory technique, and may be suitable for use by untrained staff and for automated patient home monitoring. The Oscillometric monitors may produce inaccurate readings in patients with heart and circulation problems that include arterial sclerosis, arrhythmia, preeclampsia, pulsus altemans, and pulsus paradoxus. The term NIBP, for Non-Invasive Blood Pressure, is often used to describe oscillometric monitoring equipment. [0009] The Arterial blood pressure (BP) is most accurately measured invasively through an arterial line. The Invasive arterial pressure measurement with intravascular cannulae involves direct measurement of arterial pressure by placing a cannula needle ■I ij in an artery (usually radial, femoral, dorsalis pedis or brachial. This is usually done by { an anesthesiologist or surgeon in a hospital. I .; [0010] The cannula must be connected to a sterile, fluid-filled system, which is i . connected to an electronic pressure transducer. The advantage of this system is that i pressure is constantly monitored beat-by-beat, and a waveform (a graph of pressure f against time) can be displayed. This invasive technique is regularly employed in human and veterinary intensive care medicine, anesthiology and for research purposes. ■ t [0011] The Cannulation for invasive vascular pressure monitoring is infrequently associated with complications such as thrombosis, infection and bleeding. The Patients with invasive arterial monitoring require very close supervision, as there is a danger of severe bleeding. When the line becomes disconnected. It is generally reserved for patients where rapid variations in arterial pressure are anticipated. j: [0012] The Invasive vascular pressure monitors are pressure monitoring systems II II ' designed to acquire pressure information for display and processing. There are a 1! j variety of invasive vascular pressure monitors for trauma, critical care, and operating room applications. These include single pressure, dual pressure, and multi-parameter !; (i.e. pressure / temperature), the monitors can be used for measurement and foUow- !i up of arterial, central venous, pulmonary arterial, left atrial, right atrial, femoral ■I I arterial, umbilical venous, umbilical arterial, and intracranial pressures. [0013] The Vascular pressure p^ameters are derived in the monitor's microcomputer system. Usually, the systolic, diastolic and mean pressures are displayed I simultaneously for pulsatile waveforms (i.e. arterial and pulmonary arterial). Some monitors also calculate and display the CPP (cerebral perfusion pressure) and CVP (Central Venious Pressure). Normally, a zero key on the front of the monitor makes pressure zeroing extremely fast and easy. The Alarm limits may be set to assist the medical professional responsible for observing the patient. The High and low alarms may be set on displayed temperature parameters. [0014] The Blood pressure is one of the most important vital signs used in the I assessment of a patient's cardibvascular health. In critical care, it is usually monitored continuously using an invasive fluid-filled monitoring line, also called an arterial line, in which a catheter is inserted into an artery and blood pressure from the artery is {j i| transmitted to a blood pressure transducer through fluid-filled tubing 12 to 84 inches long. The arterial pressure as measured by the transducer is displayed on an invasive blood pressure (IBP) monitor, i; [0015] The currently available sensor detection systems detect an abnormal condition or disconnection of cable connecting the transducer to the monitor. At present the detection systems sense only the presence of cables or the cable disconnection to assume the disconnection of sensor or the transducer with the PMS. Such detection arrangements generated only the confusion in detecting the presence of transducers. [0016] Hence there is a need to develop a sensor detection system to detect the disconnection of the transducer with the patient monitoring system such as IBP monitor. Also there is a further need to develop a sensor system to detect a channel fault condition. Also there is yet another need to develop a sensor system to detect a sensor -off condition, when a pressure sensor is connected to the patient monitoring system. C) OBJECT OF THE INVENTION [0017] The primary object of the present invention is to develop a transducer detection system to detect the disconnection or the absence of transducer that is connected to an IBP monitor. [0018] Another object of the present invention is to develop a transducer detection system to detect the absence of transducer by measuring the excitation voltage applied to the transducer. [0019] Yet another object of the present invention is to develop a transducer detection 'I system to sense a channel fault condition by measuring the applied excitation voltage. [0020] Yet another object of the present invention is to develop a transducer detection system to identify a sensor -off condition, when a pressure sensor is connected to the system. i [0021] These and other objects and advantages of the present invention will become i readily apparent from the following detailed description taken in conjunction with the accompanying drawings. D) SUMMARY OF THE INVENTION [0022] The abovementioned shortcomings, disadvantages and problems are addressed herein and which will be Understood by reading and studying the following I specification. [0023] The various embodiments of the present invention provide a system and method to detect the disconnection of the transducer from the monitor or the absence I of a transducer that detect the invasive blood pressure values. [0024] According to one embodiment of the present invention, a transducer detection system is provided to sense the disconnection of a transducer. An excitation voltage is applied to the system. A current sensing circuit is provided to measure the current supplied to the transducer circuit. A comparator compares the output of the current sensing circuit with a reference voltage is compared with a reference voltage to detect the disconnection of a transducer or the absence of a transducer or a channel fault. A microcontroller receives the detection signal output from the comparator and displays a message to indicate the detection result to a user. The detection result is displayed on the monitor to indicate the detection result to the user. :i i [0025] According to another embodiment of the present invention, a transducer detection method is provided to sense the absence/presence of a transducer or the disconnection of a transducer or a channel fault in an IBP monitor. According to the if transducer detection method, an excitation voltage is generated and applied to the transducer circuit. A current. sensing circuit measures the current drawn by the i: ,1 transducer circuit. The detected current value is converted into a voltage and is input into a comparator. The input detection voltage is compared with a reference voltage to detect the disconnection of a transducer or the absence/presence of a transducer or a channel fault condition. The detection signal is output from the comparator to a microcontroller. The microcontroller receives the detection signal to output a detection message. The detection message is displayed on a monitor to indicate the detection result to a user. [0026] Thus the various embodiments of the present invention provide a system and a method to detect the disconnection of a transducer from an IBP monitor or the presence/absence of a transducer or a channel fault by measuring the excitation current drawn by the transducer circuit. [0027] These and other objects and advantages of the present invention will become ■f readily apparent from the following detailed description taken in conjunction with the accompanying drawings. E) BRIEF DESCRIPTION lOF THE DRAWINGS [0028] 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: [0029] FIGURE. 1 illustrates a functional block diagram of a transducer detection system for IBP monitor according to one embodiment of the present invention. [0030] FIGURE. 2 illustrates a block circuit diagram of a transducer detection system for IBP monitor according to one embodiment of the present invention. [0031] FIGURE. 3 illustrates a flow chart explaining the operation of a transducer detection system for IBP monitor according to one embodiment of the present invention. I [0032] 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 allf of the other features in accordance with the present invention. F) DETAILED DESCRII^TION OF THE INVENTION [0033] 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. [0034] The various embodiments of the present invention provide a system and method to detect the disconnection of the transducer from the monitor or the absence of a transducer that detect the invasive blood pressure values, [0035] According to one embodiment of the present invention, a transducer detection system is provided to sense the disconnection of a transducer. An excitation voltage is applied to the system. A current sensing circuit is provided to measure the current supplied to the transducer circuit. A comparator compares the output of the current sensing circuit with a reference voltage to detect the disconnection of a transducer or the absence of a transducer or a channel fault. A microcontroller receives the detection signal output from the comparator and outputs a message to indicate the detection result to a user. The detection result is displayed on the monitor to indicate the detection result to the user. ■i [0036] According to another embodiment of the present invention, a transducer detection method is provided to sense the absence of a transducer or the disconnection of a transducer or a channel fault in an IBP monitor. According to the transducer If detection method, an excitation voltage is generated and applied to the transducer circuit. A current sensing circuit measures the current drawn by the transducer circuit. The detected current value is converted into a voltage and is input into a comparator. The input detection voltage is compared with a reference voltage to detect the disconnection of a transducer or the absence of a transducer or a channel fault condition. The detection signal is output from the comparator to a microcontroller. The microcontroller receives the detection signal to output a detection message. The detection message is displayed on a monitor to indicate the detection result to a user. the transducer, when the transducer is connected to the IBP monitor. When the transducer is not connected to the IBP monitor, the current drawn from the excitation voltage source is zero. As soon as the transducer is connected, a small current is drawn by the transducer and is picked up by the current sensing and measurement circuit. The sensed current is converted into a voltage and is compared with a reference voltage which is slightly less then the voltage observed at the output of I current to voltage converter vvhile transducer is connected. The comparator gives a logical high signal as soon as the presence of the transducer is detected. The logical high signal is sensed through a microcontroller and indicated to the User through a message on the display. T [0040] According to another embodiment of the present invention, a transducer detection method is provided to sense the absence of a transducer or the disconnection of a transducer or a channel ifault in an IBP monitor. According to the transducer detection method, an excitation voltage is supplied from a current limited voltage source in an excitation voltage generator circuit. The excitation voltage is applied to the transducer circuit through a current sensing circuit. The detected current is converted into a voltage by a current- voltage converter circuit. The converted voltage is input into a comparator. A reference voltage is produced in a reference voltage generator and supplied to the comparator. The input voltage corresponding to the detected excitation current is compared with the input reference voltage to output a detection signal. The detection signal is supplied to a microcontroller. The microcontroller outputs a message to the user to indicate the presence/ absence of a transducer based on the received detection signal from the comparator. The message ■i is displayed on the monitor. [0041] The current sensing and measurement circuit calculates the current drawn by the transducer, when the transducer is connected to the IBP monitor. When the transducer is not connected to the IBP monitor, the current drawn from the excitation voltage source is zero. As soon as the transducer is connected, a small current is dravm by the transducer and is picked up by the current sensing and measurement circuit. The sensed current is converted into a voltage and is compared with a reference voltage which is slightly less then the voltage observed at the output of current to voltage converter while transducer is connected. The comparator gives a logical high signal as soon as the presence of the transducer is detected. The logical high signal is sensed through a microcontroller and indicated to the User through a message on the display. [0042] Thus the various embodiments of the present invention provide a system and a method to detect the disconnection of a transducer from an IBP monitor or the absence of a transducer or a channel fault by measuring the excitation current drawn by the transducer circuit. [0043] The FIG. 1 illustrates a functional block diagram of a transducer detection system for IBP monitor according to one embodiment of the present invention. According to one embodiment of the present invention, a transducer detection system is provided to sense the disconnection of a transducer. The system has an excitation current generator circuit and a transducer detection circuit including an excitation current sensing and measurement circuit, a comparator and a microcontroller. The excitation current generator circuit has a current limited voltage source to produce an excitation voltage. The generated excitation voltage is passed to a transducer through a current sensing and measurement circuit. The excitation voltage is applied to the transducer to measure the arterial pressure and to measure the BP value. [0044] The current sensing and measurement circuit measures the excitation current supplied to the transducer circuit by measuring the current drawn by the transducer. The measured current is converted into a voltage using a current-voltage converter. The converted voltage is input into comparator. A reference voltage generator is connected to the comparator to supply a reference voltage to the comparator. The sensing circuit with the input reference voltage to detect the disconnection of a I transducer or the absence of a transducer or a channel fault. A microcontroller receives the detection signal output from the comparator and outputs a message to indicate the detection result to! a user. The detection result is displayed on the monitor [j to indicate the detection result to the user. [0045] A cable detection voltage circuit is provided to detect the disconnection of the cable. The current sensing and measurement circuit calculates the current drawn by the transducer, when the transducer is connected to the IBP monitor. When the transducer is not connected to the IBP monitor, the current drawn from the excitation voltage source is zero. As soon as the transducer is connected, a small current is drawn by the transducer and is picked up by the current sensing and measurement circuit. The sensed current is converted into a voltage and is compared with a reference voltage which is slightly less then the voltage observed at the output of current to voltage converter while transducer is connected. The comparator gives a logical high signal as soon as the presence of the transducer is detected. The logical high signal is sensed through a microcontroller and indicated to the User through a message on the display. [0046] The FIG. 2 illustrates a block circuit diagram of a transducer detection system for IBP monitor according to one embodiment of the present invention. According to one embodiment of the present invention, a transducer detection system is provided to sense the disconnection of a transducer. The system has an excitation current generator circuit and a transducer detection circuit including an excitation current sensing and measurement circuit, a comparator and a microcontroller. The excitation current generator circuit has a current limited voltage source to produce an excitation voltage. The generated excitation voltage is passed to a transducer through a current sensing and measurement circuit. The excitation voltage is applied to the transducer to measure the arterial pressure and to measure the BP value. [0047] The current sensing and measurement circuit measures the excitation current supplied to the transducer circuit by measuring the current drawn' by the transducer. The measured current is converted into a voltage using a current-voltage converter. The converted voltage is input into comparator. A reference voltage generator is connected to the comparator to supply a reference voltage to the comparator. The comparator compares the input voltage corresponding to the output of the current sensing circuit with the input reference voltage to detect the disconnection of a transducer or the absence of a transducer or a channel fault. A microcontroller receives the detection signal output from the comparator and outputs a message to indicate the detection result to a user. The detection resuh is displayed on the monitor to indicate the detection result to the user. I [0048] A cable detection voltage circuit is provided to detect the disconnection of the cable. The current sensing and measurement circuit calculates the current drawn by the transducer, when the transducer is connected to the IBP monitor. When the transducer is not cormected to the IBP monitor, the current drawn from the excitation voltage source is zero. As soon as the transducer is connected, a small current is drawn by the transducer and is picked up by the current sensing and measurement circuit. The sensed current i^ converted into a voltage and is compared with a reference voltage which is slightly less then the voltage observed at the output of current to voltage converter while transducer is connected. The comparator gives a logical high signal as soon as the presence of the transducer is detected. The logical high signal is sensed through ^ a microcontroller and indicated to the User through a message on the display. [0049] The FIG. 3 illustrates a flow chart explaining the operation of a transducer detection system for IBP monitor according to one embodiment of the present invention. According to another embodiment of the present invention, a transducer detection method is provided to sense the absence of a transducer or the disconnection li [j of a transducer or a channel fault in an IBP monitor. According to the transducer detection method, an excitation voltage is supplied from a current limited voltage source in an excitation voltage generator circuit (302). The excitation voltage is applied to the transducer circuit through a current sensing circuit. The excitation current drawn by the transducer circuit is detected and measured by the excitation current sensing and measurement circuit (304). The detected current is converted into a voltage by a current- voltage converter circuit. The converted voltage is input into a comparator. A reference voltage is produced in a reference voltage generator and supplied to the comparator. The input voltage corresponding to the detected excitation current is compared with the input reference voltage to output a detection signal (306). The detection signal is supplied to a microcontroller. The microcontroller outputs a message to the user to indicate the presence/ absence of a transducer based on the received detection signal from the comparator. The message is displayed on the monitor (308). [0050] The current sensing and measurement circuit calculates the current drawn by ii the transducer, when the transducer is connected to the IBP monitor. AVhen the transducer is not connected tojthe IBP monoitor, the current drawn from the excitation voltage source is zero. As soon as the transducer is connected, a small current is drawn by the transducer and;is picked up by the current sensing and measurement circuit. The sensed current is converted into a voltage and is compared with a reference voltage which is slightly less then the voltage observed at the output of current to voltage converter while transducer is connected. The comparator gives a logical high signal as soon as the presence of the transducer is detected. The logical high signal is sensed through a microcontroller and indicated to the User through a message on the display. [0051] Thus the various embodiments of the present invention provide a system and a method to detect the disconnection of a transducer from an IBP monitor or the absence of a transducer or a channel fault by measuring the excitation current drawn by the transducer circuit. G) ADVANTAGES OF THE INVENTION [0052] Thus the various embodiments of the present invention provide a system and method to detect the disconnection of the transducer from the monitor or the absence/presence of a transducer that detect the invasive blood pressure values. A transducer detection system is provided to sense the disconnection or the absence of a transducer that is connected to an IBP monitor. The system detects the absence/ presence of a transducer in the IBP monitor by measuring the excitation voltage applied to the system. The detection system senses a channel fault condition by measuring the applied excitation voltage. The transducer detection system identifies a sensor -off condition, when a pressure sensor is connected to the system. [0053] Although the invention is described with various specific embodiments, it 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. [0054] 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. [0037] According to one embodiment of the present invention, a transducer detection system is provided to sense the disconnection of a transducer. The system has an excitation current generator circuit and a transducer detection circuit including an excitation current sensing and measurement circuit, a comparator and a microcontroller. The excitation current generator circuit has a current limited voltage source to produce an excitation voltage. The generated excitation voltage is passed to a transducer through a current sensing and measurement circuit. The excitation voltage is applied to the transducer to measure the arterial pressure and to measure the BP value. [0038] The current sensing and measurement circuit measures the excitation current supplied to the transducer circuit by measuring the current drawn by the transducer. r The measured current is converted into a voltage using a current-voltage converter. The converted voltage is input into comparator. A reference voltage generator is connected to the comparator I to supply a reference voltage to the comparator. The comparator compares the input voltage corresponding to the output of the current sensing circuit with the input reference voltage to detect the disconnection of a transducer or the absence of a transducer or a channel fault. A microcontroller receives the detection signal output from the comparator and outputs a message to indicate the detection result to a user. The detection result is displayed on the monitor to indicate the detection result to the user. [0039] A cable detection voltage circuit is provided to detect the disconnection of the cable. The current sensing and measurement circuit calculates the current drawn by CLAIMS WHAT IS CLAIMED IS: 1. A transducer detection system for IBP monitor, the system comprising: A current limiting voltage source to supply an excitation voltage to a transducer; A current sensing and measurement circuit to detect and measure the current value drawn by the transducer, when the transducer is connected; ,1 A current voltage converter transforms the measured current level from the current sensing circuit into a voltage level; I A comparator to receive and compare the measured current value for with a .L reference value to generate a comparison result; and A microcontroller to receive the output of the comparator to send a detection signal to a user. 2. The system according to claim 1, wherein the micro controller forwards a detection signal to the user to display a message to the user to indicate the presence of the transducer. 3. The system according to claim 1, wherein the microcontroller forwards a detection signal to the user to display a message to the user to indicate the absence of the transducer. 4. The system according to claim 1, wherein the microcontroller forwards a detection signal to the user to display a message to the user to indicate the disconnection of the transducer. .! I i 5. The system according to claim 1, wherein the microcontroller forwards a detection signal to the user to display a message to the user to indicate a channel fault. 6. The system according to claim 1, wherein the microcontroller forwards a detection signal to the user to display a message to the user to indicate a channel fault. 7. The system according to claim 1, wherein the comparator outputs a logic high signal to indicate the presence of the transducer, when the input voltage at the comparator corresponding to the measured current level drawn by the transducer is more than the reference voltage. 8. The system according to claim 1, further comprising a reference voltage generator to produce a reference voltage' which is input into the comparator for comparison. | 9. The system according to claim 8, the reference voltage generator produces and inputs a reference voltage which is less than the actual excitation voltage supplied to the transducer, when the transducer is connected. 10. The system according to claim 1, wherein the current sensing and measurement circuit measures a zero current, when the transducer is not connected. 11. The system according to claim 1, wherein the microcontroller outputs a message to indicate the absence of the transducer, based on the detection signal output from the comparator, when the current sensing and measuring circuit measures a zero current. 12. The system according to claim 1, further comprising a cable detection circuit to sense the disconnection of the cable connecting the transducer to an IBP monitor. 13. A transducer detection method for IBP monitor, the method comprising: Supplying an excitation voltage to a transducer from a current limited voltage source; Measuring the excitation voltage drawn from the current limited voltage ■I .i source by a current [sensing and measurement circuit, when the transducer is connected; Converting the measured current level into a voltage level by a current voltage converter; Inputting the converted voltage and a reference voltage into a comparator; Comparing the input converted voltage with the input reference voltage to generate a comparison result; Generating a detection signal based on the generated comparison result; Forwarding the generated detection signal to a microcontroller to out put a message to a user to indicate the detection result. i 14. The method according to claiml3, wherein the message is output from the micro controller based on the received detection signal from the comparator to .1 the user so that thefmessage is displayed to the user to indicate the presence of the transducer. 15. The method according to claim 13, wherein the message is output from the microcontroller to the user so that the message is displayed to the user to indicate the absence of the transducer. 16. The method according to claim 13, wherein the message is output fit)m the microcontroller to the user so that the message is displayed to the user to indicate the disconnection of the transducer. 17. The method according to claim 13, wherein the message is output from microcontroller to the user to display a message to the user to indicate a channel fault. 18. The method according to claim 13, wherein the message is output from the microcontroller to the user to display a message to the user to indicate a channel fault. 19. The method according to claim 13, wherein a logic high signal is output from the comparator to i indicate the presence of the transducer, when the input voltage at the comparator corresponding to the measured current level drawn i! by the transducer is more than the reference voltage, 20. The method according to claim 13, wherein a reference voltage is input from a reference voltage generator into the comparator for comparison. 21. The method according to claim 20, wherein the inputs reference voltage is less than the actual excitation voltage supplied to the transducer, when the transducer is connected. 22. The method accotding to claim 13, wherein the current sensing and measurement circuit measures a zero current, when the transducer is not connected. 23. The method according to claim 13, wherein the microcontroller outputs a message to indicate the absence of the transducer, based on the detection signal output from the comparator, when the current sensing and measuring circuit measures a zero current. 24. The method according to claiml3, further comprising a cable detection method using a cable detection circuit to sense the discoimection of the cable connecting the transducer to an IBP monitor.

Documents:

1667-CHE-2007 FORM-1 09-10-2013.pdf

1667-CHE-2007 ASSIGNMENT 09-10-2013.pdf

1667-CHE-2007 FORM-13 09-10-2013.pdf

1667-CHE-2007 POWER OF ATTORNEY 09-10-2013.pdf

1667-CHE-2007 AMENDED PAGES OF SPECIFICATION 09-10-2013.pdf

1667-CHE-2007 AMENDED CLAIMS 13-03-2014.pdf

1667-CHE-2007 AMENDED PAGES OF SPECIFICATION 13-03-2014.pdf

1667-CHE-2007 CORRESPONDENCE OTHERS 09-10-2013.pdf

1667-CHE-2007 CORRESPONDENCE OTHERS 09-10-2013.pdf

1667-CHE-2007 CORRESPONDENCE OTHERS 24-10-2014.pdf

1667-CHE-2007 FORM-3 13-03-2014.pdf

1667-CHE-2007 FORM-6 09-10-2013.pdf

1667-CHE-2007 POWER OF ATTORNEY 13-03-2014.pdf

1667-CHE-2007 EXAMINATION REPORT REPLY RECEIVED 13-03-2014.pdf

1667-che-2007 abstract.pdf

1667-che-2007 claims.pdf

1667-che-2007 correspondence others.pdf

1667-che-2007 description(complete).pdf

1667-che-2007 drawings.pdf

1667-che-2007 form-1.pdf

1667-che-2007 form-5.pdf

1667-che-2007-correspondnece-others.pdf

1667-che-2007-description(provisional).pdf

1667-che-2007-drawings.pdf

1667-che-2007-form 1.pdf