A) TECHNICAL FIELD

[0001] The present invention generally relates to patient monitor (PM). The present invention particularly relates to medical devices in the patient monitors. More particularly the present invention relates to temperature control and protection of the medical devices in the patient monitors.

B) BACKGROUND OF THE INVENTION

[0002] Among all components in a patient monitor, the electronic medical devices emit maximum amount of heat during its operation. The electronic medical devices include many Integrated Circuit (IC) components. The heat is generated due to operation of the IC components present in the electronic medical devices. The heat continues to build up as long as the electronic medical device is operating and the temperature of a resistive element present in the medical device increases until the heat finds a flow path carded away from the resistive element. If the heat flow path is poor, the temperature continues to build up until the resistive element is destroyed thereby causing malfunction of the IC components present in the electronic medical device.

[0003] In current scenario, in one of a system, the electronic medical device includes a fan and a fan drive circuit to reduce the heat build up within the system. During the operation of the patient monitor, the fan will draw hot air out of the system to reduce the temperature of the electronic medical device. However, the fan consumes more power and increasing the life of the fan becomes another concern.

[0004] One scheme of controlling speed of the fan and power consumption of the medical device is to provide a standby operation mode and normal operation mode for the electronic medical device. While in the normal operation mode, a temperature-sensing device present in the electronic medical device will detect current temperature and control the speed of the fan to reduce the temperature of the electronic medical device. The electronic medical device is put into the standby operation mode if the device is not in operating condition. The standby operation mode does not generate much heat and hence the speed of the fan is reduced or the fan is turned off to conserve power and to increase the life of the fan. Sometimes, the heat build-up in the electronic medical device becomes extreme thereby resulting in permanent damage to the IC drive and malfunctioning of the fan.

[0005] Generally controlling the speed of the fan and power consumption of the medical device related to motor speed controls is relatively complex and expensive. In another scheme, over-temperature detection circuit employing a thermo-couple is used in a system to control the fan power on/off frequently to cool the system. When thermo-couple is subjected to a temperature change, an electromotive force is produced. Electrical leads couple the thermocouple to a current-detection circuit to compute the temperature of the thermo-couple, thereby indirectly detecting the temperature of the electronic medical device. However, the thermo-couples are expensive and yet another component has to be purchased and installed on the circuit board of the electronic medical device.

[0006] In light of foregoing discussion, there exists a need for a system for maintaining the ambient temperature of the patient monitor to ensure better reliability. Also there exists a need for the system to improve and monitor speed of the fan, to reduce acoustic noise and to limit the power consumption of the fan by reducing and controlling the unwanted rotation of the fan. Further, there is a need for increasing the life of the fan by operating the fan in the patient monitor whenever necessary. Furthermore, there is a need for increasing the system reliability by inhibiting the system ON function in case of over ambient temperature of the patient monitor and in case of the fan failure.

[0007] The above mentioned shortcomings, disadvantages and problems are addressed herein and which will be understood by reading and studying the following specification.

C) OBJECT OF THE INVENTION

[0008] The primary object of the invention is to develop a temperature control and protection system for a patient monitor, for controlling the ambient temperature of the patient monitor to protect from an over temperature damage.

[0009] Another object of the present invention is to develop a temperature control and protection system for a patient monitor to provide an ambient temperature measuring sensor for controlling temperature and for protecting the electronic medical devices in the patient monitor.

[0010] Yet another object of the present invention is to develop a temperature control and protection system for a patient monitor to provide an over temperature notification and real time temperature information to a user.

[0011] Yet another object of the present invention is to develop a temperature control and protection system for a patient monitor to provide an automatic fan speed controller system in order to turn ON the fan, when the temperature of the patient monitor reaches above a threshold level and to turn OFF the fan, when the temperature of the patient monitor goes below the threshold level.

[0012] Yet another object of the present invention is to develop a temperature control and protection system for patient monitor to shutdown the patient monitor unit to increase the reliability of the patient monitor, when the temperature of the patient monitor reaches an over ambient temperature which is very much greater than the threshold level and during the fan failure in the patient monitor thereby increasing the reliability of the patient monitor.

[0013] Yet another object of the present invention is to develop a temperature control and protection system for a patient monitor to improve and monitor the speed of patient monitor fan, to reduce acoustic noise and limit power consumption of the patient monitor fan by reducing and controlling the unwanted rotation of the patient monitor fan and to increase the life of the patient monitor fan by operating the patient monitor fan whenever necessary.

[0014] Yet another objective of the present invention is to develop temperature control and protection system for a patient monitor, to provide a visual indication to a user by blinking the system power indication LED at a specific frequency, when the temperature of the patient monitor reaches an over ambient temperature which is very much greater than the threshold level.

D) SUMMARY OF THE INVENTION

[0015] The various embodiments of the present invention provide a system and method for temperature control and protection for a patient monitor. The system provides an automatic fan speed controller system in order to turn ON the fan, when the temperature of the patient monitor reaches above a threshold level and to turn OFF the fan, when the temperature of the patient monitor goes below another threshold level. Also the system shutdowns the patient monitor automatically, when the temperature of the patient monitor reaches to an uncontrollable level which is greater than the threshold level.

[0016] According to one embodiment of the present invention, a temperature control and protection system for patient monitoring system has an ambient temperature sensor mounted on a mother board that is provided in a patient monitor. A temperature controller is connected to the ambient temperature sensor and to a power supply controller installed in the patient monitor. A fan is connected to the power supply controller. The temperature controller regulates the operation of the fan and regulates the operation of the power supply controller to switch ON/OFF the patient monitor based on the output of the ambient temperature sensor. The temperature controller notifies the measured ambient temperature to the mother board periodically.

[0017] The ambient temperature sensor measures the ambient temperature of the patient monitor in real time. The temperature controller receives the measured ambient temperature from the ambient temperature sensor and compares the measured ambient temperature data with pluralities of threshold levels to control the operation of the fan and the operation of the patient monitor. The pluralities of the threshold levels are fan ON temperature, fan OFF temperature and system shutdown temperature. The temperature controller activates an intelligent fan control mode and an intelligent shutdown mode based on the comparison of the measured ambient temperature with the pluralities of the threshold level.

[0018] The temperature controller activates the intelligent fan control mode to switch ON/OFF the fan. The temperature controller activates the intelligent fan control mode to switch ON the fan, when the measured ambient temperature exceeds the fan ON temperature. The temperature controller activates the intelligent fan control mode to switch OFF the fan, when the measured ambient temperature drops below the fan OFF temperature. The temperature controller activates the intelligent fan control mode to provide an over temperature notification to the motherboard to indicate that the ambient temperature has exceeded the fan on temperature.

[0019] The temperature controller activates the intelligent shut down mode to switch off the patient monitor. The temperature controller activates the intelligent shut down mode to switch off the patient monitor, when the ambient temperature reaches the system shutdown temperature. The temperature controller activates the intelligent shut down mode to provide an over temperature notification to the motherboard in the patient monitor that the ambient temperature has exceeded the shutdown temperature before the switching off the patient monitor, when the ambient temperature reaches the shutdown temperature. The temperature controller regulates the power supply controller to regulate the power supply to the patient monitor to prevent the restating of the patient monitor until the measured ambient temperature is below a preset acceptable level.

E) BRIEF DESCRIPTION OF THE DRAWINGS

[0020] 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:

[0021] FIG. 1 illustrates a block diagram of temperature control and protection system for patient monitor according to one embodiment of the present invention

[0022] FIG. 2 illustrates a functional block diagram of temperature control and protection system for patient monitor according to one embodiment of the present invention.

[0023] FIG.3 illustrates a flowchart explaining the operation of the temperature control and protection system for patient monitor according to one embodiment of the present invention.

[0024] FIG.4 illustrates a two dimensional graph indicating the fan ON temperature and fan OFF temperature for the fan in the patient monitor unit with respect to the ambient temperature during a temperature control process in an intelligent fan control mode operation, in the temperature control and protection system for patient monitor according to one embodiment of the present invention.

[0025] FIG.5 illustrates a two dimensional graph indicating the fan ON temperature, fan OFF temperature and fan shutdown temperature of the fan in the patient monitor unit with respect to the ambient temperature during a temperature control process in an intelligent shutdown mode operation for fan in the temperature control and protection system for patient monitor according to one embodiment of the present invention.

[0026] FIG.6 illustrates a flowchart indicating the fan ON and fan OFF routines for the fan in the patient monitor unit during an intelligent fan control mode operation in the temperature control and protection system for patient monitor according to one embodiment of the present invention.

[0027] FIG.7 illustrates a flowchart indicating the shut down routine in the patient monitor unit during an intelligent shutdown operation in the temperature control and protection system for patient monitor according to one embodiment of the present invention.

[0028] 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

[0029] 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.

[0030] The various embodiments of the present invention provide a system and method for temperature control and protection for a patient monitor. The system provides an automatic fan speed controller system in order to turn ON the fan, when the temperature of the patient monitor reaches above a threshold level and to turn OFF the fan, when the temperature of the patient monitor goes below the threshold level. Also the system provides an automatic shutdown mode to shut down the patient monitor automatically, when the temperature of the patient monitor reaches to an uncontrollable level which is greater than the threshold level.

[0031] According to one embodiment of the present invention, a temperature control and protection system for patient monitoring system has an ambient temperature sensor mounted on a mother board that is provided in a patient monitor. A temperature controller is connected to the ambient temperature sensor and to a power supply controller installed in the patient monitor. A fan is connected to the power supply controller. The temperature controller regulates the operation of the fan and regulates the operation of the power supply controller to switch ON/OFF the patient monitor based on the output of the ambient temperature sensor. The temperature controller notifies the measured ambient temperature to the mother board periodically.

[0032] The ambient temperature sensor measures the ambient temperature of the patient monitor in real time. The temperature controller receives the measured ambient temperature from the ambient temperature sensor and compares the measured ambient temperature data with pluralities of threshold levels to control the operation of the fan and the operation of the patient monitor. The pluralities of the threshold levels are fan ON temperature, fan OFF temperature and system shutdown temperature. The temperature controller activates an intelligent fan control mode and an intelligent shutdown mode based on the comparison of the measured ambient temperature with the pluralities of the threshold level.

[0033] The temperature controller activates the intelligent fan control mode to switch ON/OFF the fan. The temperature controller activates the intelligent fan control mode to switch ON the fan, when the measured ambient temperature exceeds the fan ON temperature. The temperature controller activates the intelligent fan control mode to switch OFF the fan, when the measured ambient temperature drops below the fan OFF temperature. The temperature controller activates the intelligent fan control mode to provide an over temperature notification to the mother board to indicate that the ambient temperature has exceeded the fan on temperature.

[0034] The temperature controller activates the intelligent shut down mode to switch off the patient monitor. The temperature controller activates the intelligent shut down mode to switch off the patient monitor, when the ambient temperature reaches the system shutdown temperature. The temperature controller activates the intelligent shut down mode to provide an over temperature notification to the motherboard in the patient monitor that the ambient temperature has exceeded the shutdown temperature before switching off the patient monitor, when the ambient temperature reaches the shutdown temperature. The temperature controller regulates the power supply controller to regulate the power supply to the patient monitor to prevent the restarting of the patient monitor until the measured ambient temperature is below a preset acceptable level.

[0035] FIG. 1 illustrates a block diagram of temperature control and protection system for patient monitor according to one embodiment of the present invention. With respect to FIG. 1, a temperature manager 101 is connected to a motherboard 102 through an I C bus. The temperature manager 101 is basically a low power microcontroller which is main controlling unit of the system. The temperature manager 101 continuously monitors the real time ambient temperature of the patient monitor. The temperature manager 101 includes a temperature sensor to sense the real time ambient temperature of a patient monitor during its operation. The sensed real time ambient temperature of the patient monitor is read as voltage equivalent by an Analogue to Digital Converter (ADC) port of the microcontroller. The temperature manager 101 communicates the real time sensed ambient temperature of the patient monitor each time to the motherboard 102 through I2C bus. The system also includes a fan 103 to control the temperature of the patient monitor. The fan 103 is coupled to the microcontroller's output port.

[0036] When temperature of the patient monitor reaches above a preset threshold level called "Fan ON temperature" the temperature manager 101 sends a control signal to the fan 103 to turn ON the fan 103. The temperature manager 101 sends a control signal to the fan 103 to turn OFF the fan 103 when the temperature of the patient monitor goes below the threshold level called "Fan OFF temperature". Further, when the temperature of the patient monitor builds up to an uncontrollable level which is very much greater than the threshold level due to failure of the fan 103 or failure of other components in the patient monitor, the patient monitor is automatically turned OFF. The uncontrollable threshold level is referred as "Shutdown temperature". The "Shutdown temperature" is sensed by the temperature sensor present in the temperature manager 101 and is communicated to the motherboard 102 through I2C bus prior to the shutdown operation of the patient monitor. The motherboard 102 is provided with an algorithm which is executed to shutdown the patient monitor, when the real time ambient temperature of the patient monitor reaches the "Shutdown temperature". Following the shutdown operation of the patient monitor, a visual indication is provided to a user by blinking the patient monitor power indication Light Emitting Diode (LED) at a specific frequency, to indicate that the ambient temperature of the patient monitor has reached the "shutdown temperature" level.

[0037] FIG. 2 illustrates a functional block diagram of a temperature control and protection system for a patient monitor according to one embodiment of the present invention. With respect to FIG. 2, initially real time voltage equivalent temperature is continuously sensed by a temperature sensor present in temperature manager. The temperature value is calculated from the voltage equivalent temperature sensed by the temperature sensor present in the temperature manager (201). A Voltage to temperature conversion logic controller calculates value of real time temperature of the patient monitor. The calculated value of real time temperature of the patient monitor is communicated to motherboard through I2C bus (202). The calculated value of real time temperature of the patient monitor is compared with a preset limit called threshold value (203). A comparator present in the motherboard compares the calculated value of real time temperature of the patient monitor with the threshold value.

[0038] If the calculated value of the real time temperature of the patient monitor reaches an uncontrollable level which is extremely greater than the threshold value called "Shutdown temperature", the patient monitor unit is shutdown automatically (204). The motherboard is provided with an algorithm which is executed to shutdown the patient monitor unit, when the calculated value of real time temperature of the patient monitor is greater than the "Shutdown temperature". The "Shutdown temperature" value of the patient monitor unit sensed by the temperature manager is communicated to the motherboard through I2C bus prior to the shutdown of the patient monitor unit. It is ensured that the patient monitor unit is turned ON after the shutdown operation, when the temperature of the patient monitor unit is reduced to an acceptable limit. Following the shutdown operation of the patient monitor, a visual indication is provided to a user indicating the uncontrollable "Shutdown temperature" of the patient monitor (205). When the calculated value of real time temperature of the patient monitor is above the threshold level and below the "Shutdown temperature", the temperature manager generates a control signal to turn ON the fan. When the calculated value of real time temperature of the patient monitor is below the threshold level, then the temperature manager generates a control signal to turn OFF the fan (206).

[0039] FIG.3 illustrates a flowchart explaining the operation of the temperature control and protection system for patient monitor according to one embodiment of the present invention. With respect to FIG.3, the flow chart is illustrated as below with two different operating modes namely an intelligent fan control mode and an intelligent shutdown mode. Real time ambient temperature of the patient monitor is continuously sensed by a temperature sensor present in a temperature manager. The temperature manager is basically a low power microcontroller. The sensed real time ambient temperature of the patient monitor is read as a voltage equivalent by an Analogue to Digital Converter (ADC) port of the microcontroller (301). The real time sensed temperature information of the patient monitor is sent to motherboard through I2C bus (302).

[0040] During each read cycle of the real time ambient temperature by the ADC port of the microcontroller, the microcontroller enables either one of the intelligent fan control mode or the intelligent shutdown mode. During the Intelligent fan control mode, the sensed temperature of the patient monitor is compared with preset "Fan OFF" temperature (303). If the sensed temperature of the patient monitor is less than the preset "Fan OFF" temperature, then logic in the motherboard is executed to turn OFF the fan (304). If the sensed temperature of the patient monitor is greater than the preset "Fan OFF" temperature, then the sensed temperature of the patient monitor is compared with a preset "Fan ON" temperature (305). If the sensed temperature of the patient monitor is less than the preset "Fan ON" temperature, then logic in the motherboard is executed to turn OFF the fan.

[0041] If the sensed temperature of the patient monitor is greater than the "Fan ON" temperature, then the sensed temperature is compared with "Shutdown temperature" (306). If the sensed temperature of the patient monitor is less than the "Shutdown temperature", then logic in the motherboard is executed to turn ON the fan (307). During the intelligent shutdown mode if the sensed temperature of the patient monitor is greater than the "Shutdown temperature", then the logic in the motherboard is executed to shutdown the patient monitor unit to protect the patient monitor from an over voltage damage (308).Prior to the shutdown operation of the patient monitor unit, the microcontroller sends a shutdown signal to the motherboard to initiate a soft shutdown operation. An over temperature indication is given to a user following the shutdown operation of the patient monitor unit (309). It is ensured that the patient monitor unit is turned ON after the shutdown operation, when the temperature of the patient monitor unit is reduced to an acceptable limit.

[0042] FIG.4 illustrates a two dimensional graph indicating the fan ON temperature and fan OFF temperature for the fan in the patient monitor unit with respect to the ambient temperature during a temperature control process in an intelligent fan control mode operation, in the temperature control and protection system for patient monitor according to one embodiment of the present invention. With respect to FIG. 4, substantial measurements of "UNIT AMBIENT TEMPERATURE" values and "PRESET TEMPERATURE LIMIT" values are taken along abscissa and ordinate of the two dimensional graph respectively. Curve 401 indicates rise in temperature of the patient monitor from "Fan OFF" temperature to "Fan ON" temperature during the intelligent fan control mode operation of the patient monitor, when Fan is turned OFF. Curve 402 indicates fall in temperature of the patient monitor from "Fan ON" temperature to "Fan OFF" temperature during the intelligent fan control mode operation of the patient monitor, when the fan is turned ON.

[0043] FIG.5 illustrates a two dimensional graph indicating the fan ON temperature, fan OFF temperature and fan shutdown temperature of the fan in the patient monitor unit with respect to the ambient temperature during a temperature control process in an intelligent shutdown mode operation for fan in the temperature control and protection system for patient monitor according to one embodiment of the present invention. With respect to FIG. 5, substantial measurements of "UNIT AMBIENT TEMPERATURE" values and "PRESET TEMPERATURE LIMIT" values are taken along abscissa and ordinate of the two dimensional graph respectively. Curve 501 indicates rise in temperature of the patient monitor from "Fan OFF" temperature to "Fan ON" temperature up to peak value of "Shutdown temperature" due to failure of Fan or any other component of the patient monitor unit. Curve 502 indicates fall in the temperature of the patient monitor from "shutdown temperature" to "Fan OFF" temperature, due to shutdown of the patient monitor unit during the intelligent shutdown mode operation.

[0044] FIG.6 illustrates a flowchart indicating the fan ON and fan OFF routines for the fan in the patient monitor unit during an intelligent fan control mode operation in the temperature control and protection system for patient monitor according to one embodiment of the present invention. With respect to FIG.6, the patient monitor unit checks for either one of fan ON or fan OFF condition in the patient monitor initially (601). During fan ON condition, a control signal is sent by the microcontroller to set the fan control port of the fan at "HIGH" (602). Following the HIGH status of the fan control port of the fan, a fan control switch associated with the fan connects a 12 volt power supply to the fan (603). The fan is turned ON, when the fan is connected to a 12 volt power supply (604). During the fan OFF condition, a control signal is sent by the microcontroller to set a fan control port of the fan at "LOW" (605). Following the LOW status of the fan control port of the fan, the fan control switch associated with the fan disconnects the 12 volt power supply to the fan (606). The fan is turned OFF, when the fan is disconnected from the 12 volt power supply (607).

[0045] FIG.7 illustrates a flowchart indicating the shut down routine in the patient monitor unit during an intelligent shutdown operation in the temperature control and protection system for patient monitor according to one embodiment of the present invention. With respect to FIG.7, the microcontroller sends a shutdown pulse to motherboard when the ambient temperature of the patient monitor has reached an over ambient temperature threshold level, to shutdown the patient monitor (701). Then the patient monitor unit is checked for a booting process (702). When a booting process is detected, a 10 seconds delay is observed prior to the shutdown operation of the motherboard in the patient monitor unit (703). During the shutdown operation of the patient monitor, 5 volt power supply, 9 volt power supply, and 12 volt power supply are disconnected from the patient monitor unit through the motherboard shutdown operation (704), (705) and (706).

G) ADVANTAGES OF THE INVENTION

[0046] Thus the various embodiments of the present invention provide a system and method for temperature control and protection in patient monitor system. The system maintains ambient temperature of the patient monitor to ensure better reliability. The system reduces acoustic noise and limits the power consumption of fan in the patient monitor fan by reducing and controlling the unwanted rotation of the fan in the patient monitor. The system increases the life of the patient monitor fan by operating the patient monitor fan whenever necessary. The system provides a visual indication to a user by blinking the system power indication LED at a specific frequency, when the temperature of the patient monitor reaches an over ambient temperature threshold limit.

[0047] 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.

[0048] 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 temperature control and protection system for patient monitoring system comprising a motherboard and controller, the system comprising:

An ambient temperature sensor mounted on a mother board provided in a patient monitor;

A power supply controller provided on the motherboard in the patient monitor;

A temperature controller connected to the ambient temperature sensor and to the power supply controller in the patient monitor;

A fan connected to the power supply controller;

Wherein the temperature controller regulates the operation of the fan and regulate the operation of the power supply controller to switch ON/OFF the patient monitor based on the output of the ambient temperature sensor.

2. The system according to claim 1, wherein the ambient temperature sensor measures the ambient temperature of the patient monitor in real time.

3. The system according to claim 1, wherein the temperature controller receives the measured ambient temperature from the ambient temperature sensor and compares the measured ambient temperature data with pluralities of threshold levels to control the operation of the fan and the operation of the patient monitor.

4. The system according to claim 1, wherein the pluralities of the threshold levels are fan ON temperature, fan OFF temperature and system shutdown temperature.

5. The system according to claim 1, wherein the temperature controller activates an intelligent fan control mode and an intelligent shutdown mode based on the comparison of the measured ambient temperature with the pluralities of the threshold level.

6. The system according to claim 1, wherein the temperature controller activates the intelligent fan control mode to switch ON/OFF the fan.

7. The system according to claim 1, wherein the temperature controller activates the intelligent shut down mode to switch off the patient monitor.

8. The system according to claim 1, wherein the temperature controller activates the intelligent fan control mode to switch ON the fan, when the measured ambient temperature exceeds the fan ON temperature.

9. The system according to claim 1, wherein the temperature controller activates the intelligent fan control mode to switch OFF the fan, when the measured ambient temperature drops below the fan OFF temperature.

10. The system according to claim 1, wherein the temperature controller activates the intelligent shut down mode to switch off the patient monitor, when the ambient temperature reaches the system shutdown temperature.

11. The system according to claim 1, wherein the temperature controller activates the intelligent shut down mode to provide an over temperature notification to the motherboard in the patient monitor that the ambient temperature has exceeded the shutdown temperature before switching off the patient monitor, when the ambient temperature reaches the shutdown temperature.

12. The system according to claim 1, wherein the temperature controller regulates the power supply controller to regulate the power supply to the patient monitor to prevent the restarting of the patient monitor until the measured ambient temperature is below a preset acceptable level.

13. The system according to claim 1, wherein the temperature controller activates the intelligent fan control mode to provide an over temperature notification to the mother board to indicate that the ambient temperature has exceeded the fan on temperature.

14. The system according to claim 1, wherein the temperature controller notifies the measured ambient temperature to the mother board periodically.