Power management circuit of medical instrument

Abstract

The invention relates to the technical field of medical instruments, and discloses a medical instrument power management circuit which comprises a socket externally connected with the input end of a charger; the electric quantity detection module is used for accurately measuring the voltage, the current, the electric quantity and the temperature of the battery; the single chip microcomputer module is used for reading the electric quantity of the battery pack and controlling the turn-off of the transistor; the power supply switching module is used for managing current and voltage changes in the power supply on-off and switching process and reducing instant impact and interference of power supply switching; the voltage stabilizing module is used for supplying power to the single chip microcomputer module; the electric quantity detection module and the power supply switching module are electrically connected with the single-chip microcomputer module, the socket is electrically connected with the electric quantity detection module, and the voltage stabilization module is electrically connected with the power supply switching module. The system is novel in structural design, simple in layout and low in cost, unnecessary energy consumption of a power supply can be reduced, and the service time of a battery and medical equipment is prolonged.

Description

Technical Field

[0001] The present invention relates to the field of medical device technology, in particular to the field of power management of medical devices, and specifically to a power management circuit for medical devices. Background Art

[0002] Medical devices refer to instruments, equipment, appliances, materials or other items used on the human body alone or in combination, acting on the surface and inside the human body, not through pharmacological, immunological or metabolic means, and are intended to achieve the following intended purposes. The power management of medical devices is related to the normal operation of medical devices, data preservation and patient safety. For medical devices that rely on electricity to save data, such as electronic medical record systems, image storage devices, etc., power management can prevent data loss due to power problems.

[0003] After searching, the patent with application number CN201510996125.9 discloses a power management system for medical devices and its working method. By using a main power supply and a backup power supply, the backup power supply can be enabled in the event of a failure of the main power supply, thereby improving the reliability of the power management system. At the same time, the supercapacitor as a backup power supply has the characteristics of small size, longer service life than batteries, and high reliability. As a backup power supply, the supercapacitor increases the portability of medical devices, reduces the size, extends the service life of the device, and increases reliability. Furthermore, the main power supply is a battery, and the backup power supply is a supercapacitor. The backup power supply can be charged by the main power supply, thereby ensuring the power of the backup power supply, thereby ensuring the reliability of the power management system. Furthermore, the voltage of the replaced main power supply is detected to ensure the power of the replaced main power supply, thereby ensuring the reliability of the power management system.

[0004] There are two types of power switches for medical devices. The first is mechanical, which works by opening and closing mechanical contacts to allow current to flow (when closed) or completely block current flow (when open). Mechanical switches are passive devices that do not consume electricity, so they are very efficient. However, electromechanical switches are large in size, poorly waterproof, and extremely user-friendly and easy to use. If the user forgets to turn off the switch after use, the battery will be exhausted when the user uses it again.

[0005] The second situation is standby mode, which works by using a smaller current to keep a part of the circuit (MCU, sensor, etc.) working. When the trigger condition (button, sensor, etc.) is reached, it will start working, and when another trigger condition is reached, it will shut down. This method cannot completely block power consumption (usually several mA current, that is, several μA current when the MCU enters sleep mode). These consumptions should be avoided as much as possible for battery-powered medical devices.

[0006] In addition, medical devices currently powered by lithium batteries cannot accurately display the remaining power.

[0007] The patent CN216118434U is a medical electronic device switch circuit. Although it provides a solution to the above problems, it cannot solve the problem that the user cannot force shut down the device during use, nor can it solve the problem of accurately displaying the remaining battery power. Therefore, we need to propose a medical device power management circuit. Summary of the invention

[0008] The purpose of the present invention is to provide a medical device power management circuit with novel structural design, simple layout and low cost, which can reduce unnecessary energy consumption of the power supply and extend the use time of the battery and the medical device to solve the problems raised in the above background technology.

[0009] To achieve the above object, the present invention provides the following technical solution: a medical device power management circuit, comprising:

[0010] Socket for external charger input;

[0011] A power detection module that accurately measures battery voltage, current, power and temperature;

[0012] A microcontroller module for reading the battery pack's charge and controlling transistor shutdown;

[0013] A power switching module used to manage current and voltage changes during power on / off and switching, and to reduce instantaneous impact and interference during power switching;

[0014] A voltage regulator module that supplies power to the microcontroller module;

[0015] The power detection module and the power switching module are both electrically connected to the single-chip computer module, the socket is electrically connected to the power detection module, and the voltage stabilizing module is electrically connected to the power switching module.

[0016] Preferably, the single-chip microcomputer module includes a main control chip U1, the power detection module includes a power monitoring chip U2, a lithium battery pack DC is connected between the connection terminals of pins 7 and 9 of the power monitoring chip U2 and pin 8, pin 4 of the power monitoring chip U2 is connected to pin 40 of the main control chip U1, pin 5 of the power monitoring chip U2 is connected to pin 42 of the main control chip U1, and pin 6 of the power monitoring chip U2 is connected to pin 41 of the main control chip U1.

[0017] Preferably, a resistor R3 is connected to pin 4 of the power monitoring chip U2, a resistor R4 is connected to pin 5 of the power monitoring chip U2, and a resistor R5 is connected to pin 6 of the power monitoring chip U2. One end of the resistor R3, the resistor R4, and the resistor R5 are all connected to 3.3V.

[0018] Preferably, the socket includes a connector P1, the VBUS pin of the connector P1 is connected to pin 1 of the power monitoring chip U2, and a current detection resistor R12 is connected between the VBUS pin of the connector P1 and pin 8 of the power monitoring chip U2, and the GND pin of the connector P1 is connected to pins 2 and 3 of the power monitoring chip U2.

[0019] Preferably, the power switching module includes a MOS tube Q1, a switch SW1, a transistor Q1, and a transistor Q2. The VBUS pin of the connector P1 and pin 1 of the power monitoring chip U2 are both connected to the source of the MOS tube Q1. A resistor R1 is connected between the base and source of the MOS tube Q1. Pin 1 of the switch SW1 is connected to the base of the MOS tube Q1. Pin 2 of the switch SW1 is respectively connected to a resistor R6 and a capacitor C1.

[0020] Preferably, a resistor R2 is connected between the collector of the transistor Q2 and the base of the MOS tube Q1, a resistor R9 and a resistor R10 are connected between the base of the transistor Q2 and the collector of the transistor Q3, the connection terminals of the resistor R9 and the resistor R10 are respectively connected to a capacitor C3 and a resistor R8, a resistor R7 is also connected to the collector of the transistor Q3, and a resistor R11 is connected between the base of the transistor Q3 and pin 37 of the main control chip U1.

[0021] Preferably, the voltage stabilizing module includes a chip U3, pin 2 of the chip U3 is connected to the drain of the MOS tube Q1 and connected to the supply voltage, the resistor R6 and the resistor R7 are both connected to the drain of the MOS tube Q1, the pin 2 of the chip U3 and the connection terminal of the drain of the MOS tube Q1 are respectively connected to capacitors C2 and C4, and the pin 3 of the chip U3 is respectively connected to capacitors C5 and C6.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] The present invention has novel structural design, simple layout and low cost, and can reduce unnecessary energy consumption of a power source and extend the service life of batteries and medical devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A circuit diagram of the present invention;

[0025] Figure 2 It is a system block diagram of the present invention. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] See also Figure 1-2 The present invention provides a technical solution: a medical device power management circuit, comprising:

[0028] The socket at the input end of the external charger; the socket is a TYPE-C 6P socket. Depending on the voltage of the lithium battery pack, the external charger is a 5V, 8.2V, 12.6V, 16.8V charger that does not exceed 60V.

[0029] A power detection module that accurately measures battery voltage, current, power and temperature;

[0030] A microcontroller module for reading the battery pack's charge and controlling transistor shutdown;

[0031] The single-chip microcomputer module includes a main control chip U1, and the power detection module includes a power monitoring chip U2. A lithium battery pack DC is connected between the connection terminals of pins 7 and 9 of the power monitoring chip U2 and pin 8. Pin 4 of the power monitoring chip U2 is connected to pin 40 of the main control chip U1, pin 5 of the power monitoring chip U2 is connected to pin 42 of the main control chip U1, and pin 6 of the power monitoring chip U2 is connected to pin 41 of the main control chip U1.

[0032] The model of the power monitoring chip U2 is LTC2944, which has the function of measuring voltage, current, power and temperature. When measuring, a current detection resistor R12 is used between the charger and the battery (when charging) or between the battery and the load (when discharging). The power monitoring chip U2 can detect the voltage of the resistor (R12) and integrate the current, convert it into a digital signal through an analog-to-digital converter, and store it in the internal register. The main control chip U1 reads the internal register of the power monitoring chip U2 through the I2C bus, realizing the accurate measurement of the battery voltage, current, power and temperature.

[0033] Pin 4 of the power monitoring chip U2 is connected to a resistor R3, pin 5 of the power monitoring chip U2 is connected to a resistor R4, and pin 6 of the power monitoring chip U2 is connected to a resistor R5. One end of the resistors R3, R4, and R5 are all connected to 3.3V.

[0034] The socket includes a connector P1, the VBUS pin of the connector P1 is connected to pin 1 of the power monitoring chip U2, and a current detection resistor R12 is connected between the VBUS pin of the connector P1 and pin 8 of the power monitoring chip U2, and the GND pin of the connector P1 is connected to pins 2 and 3 of the power monitoring chip U2.

[0035] A power switching module used to manage current and voltage changes during power on / off and switching, and to reduce instantaneous impact and interference during power switching;

[0036] The power switching module includes a MOS tube Q1, a switch SW1, a transistor Q1, and a transistor Q2. The VBUS pin of the connector P1 and the pin 1 of the power monitoring chip U2 are both connected to the source of the MOS tube Q1. A resistor R1 is connected between the base and the source of the MOS tube Q1. The pin 1 of the switch SW1 is connected to the base of the MOS tube Q1. The pin 2 of the switch SW1 is respectively connected to a resistor R6 and a capacitor C1.

[0037] A resistor R2 is connected between the collector of the transistor Q2 and the base of the MOS transistor Q1, a resistor R9 and a resistor R10 are connected between the base of the transistor Q2 and the collector of the transistor Q3, a capacitor C3 and a resistor R8 are connected to the wiring ends of the resistor R9 and the resistor R10 respectively, a resistor R7 is also connected to the collector of the transistor Q3, and a resistor R11 is connected between the base of the transistor Q3 and pin 37 of the main control chip U1.

[0038] like Figure 1 As shown in the figure, when MOS tube Q1 is turned on, other circuits of the medical device are powered and start working. When it is turned off, other circuits of the medical device stop working due to power failure, so that the static power consumption of the lithium battery is minimized. The conduction of MOS tube Q1 is determined by the voltage at point G. When the voltage at point G is basically equal to the voltage at point A, MOS tube Q1 is turned off; when the voltage at point G is much lower than the voltage at point A, MOS tube Q1 is turned on. The voltage at point G is determined by transistor Q2 and switch SW1.

[0039] When transistor Q2 is turned on, the voltage at point G is pulled down, making the voltage at point G much lower than the voltage at point A, thus turning on MOS tube Q1. The conduction of transistor Q2 is determined by point F, and the voltage at point F is determined by the voltage at point B and the state of transistor Q3.

[0040] When transistor Q3 is turned on, the voltage at point C will be pulled down to 0.3V, so that the voltage at point F cannot reach the condition for transistor Q2 to turn on, and then the voltage at point G is basically equal to the voltage at point A, and finally the MOS tube Q1 is turned off. The state of transistor Q3 is controlled by the main control chip U1. When the PA14 pin of the main control chip U1 outputs a high level, transistor Q3 is turned on; when the PA14 pin of the main control chip U1 outputs a low level, transistor Q3 is turned off.

[0041] When the switch SW1 is pressed down to conduct, the result obtained will be different depending on whether the capacitor C1 is fully charged. When the voltage on the capacitor C1 is 0V, due to the short circuit of the switch SW1, the voltage at point G is forced to be pulled down and is much smaller than the voltage at point A, and the MOS tube Q1 is turned on. When the capacitor C1 is fully charged, the voltage at point D is equal to the voltage at point B, and point B is basically equal to the voltage at point A, so the voltage at point D is basically equal to the voltage at point A. Due to the short circuit of the switch SW1, the voltage at point G is forced to be pulled up and equal to the voltage at point A, and the MOS tube Q1 is turned off.

[0042] A 3.3V voltage regulator module that supplies power to the microcontroller module;

[0043] The voltage stabilizing module includes a chip U3, which is an LDO linear voltage regulator. Pin 2 of the chip U3 is connected to the drain of the MOS tube Q1 and connected to the power supply voltage. The resistor R6 and the resistor R7 are both connected to the drain of the MOS tube Q1. The pin 2 of the chip U3 and the connection terminal of the drain of the MOS tube Q1 are respectively connected to capacitors C2 and C4. The pin 3 of the chip U3 is respectively connected to capacitors C5 and C6.

[0044] The power detection module and the power switching module are both electrically connected to the single-chip computer module, the socket is electrically connected to the power detection module, and the voltage stabilizing module is electrically connected to the power switching module.

[0045] In addition, the socket and the power detection module are both electrically connected to the power switching module.

[0046] Circuit principle:

[0047] In the initial state of the circuit, the MOS tube Q1 is turned off, the voltage at point G = the voltage at point A = the voltage of the lithium battery pack, the voltage at point B = the voltage at point C = the voltage at point D = the voltage at point E = the voltage at point F = the voltage at point H = 0V;

[0048] When the switch SW1 is pressed, the power supply charges the capacitor C1 through the resistor R1 and the switch SW1, and the voltage at point D slowly rises from 0V. At the same time, the voltage at point G is equal to point D. The MOS tube Q1 is on, and the MOS tube Q1 is on. Then the voltage at point B is equal to point A. At the same time, the voltage at point B is divided by the resistors R7, R10 and R8, so that the voltage at point E is approximately equal to two-thirds of the voltage at point B. The voltage at point E is added to the base of the transistor Q2 through the resistor R9 (the voltage at point F is about 0.7V), so that the transistor Q2 is turned on, thereby forcibly pulling the voltage at point G down to one-fifth of the voltage at point A. At this time, even if the switch SW1 is turned off, the MOS tube Q1 remains on. During the on-time of the MOS tube Q1, the voltage at point B charges the capacitor C1 through the resistor R6, and finally: the voltage at point B = the voltage at point D.

[0049] Because MOS tube Q1 is turned on, the VCC voltage is reduced to 3.3V through chip U3 to power the main control chip U1. The single-chip microcomputer module can read the power information on the lithium battery pack through I2C, and then display the power information through a display device such as a screen. At the same time, other functional components of the medical device start working due to power supply.

[0050] The main control chip U1 also has the authority to force the MOS tube Q1 to turn off, so that the medical device stops working, which can save the energy consumption of lithium batteries. When the MOS tube Q1 is turned on, the main control chip U1 works because of 3.3V. After the main control chip U1 is initialized, the PA14 of the main control chip U1 outputs a low level, and the transistor Q3 is turned off. The transistor Q3 will not affect the voltage at point C, and then it will not affect the MOS tube Q1. When the PA14 of the main control chip U1 outputs a high level, the transistor Q3 is turned on, and the transistor Q3 pulls the voltage at point C down to nearly 0.3V, and the point E is equal to 0V, resulting in the transistor Q2 being turned off, the voltage at point A = the voltage at point G, the MOS tube Q1 being turned off, and all circuits behind the MOS tube Q1 losing power and stopping working.

[0051] During the conduction period of MOS tube Q1, pressing switch SW1 can also force the MOS tube Q1 to be turned off. During the conduction period of MOS tube Q1, the voltage at point B charges capacitor C1 through resistor R6, and the result is: voltage at point B = voltage at point D;

[0052] When the switch SW1 is pressed and short-circuited, the voltage at point G = the voltage at point B = the voltage at point D;

[0053] The MOS tube Q1 cannot reach the conduction condition and is turned off. The remaining power on the capacitor C1 is discharged through the resistors R6, R7, R10 and R8, and the circuit returns to the initial state.

[0054] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A medical device power management circuit, characterized in that: include: Socket for external charger input; A power detection module that accurately measures battery voltage, current, power and temperature; A microcontroller module for reading the battery pack's charge and controlling transistor shutdown; A power switching module used to manage current and voltage changes during power on / off and switching, and to reduce instantaneous impact and interference during power switching; A voltage regulator module that supplies power to the microcontroller module; The power detection module and the power switching module are both electrically connected to the single-chip computer module, the socket is electrically connected to the power detection module, and the voltage stabilizing module is electrically connected to the power switching module.

2. A medical device power management circuit according to claim 1, characterized in that: The single-chip microcomputer module includes a main control chip U1, and the power detection module includes a power monitoring chip U2. A lithium battery pack DC is connected between the connection terminals of pins 7 and 9 of the power monitoring chip U2 and pin 8. Pin 4 of the power monitoring chip U2 is connected to pin 40 of the main control chip U1, pin 5 of the power monitoring chip U2 is connected to pin 42 of the main control chip U1, and pin 6 of the power monitoring chip U2 is connected to pin 41 of the main control chip U1.

3. A medical device power management circuit according to claim 2, characterized in that: Pin 4 of the power monitoring chip U2 is connected to a resistor R3, pin 5 of the power monitoring chip U2 is connected to a resistor R4, and pin 6 of the power monitoring chip U2 is connected to a resistor R5. One end of the resistors R3, R4, and R5 are all connected to 3.3V.

4. A medical device power management circuit according to claim 3, characterized in that: The socket includes a connector P1, the VBUS pin of the connector P1 is connected to pin 1 of the power monitoring chip U2, and a current detection resistor R12 is connected between the VBUS pin of the connector P1 and pin 8 of the power monitoring chip U2, and the GND pin of the connector P1 is connected to pins 2 and 3 of the power monitoring chip U2.

5. A medical device power management circuit according to claim 4, characterized in that: The power switching module includes a MOS tube Q1, a switch SW1, a transistor Q1, and a transistor Q2. The VBUS pin of the connector P1 and the pin 1 of the power monitoring chip U2 are both connected to the source of the MOS tube Q1. A resistor R1 is connected between the base and the source of the MOS tube Q1. The pin 1 of the switch SW1 is connected to the base of the MOS tube Q1. The pin 2 of the switch SW1 is respectively connected to a resistor R6 and a capacitor C1.

6. A medical device power management circuit according to claim 5, characterized in that: A resistor R2 is connected between the collector of the transistor Q2 and the base of the MOS transistor Q1, a resistor R9 and a resistor R10 are connected between the base of the transistor Q2 and the collector of the transistor Q3, a capacitor C3 and a resistor R8 are connected to the wiring ends of the resistor R9 and the resistor R10 respectively, a resistor R7 is also connected to the collector of the transistor Q3, and a resistor R11 is connected between the base of the transistor Q3 and pin 37 of the main control chip U1.

7. A medical device power management circuit according to claim 6, characterized in that: The voltage stabilizing module includes a chip U3, wherein pin 2 of the chip U3 is connected to the drain of the MOS tube Q1 and connected to the power supply voltage, the resistor R6 and the resistor R7 are both connected to the drain of the MOS tube Q1, the pin 2 of the chip U3 and the connection terminal of the drain of the MOS tube Q1 are respectively connected to capacitors C2 and C4, and the pin 3 of the chip U3 is respectively connected to capacitors C5 and C6.

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