CN214157295U - Detection circuit and pulse oximeter - Google Patents

Abstract

The embodiment of the utility model discloses detection circuitry and pulse oximeter belongs to the medical instrument field, detection circuitry includes microprocessor module, light emission module, light signal commentaries on classics signal of telecommunication module, display module, power module etc, wherein, light signal commentaries on classics signal of telecommunication module adopts photoelectric sensor and signal conversion circuit to convert the light signal after the attenuation of physiology tissue into digital signal, analog signal's direct conversion has been realized, it is analog signal to have overcome traditional light receiving sensor conversion output, receive the problem of interference easily, the required extra circuit of avoidd interference signal has been reduced, and the cost is reduced. The utility model discloses a photoelectric sensor and signal conversion circuit replace the light receiving sensor and outside jam-proof circuit among the prior art, and the signal receives external disturbance influence little, and the precision is high moreover, the uniformity is good.

Description

Detection circuit and pulse oximeter

Technical Field

The utility model relates to the field of medical equipment, in particular to detection circuitry and pulse oximeter.

Background

For a circuit capable of detecting the blood oxygen saturation, the conversion of the optical signal into the electrical signal is an essential part. When a common optical signal is converted into an electrical signal, a filter circuit, a follower circuit, an amplifier circuit, an analog-to-digital conversion circuit and the like are generally required to be arranged, and the circuit design is complex and is easily interfered by the outside world. And the additional circuit added for avoiding signal interference also increases the circuit cost.

Disclosure of Invention

The embodiment of the utility model provides a detection circuitry and pulse oximeter is proposed, and this detection circuitry adopts photoelectric sensor and signal conversion circuit to convert the light signal after the attenuation of physiology tissue into digital signal, utilizes signal conversion circuit, has realized analog signal's direct conversion.

In order to achieve the above purpose, the utility model discloses a scheme is:

a detection circuit for calculating blood oxygen saturation, comprising: the microprocessor module receives the output signal of the optical signal-to-electric signal conversion module and calculates the value of the blood oxygen saturation;

the optical signal to electrical signal conversion module comprises a photoelectric sensor and a signal conversion circuit, and the output of the signal conversion circuit is a non-current signal;

the optical transmission module is connected with the optical signal to electrical signal conversion module;

the display module is connected with the microprocessor module and is used for displaying the blood oxygen saturation value;

and the power supply module is used for supplying power to each module.

Further, the photoelectric sensor is a silicon photocell, the model is BPW34 or BP104 or other chips capable of realizing similar functions, and the signal conversion circuit is TS9514 or TS9517 or other chips capable of realizing similar functions.

Further, the optical signal to electrical signal conversion module further includes a voltage reference unit, where the voltage reference unit may be a resistor network or an integrated circuit, and the resistor network includes a first resistor R1, a second resistor R2, a third resistor R3, a first capacitor C1, and a second capacitor C2. A first end of the first resistor R1 is connected to the first power supply voltage V1, a second end of the first resistor R1 is connected to a first end of the second resistor R2, a second end of the second resistor R2 is connected to a first end of the third resistor R3, a second end of the third resistor R3 is connected to the network ground VGG, a first end of the third resistor R3 is connected to a first end of the first capacitor C1, a second end of the third resistor R3 is connected to a second end of the first capacitor C1, a first end of the second resistor R2 is connected to a first end of the second capacitor C2, and a second end of the second capacitor C2 is connected to the network ground VGG. The first end of the second resistor R2 and the first end of the third resistor R3 are connected with the signal conversion circuit.

Further, the light emitting module comprises light emitting tubes emitting at least two different wavelengths, the wavelengths generally need to include 660nm and 940nm, the light emitting tubes adopt surface-mounted bonding pads, and the bonding pads comprise four parts: the first rectangular bonding pad is connected with the first circular bonding pad, the second rectangular bonding pad is connected with the second circular bonding pad, the first rectangular bonding pad and the second rectangular bonding pad form a second light-emitting tube bonding pad, and the first circular bonding pad and the second circular bonding pad form a first light-emitting tube bonding pad.

Further, the power management module includes a first power chip P1 and a second power chip P2, and the first power chip P1 includes: the first output terminal OUT1 outputs a first supply voltage VDD1, and the first input terminal IN1, the first output terminal OUT1, and the first enable terminal EN1, the first enable terminal EN1 may be connected with a microprocessor port or a pull-up resistor or a pull-down resistor as needed; the second power supply chip P2 includes: the second input end IN2, the second output end OUT2, the second enable end EN2, the second enable end EN2 can be connected with the port of the microprocessor or a pull-up resistor as required, the second output end OUT2 outputs a second supply voltage VDD2, and the first supply voltage VDD1 and the second supply voltage VDD2 are connected with the signal conversion circuit.

Further, the detection circuit further comprises a direction detection module and an alarm module.

Further, the alarm module comprises a buzzer Q1, a first resistor SR1, a second resistor SR2, a diode D, a triode Y1 or a MOS tube Y2, wherein the buzzer can be an active buzzer or a passive buzzer, the first resistor SR1 is connected with the base of the triode Y1 (or the grid of the MOS tube Y2), one end of the second resistor SR2 is connected with the collector of the triode Y1 (or the grid of the MOS tube Y2), the other end of the second resistor SR2 is connected with the anode of the diode D, the cathode of the diode D is connected with the 1 pin of the buzzer Q1, the 2 pin of the buzzer Q1 is connected with the cathode of the diode D, and the 3 pin and the 4 pin of the buzzer Q1 are connected with a network ground VGG.

Further, the direction detection module includes: a gravitational acceleration sensor.

A pulse oximeter comprising: casing, apron, circuit board, the circuit board includes detection circuitry as above.

The utility model has the advantages that:

the embodiment of the utility model provides an adopt photoelectric sensor and signal conversion circuit to convert the light signal after the attenuation of physiology tissue into digital signal, it is analog signal to have overcome traditional light receiving sensor conversion output, receives the problem of interference easily, has reduced the required extra circuit of avoidng interfering signal, and the signal receives external disturbance to influence for a short time, and the precision is high moreover, the uniformity is good.

The present invention will be described in detail with reference to the accompanying drawings and examples.

Drawings

FIG. 1 is a schematic diagram of the overall detection circuit;

FIG. 2 is a schematic diagram of an optical signal to electrical signal conversion circuit;

FIG. 3 is a circuit diagram of an optical signal to electrical signal conversion module;

FIG. 4 is a schematic diagram of a bonding pad structure attached to a surface of a light emitting tube of a light emitting module;

FIG. 5 is a circuit diagram of a power management module;

FIG. 6 is a circuit diagram of an alarm module;

fig. 7 is a schematic diagram of a pulse oximeter including a detection circuit.

Detailed Description

Example (b):

a detection circuit is used for detecting physiological parameters such as blood oxygen saturation and the like, converting optical signals attenuated by physiological tissues into digital signals and is at least used for signal acquisition of pulse oximeters such as finger-clip type, handheld type, desk type and wrist type. As shown in fig. 1, the detection circuit 10 includes a microprocessor module 1, an optical signal to electrical signal conversion module 2, a light emitting module 3, a direction detection module 4, an alarm module 5, a display module 6, a power management module 7, and a power supply module 8.

The microprocessor module 1 comprises a microprocessor 1-1, the microprocessor 1-1 is a control center of the pulse oximeter, is connected with each part of the detection circuit 10 through an interface or an electrical connection, and realizes each function of the product by running a program in a memory of the microprocessor module and storing data, wherein the realized functions include but are not limited to collecting an output signal of the optical signal to electrical signal conversion module 2, calculating to obtain physiological parameters such as blood oxygen saturation, controlling the working output voltage of the power management module to supply power to each module, and the like.

The optical signal is an optical signal attenuated by the physiological tissue, and the electrical signal is a non-current signal, such as a frequency signal related to the light intensity or a voltage signal related to the light intensity. As shown in fig. 2, the optical signal to electrical signal conversion module 2 includes a photoelectric sensor 2-1 and a signal conversion circuit 2-2, the signal conversion circuit outputs a non-current signal, and the photoelectric sensor is electrically connected to the signal conversion circuit. The pulse oximeter has a limited volume and a small available area of a circuit board, in order to facilitate layout of devices, the photoelectric sensor and the signal conversion circuit are independently arranged on the circuit board, and in order to ensure stability of signals and ensure that the electrical distance is as close as possible, the pulse oximeter further comprises a voltage reference unit 2-3. The photoelectric sensor is a silicon photocell, the model is BPW34 or BP104 or other chips which can realize similar functions, and the signal conversion circuit is TS9514 or TS9517 or other chips which can realize similar functions. Further, the photoelectric sensor is BPW34 and the signal conversion circuit is TS9514, and as shown in FIG. 3, the photoelectric sensor 2-1 (BPW 34) is connected to the signal conversion circuit 2-2. The voltage reference unit 2-3 may be a resistor network, or an integrated circuit, such as TL431, which can provide a stable output voltage. The resistor network comprises a first resistor R1, a second resistor R2, a third resistor R3, a first capacitor C1 and a second capacitor C2. A first end of the first resistor R1 is connected to the first power supply voltage V1, a second end of the first resistor R1 is connected to a first end of the second resistor R2, a second end of the second resistor R2 is connected to a first end of the third resistor R3, a second end of the third resistor R3 is connected to the network ground VGG, a first end of the third resistor R3 is connected to a first end of the first capacitor C1, a second end of the third resistor R3 is connected to a second end of the first capacitor C1, a first end of the second resistor R2 is connected to a first end of the second capacitor C2, and a second end of the second capacitor C2 is connected to the network ground VGG. A first end of the second resistor R2 is connected to the CS pin of the signal conversion circuit 2-2, and a first end of the third resistor R3 is connected to the SDI pin of the signal conversion circuit 2-2. The anode of the silicon photocell is connected with the ANOD pin of the signal conversion circuit 2-2, the cathode of the silicon photocell is connected with the IN pin of the signal conversion circuit, and the photoelectric sensor 2-1 comprises a silicon photocell or a parallel combination of a plurality of silicon photocells.

Light emission module 3 is connected with light signal commentaries on classics signal of telecommunication module 2, light emission module 3 is including the luminotron that sends two wavelength at least, and the luminotron of two different wavelength is located a encapsulation, and the encapsulation of using always is cut straightly the encapsulation, and generally cut straightly needs the through-hole, and the through-hole can destroy PCB's structure and the pin can occupy space, and then increases pulse oximeter's volume. In order to reduce the space occupation of the pins, the pins can be cut short, the original through holes are changed into the first sensor bonding pads in a surface-mounted mode, then welding is carried out, and the pins do not penetrate through the circuit board any more. Further, in order to reduce the step of cutting short pins of the direct-insertion light-emitting tube, surface-mount packaging is adopted. As shown in fig. 4, the bonding pads on the circuit board for soldering the light emitting tube at least include four parts: first rectangle pad A1, second rectangle pad A2, first circular pad B1, second circular pad B2, first rectangle pad A1 is connected with first circular pad B1, second rectangle pad A2 is connected with second circular pad B2, second sensor pad S2 is constituteed to first rectangle pad A1, second rectangle pad A2, and first sensor pad S1 is constituteed to first circular pad B1, second circular pad B2, when the device of adopting the cut-through encapsulation, second sensor pad S2 is located the projection region on the circuit board after the cut-through welding is accomplished. Because the first sensor bonding pad S1 is located the dorsal part of emergent light behind the welding of straight plug-in components, can form the reverberation, can increase the light intensity of luminotron output, the sensor of a plurality of models can be compatible in this table design of pasting the bonding pad, foreseeable be this table to paste the bonding pad design also can be used for the welding of other sensors.

And the power supply module 8 comprises a disposable battery or a non-disposable battery.

The power management module 7 includes a first power chip P1 and a second power chip P2, as shown in fig. 5, the first power chip P1 includes: the first output terminal OUT1 outputs a first supply voltage VDD1, and the first output terminal OUT1 and the first enable terminal EN1, where the first enable terminal EN1 may be connected to a port of the microprocessor 1 or a pull-up resistor or a pull-down resistor as needed; the second power chip P2 includes: the second input end IN2, the second output end OUT2, the second enable end EN2, the second enable end EN2 can be connected with the port of the microprocessor 1 or a pull-up resistor as required, the second output end OUT2 outputs a second power supply voltage VDD2, and the first power supply voltage VDD1 and the second power supply voltage VDD2 are connected with the signal conversion circuit 2-2.

As shown in fig. 6, the alarm module 5 includes a buzzer Q1, a first resistor SR1, a second resistor SR2, a diode D, a triode Y1, or a MOS transistor Y2, where the buzzer may be an active buzzer or a passive buzzer, a first end of the first resistor SR1 is electrically connected to the microprocessor, a second end of the first resistor SR1 is connected to a base of the triode Y1 (or a gate of the MOS transistor Y2), a first end of the second resistor SR2 is connected to a collector of the triode Y1 (or a source of the MOS transistor Y2), a second end of the second resistor SR2 is connected to an anode of the diode D, a cathode of the diode D is connected to pin 1 of the buzzer Q1, a pin 2 of the buzzer Q1 is connected to a cathode of the diode D, and pins 3 and 4 of the buzzer Q1 are connected to a network ground VGG.

The direction detection module 4 includes: and a gravity acceleration sensor GA.

The display module 6 comprises a display screen 6-1 for displaying information such as numerical values of the physiological parameters. In some embodiments, the Display 6-1 may be a Liquid Crystal Display (LCD) or Organic Light-Emitting Diode (OLED) type Display. In some embodiments, when the display 6-1 is a liquid crystal display, the display 6-1 may include a backlight module, a lower polarizer, an array substrate, a liquid crystal layer, a color filter substrate, an upper polarizer, and the like, which are sequentially stacked. When the display screen 6-1 is an organic light emitting diode display screen, the display screen 6-1 may include a base layer, an anode layer, an organic layer, a conductive layer, an emission layer, a cathode layer, and the like, which are sequentially stacked. In some embodiments, the display screen 6-1 may be a transparent display screen or a non-transparent display screen. The structure of the display screen 6-1 is not limited to this. For example, the display screen 6-1 may be a shaped screen. The display screen 6-1 is provided with a display surface and a non-display surface which are opposite, and the display screen 6-1 displays through the display surface, and the display surface is arranged towards the external direction of the pulse oximeter. The non-display surface of the display screen 6-1 is not displayed, and the non-display surface is positioned inside the pulse oximeter. The non-display surface of the display screen 6-1 is arranged on the inner surface of the frame in a laminating way, and the frame plays a role in bearing and protecting the display screen. The frame can be made of plastic materials, and can also be formed by matching metal and plastic. It should be noted that the frame may also be made of other materials. In some embodiments, the outer surface of the frame is provided with a positioning structure, which may be detachably or fixedly connected with the circuit board. The positioning structure is a cylinder, and a circular hole is formed in the corresponding circuit board.

As shown in fig. 7, the pulse oximeter 20 includes a detection circuit 10 for calculating physiological parameters such as blood oxygen saturation and pulse rate, and is divided into: finger clip, hand-held, desk-top, wrist, etc., the utility model is not particularly specified. The pulse oximeter 20 further comprises a cover plate 11 and a housing 12, wherein the cover plate 11 is mounted on the housing 12 for covering the display screen 6-1, and the cover plate 11 may be made of a transparent plastic material so that the display screen can display through the cover plate 11. In some embodiments, the cover plate 11 may be made of glass or sapphire.

Wherein the housing 12 may form the outer contour of the pulse oximeter 20, as well as the cavity in which the fingers are placed. The case 12 may include an upper case 12-1, a lower case 12-2, the upper case 12-1 and the lower case 12-2 being combined with each other to form the case 12, and an upper surface of the lower case 12-2 and a lower surface of the upper case 12-1 indicate a cavity for receiving a finger, and the upper case 12-1 may receive a display screen 6-1 and the like, and the lower case 12-2 may receive a light emitting module 3, a battery and the like.

The circuit board is installed inside the shell, and specifically, the circuit board can be screwed on the shell through a screw and/or be clamped on the shell in a buckling mode. One, two or more of at least one sensor, microprocessor, motor, memory, etc. functional components may be integrated on the circuit board.

Finally, the above embodiments are merely to illustrate the technical solutions of the present invention and not to limit the same, although the present invention is described in detail with reference to the preferred embodiments. It will be understood by those skilled in the art that all other embodiments obtained without the inventive step are intended to fall within the scope of the present invention.

Claims (9)

1. A detection circuit for calculating blood oxygen saturation, the detection circuit comprising:

the microprocessor module receives the output signal of the optical signal-to-electric signal conversion module and calculates the value of the blood oxygen saturation;

the optical signal to electrical signal conversion module comprises a photoelectric sensor and a signal conversion circuit, and the output of the signal conversion circuit is a non-current signal;

the optical transmission module is connected with the optical signal to electrical signal conversion module;

the display module is connected with the microprocessor module and is used for displaying the blood oxygen saturation value;

and the power supply module is used for supplying power to each module.

2. A detection circuit according to claim 1, wherein said photoelectric sensor is a silicon photocell, model BPW34 or BP104, and said signal conversion circuit is TS9514 or TS 9517.

3. The detecting circuit of claim 2, wherein the optical signal to electrical signal converting module further comprises a voltage reference unit, the voltage reference unit can be a resistor network or an integrated circuit, the resistor network comprises a first resistor R1, a second resistor R2, a third resistor R3, a first capacitor C1, and a second capacitor C2, a first end of the first resistor R1 is connected to the first supply voltage V1, a second end of the first resistor R1 is connected to a first end of the second resistor R2, a second end of the second resistor R2 is connected to a first end of the third resistor R3, a second end of the third resistor R3 is connected to the network ground VGG, a first end of the third resistor R3 is connected to a first end of the first capacitor C1, a second end of the third resistor R3 is connected to a second end of the first capacitor C1, a first end of the second resistor R2 is connected to a first end of the second capacitor C2, and a second end of the second capacitor C2 is connected to the network ground VGG 6857, the first end of the second resistor R2 and the first end of the third resistor R3 are connected with the signal conversion circuit.

4. The detection circuit as claimed in claim 3, wherein the light emitting module comprises light emitting tubes emitting at least two different wavelengths, the light emitting tubes are surface-mounted pads, and the pads comprise four parts: the first rectangular bonding pad is connected with the first circular bonding pad, the second rectangular bonding pad is connected with the second circular bonding pad, the first rectangular bonding pad and the second rectangular bonding pad form a second light-emitting tube bonding pad, and the first circular bonding pad and the second circular bonding pad form a first light-emitting tube bonding pad.

5. The detection circuit according to claim 1, further comprising a power management module, wherein the power management module comprises a first power chip P1, a second power chip P2, and the first power chip P1 comprises: the first output terminal OUT1 outputs a first supply voltage VDD1, and the first input terminal IN1, the first output terminal OUT1, and the first enable terminal EN1, the first enable terminal EN1 may be connected with a microprocessor port or a pull-up resistor or a pull-down resistor as needed; the second power supply chip P2 includes: the second input end IN2, the second output end OUT2, the second enable end EN2, the second enable end EN2 can be connected with the port of the microprocessor or a pull-up resistor as required, the second output end OUT2 outputs a second supply voltage VDD2, and the first supply voltage VDD1 and the second supply voltage VDD2 are connected with the signal conversion circuit.

6. A detection circuit according to claim 3 or 4, characterized in that the detection circuit further comprises a direction detection module and an alarm module.

7. The detection circuit as claimed in claim 6, wherein the alarm module comprises a buzzer Q1, a first resistor SR1, a second resistor SR2, a diode D, a transistor Y1 or a MOS tube Y2, the buzzer can be an active buzzer or a passive buzzer, the first resistor SR1 is connected with the base of a transistor Y1 or the gate of a MOS tube Y2, one end of the second resistor SR2 is connected with the collector of a transistor Y1 or the gate of a MOS tube Y2, the other end of the second resistor SR2 is connected with the anode of a diode D, the cathode of the diode D is connected with the 1 pin of the buzzer Q1, the 2 pin of the buzzer Q1 is connected with the cathode of the diode D, and the 3 pin and the 4 pin of the buzzer Q1 are connected with a network ground VGG.

8. The detection circuit of claim 6, wherein the direction detection module comprises: a gravitational acceleration sensor.

9. A pulse oximeter comprising: housing, cover plate, circuit board, characterized in that the circuit board comprises a detection circuit according to any one of claims 1-8.

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