Neonatal jaundice blue light radiation light source control circuit

Abstract

The invention discloses a neonatal jaundice blue light radiation light source control circuit, which comprises a plurality of blue light diode series lamp strips, and also comprises a lamp strip current driving circuit which is electrically connected with the blue light diode series lamp strips; the lamp strip current driving circuit is used for adjusting the current of the blue light diode series lamp strip; the current signal conditioning circuit is connected with the lamp strip driving circuit, and the current signal conditioning circuit is used for accurately sampling the voltage of the lamp strip driving circuit; the control module is respectively connected with the lamp strip current driving circuit and the current signal conditioning circuit; and the control module calculates the current of the lamp strip current driving circuit according to the sampled voltage, and outputs an instruction according to a calculation result to control the current of the blue light diode series lamp strip to be stabilized at a set value. According to the invention, the driving current of the blue light source at different angle positions can be controlled, the adjustment is convenient, and the control is simple and stable.

Description

Technical Field

[0001] The invention relates to the technical field of medical electronics, and in particular to a blue light radiation light source control circuit for neonatal jaundice. Background Art

[0002] Neonatal hyperbilirubinemia (jaundice) is one of the common diseases in the neonatal period. About 60% to 80% of premature infants have visible jaundice in the first week after birth. Bilirubin encephalopathy induced by jaundice seriously threatens the life and health of newborns. It is one of the main causes of hearing impairment, visual abnormalities and intellectual retardation in infants, and even death in severe cases. Blue light phototherapy (phototherapy) is widely used as the main treatment method for neonatal jaundice due to its non-invasive, effective, simple and economical characteristics. The reason is that bilirubin can absorb light waves, and under the action of light, unconjugated bilirubin is converted into water-soluble isomers, which are excreted into the intestinal cavity through bile or excreted from urine. Applying the above principle, doctors often use visible blue light with a wavelength of 400 to 550nm to irradiate the patient's skin surface, so that the unconjugated bilirubin in the epidermal blood undergoes the above biochemical reaction, thereby reducing the serum bilirubin concentration and achieving the purpose of treating jaundice. Therefore, the wavelength, intensity and irradiation angle of blue light are crucial to the treatment effect of neonatal jaundice. Doctors optimize the wavelength of the blue light source, the light intensity at different angles, and the exposure time according to the changes in the condition to achieve the best treatment effect. Since the wavelength and intensity of the blue light LED are determined by the driving current flowing through the light source, the accuracy and stability of the driving current are directly related to the accuracy and stability of the wavelength and light intensity, so it is necessary to control the driving current of the blue light source at different angles. Summary of the invention

[0003] The purpose of the present invention is to provide a blue light radiation light source control circuit for neonatal jaundice. The present invention can control the driving current of the blue light source at different angles, and has the advantages of convenient adjustment, simple and stable control.

[0004] The technical solution of the present invention is: a blue light radiation light source control circuit for neonatal jaundice, comprising a plurality of blue light diode series light strips, wherein the plurality of blue light diode series light strips are respectively used to irradiate different parts of the neonate; and further comprising:

[0005] A light strip current driving circuit, the light strip driving circuit is electrically connected to the blue light diode series light strip; the light strip current driving circuit is used to adjust the current of the blue light diode series light strip;

[0006] A current signal conditioning circuit, wherein the current signal conditioning circuit is connected to the light strip driving circuit, and the current signal conditioning circuit is used to achieve accurate sampling of the voltage of the light strip driving circuit;

[0007] A control module, wherein the control module is connected to the light strip current driving circuit and the current signal conditioning circuit respectively; the control module is used to calculate the current of the light strip current driving circuit according to the voltage sampled by the current signal conditioning circuit, and output instructions according to the calculation results to control the current of the blue light diode series light strip to be stable at a set value.

[0008] The above-mentioned neonatal jaundice blue light radiation light source control circuit, the said blue light diode series light strip is provided with three strips, wherein the first blue light diode series light strip realizes irradiation of the head and neck part of the newborn, the second blue light diode series light strip realizes irradiation of the neck to the perineum part of the newborn, and the third blue light diode series light strip realizes irradiation of the neck to the soles of the feet of the newborn.

[0009] The above-mentioned neonatal jaundice blue light radiation light source control circuit, the first blue light diode series light strip current driving circuit includes a capacitor C 1 , resistor R 1 、Inductance L 1 、Diode D 1 And NMOS tube Q 1 One end of the first blue light diode series light strip is connected to the DC power supply voltage VD+, and the other end of the first blue light diode series light strip is connected to the resistor R 1 and inductor L 1 connected in series; the capacitor C 1 The inductor L is connected in parallel with the first blue light diode series light strip; 1 With NMOS tube Q 1 The drain connection of NMOS tube Q 1 The source of NMOS tube Q is grounded. 1 The gate of the diode D is connected to the control module; 1 The anode of the inductor L is connected to 1 With NMOS tube Q 1 Between the drain of diode D 1 The cathode is connected between the first blue light diode series light strip and the DC power supply voltage VD+.

[0010] The aforementioned neonatal jaundice blue light radiation light source control circuit, the second blue light diode series light strip current driving circuit includes a capacitor C 2 , resistor R 2 、Inductance L 2 、Diode D 2 And NMOS tube Q 2 One end of the second blue light diode series light strip is connected to the DC power supply voltage VD+, and the other end of the second blue light diode series light strip is connected to the resistor R 2 and inductor L 2 connected in series; the capacitor C2 The inductor L is connected in parallel with the second blue light diode series light strip; 2 With NMOS tube Q 2 The drain connection of NMOS tube Q 2 The source of NMOS tube Q is grounded. 2 The gate of the diode D is connected to the control module; 2 The anode of the inductor L is connected to 2 With NMOS tube Q 2 Between the drain of diode D 2 The cathode is connected between the second blue light diode series light strip and the DC power supply voltage VD+.

[0011] The aforementioned neonatal jaundice blue light radiation light source control circuit, the third blue light diode series light strip current driving circuit comprises a capacitor C 3 , resistor R 3 、Inductance L 3 、Diode D 3 And NMOS tube Q 3 One end of the third blue light diode series light strip is connected to the DC power supply voltage VD+, and the other end of the third blue light diode series light strip is connected to the resistor R 3 and inductor L 3 connected in series; the capacitor D 3 The inductor L is connected in parallel with the third blue light diode series light strip; 3 With NMOS tube Q 3 The drain connection of NMOS tube Q 3 The source of NMOS tube Q is grounded. 3 The gate of the diode D is connected to the control module; 3 The anode of the inductor L is connected to 3 With NMOS tube Q 3 Between the drain of diode D 3 The cathode is connected between the third blue light diode series light strip and the DC power supply voltage VD+.

[0012] The above-mentioned neonatal jaundice blue light radiation source control circuit, the current signal conditioning circuit includes a differential amplifier AMP 1 , operational amplifier OP1, resistor resistance resistance resistance and filtering circuit; the differential amplifier AMP 1 The non-inverting input terminal and the inverting input terminal of the differential amplifier AMP are respectively connected to the light belt current driving circuit; 1 The output terminal and the resistor Connect one end of the resistor The other end is connected to the non-inverting input of the operational amplifier OP1 and the resistor one end of the resistor The other end is connected to the reference voltage V ref Connect the inverting input terminal of the operational amplifier OP1 to the resistor Connect one end of the resistor The other end of the operational amplifier OP1 is connected to the filter circuit and the resistor Connect one end of the resistor The other end is connected to the inverting input of the operational amplifier OP1 and the resistor The output end of the filter circuit is connected to the control module.

[0013] The aforementioned neonatal jaundice blue light radiation source control circuit also includes a step-down circuit, the input end of the step-down circuit is connected to the DC power supply voltage VD+, and the output end of the input end of the step-down circuit is connected to the control circuit and the current signal conditioning circuit.

[0014] The aforementioned neonatal jaundice blue light radiation light source control circuit, the control module is MCU.

[0015] Compared with the prior art, the present invention divides the blue light source LED into multiple blue light diode series light strips, and the multiple blue light diode series light strips respectively illuminate different body parts of the newborn, and then respectively set the light strip current drive circuit for independent control, so that different blue light diode series light strips provide different illumination intensities, which can meet different illumination requirements. At the same time, the present invention has the advantages of convenient adjustment, simple and stable control. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a schematic diagram of a circuit of the present invention;

[0017] Figure 2 is a circuit diagram of a current signal conditioning circuit of the present invention;

[0018] Figure 3 It is a schematic diagram of the process of the control method of the present invention. DETAILED DESCRIPTION

[0019] The present invention is further described below in conjunction with the accompanying drawings and examples, but they are not intended to limit the present invention.

[0020] Embodiment: A blue light radiation source control circuit for neonatal jaundice, comprising a plurality of blue light diodes connected in series, the plurality of blue light diodes connected in series are used to irradiate different parts of the neonate respectively; and further comprising:

[0021] A light strip current driving circuit, the light strip driving circuit is electrically connected to the blue light diode series light strip; the light strip current driving circuit is used to adjust the current of the blue light diode series light strip;

[0022] A current signal conditioning circuit, wherein the current signal conditioning circuit is connected to the light strip driving circuit, and the current signal conditioning circuit is used to achieve accurate sampling of the voltage of the light strip driving circuit;

[0023] A control module, wherein the control module is connected to the light strip current driving circuit and the current signal conditioning circuit respectively; the control module is used to calculate the current of the light strip current driving circuit according to the voltage sampled by the current signal conditioning circuit, and output instructions according to the calculation results to control the current of the blue light diode series light strip to be stable at a set value.

[0024] In this embodiment, three blue light diode series light strips are provided, wherein the first blue light diode series light strip is used to illuminate the head and neck of the newborn, the second blue light diode series light strip is used to illuminate the neck to perineum of the newborn, and the third blue light diode series light strip is used to illuminate the neck to soles of the newborn.

[0025] Specifically, the first blue light diode series light strip current driving circuit includes a capacitor C 1 , resistor R 1 、Inductance L 1 、Diode D 1 And NMOS tube Q 1 One end of the first blue light diode series light strip is connected to the DC power supply voltage VD+, and the other end of the first blue light diode series light strip is connected to the resistor R 1 and inductor L 1 connected in series; the capacitor C 1 The inductor L is connected in parallel with the first blue light diode series light strip; 1 With NMOS tube Q 1 The drain connection of NMOS tube Q 1 The source of NMOS tube Q is grounded. 1 The gate of the diode D is connected to the control module; 1 The anode of the inductor L is connected to 1 With NMOS tube Q 1 Between the drain of diode D 1 The cathode of is connected between the first blue light diode series light strip and the DC power supply voltage VD+. In the light strip current driving circuit of the first blue light diode series light strip, the capacitor C 1 Stabilize the current of the first blue light diode in series with the lamp; resistor R 1 Used to convert the current signal i 1 Converted into voltage signal v1 ; Inductance L 1 As an energy storage component, it plays a role in smoothing the current of the first blue light diode series light strip; NMOS tube Q 1 It is a power switch with the advantages of high switching frequency, low internal resistance and small loss, and can regulate the current of the first blue light diode series light strip. 1 It is an anti-parallel diode. 1 When turned off, the inductor L 1 The current provides a freewheeling current. This part controls the NMOS tube Q 1 The duty cycle and working time of the PWM drive signal can be used to adjust the light intensity and illumination time of the first blue light diode series light strip to achieve jaundice treatment in the head and neck of newborns.

[0026] The second blue light diode series light strip current driving circuit comprises a capacitor C 2 , resistor R 2 、Inductance L 2 、Diode D 2 And NMOS tube Q 2 One end of the second blue light diode series light strip is connected to the DC power supply voltage VD+, and the other end of the second blue light diode series light strip is connected to the resistor R 2 and inductor L 2 connected in series; the capacitor C 2 The inductor L is connected in parallel with the second blue light diode series light strip; 2 With NMOS tube Q 2 The drain connection of NMOS tube Q 2 The source of NMOS tube Q is grounded. 2 The gate of the diode D is connected to the control module; 2 The anode of the inductor L is connected to 2 With NMOS tube Q 2 Between the drain of diode D 2 The cathode of is connected between the second blue light diode series light strip and the DC power supply voltage VD+. In the light strip current driving circuit of the second blue light diode series light strip, the capacitor C 2 Stabilize the current of the second blue light diode in series with the lamp; resistor R 2 Used to convert the current signal i 2 Converted into voltage signal v 2 ; Inductance L 2 As an energy storage component, it plays a role in smoothing the current of the second blue light diode series light strip; NMOS tube Q 2 It is a power switch with the advantages of high switching frequency, low internal resistance and small loss, and can regulate the current of the second blue light diode series light strip. 2It is an anti-parallel diode. 2 When turned off, the inductor L 2 The current provides a freewheeling current. This part controls the NMOS tube Q 2 The duty cycle and working time of the PWM drive signal can be used to adjust the light intensity and lighting time of the second blue light diode series light strip to achieve jaundice treatment from the neck to the perineum of the newborn.

[0027] The third blue light diode series light strip current driving circuit comprises a capacitor C 3 , resistor R 3 、Inductance L 3 、Diode D 3 And NMOS tube Q 3 One end of the third blue light diode series light strip is connected to the DC power supply voltage VD+, and the other end of the third blue light diode series light strip is connected to the resistor R 3 and inductor L 3 connected in series; the capacitor D 3 The inductor L is connected in parallel with the third blue light diode series light strip; 3 With NMOS tube Q 3 The drain connection of NMOS tube Q 3 The source of NMOS tube Q is grounded. 3 The gate of the diode D is connected to the control module; 3 The anode of the inductor L is connected to 3 With NMOS tube Q 3 Between the drain of diode D 3 The cathode of is connected between the third blue light diode series light strip and the DC power supply voltage VD+. In the light strip current driving circuit of the third blue light diode series light strip, the capacitor C 3 Stabilize the current of the third blue light diode in series with the lamp; resistor R 3 Used to convert the current signal i 3 Converted into voltage signal v 3 ; Inductance L 3 As an energy storage component, it plays a role in smoothing the current of the third blue light diode series light strip; NMOS tube Q 3 It is a power switch with the advantages of high switching frequency, low internal resistance and small loss, and can regulate the current of the third blue light diode in series. 3 It is an anti-parallel diode. 3 When turned off, the inductor L 3 The current provides a freewheeling current. This part controls the NMOS tube Q 3The duty cycle and working time of the PWM drive signal can be used to adjust the light intensity and lighting time of the third blue light diode series light strip to achieve jaundice treatment from the neck to the soles of the newborn.

[0028] The control module is a microprocessor MCU, which samples the current flowing through the inductor L through AD1, AD2 and AD3. 1 、Inductance L 2 and inductor L 3 The current value i 1 、i 2 and i 3 , and the NMOS tube Q is calculated by the MCU built-in program 1 、NMOS tube Q 2 And NMOS tube Q 3 The PWM drive signals PWM1, PWM2 and PWM3 make the current flowing through the inductor L 1 、Inductance L 2 and inductor L 3 The current i 1 、i 2 and i 3 Stable at the set value.

[0029] In this embodiment, three current signal conditioning circuits are provided, and their circuit structures and parameters are the same, and they are respectively connected to three light strip current driving circuits; in this embodiment, for the convenience of description, the current signal conditioning circuit 1 connected to the light strip current driving circuit of the first blue light diode series light strip is taken as an example. Figure 2 , the differential amplifier AMP 1 , operational amplifier OP1, resistor resistance resistance resistance and filtering circuit; the differential amplifier AMP 1 The non-inverting input and the inverting input are connected to the resistor R 1 The two ends of the differential amplifier AMP 1 The output terminal and the resistor Connect one end of the resistor The other end is connected to the non-inverting input of the operational amplifier OP1 and the resistor one end of the resistor The other end is connected to the reference voltage V ref Connect the inverting input terminal of the operational amplifier OP1 to the resistor Connect one end of the resistor The other end of the operational amplifier OP1 is connected to the filter circuit and the resistor Connect one end of the resistor The other end is connected to the inverting input of the operational amplifier OP1 and the resistor The output end of the filter circuit is connected to the control module. In the current signal conditioning circuit, the resistor R 1 The current i 1 Converted into voltage signal v 1 In order to suppress the temperature change on the resistor R 1 and measurement accuracy, the resistor R 1 Choose a smaller resistance. Therefore, the resistor R 1 The voltage across the two ends is v 1 Very small. 1 with i 1 Satisfies the following formula:

[0030] v 1 =R 1 ×i 1 ; (1)

[0031] Differential Amplifier AMP 1 For the resistor R 1 The weak voltage signal v at both ends 1 Perform differential amplification to obtain an amplified voltage signal The differential amplifier AMP1 mainly plays two roles: 1. Suppression resistor R 1 Common mode interference and noise of upper voltage signal; 2. Differential amplifier AMP 1 The output voltage signal It has a strong output current capability and improves the load capacity. With v 1 Satisfies the following formula:

[0032] v o1 =K D ×v i ; (2)

[0033] Where: K D For the differential amplifier AMP 1 The magnification factor of

[0034] Operational amplifier OP1, resistor resistance resistance and resistor A DC bias amplifier circuit; resistor resistance resistance and resistor satisfy:

[0035]

[0036] Where: A is the resistance multiple;

[0037] From the knowledge of electrical engineering, we know that the operational amplifier OP1, the resistor resistance resistance and resistor The DC bias amplifier circuit consists of:

[0038]

[0039] Combining (4) and (5), we can get:

[0040]

[0041] Combining (1), (2) and (6), we can obtain:

[0042]

[0043] It can be seen that the reasonable selection of resistance multiple A and differential amplifier AMP 1 The magnification factor K D and resistor R 1 The value of i 1 When changing within the setting range, It is always in the optimal range of AD sampling voltage to achieve high-precision sampling and control of current.

[0044] Input connection of filter circuit The output end is connected to the AD1 port of the MCU to filter out The high-frequency interference gets the sampling voltage v samp1 The filter circuit in this embodiment can be implemented by using a conventional filter.

[0045] Furthermore, in this embodiment, a step-down circuit is also provided, the input end of the step-down circuit is connected to the DC power supply voltage VD+, and the output end of the input end of the step-down circuit is connected to the control circuit and the current signal conditioning circuit. The step-down circuit (including but not limited to DC / DC or linear voltage regulator circuit LDO) steps down the input DC power supply voltage VD+ to obtain a 5V output voltage for powering the MCU and the current signal conditioning circuit.

[0046] How it works

[0047] See also Figure 3 After the neonatal jaundice blue light radiation source control circuit proposed by the present invention is powered on, the doctor sets the current setting value of the first blue light diode series light strip according to the neonatal jaundice condition. 2. Blue LED series light strip current setting value 3. Blue LED series light strip current setting value And the corresponding work setting time and The MCU obtains the above parameters and starts working, sampling the voltage v of the AD1, AD2 and AD3 ports in real time. samp1 、v samp2 and v samp3 , and calculate the current value i of the first blue light diode series light strip according to formula (7) 1 , the current value of the second blue light diode series light strip i 2 , the current value of the third blue light diode series light strip i 3 Based on the obtained i 1 、i 2 and i 3 , run their respective current closed-loop control algorithms to obtain the NMOS tube Q 1 、NMOS tube Q 2 And NMOS tube Q 3 The PWM signals PWM1, PWM2 and PWM3 are used to adjust the NMOS tube Q in real time. 1 、NMOS tube Q 2 And NMOS tube Q 3 The duty cycle of control i 1 、i 2 and i 3 Stable and And the NMOS tube Q 1 、NMOS tube Q 2 And NMOS tube Q 3 The working time is timed so that the blue light diode series light strip works at the set time.

Claims

1. A blue light radiation source control circuit for neonatal jaundice, comprising a plurality of blue light diodes connected in series, the plurality of blue light diodes connected in series are used to irradiate different parts of the neonate respectively; characterized in that: Also includes: A light strip current driving circuit, wherein the light strip driving circuit is electrically connected to the blue light diode series light strip; The light strip current driving circuit is used to adjust the current of the blue light diode series light strip; A current signal conditioning circuit, the current signal conditioning circuit is connected to the light strip driving circuit, and the current signal conditioning circuit is used to achieve accurate sampling of the voltage of the light strip driving circuit; A control module, wherein the control module is connected to the light strip current driving circuit and the current signal conditioning circuit respectively; the control module is used to calculate the current of the light strip current driving circuit according to the voltage sampled by the current signal conditioning circuit, and output instructions according to the calculation results to control the current of the blue light diode series light strip to be stable at a set value.

2. The neonatal jaundice blue light radiation source control circuit according to claim 1, characterized in that: The blue light diode series light strips are provided with three strips, wherein the first blue light diode series light strip is used to illuminate the head and neck of the newborn, the second blue light diode series light strip is used to illuminate the neck to perineum of the newborn, and the third blue light diode series light strip is used to illuminate the neck to soles of the newborn.

3. The neonatal jaundice blue light radiation source control circuit according to claim 2, characterized in that: The light strip current driving circuit of the first blue light diode series light strip includes a capacitor C1, a resistor R1, an inductor L1, a diode D1 and an NMOS tube Q1; one end of the first blue light diode series light strip is connected to the DC power supply voltage VD+, and the other end of the first blue light diode series light strip is connected in series with the resistor R1 and the inductor L1 in sequence; the capacitor C1 is connected in parallel with the first blue light diode series light strip; the inductor L1 is connected to the drain of the NMOS tube Q1, the source of the NMOS tube Q1 is grounded, and the gate of the NMOS tube Q1 is connected to the control module; the anode of the diode D1 is connected between the inductor L1 and the drain of the NMOS tube Q1, and the cathode of the diode D1 is connected between the first blue light diode series light strip and the DC power supply voltage VD+.

4. The neonatal jaundice blue light radiation source control circuit according to claim 2, characterized in that: The light strip current driving circuit of the second blue light diode series light strip includes a capacitor C2, a resistor R2, an inductor L2, a diode D2 and an NMOS tube Q2; one end of the second blue light diode series light strip is connected to the DC power supply voltage VD+, and the other end of the second blue light diode series light strip is connected in series with the resistor R2 and the inductor L2 in sequence; the capacitor C2 is connected in parallel with the second blue light diode series light strip; the inductor L2 is connected to the drain of the NMOS tube Q2, the source of the NMOS tube Q2 is grounded, and the gate of the NMOS tube Q2 is connected to the control module; the anode of the diode D2 is connected between the inductor L2 and the drain of the NMOS tube Q2, and the cathode of the diode D2 is connected between the second blue light diode series light strip and the DC power supply voltage VD+.

5. The neonatal jaundice blue light radiation source control circuit according to claim 2, characterized in that: The light strip current driving circuit of the third blue light diode series light strip includes a capacitor C3, a resistor R3, an inductor L3, a diode D3 and an NMOS tube Q3; one end of the third blue light diode series light strip is connected to the DC power supply voltage VD+, and the other end of the third blue light diode series light strip is connected in series with the resistor R3 and the inductor L3 in sequence; the capacitor D3 is connected in parallel with the third blue light diode series light strip; the inductor L3 is connected to the drain of the NMOS tube Q3, the source of the NMOS tube Q3 is grounded, and the gate of the NMOS tube Q3 is connected to the control module; the anode of the diode D3 is connected between the inductor L3 and the drain of the NMOS tube Q3, and the cathode of the diode D3 is connected between the third blue light diode series light strip and the DC power supply voltage VD+.

6. The neonatal jaundice blue light radiation source control circuit according to claim 1, characterized in that: The current signal conditioning circuit includes a differential amplifier AMP1, an operational amplifier OP1, a resistor resistance resistance resistance and filtering circuit; the non-inverting input terminal and the inverting input terminal of the differential amplifier AMP1 are respectively connected to the lamp belt current driving circuit; the output terminal of the differential amplifier AMP1 is connected to the resistor Connect one end of the resistor The other end is connected to the non-inverting input of the operational amplifier OP1 and the resistor one end of the resistor The other end is connected to the reference voltage V ref Connect the inverting input terminal of the operational amplifier OP1 to the resistor Connect one end of the resistor The other end of the operational amplifier OP1 is connected to the filter circuit and the resistor Connect one end of the resistor The other end is connected to the inverting input of the operational amplifier OP1 and the resistor The output end of the filter circuit is connected to the control module.

7. The neonatal jaundice blue light radiation source control circuit according to claim 1, characterized in that: It also includes a step-down circuit, the input end of which is connected to a DC power supply voltage VD+, and the output end of the input end of the step-down circuit is connected to a control circuit and a current signal conditioning circuit.

8. The neonatal jaundice blue light radiation source control circuit according to claim 1, characterized in that: The control module is MCU.

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