Medical electrical equipment common mode rejection ratio testing device

Abstract

The utility model discloses a medical electrical equipment common mode rejection ratio testing device, the input end of which is connected with a signal generator, and the output end of which is connected with electrical equipment to be tested. The circuit board is mounted in the shielding shell; one side surface of the shielding shell is provided with a first connecting hole for connecting a first connecting wire, and the other side surface of the shielding shell is provided with a plurality of second connecting holes for connecting a plurality of second connecting wires; a protective grounding terminal is arranged at the bottom of the shielding shell, the shielding shell is connected inside the protective grounding terminal, and a connecting end is provided outside the protective grounding terminal; the connection between the testing device and the signal generator is realized through the first connecting wire, and the connection between the testing device and the electrical equipment to be tested is realized through the plurality of second connecting wires. The testing device is provided with the shielding shell, pickup of unwanted external noise can be effectively reduced, and in order to better exert shielding effectiveness, the shielding shell is provided with the protection grounding terminal, and complete grounding protection can be provided for equipment.

Description

Technical Field

[0001] The utility model relates to the technical field of electrical equipment, in particular to a common mode rejection ratio test device for medical electrical equipment. Background Art

[0002] An electromyographic biofeedback device is an instrument that uses surface motors to collect the body's electromyographic signals as physiological information, and feeds back to the patient in the form of vision or hearing, so that the patient can learn to consciously control his or her own psychological and physiological activities to treat diseases.

[0003] The common mode rejection ratio test device is made according to the YY / T 1095-2015 electromyography biofeedback instrument standard. It is mainly used to test whether the rejection capability from the input end to the amplifier end of medical electrical equipment meets the requirements.

[0004] like Figure 1 The following is a schematic diagram of a conventional test setup. This circuit uses a 51kΩ resistor and a 47nF capacitor to simulate the skin-electrode impedance, with the reference electrode grounded. In practice, measurements on a high-input-impedance amplifier are difficult because the 51kΩ resistor introduces significant noise, leaving room for improvement. Utility Model Content

[0005] The purpose of the utility model is to provide a common mode rejection ratio test device for medical electrical equipment, which can at least solve one of the above problems.

[0006] According to one aspect of the present invention, a common mode rejection ratio test device for medical electrical equipment is provided, wherein the input end thereof is connected to a signal generator and the output end thereof is connected to the electrical equipment to be tested. The test device comprises at least:

[0007] Shielding shell;

[0008] A circuit board is installed in the shielding shell;

[0009] A first connection hole for receiving a first wire is formed on one side of the shielding shell, and a plurality of second connection holes for receiving a plurality of second wires are formed on the other side of the shielding shell;

[0010] A protective grounding terminal is provided at the bottom of the shielding shell, the inside of the protective grounding terminal is connected to the shielding shell, and a connection end is provided on the outside;

[0011] The test device is connected to the signal generator through a first connection, and the test device is connected to the electrical device to be tested through a plurality of second connections;

[0012] During the test, the test device is connected to the electrical equipment under test through the second connection and to the signal generator through the first connection. The signal generator is adjusted to output a signal with an amplitude Vin of 1Vrms-5Vrms and a frequency of 2 times the power frequency. The displayed value of the electrical equipment under test is read and the total value is calculated according to formula (1).

[0013]

[0014] Mode suppression ratio:

[0015] Where CMRR is the common mode rejection ratio, Vin is the output value of the signal generator, and Vo is the display value of the electrical equipment under test.

[0016] In some embodiments, the first wiring is a two-wire wire, and the input ends of the first wiring are respectively connected to the positive and negative electrodes of the signal generator.

[0017] In some embodiments, the number of second wires is three, two of which serve as output terminals facing output electrodes of the electrical device under test, and the other serves as a reference electrode facing the reference electrode of the electrical device under test.

[0018] In some embodiments, the circuit board is integrated with an input interface corresponding to the first connection hole and three output interfaces, namely, a first output interface, a second output interface, and a third output interface corresponding to the second connection hole.

[0019] In some embodiments, the circuit board also includes a fourth resistor, a first resistor, a first capacitor, a second capacitor, and a third capacitor arranged between the input interface and the first output interface, the fourth resistor is connected in series with the input interface, the first resistor, the first capacitor, the second capacitor, and the third capacitor form a first parallel circuit, and the two ends of the first parallel circuit are respectively connected in series with the fourth resistor and the first output interface.

[0020] In some embodiments, the circuit board also includes a third resistor, a fourth capacitor, a fifth capacitor, a sixth capacitor, a seventh capacitor, and an eighth capacitor arranged between the input interface and the second output interface. The fourth capacitor and the eighth capacitor form a second parallel circuit and are connected in series with the input interface. The third resistor, the fifth capacitor, the sixth capacitor, and the seventh capacitor form a third parallel circuit and the two ends of the third parallel circuit are respectively connected in series with the second parallel circuit and the second output interface.

[0021] In some embodiments, the circuit board also includes a second resistor and a ninth capacitor arranged between the input interface and the third output interface, the second resistor and the ninth capacitor form a fourth parallel circuit, and the two ends of the fourth parallel circuit are respectively connected in series with the second parallel circuit and the third output interface.

[0022] In some embodiments, the circuit board further includes a fifth resistor, which is connected in series with the second resistor, the ninth capacitor, and the protective grounding terminal.

[0023] Beneficial effects of the utility model:

[0024] The utility model provides a test device that can quickly test the common-mode rejection ratio of medical electrical equipment. When in use, the test device is respectively connected to a signal generator and the electrical equipment to be tested to form a complete test circuit. A shielding shell is provided to effectively reduce the pickup of unwanted external noise. In order to better exert the shielding effect, the shielding shell is provided with a protective grounding terminal to provide complete grounding protection for the equipment.

[0025] The common-mode rejection ratio test device for medical electrical equipment of the utility model can simplify and make portable complex tests, thereby reducing the difficulty of the test and saving the test time. The fixed test device makes the test more convenient and quick. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A circuit schematic diagram of a test device in the prior art;

[0027] Figure 2 This is a schematic diagram of the three-dimensional structure of the testing device of the present utility model;

[0028] Figure 3 for Figure 1 One of the three-dimensional structural schematic diagrams of the shielding shell of the common mode rejection ratio test device of medical electrical equipment is shown;

[0029] Figure 4 for Figure 1 The second schematic diagram of the three-dimensional structure of the shielding shell of the common mode rejection ratio test device of medical electrical equipment is shown;

[0030] Figure 5 This is a circuit diagram of the test device of the present utility model;

[0031] Figure 6 This is a schematic diagram of the application of the testing device of the present utility model.

[0032] Figures 2 to 6The figure marks in the figure are: 100-test device; 200-signal generator; 300-electrical equipment to be tested; 1-shielding shell; 2-circuit board; 3-first wiring; 4-second wiring; 11-first connecting hole; 12-second connecting hole; 13-third connecting hole; GND-protective grounding terminal; Pin1-input interface; P1-first output interface; P2-second output interface; GND1-third output interface; R1-first resistor; R2-second resistor; R3-third resistor; R4-fourth resistor; R5-fifth resistor; C1-first capacitor; C2-second capacitor; C3-third capacitor; C4-fourth capacitor; C5-fifth capacitor; C6-sixth capacitor; C7-seventh capacitor; C8-eighth capacitor; C9-ninth capacitor. DETAILED DESCRIPTION

[0033] The present invention will be further described in detail below with reference to the accompanying drawings.

[0034] Figures 2 to 6 The figure schematically shows a common mode rejection ratio test device for medical electrical equipment according to an embodiment of the present invention.

[0035] like Figures 2 to 6 As shown, the medical electrical equipment common mode rejection ratio test device 100 has an input end connected to a signal generator 200 and an output end connected to the electrical equipment to be tested 300. The test device 100 at least includes:

[0036] Shielding shell 1;

[0037] The circuit board 2 is installed in the shielding shell 1;

[0038] A first connection hole 11 for receiving the first wire 3 is formed on one side of the shielding shell 1, and a plurality of second connection holes 12 for receiving the plurality of second wires 4 are formed on the other side.

[0039] A protective grounding terminal GND is provided at the bottom of the shielding shell 1. The internal part of the protective grounding terminal GND is connected to the shielding shell 1 and the external part provides a connection terminal.

[0040] The test device 100 is connected to the signal generator 200 via the first connection 3, and the test device 100 is connected to the electrical device under test 300 via multiple second connections 4;

[0041] During the test, the test device 100 is connected to the electrical device under test 300 through the second connection 4 and to the signal generator 200 through the first connection 3. The signal generator 200 is adjusted to output a signal with an amplitude Vin of 1Vrms-5Vrms and a frequency of 2 times the power frequency. The display value of the electrical device under test 300 is read, and the common mode rejection ratio is calculated according to formula (1):

[0042]

[0043] Wherein, CMRR is the common mode rejection ratio, Vin is the output value of the signal generator 200, and Vo is the display value of the electrical device under test 300.

[0044] The first connection 3 is a two-wire wire, and the input end of the first connection 3 is connected to the positive and negative poles of the signal generator 200 respectively.

[0045] The second connections 4 consist of three wires, two of which serve as output terminals facing the output electrodes of the electrical device 300 under test, and the other serves as a reference electrode facing the reference electrode of the electrical device 300 under test.

[0046] like Figure 5 As shown, the circuit board 2 is integrated with an input interface Pin1 corresponding to the first connection hole 11 and three output interfaces, namely a first output interface P1 , a second output interface P2 and a third output interface GND1 corresponding to the second connection hole 12 .

[0047] The circuit board 2 also includes a fourth resistor R4, a first resistor R1, a first capacitor C1, a second capacitor C2 and a third capacitor C3 arranged between the input interface Pin1 and the first output interface P1. The fourth resistor R4 is connected in series with the input interface Pin1, and the first resistor R1, the first capacitor C1, the second capacitor C2 and the third capacitor C3 form a first parallel circuit and the two ends of the first parallel circuit are respectively connected in series with the fourth resistor R4 and the first output interface P1.

[0048] The circuit board 2 also includes a third resistor R3, a fourth capacitor C4, a fifth capacitor C5, a sixth capacitor C6, a seventh capacitor C7 and an eighth capacitor C8, which are arranged between the input interface Pin1 and the second output interface P2. The fourth capacitor C4 and the eighth capacitor C8 form a second parallel circuit and are connected in series with the input interface Pin1. The third resistor R3, the fifth capacitor C5, the sixth capacitor C6 and the seventh capacitor C7 form a third parallel circuit and the two ends of the third parallel circuit are respectively connected in series with the second parallel circuit and the second output interface P2.

[0049] The circuit board 2 also includes a second resistor R2 and a ninth capacitor C9 arranged between the input interface Pin1 and the third output interface GND1. The second resistor R2 and the ninth capacitor C9 form a fourth parallel circuit and the two ends of the fourth parallel circuit are respectively connected in series with the second parallel circuit and the third output interface GND1.

[0050] The circuit board 2 further includes a fifth resistor R5 , which is connected in series with the second resistor R2 , the ninth capacitor C9 , and the protective ground terminal GND.

[0051] Preferably, in this embodiment, the resistance of the first resistor R1 is 51kΩ, the resistance of the second resistor R2 is 51kΩ, the resistance of the third resistor R3 is 51kΩ, the resistance of the fourth resistor R4 is 0Ω, the resistance of the fifth resistor R5 is 0Ω, the capacitance of the first capacitor C1 is 47nF, the capacitance of the second capacitor C2 is 47nF, the capacitance of the third capacitor C3 is 47nF, the capacitance of the fourth capacitor C4 is 10nF, the capacitance of the fifth capacitor C5 is 47nF, the capacitance of the sixth capacitor C6 is 47nF, the capacitance of the seventh capacitor C7 is 47nF, the capacitance of the eighth capacitor C8 is 100pF, and the capacitance of the ninth capacitor C9 is 47nF.

[0052] The present utility model provides a test device 100 capable of quickly testing the common-mode rejection ratio of medical electrical equipment. When in use, the test device 100 is respectively connected to a signal generator 200 and an electrical device to be tested 300 to form a complete test circuit. A shielding shell 1 is provided, which can effectively reduce the pickup of unwanted external noise. In order to better exert the shielding effectiveness, the shielding shell 1 is provided with a protective grounding terminal GND, which can provide complete grounding protection for the equipment.

[0053] The common-mode rejection ratio test device 100 of medical electrical equipment of the present invention can simplify and make complex tests portable, thereby reducing the difficulty of testing and saving testing time. The fixed test device 100 makes testing more convenient and quick.

[0054] The above descriptions are only some embodiments of the present invention. For those skilled in the art, several modifications and improvements can be made without departing from the inventive concept of the present invention, and these all fall within the scope of protection of the present invention.

Claims

1. A common mode rejection ratio test device for medical electrical equipment, wherein the input end is connected to a signal generator (200) and the output end is connected to the electrical equipment to be tested (300), characterized in that: The testing device (100) comprises at least: Shielding shell (1); A circuit board (2) is installed in the shielding shell (1); A first connection hole (11) for receiving a first wire (3) is provided on one side of the shielding shell (1), and a plurality of second connection holes (12) for receiving a plurality of second wires (4) are provided on the other side. A protective grounding terminal (GND) is provided at the bottom of the shielding shell (1), the interior of the protective grounding terminal (GND) is connected to the shielding shell (1), and the exterior provides a connection end; The test device (100) is connected to the signal generator (200) via the first connection (3), and the test device (100) is connected to the electrical device to be tested (300) via a plurality of second connections (4); During testing, the test device (100) is connected to the electrical device to be tested (300) via the second connection (4) and to the signal generator (200) via the first connection (3). The signal generator (200) is adjusted to output a signal with an amplitude Vin of 1Vrms-5Vrms and a frequency twice the power frequency. The display value of the electrical device to be tested (300) is read, and the common mode rejection ratio is calculated according to formula (1): Wherein, CMRR is the common mode rejection ratio, Vin is the output value of the signal generator (200), and Vo is the display value of the electrical device (300) to be tested.

2. The common mode rejection ratio test device for medical electrical equipment according to claim 1, characterized in that: The first wiring (3) is a two-wire wire, and the input end of the first wiring (3) is respectively connected to the positive and negative poles of the signal generator (200).

3. The common mode rejection ratio test device for medical electrical equipment according to claim 1, characterized in that: The second wiring (4) consists of three wires, two of which serve as output terminals facing the output electrodes of the electrical device under test (300), and the other serves as a reference electrode facing the reference electrode of the electrical device under test (300).

4. The common mode rejection ratio test device for medical electrical equipment according to claim 3, characterized in that: The circuit board (2) is integrated with an input interface (Pin1) corresponding to the first connection hole (11) and three output interfaces, namely a first output interface (P1), a second output interface (P2) and a third output interface (GND1) corresponding to the second connection hole (12).

5. The common mode rejection ratio test device for medical electrical equipment according to claim 4, characterized in that: The circuit board (2) further comprises a fourth resistor (R4), a first resistor (R1), a first capacitor (C1), a second capacitor (C2) and a third capacitor (C3) arranged between the input interface (Pin1) and the first output interface (P1); the fourth resistor (R4) is connected in series with the input interface (Pin1); the first resistor (R1), the first capacitor (C1), the second capacitor (C2) and the third capacitor (C3) form a first parallel circuit, and two ends of the first parallel circuit are respectively connected in series with the fourth resistor (R4) and the first output interface (P1).

6. The common mode rejection ratio test device for medical electrical equipment according to claim 5, characterized in that: The circuit board (2) further comprises a third resistor (R3), a fourth capacitor (C4), a fifth capacitor (C5), a sixth capacitor (C6), a seventh capacitor (C7) and an eighth capacitor (C8) arranged between the input interface (Pin1) and the second output interface (P2); the fourth capacitor (C4) and the eighth capacitor (C8) form a second parallel circuit and are connected in series with the input interface (Pin1); the third resistor (R3), the fifth capacitor (C5), the sixth capacitor (C6) and the seventh capacitor (C7) form a third parallel circuit, and the two ends of the third parallel circuit are respectively connected in series with the second parallel circuit and the second output interface (P2).

7. The common mode rejection ratio test device for medical electrical equipment according to claim 6, characterized in that: The circuit board (2) further comprises a second resistor (R2) and a ninth capacitor (C9) arranged between the input interface (Pin1) and the third output interface (GND1); the second resistor (R2) and the ninth capacitor (C9) form a fourth parallel circuit, and two ends of the fourth parallel circuit are respectively connected in series with the second parallel circuit and the third output interface (GND1).

8. The common mode rejection ratio test device for medical electrical equipment according to claim 7, characterized in that: The circuit board (2) further comprises a fifth resistor (R5), and the fifth resistor (R5) is connected in series with the second resistor (R2), the ninth capacitor (C9), and the protective ground terminal (GND).

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