Pressure detection device

Abstract

The utility model provides a pressure detection device, and the device comprises a magnet, a magnetic sensor, a spring, an inner core support, and a signal processing unit. One end of the inner core bracket is connected with the treatment head; the magnet is fixed on the inner core bracket; the spring is arranged on the inner core bracket; the magnetic sensor and the magnet are arranged in the contact type hand tool shell at a preset distance; the signal processing unit is electrically connected with the magnetic sensor; the inner core support is used for driving the spring to deform and driving the magnet to move in response to pressing of the treatment head, so that the distance between the magnet and the magnetic sensor is changed, and the magnetic field intensity is changed. And the signal processing unit is used for converting the magnetic intensity change signal sent by the magnetic sensor into a pressure value. According to the pressure detection device, the pressure is indirectly measured through the distance change between the magnet and the magnetic sensor, the size is small, the weight is light, the price is low, a complex signal conditioning circuit is not needed, the structure is simple, and the anti-interference capability is high.

Description

Technical Field

[0001] This disclosure relates to the field of medical device technology, and in particular to a pressure detection device. Background Technology

[0002] In radiofrequency medical devices, ultrasound medical devices, and laser medical devices (such as radiofrequency beauty devices and radiofrequency therapy devices), the handpiece must be in close contact with the human skin to ensure treatment effectiveness and safety. Figure 1 As shown, traditional pressure detection schemes employ pressure sensors 101, such as strain gauge or piezoelectric sensors, combined with a mechanical structure consisting of a mounting base 242, a T-shaped spring guide rod 102, a spring 23, an inner core support 24, and a treatment head 1. When the handpiece presses against the skin, the spring compresses, triggering the pressure sensor to collect the pressure signal. However, this scheme has the following drawbacks: 1. High cost: The pressure sensor itself is expensive and requires precise calibration. 2. Large size and weight: The sensor and its accessories occupy internal space, affecting the portability of the handpiece. 3. Limited reliability: The pressure sensor is susceptible to environmental interference (such as temperature and humidity). 4. Complex design: The pressure sensor signal is small, requiring additional signal amplification, filtering, and conditioning circuitry. Summary of the Invention

[0003] The technical problem to be solved by this disclosure is to overcome the shortcomings of low reliability and high cost of pressure detection in traditional hand tools in the prior art, and to provide a pressure detection device.

[0004] This disclosure solves the above-mentioned technical problems through the following technical solution:

[0005] This disclosure provides a pressure detection device for use in a contact handpiece, the contact handpiece including a treatment head; the pressure detection device includes: a magnet, a magnetic sensor, a spring, an inner core support, and a signal processing unit;

[0006] One end of the inner core support is connected to the treatment head; the magnet is fixed to the inner core support; the spring is disposed on the inner core support; the magnetic sensor is disposed inside the contact handpiece housing at a preset distance from the magnet; the signal processing unit is electrically connected to the magnetic sensor;

[0007] The inner core support is used to respond to the pressure on the treatment head, causing the spring to deform and the magnet to move, so that the distance between the magnet and the magnetic sensor changes and the magnetic field strength is altered.

[0008] The signal processing unit is used to convert the magnetic intensity change signal sent by the magnetic sensor into a pressure value.

[0009] Preferably, the inner core support includes a spring guide rod and a fixing seat;

[0010] The spring and the fixed seat are disposed on the spring guide rod;

[0011] The fixing seat is used to fix one end of the spring.

[0012] The spring is used to compress in response to pressure on the treatment head, thereby moving the magnet on the spring guide rod and reducing the distance between the magnet and the magnetic sensor; it is also used to reset the position of the inner core support when the treatment head changes from a compressed state to a stretched state after it is no longer compressed.

[0013] Preferably, the spring is disposed between the treatment head and the inner core support;

[0014] The spring is used to compress the treatment head in response to pressure, thereby moving the magnet on the inner core support and reducing the distance between the magnet and the magnetic sensor; it is also used to reset the position of the treatment head and the inner core support when the treatment head is no longer compressed and changes from a compressed state to a stretched state.

[0015] Preferably, the magnetic sensor and the signal processing unit are integrated on a PCB board; the PCB board is located inside the housing of the contact handpiece.

[0016] Preferably, the magnet is fixed to the inner core support by interference fit or adhesive bonding.

[0017] Preferably, the magnet is fixed to the other end of the inner core support.

[0018] Preferably, the magnet is fixed to the column of the inner core support.

[0019] Based on common knowledge in the field, the above-mentioned preferred conditions can be combined arbitrarily to obtain various preferred embodiments of this disclosure.

[0020] The positive and progressive effects of this disclosure are as follows:

[0021] The pressure detection device disclosed herein replaces the bulky pressure sensor with a magnetic sensor. It measures the magnetic field strength by utilizing the change in the distance between the magnet and the magnetic sensor, thereby indirectly measuring the pressure. It has the advantages of small size, light weight, low price, no need for complex signal conditioning circuits, simple structure, and strong anti-interference ability. Attached Figure Description

[0022] Figure 1 A schematic diagram of the structure of an existing pressure detection device;

[0023] Figure 2 This is a first structural schematic diagram of a pressure detection device provided in Embodiment 1;

[0024] Figure 3This is a schematic diagram of the second structure of a pressure detection device provided in Embodiment 1;

[0025] Figure 4 This is a third structural schematic diagram of a pressure detection device provided in Embodiment 1;

[0026] Figure 5 A diagram showing the relationship between the magnetic field and displacement distance of a pressure detection device provided in Example 1;

[0027] Figure 6 This is a flowchart illustrating a specific example of a pressure detection method using a pressure detection device provided in Embodiment 1. Detailed Implementation

[0028] The present disclosure is further illustrated below by way of embodiments, but the present disclosure is not limited to the scope of the embodiments described herein.

[0029] The prefixes such as "first" and "second" used in this disclosure are merely for distinguishing different descriptive objects and do not limit the position, order, priority, quantity, or content of the described objects. The use of ordinal numbers and other prefixes used to distinguish descriptive objects in this disclosure does not constitute a limitation on the described objects. The description of the described objects is given in the claims or the context of the embodiments, and should not be construed as an unnecessary limitation. Furthermore, in the description of this embodiment, unless otherwise stated, "multiple" means two or more.

[0030] Example 1

[0031] This embodiment provides a pressure detection device applied to a contact handpiece, which includes a treatment head. See also... Figure 2 The pressure detection device includes: a magnet 21, a magnetic sensor 31, a spring 23, an inner core support 24, and a signal processing unit 32.

[0032] One end of the inner core support 24 is connected to the treatment head 1. Magnet 21 is fixed to the inner core support 24. Spring 23 is disposed on the inner core support 24. Magnetic sensor 31 is disposed inside the contact handpiece housing at a preset distance from magnet 21. Signal processing unit 32 is electrically connected to magnetic sensor 31.

[0033] The preset distance can be set according to the actual situation. In this embodiment, the preset distance is preferably 1 to 10 millimeters.

[0034] In one alternative implementation, such as Figure 3 The magnet 21 shown is fixed to the other end of the inner core support 24.

[0035] In one alternative implementation, such as Figure 4As shown, magnet 21 is fixed to the column of inner core support 24.

[0036] In an optional implementation, the magnetic sensor 31 and the signal processing unit 32 are integrated on the PCB board 3 (printed circuit board). See also Figure 3 and Figure 4 PCB board 3 is located inside the housing of the contact handpiece.

[0037] In an alternative implementation, the magnet is fixed to the inner core support by interference fit or adhesive bonding.

[0038] See Figure 3 and Figure 4 The inner core support 24 is used to respond to the pressure on the treatment head 1, causing the spring 23 to deform and the magnet 21 to move, so that the distance between the magnet 21 and the magnetic sensor 31 changes, thereby changing the magnetic field strength.

[0039] The signal processing unit 32 is used to convert the magnetic intensity change signal sent by the magnetic sensor 31 into a pressure value.

[0040] In this embodiment, the pressure detection device replaces the bulky pressure sensor with a magnetic sensor. It measures the magnetic field strength by utilizing the change in the distance between the magnet and the magnetic sensor, thereby indirectly measuring the pressure. It has the advantages of small size, light weight, low price, no need for complex signal conditioning circuits, simple structure, and strong anti-interference ability.

[0041] In one alternative implementation, such as Figure 3 and Figure 4 As shown, the inner core support 24 includes a spring guide rod 241 and a fixing seat 242. The spring guide rod 241 can be a T-shaped spring guide rod.

[0042] Spring 23 and fixing seat 242 are mounted on spring guide rod 241.

[0043] The fixing seat 242 is used to fix one end of the spring 23.

[0044] Spring 23 is used to compress in response to pressure on the treatment head 1, thereby moving the magnet 21 on the spring guide rod 241 and reducing the distance between the magnet 21 and the magnetic sensor 31. Spring 23 is also used to reset the position of the inner core support 24 when the treatment head 1 is no longer compressed and changes from a compressed state to a stretched state.

[0045] In an alternative implementation, the spring is disposed between the treatment head and the inner core support.

[0046] The spring is used to compress the treatment head in response to pressure, thereby moving the magnet on the inner core support and reducing the distance between the magnet and the magnetic sensor. It is also used to reset the position of the treatment head and inner core support when the treatment head is no longer compressed and transitions from a compressed to a stretched state.

[0047] In both of the above embodiments, when the treatment head presses against the target (e.g., skin), the spring compression can cause the inner core support to move the magnet. The change in the distance between the magnet and the magnetic force sensor causes a change in the magnetic field strength. The actual pressure value is calculated by the calibrated displacement-magnetic field-pressure relationship, thereby determining whether it is in close contact with the skin.

[0048] It should be noted that the inner core support in this embodiment can be replaced with other connecting components, as long as the magnet can be displaced when the treatment head contacts the target.

[0049] It should be noted that in this embodiment, the magnet and the magnetic sensor are coupled together, and the position of the magnet can be at one end of the inner core support or at any part of the inner core support, as long as the magnet and the magnetic sensor are coupled together.

[0050] This solution can also be extended to industrial equipment, robotic tactile sensing, and other scenarios where pressure needs to be measured through displacement.

[0051] The following is a specific example to illustrate the pressure detection device of this embodiment in detail.

[0052] The pressure detection device in this example includes a magnet: fixed to the end of the inner core support; a magnetic force sensor: installed at a preset distance from the magnet; a spring: connecting the treatment head and the inner core support, generating linear displacement when compressed; a signal processing unit: including a microcontroller that reads the magnetic force sensor signal, converts the change in magnetic field strength into a pressure value, and determines the contact state; and an inner core support: connected to the treatment head at one end and to the magnet at the other end.

[0053] When the treatment head of the contact handpiece presses against the target (e.g., skin), the spring compression causes the inner core support to move the magnet. The change in the distance between the magnet and the magnetic sensor causes a change in the magnetic field strength. The actual pressure value is calculated by the calibrated displacement-magnetic field-pressure relationship, thereby determining whether it is in close contact with the skin.

[0054] The treatment head is connected to the inner core support via a spring, and a magnet is fixed to the end of the inner core support.

[0055] The magnet can be a round or square permanent magnet (such as a neodymium iron boron magnet). It should be noted that the shape of the magnet is not restricted, but when placing the magnet, either the north pole or the south pole must be facing the magnetic sensor; otherwise, the detection effect will be weakened. A property of magnets is that the magnetic field strength increases the closer the magnet is to the sensor.

[0056] The model of the magnetic sensor is not limited. The magnetic sensor is mainly used to output the magnetic induction intensity as an electrical signal. The model can be HX6659IUA-B. The range of the sensing magnetic field is ±1200Gs (gauss, a unit used to measure magnetic field strength). When different magnetic field strengths are sensed, the output voltage is different. Specifically, it is 2.5V (volts) when there is no magnetic field strength. When the N pole magnetic field of the magnet is close, the magnetic sensor output decreases according to the magnetic field strength of 2mV / Gs (millivolts / gauss). When the S magnetic pole is close, the magnetic sensor output increases according to the magnetic field strength of 2mV / Gs.

[0057] The magnetic sensor (such as a Hall sensor or magnetoresistive sensor) is installed inside the handpiece housing, with an initial distance of 1 to 10 millimeters from the magnet.

[0058] As the spring is compressed, the inner core support moves the magnet toward the magnetic sensor, causing the magnet to move closer to the magnetic sensor. This increases the magnetic field strength on the magnetic sensor. In other words, when the treatment head of the contact hand presses against the target (e.g., skin), the spring is compressed, the inner core support moves the magnet toward the magnetic sensor, the distance between the magnet and the magnetic sensor decreases, and the magnetic field strength increases. Figure 5 This is a graph showing the relationship between magnetic field strength and distance. Figure 5 The horizontal axis is used to characterize the distance between the magnet and the magnetic sensor. Figure 5 The ordinate is used to characterize the magnetic field strength. As the distance between the magnet and the magnetic sensor increases, the magnetic field strength decreases.

[0059] The voltage output of the magnetic sensor is read by the microcontroller's Analog-to-Digital Conversion (ADC) function, which converts analog signals into digital signals. This is then converted into the magnitude of the magnetic field strength. By calibrating the pressure detection device, a table showing the correspondence between distance and magnetic field strength is obtained, allowing the distance to be calculated based on the magnetic field strength. Finally, the pressure exerted on the treatment head is calculated using the following formula and the known spring constant k.

[0060] F = k * x;

[0061] Where F represents the pressure value applied to the treatment head; k represents the spring force coefficient; and x represents the displacement distance between the magnet and the magnetic sensor.

[0062] Taking the HX6659IUA-B magnetic sensor as an example, the microcontroller acquires the output voltage of the HX6659IUA-B via an ADC. If the acquired voltage is 3.2V, the corresponding magnetic field strength is approximately (3.6V-2.5V) / 0.002 = 550Gs (where 2.5V is the output without a magnetic field, and 0.002mV / Gs is the sensitivity of the magnetic sensor). During calibration, the relationship between displacement distance and magnetic field strength is shown in the table below:

[0063]

[0064] The table above shows that when the magnetic field strength is 550 Gs, the displacement distance falls within the range of 1 mm to 1.5 mm. This can be determined using the following linear interpolation equation:

[0065] ;

[0066] in, Used to characterize the first displacement distance Used to characterize the second displacement distance, Used to characterize the third displacement distance Used to characterize the first magnetic field strength corresponding to the first displacement distance. Used to characterize the second magnetic field strength corresponding to the second displacement distance. This is used to characterize the third magnetic field strength corresponding to the third displacement distance. The experimental values ​​obtained from the table above show... =1mm, =1.5mm, =585Gs, =454Gs, =550Gs, then we can calculate =1.134mm.

[0067] Therefore, using the linear interpolation formula through the calibration relationship table, the current distance between the magnet and the magnetic sensor can be calculated to be approximately 1.134 mm. Given a spring constant k = 50 N / mm (Newtons per millimeter), the pressure is approximately 50 * (5.5 - 1.134) = 218 N (Newtons). It should be noted that in this example, when the pressure is 0, the distance between the magnet and the magnetic sensor is 5.5 mm.

[0068] At this point, a preset pressure threshold can be set to determine different states such as "no contact," "close contact," and "excessive pressure," allowing contact-type handpieces to handle them differently. Again, using the magnetic sensor model HX6659IUA-B and the pressure threshold of a permanent magnet as an example:

[0069] When the absolute value of the magnetic field strength falls within the range of 0~350Gs and the pressure value is 152N, the contact state between the contact hand and the contact target is determined to be non-contact.

[0070] When the absolute value of the magnetic field strength falls within the range of 351~700Gs and the pressure value is 152~229N, the contact state between the contact hand and the contact target is determined to be a tight contact state.

[0071] When the absolute value of the magnetic field strength falls within the range of 701~1200Gs and the pressure value is above 229N, the contact state between the contact hand and the contact target is determined to be excessive pressure.

[0072] It should be noted that if the N pole of the permanent magnet is facing the magnetic sensor chip, the output voltage of the HX6659IUA-B magnetic sensor will be less than 2.5V, and the obtained magnetic field strength will be negative. If the S pole of the permanent magnet is facing the magnetic sensor chip, the output voltage of the HX6659IUA-B magnetic sensor will be greater than 2.5V, and the obtained magnetic field strength will be positive. Therefore, the magnetic field strength in this example uses absolute values. In this example, either the N pole or the S pole of the permanent magnet can be facing the magnetic sensor.

[0073] The following is a specific example illustrating the pressure detection method of the pressure detection device in this embodiment. Figure 6 Here is the flowchart for this example:

[0074] S601, The treatment head of the contact handpiece is under pressure.

[0075] S602, the spring deforms, and at the same time the inner core bracket drives the magnet to approach the magnetic sensor.

[0076] S603: When the magnetic sensor detects an increase in magnetic field strength, the output signal changes accordingly.

[0077] The S604 signal processing unit's microcontroller acquires the corresponding changes, calculates the magnetic field strength based on the properties of the magnetic sensor, and calculates the displacement distance of the inner core support based on the calibration relationship table between magnetic field strength and displacement distance. Then, it calculates the pressure magnitude based on the spring force coefficient.

[0078] While specific embodiments of this disclosure have been described above, those skilled in the art should understand that these are merely illustrative examples, and the scope of protection of this disclosure is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of this disclosure, but all such changes and modifications fall within the scope of protection of this disclosure.

Claims

1. A pressure detection device, characterized in that, The device is applied to a contact handpiece, which includes a treatment head; the pressure detection device includes: a magnet, a magnetic sensor, a spring, an inner core support, and a signal processing unit. One end of the inner core support is connected to the treatment head; the magnet is fixed to the inner core support; the spring is disposed on the inner core support; the magnetic sensor is disposed inside the contact handpiece housing at a preset distance from the magnet; the signal processing unit is electrically connected to the magnetic sensor; The inner core support is used to respond to the pressure on the treatment head, causing the spring to deform and the magnet to move, so that the distance between the magnet and the magnetic sensor changes and the magnetic field strength is altered. The signal processing unit is used to convert the magnetic intensity change signal sent by the magnetic sensor into a pressure value.

2. The pressure detection device as described in claim 1, characterized in that, The inner core support includes a spring guide rod and a fixing seat; The spring and the fixed seat are disposed on the spring guide rod; The fixing seat is used to fix one end of the spring. The spring is used to compress in response to pressure on the treatment head, thereby moving the magnet on the spring guide rod and reducing the distance between the magnet and the magnetic sensor; it is also used to reset the position of the inner core support when the treatment head changes from a compressed state to a stretched state after it is no longer compressed.

3. The pressure detection device as described in claim 1, characterized in that, The spring is disposed between the treatment head and the inner core support; The spring is used to compress in response to pressure on the treatment head, thereby moving the magnet on the inner core support and reducing the distance between the magnet and the magnetic sensor; it is also used to reset the position of the treatment head and the inner core support when the treatment head is no longer compressed and changes from a compressed state to a stretched state.

4. The pressure detection device as described in claim 1, characterized in that, The magnetic sensor and the signal processing unit are integrated on a PCB board; the PCB board is located inside the housing of the contact hand.

5. The pressure detection device as described in claim 1, characterized in that, The magnet is fixed to the inner core support by interference fit or adhesive bonding.

6. The pressure detection device as described in claim 1, characterized in that, The magnet is fixed to the other end of the inner core support.

7. The pressure detection device as described in claim 1, characterized in that, The magnet is fixed to the column of the inner core support.

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