JP7286279B2 - dental unit - Google Patents

Description

The present invention relates to a dental unit having a patient chair on which a patient sits in dentistry.

A dental unit is a unit provided with various equipment used in dental treatment, and includes a patient chair on which a patient sits. Surrounding it are a doctor unit where various instruments used by the practitioner for dental treatment are placed, an assistant hanger equipped with various instruments mainly used by assistants, a water supply unit that supplies gargling water etc. to the patient, A spittoon for draining this water, a dental light for illuminating the patient's oral cavity, and the like are provided. In addition, there may be a chair around the dental unit on which the practitioner sits.
Here, the patient chair is configured so that the patient can be raised and lowered and the backrest can be tilted to stand up in order to put the patient in a posture that facilitates treatment.

However, since the patient chair can be raised and lowered and can be tilted and erected, other objects may be included in the movable range, which may become obstacles and cause collisions. Such collisions should of course be avoided. Alternatively, even if there is a collision, it should be detected and the patient's chair should be quickly stopped from moving up and down or tilting and standing.

Therefore, Patent Literature 1 discloses a technique in which security switches are provided at three locations: between the backrest (backboard) and the seating portion (seatboard), the assistant holder, and the backrest. According to this, when the backrest moves in the tilting and erecting direction, an abnormality can be detected by applying force to the safety switch. Further, Patent Literature 2 discloses a technique in which a plurality of predetermined areas around a dental unit (chair unit) are used as detection areas, and obstacles are detected by non-contact sensors in each area.

JP-A-7-96014 JP-A-2005-177131

With the techniques described in Patent Documents 1 and 2, it is necessary to newly provide safety switches, non-contact sensors, and the like in order to prevent collisions, which may lead to complication of the device.
In addition, when a non-contact type sensor is used as in Patent Document 2, an obstacle is detected when some external force is applied, for example, when the patient moves when the patient chair is raised or lowered and when the patient stands upright. In some cases, the patient's chair was mistakenly recognized as an object, and the patient's chair stopped moving up and down or tilted and stood up. Since this is a safer operation, it may be possible, but from the viewpoint of the efficiency of a series of operations such as treatment, it is an unnecessary stop and should be avoided. If the frequency of unnecessary stoppages due to such misrecognition increases, the efficiency will decrease which cannot be ignored.

In view of the above problems, it is an object of the present invention to provide a dental unit that can operate safely against collisions with a simpler configuration and that can reduce misidentification.

The present invention will be described below.

One aspect of the present invention is a patient chair including a seat portion that can be raised and lowered, a backrest that can be tilted and raised by rotating with respect to the seat portion, a sensor that detects the posture of the backrest, and a sensor. and a collision calculation means for calculating that the backrest has collided with an obstacle from the output result of the collision calculation means, based on the output result from the sensor, the current posture of the backrest and the posture of the backrest at a point in time before that. The dental unit determines whether or not there is a collision based on the difference between the posture of the

In the above dental unit, the posture of the backrest can be the inclination angle of the backrest.

According to the dental unit of the present invention, a sensor for controlling the lifting and tilting of the backrest and the tilting and erecting posture can be used to determine whether a collision has occurred. can also be avoided.

1 is an external perspective view of a dental unit 1. FIG. 1 is a plan view of a dental unit 1; FIG. 4 is a diagram for explaining collision calculation means 50. FIG. FIG. 10 is a diagram showing the flow of collision calculation and the resulting control of the dental unit 10. FIG.

The present invention will be described based on the embodiments shown in the drawings. However, the present invention is not limited to these forms.

1 and 2 show the appearance of a dental unit 1 according to one form. 1 is a perspective view, and FIG. 2 is a view seen from above.
The dental unit 1 comprises a base 20 , a patient chair 10 , a dental lighting 2 , an assistant unit 4 , a doctor unit 30 and collision calculation means 50 .

The base 20 is arranged below the patient chair 10 and serves as the base of the patient chair 10 . The base 20 has an outer shell formed by a housing, and various control devices are included inside the housing. Examples of control devices included herein include a hydraulic circuit for raising and lowering the patient chair 10, tilting and standing up, and hydraulic control means for controlling the hydraulic circuit. Therefore, a foot switch 21 is provided on the back side of the patient chair 10 in the base 20 as shown in FIG. The practitioner operates the footswitch 21 and the operation switch of the operation panel 33 of the doctor unit 30 to issue a command to the hydraulic control means to control the hydraulic circuit to raise and lower the patient chair 10, tilt it, and stand it up. can be done.

Here, a linear potentiometer is arranged as a sensor in order to obtain the height position of the seating portion 11 of the patient chair 10 (the height position of the backrest 12) when controlling the elevation of the patient chair 10. A rotary potentiometer is provided as a sensor to obtain the tilt angle of the backrest when controlling the tilting and standing of the backrest 12 of the patient chair 10 . As will be described later, these sensors are used not only to control the posture of the dental chair, but also to judge collisions with obstacles.

In this embodiment, the patient chair 10 includes a seat portion 11 , a backrest 12 , a headrest 13 , a legrest 14 and a footrest 15 .

The seat portion 11 is mounted above the base 20 so as to be able to move up and down. The seat portion 11 is moved up and down by the hydraulic circuit housed in the base 20 as described above. Specifically, the practitioner operates the foot switch 21 or an operation panel 33 of the doctor unit 30, which will be described later, and the hydraulic control means that receives the operation command appropriately operates the hydraulic cylinder incorporated in the hydraulic circuit. As a result, the seat portion 11 moves up and down. The backrest 12 , the headrest 13 , the legrest 14 and the footrest 15 move up and down integrally with the seat portion 11 .
At this time, the height position of the seat is detected by a sensor (seat sensor), and the height position is controlled accordingly. Although the type of sensor used here is not particularly limited, for example, a linear potentiometer can be mentioned.

The backrest 12 is a member that is rotatable around one end of the seat 11 and supports the trunk of the patient. The backrest 12 is capable of tilting and standing so that the patient can assume a sitting position and a supine position. The backrest 12 is tilted and raised by a hydraulic circuit connected from within the base 20 . Specifically, the operator operates the foot switch 21 or the operation panel 33 of the doctor unit 30, and the hydraulic control means that receives the operation command appropriately operates the hydraulic cylinder incorporated in the hydraulic circuit. The backrest 12 is tilted and erected.
At this time, the tilt of the backrest 12 is controlled by detecting the tilt angle with a sensor (backrest sensor). Although the type of sensor used here is not particularly limited, for example, a rotary potentiometer can be mentioned.

The headrest 13 is a member arranged at the end of the backrest 12 opposite to the side where the seating portion 11 is arranged, and is a member that supports the patient's head. The headrest 13 is formed so as to be movable and rotatable in order to position the patient's head in a posture convenient for treatment. Such movement of the headrest 13 is performed by a mechanism including a motor incorporated inside the backrest 12 . Specifically, the operator operates a switch (not shown) provided on the back side of the backrest 12 or the headrest 13 or an operation panel 33 of the doctor unit 30, which will be described later, and the mechanism receives the operation command. The operation causes the headrest 13 to move and rotate.

The leg rest 14 is a member that is rotatable around the end of the seat portion 11 opposite to the side on which the backrest 12 is arranged, and supports the patient's legs. It is. The leg rest 14 is rotatable so that it can take a vertical or horizontal posture according to the tilted standing posture of the backrest 12 . Such rotation of the leg rest 14 is performed by a link mechanism that operates in conjunction with the tilting and erecting of the backrest 12 . Specifically, when the practitioner operates the footswitch 21 or the operating panel 33 of the doctor unit 30, the backrest 12 tilts and stands, and the legrest 14 rotates in conjunction with this.

The footrest 15 is a member provided movably in a direction in which the legrest 14 extends from the legrest 14 and in the opposite direction, and supports the feet of the patient when the patient is lying on his or her back. Specifically, in a posture in which the backrest 12 stands up, that is, in a sitting posture, the footrest 15 overlaps the legrest 14 and does not protrude. On the other hand, when the backrest is tilted and the patient lies on his/her back, the footrest 15 protrudes so as to extend the legrest 14 as shown in FIGS. As a means for such movement of the footrest 15, hydraulic pressure, a motor, a link mechanism, or the like can be used, but it is not particularly limited.

The dental lighting 2 is attached via an arm 3 that can be moved and rotated with a high degree of freedom by a universal joint or the like so that the intraoral area of the patient can be illuminated accurately during treatment. Therefore, by adjusting the position and angle of the dental lighting device 2, it is possible to move the dental lighting device 2 to a position where the practitioner can appropriately observe the inside of the patient's oral cavity. The dental lamp 2 may be moved manually or automatically by a gas spring or air cylinder provided in the arm 3 .

The assistant unit 4 is provided on one side of the patient chair 10 and includes an assistant hanger 5 , a spittoon 6 and a water supply device 7 .

The assistant hanger 5 is a part provided with equipment mainly used by the assistant. The assistant hanger 5 includes a hanger portion 5a and a hanger support column 5b.
The hanger post 5b is a tubular (hollow columnar) member, and its lower end is rotatably provided at the lower end of the assistant unit 4. As shown in FIG. The rotatable direction of the hanger support column 5b is rotation in a vertical plane at least around the lower end. However, rotation in the horizontal plane may be possible. Moreover, the hanger part 5a is provided at the upper end of the hanger support 5b, and each instrument used by the assistant is suspended. The hanger portion 5a is installed on the upper end of the hanger support 5b so as to be rotatable in the horizontal plane. As a result, the hanger portion 5a can be rotated in the front-rear direction (the up-down direction on the paper surface of FIG. 2) and can change its orientation in the horizontal plane. Examples of instruments suspended on the assistant hanger 5 include handpieces such as a vacuum, a saliva ejector, and a syringe. A vacuum or saliva ejector is connected to the vacuum unit via a suction tube.

The spittoon 6 is used when the patient gargles with water supplied from the water supply unit 7 during or after treatment to wash the oral cavity. Therefore, the spitting receptacle 6 is bowl-shaped in order to spit out the water in the oral cavity after gargling. Saliva and water discharged to the spittoon 6 are discharged through a drain trap in the water unit. Here, the spittoon 6 is rotatable in a horizontal plane toward the front side of the patient. This allows the spittoon 6 to be placed in front of the patient, improving convenience.

The doctor unit 30 is provided on the side of the patient chair 10 opposite to the assistant unit 4 , and has a workbench 31 , a first arm 40 and a second arm 45 .
The workbench 31 is a part provided with various instruments, switches, and the like required by the operator. Specifically, the workbench 31 has a work surface 31a on its upper surface, and a group of handpieces 32 used by the practitioner for treatment and a handpiece group 32 are housed at the rear end of the patient chair 10. A holder is provided. Examples of handpieces included in the handpiece group 32 include air turbines, micromotors, scalers, syringes, and the like. Almost all handpieces are connected to electrical circuits, water circuits, air circuits, etc. through tubing. An operation panel 33 is provided between the work surface 31a and the holder. Various kinds of operation switches are provided on the operation panel 33, and for example, the patient chair 10 can be tilted and raised, the operation of raising and lowering can be performed, and the dental lighting 2 can be switched on and off.
In this way, the instruments and parts operated and handled by the practitioner are gathered on the back side of the patient chair 10 in the working table 31 . As a result, the convenience of the practitioner who proceeds with the treatment near the patient's head is achieved.

The first arm 40 is a hollow rod-shaped so-called arm member, one end of which is arranged below the base 20 and is rotatable in a horizontal plane. Therefore, the first arm 40 can rotate in the direction indicated by the arrow IIa in FIG.
The second arm 45 is also a hollow rod-shaped arm member. One end of the second arm 45 is arranged at the other end of the first arm 40 opposite to the base 20 side. A workbench 31 is arranged at the other end of the second arm 45 .

The collision calculation means 50 monitors the height position of the dental chair 10 and the progress of the inclination angle of the backrest 12 to determine whether the dental chair 10 has collided with other devices or members. Issue a command to stop movement and rotation of the chair. At this time, the collision calculation means 50 has a configuration for preventing erroneous determination of a collision when the dental chair 10 does not collide with other devices or members, such as when the patient moves. It is possible to avoid stopping the lifting and tilting of the dental chair due to misidentification. FIG. 3 conceptually shows the configuration of the collision calculation means 50 .
As can be seen from FIG. 3, the collision calculation means 50 comprises an operator 51, a RAM 52, a storage means 53, a reception means 54, and an output means 55. FIG.

The operator 51 is composed of a so-called CPU (Central Operator), and is a means for connecting to and controlling each of the constituent members described above. The computing means 51 also executes various programs stored in the storage means 53 functioning as a storage medium, and performs computation as means for generating various data and selecting data based on the programs.

The RAM 52 is a component that functions as a work area for the operator 51 and as temporary data storage means. The RAM 52 can be composed of SRAM, DRAM, flash memory, or the like, and is similar to known RAM.

The storage unit 53 is a member that functions as a storage medium in which programs and data that serve as the basis for various calculations are stored. Further, the storage means 53 may be capable of storing various intermediate and final results obtained by executing the program.

In this embodiment, one of the programs stored in the storage means 53 is to monitor the progress of the height position of the dental chair 10 and the tilt angle of the backrest 12 and prevent the dental chair 10 from colliding with other devices or members. If it is determined that a collision has occurred, a collision calculation is included to issue a command to stop the lifting and tilting of the dental chair. At this time, this calculation includes a calculation for preventing erroneous determination of a collision when the dental chair 10 does not collide with other devices or members, such as when the patient moves.

For example, the calculation for collision determination can be performed in the following manner.
In the collision determination calculation of this embodiment, the posture of the backrest 12 is monitored while each part of the dental chair 10 is raised, lowered, tilted, and stood according to a command to the dental chair 10 . Then, in spite of the fact that it is in a situation in which the robot should move up and down and tilt and stand up according to the command, when the robot moves up and down and tilts and stands up to meet predetermined conditions to be described later, it collides with an obstacle and goes up and down. , it is judged that leaning and standing is hindered.

Specifically, the operation of the footswitch 21 and the doctor unit 30 instructs the dental chair 10 to move up and down and/or to tilt and stand up. The current average tilt angle of the backrest and the previous point in time based on the output results from the sensor provided to control the lifting and tilting when the movement and rotation of the backrest are being performed. It is determined whether the backrest 12 has collided with an obstacle based on the difference between the average inclination angle of the backrest at . As a more specific example, in this embodiment, calculation is performed as follows.

At first, posture information (inclination angle) of the backrest 12 is acquired at intervals of 0.05 seconds from the sensor for controlling the tilting and standing of the backrest during the lifting and/or tilting and standing of the backrest. Here, the tilt angle in the posture information is 0° when the backrest 12 is tilted most, and is maximum (for example, 90°) when the backrest 12 is most vertically upright. Therefore, when the backrest 12 is deformed from the tilted state to the standing state, the tilt angle changes in the positive (+) direction. It means that there is a change in the tilt angle in the direction.
When the posture information of the backrest is obtained by a rotary potentiometer as described above, the posture information is obtained as an output voltage at intervals of 0.05 seconds and converted to an inclination angle. This gives the tilt angle of the backrest 12 every 0.05 seconds. Then, this is accumulated as tilt angle information for one unit of the backrest 12 . The method of converting the output voltage from the sensor to the tilt angle is well known.

Next, the following three values are calculated for the inclination angle information of the backrest 12 based on the output result from the sensor obtained as described above.
(A) Current Average Tilt Angle This is the average value of the current tilt angle information and the tilt angle information for a total of 8 units of the tilt angle information for the previous 7 units.
(B) Average tilt angle of 0.5 seconds ago This is the average value of tilt angle information for a total of 8 units of tilt angle information 0.5 seconds before and the tilt angle information of the previous 7 units. be.
(C) Average tilt angle of 1.0 seconds ago This is the average value of the tilt angle information for a total of 8 units of tilt angle information 1.0 seconds before and the tilt angle information of the previous 7 units. be.

Here, when the posture information of the backrest is obtained by a rotary potentiometer, the tilt angle information is obtained as described above, so (A) to (C) are represented by angles (°).

Then, the presence or absence of a collision with an obstacle is determined by calculating the following determination conditions.
(1) When the backrest tilts only: "Current average tilt angle" - "Average tilt angle 0.5 seconds ago" ≥ -0.065°
(2) When the backrest tilts and descends "current average tilt angle" - "average tilt angle 0.5 seconds ago" ≥ -0.065°
(3) When only the backrest moves down "current average tilt angle" - "average tilt angle 1.0 seconds ago" ≥ 0.65°

When there is a change in the posture of the backrest (a change in the average inclination angle) within the range of (1) to (3), it is determined that there is a collision with an obstacle, and the dental chair stops descending and/or tilting. do.
On the other hand, when there is a change in the posture of the backrest (a change in the average inclination angle) outside the range of (1) to (3), it indicates that the dental chair is properly deformed normally or not. Such changes are not due to collisions, but to other causes such as patient movement, and do not stop lowering and/or tilting of the dental chair.
By performing such calculations, inappropriate stopping can be avoided, and a decrease in treatment efficiency can be suppressed.

The above (1) to (3) will be explained in more detail as follows.
In the case of "(1) only the action of tilting the backrest", the backrest 12 is rotating in the negative (-) direction, and "current average tilt angle" - "average tilt angle 0.5 seconds ago ” changes by -0.065° or more, the degree of rotation (tilting) is small even though it should rotate in the negative direction, or it rotates in the opposite (positive) direction. means to Therefore, at this time, it can be considered that the vehicle collided with the obstacle because the tilting of the backrest was hindered.
On the other hand, an angle change where this is less than -0.065°, i.e., a change that causes the tilt to become more abrupt, indicates that the tilting of the backrest is progressing normally, or even if the dental unit normally performs tilt angle changes. , it is difficult to think that the collision is with an obstacle, and it is possible that the patient sitting on the dental chair 10 has moved. Therefore, it is not necessary to stop the deformation of the dental chair.
(2) can also be considered in the same way.

In the case of "(3) only the action of lowering the backrest", the inclination angle of the backrest 12 does not change, but the "current average inclination angle" - "average inclination angle 1.0 seconds ago" is 0. A change of 0.65° or more means that the backrest is largely rotated in the upright direction, although there is no change in nature. Therefore, at this time, it can be considered that the backrest (dental chair) collided with the obstacle because the lowering of the backrest (dental chair) was hindered.
On the other hand, an angle change that is less than 0.65°, i.e., a small degree of change in the upright direction, or a change in the tilting direction, may cause obstacles to fall even if there is essentially no change in the tilt angle. It is difficult to think that it was due to the collision, and it is possible that the patient sitting on the dental chair 10 moved, so there is no need to stop the deformation of the dental chair.

In the present embodiment, each item is described using specific numerical values for ease of understanding, but these numerical values are not limited to this example, and various numerical values can be appropriately set as necessary. That is, in judging whether the backrest has collided with an obstacle, it is judged whether the backrest 12 has collided with an obstacle based on the difference between the current inclination angle of the backrest and the inclination angle of the backrest at a previous point in time. It is sufficient if the operation is included.

In this embodiment, only the backrest is targeted for determining whether or not there is a collision. This is because the backrest has a high possibility of colliding with an obstacle, and it is a member that moves abruptly against an external force such as movement of a patient. However, the present invention is not limited to this, and it may be configured to similarly determine whether or not there is a collision with other members provided in the dental chair.
Further, in this embodiment, the determination of the presence or absence of a collision is targeted only for lowering and/or tilting of the backrest, out of lifting and tilting of the backrest. This is because it is difficult to assume that the backrest will collide with other members when the backrest is erected and/or raised, and it is not always possible to determine whether or not there will be a collision. However, the present invention is not limited to this, and whether or not there is a collision may be determined for all of the lifting and/or tilting of the backrest.

The receiving means 54 is a structural member having a function of appropriately taking in information from the outside into the collision calculating means 50, and is connected to at least a sensor provided on the patient chair.

The output means 55 is a structural member having a function of appropriately outputting information to the outside among the obtained results, and is connected to the hydraulic control means in this embodiment. Accordingly, when the collision calculation means 50 determines that the patient chair 10 has collided with another member or the like, a command is issued to the hydraulic control means to stop the movement and rotation of the patient chair 10 .

Next, the permission and regulation of lifting and tilting of the patient chair 10 by the collision calculation means 50 will be described. The flow is shown in FIG. As can be seen from FIG. 4, the computation by the collision computation means 50 includes steps S11 to S17. Each process will be described below.

In step S11, a command is given to transform the dental chair 10 (elevate, tilt and stand up). Such a deformation command is issued by, for example, the foot switch 21 or the doctor unit 30 as described above.

A step S12 acquires posture information of the backrest 12 of the dental chair 10 . The posture of the backrest 12 is determined by sensors located on the dental chair 10 as described above. In this embodiment, such posture information is acquired and accumulated every 0.05 seconds (0.05 seconds from process S12 until information is acquired again in process S12).

In step S13, the conditions for making the above-described determination of the collision are calculated. Specifically, in this embodiment, the left sides of (1) to (3) described above are calculated.

In step S14, the calculation performed in step S13 is judged under the conditions (1) to (3) described above.
Then, when the condition is satisfied, it is assumed that this is a collision, and Yes is selected to move to step S15, where the deformation of the dental chair is stopped and ended.
On the other hand, if the condition is not satisfied, there is no collision, and the dental chair has moved due to normal deformation or some other cause other than the collision. is continued.

In step S17, after the deformation of the dental chair is continued in step S16, it is determined whether or not the originally planned deformation has been completed.
If the originally planned deformation is completed, Yes is selected and the process ends.
On the other hand, if the originally planned deformation has not been completed yet, No is selected and the process returns to step S12.

As described above, according to the dental unit 1 having the collision calculation means 50, it is possible to reduce misunderstandings in judging a collision, suppress erroneous stoppage of the patient chair due to reasons other than collision, and suppress a decline in treatment efficiency. Is possible. Such a collision can be determined using a sensor for controlling the posture of the dental chair, and there is no need to provide additional sensors for detecting obstacles, so the configuration is simple. can be

1 dental unit 2 dental lighting 3 arm 4 assistant unit 5 assistant hanger 5a hanger portion 5b hanger support 6 spittoon 7 water supply device 10 patient chair 11 seating portion 13 headrest 14 legrest 15 footrest 20 base 21 footswitch 30 doctor unit 31 Work table 31a Work surface 32 Hand piece group 33 Operation panel 40 First arm 45 Second arm 50 Collision calculation means 51 Operator 52 RAM
53 storage means 54 receiving means 55 output means

Claims (2)

a patient chair comprising a seat that can be raised and lowered, and a backrest that can be tilted and raised by rotating with respect to the seat;
a sensor that detects the posture of the backrest;
collision calculation means for calculating that the backrest has collided with an obstacle from the output result of the sensor;
In the collision calculation means, from the output result from the sensor, the average of the posture of the backrest in a predetermined range of time including the current time and the posture of the backrest in the predetermined range of time even before that and the difference between the average of and the presence or absence of said collision. 2. Dental unit according to claim 1, wherein the posture of the backrest is the inclination angle of the backrest.

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