HK1254363B - A device for periodontal cleaning and a method of controlling a device periodontal cleaning - Google Patents

Description

Device for periodontal cleaning and method for controlling a periodontal cleaning device

Technical Field

The present invention relates to a device for periodontal cleaning and a method for controlling a periodontal cleaning device.

Background Art

The goal of periodontal cleaning of the gum cavities of human or animal subjects is to treat gum diseases and prevent them. Such treatment may include introducing a cleaning fluid into the subject's mouth, in particular into the crevices between the teeth and gums, into the cavities where bacteria that cause such diseases can reside and multiply. The introduced cleaning fluid rinses the cavities. The introduced cleaning fluid may also include antibiotics or other drugs to combat any pathological conditions of the gums. The cleaning fluid may be introduced, for example, at high pressure so that it can penetrate the cavities. However, the penetration of the fluid has been shown to be insufficient, and the high-pressure introduction of the fluid includes overflow of the fluid, which causes unhygienic conditions.

Alternatively, according to U.S. Patent No. 5,145,367, a known vacuum device is used for dental hygiene and dental treatment, and is intended for periodontal treatment of tooth cavities. The device according to US5145367 has an elastic suction cap that can create a sealed vacuum on the gum cavity and interdental fissures. The treatment liquid is supplied to the suction cap and removed by suction. The intermittent application of vacuum produces a pumping action, and a similar intermittent rinsing causes the cavity to be cleaned to its base by this pumping action. However, the intermittent application of vacuum, together with the introduction of cleaning fluid, causes an uncontrollable amount of cleaning fluid to be sucked before it has properly performed its cleaning and antibacterial effects. In addition, the suction cap cannot provide a sufficiently low pressure (i.e., a vacuum for the cleaning fluid to fully penetrate the tooth fissures and gum cavity). This occurs especially when there is an overlap between applying vacuum to the cap and releasing the cleaning fluid. In addition, the uncontrollable amount of cleaning fluid can cause overflow of the fluid, contamination of the cleaning rinsing fluid, thereby leading to unsanitary conditions.

Summary of the Invention

It is therefore an object of the present invention to provide a periodontal cleaning with improved action and improved hygiene.

This object is achieved by a periodontal cleaning device comprising a cleaning head having a fluid outlet for releasing a cleaning fluid and a suction member for sucking out waste fluid; a cleaning fluid source connected to the fluid outlet; a controllable suction device connected to the suction member via a suction line; and a controllable fluid feed device for controlling the flow of cleaning fluid from the cleaning fluid source to the fluid outlet. The periodontal cleaning device further comprises a control unit arranged to control the controllable suction device to generate a vacuum pulse in the suction member, control the controllable fluid feed device to generate a fluid flow pulse in the fluid outlet in response to the vacuum pulse, and control the controllable suction device to generate a subsequent vacuum pulse in the suction member; and the control unit is arranged to pause for a predetermined period of time between generating a cleaning fluid flow pulse in the fluid outlet and generating a subsequent vacuum pulse in the suction member.

The cleaning head can be applied to the periodontal area of the subject's mouth, more specifically, to the crevices between the teeth and gums, and to the cavities that need cleaning. A pause of a predetermined period of time between a pulse of cleaning fluid flow and a subsequent vacuum pulse in the suction member allows the cleaning fluid to penetrate the cavity, where it can perform its cleaning action. It also allows the removal of the fluid contents of the cavity, which contain many pathogenic enzymes from microorganisms and leukocytes, which have plaque and/or other contaminants to be softened and contained by the cleaning fluid and subsequently removed from the crevices and cavities. The cleaning fluid supply and the suction of waste fluid have completely separate paths, so waste fluid cannot enter the cleaning fluid supply line. This allows for hygienic use of the device.

Subsequent vacuum pulses allow waste fluid (i.e., cleaning fluid with contaminants impregnated therein) to be effectively removed from the subject's mouth. It has been found that pausing is extremely effective and significantly improves the performance of periodontal cleaning. In addition, the suction pulses after the pause allow the removal of waste fluid, thereby preventing the contaminants in the waste fluid from contaminating and/or infecting other parts of the subject's mouth. This improves the subject's comfort during cleaning because waste fluid is no longer discharged through the subject's mouth.

The fluid outlet for releasing the cleaning fluid is coaxially centered within the suction member. Thus, the cleaning fluid can be injected into the center of the periodontal area in which the suction member is located.

In one embodiment, the fluid outlet resiliently extends beyond the suction member. This allows the periodontal cleaning device to be used by an individual patient themselves. By allowing the fluid outlet to rub or contact the gums, the suction cup can be easily stabilized, and the patient can also identify the most sensitive area for the cleaning action of the periodontal cleaning device. Thus, the periodontal cleaning device can be used at home independently of a dentist or dental hygienist.

In one embodiment, the predetermined time period is in the range of 150ms to 500ms, preferably in the range of 200ms to 300ms. More preferably, the predetermined time period is in the range of 240ms to 260ms. It has been experimentally confirmed that due to the pause duration of approximately 250ms, the vacuum pulse requires a relatively low vacuum (i.e., negative pressure or low pressure). Such negative pressure may be on the order of 35mmHG. In addition, the amount of cleaning fluid and the pressure used to apply the cleaning fluid may be low. Also due to the vacuum pulse duration and cleaning fluid pulse duration of approximately 250ms, the cleaning cycle of the vacuum pulse, cleaning fluid pulse, and pause pulse lasts approximately 750ms. For sufficient cleaning of the cavity, 6 to 13 cycles may be required, thus achieving a total cleaning time on the order of 4.5s to 10s.

In one embodiment, the control unit is arranged to generate cleaning fluid flow pulses in the fluid outlet in response to generating vacuum pulses between vacuum pulses. In other words, there is no overlap between the vacuum pulses and the cleaning fluid flow pulses. This prevents the cleaning fluid from being drawn away from the subject's mouth before it can perform its periodontal cleaning function on the subject's mouth.

In one embodiment, generating the cleaning fluid flow pulses comprises generating a predetermined amount of cleaning fluid. This ensures proper dosing of the cleaning fluid and prevents unnecessary use or spillage thereof.

In one embodiment, the controllable fluid feed means comprises a fluid pump between the cleaning fluid source and the fluid outlet.The fluid pump allows for efficient control and generation of cleaning fluid flow pulses by switching the fluid pump on and off at appropriate times.

In one embodiment, the controllable fluid feeding device includes a first controllable valve between the cleaning fluid source and the fluid outlet. The first controllable valve has a downstream flow in the direction toward the fluid outlet. This prevents used cleaning fluid (i.e., waste fluid) from flowing back into the cleaning fluid feed line and contaminating the periodontal cleaning device. Therefore, hygiene is guaranteed. The first controllable valve can be controlled so that a fluid flow pulse is generated when there is sufficient pressure in the cleaning fluid supply line. This allows the generation of sharp cleaning fluid pulses. In combination with the fluid pump, the first controllable valve can be excited later after the fluid pump is excited.

In one embodiment, the cleaning fluid source comprises a cleaning fluid container. This allows for independent use of the periodontal cleaning device. In use, the periodontal cleaning device does not need to be connected to a waste fluid drain line and is therefore portable.

In one embodiment, the controllable suction device comprises a fluid suction pump. This allows for the creation of a vacuum in the suction member and the removal of waste fluid and aspirated air from the suction member, while the waste fluid can be freely discharged from the periodontal cleaning device without the need to maintain a vacuum on the discharge side of the pump. This increases the reliability of the periodontal cleaning device.

In one embodiment, the suction line includes a second controllable valve between the controllable suction device and the suction member. The second controllable valve is arranged to allow waste fluid and air to flow only when there is a sufficiently low pressure on the controllable suction device side of the valve. This prevents waste fluid from entering the controllable suction device when the periodontal cleaning device is not in use (i.e., not working). Therefore, the hygiene of the periodontal cleaning device is improved. The second controllable valve can be controlled so that a vacuum pulse is generated when there is a sufficiently low pressure in the suction line. This allows the generation of sharp vacuum pulses. In combination with a vacuum pump, the second controllable valve can be excited later after the vacuum pump is excited. Alternatively, when vacuum or low pressure is applied via the waste fluid discharge line, the required vacuum pulse can be generated only by the second controllable valve.

In one embodiment, the suction line includes a filter between the suction member and the controllable suction device. This prevents particles of waste fluid trapped in the filter from entering the controllable suction device. Thus, clogging and wear of the controllable suction device are prevented, thereby extending the life of the periodontal cleaning device.

In one embodiment, the periodontal cleaning device further comprises a waste fluid container connected to the controllable suction means. This also allows for independent use of the periodontal cleaning device, in which the periodontal cleaning device does not need to be connected to a waste fluid discharge line and is therefore portable.

The object is also achieved by a method of controlling a periodontal cleaning device as described above, wherein the method of controlling the periodontal cleaning device is performed outside of a subject's mouth. The method comprises controlling a controllable suction device to generate a vacuum pulse in a suction member, controlling a controllable fluid feed device to generate a cleaning fluid flow pulse in a fluid outlet in response to the vacuum pulse, and controlling the controllable suction device to generate a subsequent vacuum pulse in the suction member. The controllable suction device may be controlled to introduce a pause of a predetermined period of time between the cleaning fluid flow pulse and the subsequent vacuum pulse in the suction member.

In one embodiment, controlling the fluid feed means to generate a fluid flow pulse in the fluid outlet is performed in response to the vacuum pulse after the generation of the vacuum pulse.

The present invention will be explained using the accompanying drawings explained below.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a perspective view of a periodontal cleaning device according to an embodiment of the present invention.

FIG. 2 a shows a schematic diagram of a periodontal cleaning device according to an embodiment of the present invention.

FIG. 2 b shows a schematic diagram of a periodontal cleaning device according to another embodiment of the present invention.

FIG. 2 c shows a timing diagram for operating a periodontal cleaning device according to an embodiment of the invention.

FIG. 3 a shows a cleaning head of a periodontal cleaning device according to an embodiment of the present invention.

3 b shows a cross-sectional view of a suction member of a periodontal cleaning device according to an embodiment of the present invention.

3 c shows a cross-sectional view of a suction member of a periodontal cleaning device according to an embodiment of the present invention.

It should be noted that the drawings are schematic only and are not drawn to scale unless otherwise indicated. Wherever possible, like reference numerals have been used for like elements of different embodiments.

DETAILED DESCRIPTION

1 shows a periodontal cleaning device 100 having an operating member 102 connected to a base station 101 via a hose 103. In the example of FIG1 , the base station 101 has a cleaning fluid container 104, an operating controller 105, an operating member holder 107, and a base 108 on which the base station 101 is mounted.

The base station 101 may be swiveled, for example, about a central axis connecting the base 108 to the base station 101 .

The operating member 102 has a handle 112 and a cleaning head 107. The operating member 102 may be provided with an operating control 111 for triggering the periodontal cleaning device (ie, the operating member 102).

The cleaning head 107 has a suction member 109 at its distal end that can be applied to the subject's gums in the subject's mouth to perform periodontal cleaning. Application of the suction member 109 can be performed by an operator or user of the periodontal cleaning device by gripping the operating member at the handle and positioning the suction head 109 in the subject's mouth for cleaning. The suction member 109 is designed to both apply a vacuum or low pressure to the subject's gums and subsequently discharge a cleaning fluid to the subject's gums. A subsequent new vacuum allows the discharged cleaning fluid (now waste fluid) to be aspirated and a new vacuum to be created for a new cycle.

The hose 103 is provided with a suction channel and a cleaning fluid channel. In addition, the hose 103 may be provided with a control wiring (not shown) for allowing an operator to control the periodontal cleaning device 101 using an operating controller 111 .

In the schematic diagram of FIG2a , the periodontal cleaning device 100 is shown in its simplest form. In this example, a controllable fluid feed device 203 is shown, which is arranged to start and stop the supply of cleaning fluid from a cleaning fluid supply line 206 through the hose 103, the operating member 102, and the cleaning head 107 to the suction member 109 to the cleaning fluid channel 204, where the cleaning fluid is discharged into the subject's mouth. The controllable fluid feed device 203 may, for example, be a valve that can be alternately opened and closed by the control unit 201. In this case, the cleaning fluid can be supplied from outside the periodontal cleaning device via the supply line 206 under external pressure. Alternatively, the controllable fluid feed device 203 is a cleaning fluid pump that allows the cleaning fluid to be drawn through the supply line 206 and pumped into the cleaning fluid channel 204. With a cleaning fluid pump, the cleaning fluid does not need to be externally pressurized to reach the suction member 109.

By applying low pressure to the waste fluid discharge line 207, suction in the suction head 109 of the cleaning head 107 can be achieved through the suction line 205. In this example, the controllable suction device 202 can be a vacuum valve that can be intermittently controlled to apply vacuum from the waste discharge line 207 to the suction line 205 under the control of the control unit 201. The air and/or waste fluid in the waste fluid line 207 can be discharged outside the base station 101. A skilled person will be aware of various solutions for separating the waste fluid from the sucked air.

The controllable suction device 202 is preferably a suction pump that can suck air and/or waste fluid from the suction member 109 and the suction line 205. The suction pump 202 pumps the waste fluid and the sucked air into the waste fluid discharge line 207. The waste fluid and the sucked air of the suction line 205 can be easily arranged inside or outside the base station 101. The suction pump can be, for example, a membrane pump.

In Figure 2b, a more detailed example of a periodontal cleaning device is schematically shown. The base station 101 of the example of Figure 2b has a cleaning fluid container 104 and a waste fluid container 110. This allows the periodontal cleaning device 100 to be used as a separate device independent of the cleaning fluid supply line or the waste fluid discharge line. In this example, the controllable fluid feeding device 203 is a cleaning fluid pump as described in Figure 2a. In the cleaning fluid supply line 204, a controllable valve 210 for sharply opening and closing the cleaning fluid supply line in the supply line 204 is preferably included. This controllable valve 210 can be timed by the control unit 201 so that the controllable valve 210 opens slightly after starting the pump 203 to compensate for the startup delay of the pump 203.

Similarly, a controllable suction valve 209 may be included in the suction line 205. This controllable suction valve 209 can compensate for the startup delay of the suction pump 202, which is required for this embodiment. The controllable suction valve 209 allows for the rapid application of vacuum (i.e., suction in the suction line 205 and subsequently the suction member 109). The controllable suction valve 209 is controlled simultaneously with the suction pump 202 by the control unit 201.

The skilled person will recognize that the location of the suction pump 202, controllable suction valve 209, cleaning fluid pump 203 and cleaning fluid valve 210 in the operating member 102 and/or the waste station 101 is arbitrary. These components may be housed in both components 101, 102 of the periodontal cleaning device.

The control unit 201 is shown separate from the waste station 101 and the operating member 102 , however the skilled person will appreciate that the control unit 201 may be housed in either of the components 101 , 102 of the periodontal cleaning device or external to the base station 101 .

A filter 208 may be introduced in the suction line 205 to prevent larger particles from entering the controllable valve 209 and/or the suction pump 202. To facilitate maintenance, the filter 208 may be removable and/or cleanable.

FIG2c shows a timing diagram for controlling the controllable suction device 202 and/or vacuum valve 209, see curve I. A vacuum, having a negative pressure or low pressure _P1, is generated in a manner similar to a periodic pulse, with a time period T and a duty cycle determined by a pulse width _td1 and a pause _td3 until the next vacuum pulse. In curve I, the vertical axis shows the negative pressure in the direction of the arrow for pressure P. In curve I, pressure 0 represents ambient pressure, while _P1 represents the vacuum or negative pressure relative to ambient pressure. The negative pressure shown in FIG2c is assumed to exist in the suction line 205, while fluid flow is assumed to exist in the cleaning fluid feed line 204.

After the vacuum pulse terminates at _t2 , a cleaning fluid flow pulse begins at time _t3 , as shown in curve II. Curve II illustrates the cleaning fluid flow F. The cleaning fluid flow pulse has a debit of _D1 mL/second. Time _t3 may coincide with _t2 or may be slightly later than _t2 . The cycle time T is in the range of approximately 0.5 s to 1.5 s. Preferably, the cycle time T is approximately 0.75 s. The pulse width _td1 of the vacuum pulse and the pulse width _td2 of the cleaning fluid flow pulse are preferably on the order of 0.25 s.

After terminating the supply of cleaning fluid at time t ₄ , a pause of length t _d4 is introduced until t′ ₁ , which marks the start of a new cycle, ie the entire cycle repeats itself with a time period T from _{time t′ 1 .}

The vacuum _P1 generated by the controllable suction device 202 in the suction line 205 is of the order of 25 mmHg to 50 mmHg. Preferably, the vacuum is 35 mmHg. In addition, the amount of cleaning fluid generated in the cleaning fluid feed line 204 is of the order of 50 mL to 200 mL. Preferably, the amount of cleaning fluid is 90 mL.

In FIG3 a , the cleaning head 107 is shown in more detail. The cleaning head 107 is mounted to the handle 111, for example, by means of a nut 307. The cleaning fluid feed line 204 is coaxially arranged within the suction line 205. In this example, the suction line 205 forms the outer wall of the cleaning head 107. Alternatively, the suction line 205 and the cleaning fluid feed line 204 may be contained within an outer sheath of the cleaning head 102. The cleaning fluid feed line 204 may extend through the cleaning head into the handle 111 to connect to the suction pump 202 and/or filter 208 at the end of the cleaning head 107, with the suction member attached to the outer end of the suction line 205, for example, by sandwiching a suction member edge 301. In FIG3 a , the cleaning fluid feed line 204 is shown as having a tip 302 extending through the suction member 109. The suction member 109 is formed so that a cup is formed around the cleaning fluid feed line tip 302 to facilitate the creation of a vacuum at the subject's gums, where the suction member 109 is placed. The suction member 109 can be mounted on the cleaning head, for example, by clamping its edge 301 at the end of the cleaning head. Various ways of mounting the suction member are available to the technician.

FIG3 b shows the suction member 109 attached to the suction line 205. The suction member 109 has an inwardly curved collar 303 that serves as a support for the cleaning fluid feed line 204, which extends through the suction member 109 and terminates at a tip 302. The inner diameter of the collar 303 is selected relative to the outer diameter of the cleaning fluid feed line 204 so as to form a passage 309 for the suctioned air and/or waste fluid. The passage 309 allows a vacuum to be built up within the suction member wand 306 and allows air and/or waste fluid to enter the suction member 109 and the cleaning head 107, as indicated by arrow 305. The direction of discharge of cleaning fluid from the cleaning fluid feed line 204 is indicated by arrow 304.

Furthermore, when the suction member 109 has not yet been applied to the subject's gums, the cleaning feed line 204 is configured so that the tip 302 extends from the suction member 109 beyond the suction cup 306 by a distance d1. This allows the cleaning fluid feed line tip 302 to be used as a tactile instrument for the subject to establish a sensitive gum area in the subject's mouth.

3c, it is shown that when the suction cup 306 is applied to the gums of a subject, the tip 302 can be pushed a distance d2 inside the suction member 109. This is achieved by manufacturing the cleaning fluid feed line 204 from an elastic material and applying sufficient tolerances in the suction line 205 so that the cleaning fluid feed line tip 302 can therefore easily move back and forth within the suction member collar 303.

The suction member 109 is preferably made of a soft, resilient material such as rubber, silicone rubber or the like. This allows the suction member to be applied to the gums of a subject without causing irritation or pain.

The above embodiments are described by way of example only and modifications are possible without departing from the scope of protection defined by the claims explained below.

Reference numerals

100 Periodontal Cleaning Device

101 Base Station

102 operating components

103 Connecting hose

104 Cleaning fluid container

105 Operation Controller

106 Cleaning the Head Retainer

107 Cleaning the head

108 base

109 suction member

110 Waste fluid container

111 Operation Controller

112 handle

201 control unit

202 Controllable suction device (202)

203 Controllable fluid feeding device

204 Cleaning fluid feed lines

205 Suction line

206 Cleaning fluid supply lines

207 Waste fluid discharge line

208 filters

209 Controllable Suction Valve

210 Controllable Clean Fluid Inlet Valve

301 suction member edge

302 Fluid outlet top

303 Suction element collar

304 Cleaning fluid feed direction

305 Waste fluid suction direction

306 Suction Cup

307 Nut

308 bend

309 Suction opening

d1 fluid outlet extension distance

d2 Fluid outlet retraction distance

I Vacuum pulse

II Clean Fluid Stream Pulse

t _d4 pause

Claims (20)

1. A periodontal cleaning device (100), comprising: - A cleaning head (107) having a fluid outlet (302) for discharging cleaning fluid and a suction member (109) for suctioning waste fluid, wherein the cleaning head is configured to be applied to the periodontal region of the subject's mouth, the periodontal region including the gaps between teeth and gums and cavities that need to be cleaned. - A clean fluid source (104, 206) connected to the fluid outlet (302) via a fluid feed line (204); - A controllable suction device (202) is connected to the suction member (109) via a suction line (205), wherein the suction member (109) is made of a soft, elastic material that can be applied to the gums of a subject without causing irritation or pain. - A controllable fluid feed device (203) for controlling the flow of the cleaning fluid from the cleaning fluid source (104, 206) to the fluid outlet (302); - Control unit (201), the control unit (201) being arranged as follows: • Control the controllable suction device (202) to generate a vacuum pulse (I) in the suction member (109); • In response to the vacuum pulse (I), the controllable fluid feed device (203) is controlled to generate a clean fluid flow pulse (II) at the fluid outlet (302), and • Control the controllable suction device (202) to generate subsequent vacuum pulses (I) in the suction member (109); in, The control unit (201) is arranged to pause for a predetermined time period (td4) between the generation of the clean fluid flow pulse (II) in the fluid outlet (302) and the generation of the subsequent vacuum pulse (I) in the suction member ( ₁₀₉ ). - The fluid outlet (302) for releasing cleaning fluid is coaxially centered within the suction member (109). - The suction component (109) includes a suction cup (306), an inwardly curved collar (303), and a passage (309) for suctioning air and/or waste fluid. - The suction member (109) is formed such that the suction cup (306) is formed around the fluid outlet (302). 2. The periodontal cleaning device (100) according to claim 1, wherein the fluid outlet (302) extends elastically beyond the suction member (109). 3. The periodontal cleaning device (100) according to claim 1 or 2, wherein the predetermined time period ( _td4 ) is in the range of 150ms to 500ms. 4. The periodontal cleaning device (100) according to claim 3, wherein the predetermined time period (t _d4 ) is preferably in the range of 200ms to 300ms. 5. The periodontal cleaning device (100) according to claim 4, wherein the predetermined time period ( _td4 ) is more preferably in the range of 240ms to 260ms. 6. The periodontal cleaning device (100) according to claim 1 or 2, wherein the control unit (201) is arranged to generate a cleaning fluid flow pulse (II) in the fluid outlet (302) in response to the vacuum pulse (I) between generating vacuum pulses (I). 7. The periodontal cleaning device (100) according to claim 1 or 2, wherein generating the cleaning fluid flow pulse (II) includes generating a predetermined amount of cleaning fluid. 8. The periodontal cleaning device (100) according to claim 1 or 2, wherein the controllable fluid feed device (203) comprises a fluid pump between the cleaning fluid source (104, 206) and the fluid outlet (302). 9. The periodontal cleaning device (100) according to claim 1 or 2, wherein the controllable fluid feed device (203) includes a first controllable valve between the cleaning fluid source (104, 206) and the fluid outlet (302). 10. The periodontal cleaning device (100) according to claim 1 or 2, wherein the cleaning fluid source (104, 206) comprises a cleaning fluid container. 11. The periodontal cleaning device (100) according to claim 1 or 2, wherein the controllable suction device (202) includes a fluid suction pump. 12. The periodontal cleaning device (100) according to claim 1 or 2, wherein the suction line (205) includes a second controllable valve between the controllable suction device (202) and the suction member (109), the second controllable valve being arranged to allow the flow of waste fluid and air only when there is a sufficiently low pressure on the controllable suction device (202) side of the valve. 13. The periodontal cleaning device (100) according to claim 1 or 2, wherein the suction line (205) includes a filter between the suction member (109) and the controllable suction device (202). 14. The periodontal cleaning device (100) according to claim 1 or 2 further includes a waste fluid container connected to the controllable suction device (202). 15. A method of controlling a periodontal cleaning device (100) by means of a control unit (201) included in a periodontal cleaning device (100) according to any one of claims 1 to 14, wherein the method of controlling the periodontal cleaning device (100) is performed outside the mouth of a subject, the method comprising: - Control the controllable suction device (202) to generate a vacuum pulse (I) in the suction member (109); - In response to the vacuum pulse (I), the controllable fluid feed device (203) is controlled to generate a clean fluid flow pulse (II) at the fluid outlet (302), and - Control the controllable suction device (202) to generate subsequent vacuum pulses (I) in the suction member (109); The method also includes - A predetermined time interval (t _d4 ) is paused between the generation of the clean fluid flow pulse (II) in the fluid outlet (302) and the generation of the subsequent vacuum pulse (I) in the suction member (109). 16. The method of claim 15, wherein controlling the fluid feed device to generate a fluid flow pulse in the fluid outlet (302) is performed in response to the vacuum pulse (I) after the vacuum pulse (I) is generated. 17. The method according to any one of claims 15 to 16, wherein the predetermined time period (t _d4 ) is in the range of 150 ms to 500 ms. 18. The method according to claim 17, wherein the predetermined time period (t _d4 ) is preferably in the range of 200ms to 300ms. 19. The method according to claim 18, wherein the predetermined time period (t _d4 ) is more preferably in the range of 240ms to 260ms. 20. The method according to any one of claims 15 to 16, wherein generating the cleaning fluid flow pulse (II) comprises generating a predetermined amount of cleaning fluid.