Disclosure of Invention
The invention aims to provide a tubular negative pressure drainage device for orthopaedics, which solves the problems of troublesome replacement of sponge and incapability of taking out the sponge in the existing drainage device.
The technical scheme includes that the tubular negative pressure drainage device for orthopaedics comprises an inner tube positioned in a wound and an outer tube positioned outside the wound, wherein the outer tube is positioned at the top of the inner tube, the inner tube is communicated with the outer tube, a plurality of side holes which are uniformly distributed are formed in the side wall of the inner tube, the distances between adjacent side holes from the top end to the bottom end of the inner tube are the same, the pore sizes of the side holes are different, and VSD sponge is filled in the inner tube.
The technical proposal adopted by the invention is also characterized in that,
The pore size distribution of the side holes meets the following requirements:
Wherein the section of the pipe from the hole k to the hole k+1 is the kth section of the pipe, k is more than or equal to 1, sdk is the sectional area of the hole k, ρ is the density of the pipe, g is the gravity acceleration, hf is the along-the-path head loss, p0 is the suction force of the outlet of the inner pipe, pk is the suction force of the kth section of the pipe, and sdk is the sectional area of the hole k.
The bottom of the inner tube is of a closed structure.
The outer tube is of a double-layer sleeve structure, the inner diameter of the outer tube is smaller than the inner diameter of the inner tube.
One end of the outer tube far away from the inner tube is connected with a negative pressure suction port.
The joint level of outer tube and inner tube is equipped with the baffle, and the baffle is annular structure, and the outward flange round of baffle is integrated with inner tube and outer tube respectively.
One end of the outer tube far away from the inner tube is a hose.
The device has the beneficial effects that in the device, the surface of the sponge placed at the bottom of a wound or a sinus is provided with a layer of inner tube, the side wall of the inner tube is provided with the side hole, so that the wound or the side arm of the sinus can be uniformly stressed in the negative pressure suction process, the outer tube is designed as a double-layer sleeve, the inner diameter of the double-layer sleeve is smaller than that of the inner tube, the sponge of the tubular negative pressure drainage device is ensured not to fall off, and the sponge can be completely taken out in a very good way when the sponge needs to be taken out, the generation of dead space is avoided, thereby accelerating the healing of the wound.
Detailed Description
The invention is further described below with reference to the drawings and the detailed description.
The invention discloses a tubular negative pressure drainage device for orthopaedics, which is shown in fig. 1 and is structurally schematic, and comprises an inner tube 1 positioned in a wound and an outer tube 2 positioned outside the wound, wherein the outer tube 2 is positioned at the top of the inner tube 1, the inner tube 1 is communicated with the outer tube 2, the inner tube 1 is used for feeding liquid, the outer tube 2 is used for discharging liquid, the bottom end of the inner tube 1 is of a closed structure, a plurality of side holes 3 which are uniformly distributed are formed in the side wall of the inner tube 1, the side holes 3 of the inner tube 1 are used for feeding liquid, and the inside of the inner tube 1 is filled with VSD sponge 5.
The end of the outer tube 2 far away from the inner tube 1 is connected with a negative pressure suction port.
The pore sizes of the side holes 3 are different, the distances between the adjacent side holes 3 from the top end to the bottom end of the inner tube 1 are the same, and the pore size distribution of the side holes 3 meets the following requirements:
Where there are k holes in the direction from the top to the bottom of the inner tube, k=1, 2..the section of tube from hole k to hole k+1 is the k-th section of tube, sdk is the sectional area of hole k, ρ is the density of the tube, g is the gravitational acceleration, hf is the along-the-path head loss, p0 is the suction at the outlet of the inner tube, pk is the suction at the k-th section of tube, sdk is the sectional area of hole k.
As shown in fig. 2, one end of the hole k is externally connected with a negative pressure suction port, k holes are formed in the direction from the top to the bottom of the inner tube, k=1, 2. For the kth segment of the tube, it is available according to Bernoulli's equation
Wherein, pk is the suction of the inlet of the kth section of pipe, p 'k is the suction of the outlet of the kth section of pipe, ρ is the density, vk is the flow rate of the kth section of pipe, v'k is the flow rate of the kth section of pipe, g is the gravitational acceleration, and hf is the along-the-path head loss.
From the law of conservation of mass:
Qk＝Akvk＝Q′k＝A′kv′k (0.2)
Wherein the cross-sectional area of the orifice k is sdk, the flow rate vdk,QK is the volume flow through the orifice k inlet, Q'k is the volume flow through the orifice k outlet, and the flow through the orifice k into the tube is:
ΔQk＝sdkvdk (0.3)
Assuming that the hole k is small, the suction force of the left and right side sections of the hole k is approximately equal, that is:
pk＝p′k-1 (0.4)
according to the bernoulli equation, the flow velocity vdk can be expressed as:
since the hole k is assumed to be small, the left-side sectional area and the right-side sectional area of the hole k are approximately equal, that is:
A′k-1＝Ak (0.6)
thus, according to equations (0.2) and (0.6), it is possible to:
Akvk＝Ak+1v′k (0.7)
Analysis:
for the case of constant pipe diameter and same bore diameter, i.e
Ak＝Ak+1 (0.8)
sdk＝sdk+1 (0.9)
From equations (0.2) and (0.8)
vk＝v′k (0.10)
From equations (0.1) and (0.10)
pk＝p′k+ρghfk (0.11)
The flow rate of the hole k is
The flow rate of the hole k+1 is
As can be seen by comparing equations (0.12) and (0.13), the flow velocity vdk+1 of the orifice k+1 is greater than the flow velocity vdk of the orifice k. Also, because the cross-sectional area sdk+1 of the hole k+1 and the cross-sectional area sdk of the hole k are equal, the flow rate Δqk+1 of the hole k+1 is larger than the flow rate Δqk of the hole k according to equation (0.3). The closer to the negative pressure suction port, the greater the suction force of the hole.
To keep the suction force of each hole the same, the following two approaches can be taken.
Scheme 1. The diameter of pipe is kept unchanged, and the aperture is changed.
In the case of constant pipe diameter, i.e.
Ak＝Ak+1 (0.14)
From equations (0.2) and (0.14)
vk＝v′k (0.15)
From equations (0.1) and (0.15)
pk＝p′k+ρghfk (0.16)
The flow rates of the holes k and k+1 are respectively
To equalize the suction forces of holes k and k+1, i.e
ΔQk＝ΔQk+1 (0.19)
Then to meet
Namely, the hole near the top of the inner tube is smaller, and the hole far from the top of the inner tube is larger, and the scheme 1 is adopted.
Scheme 2, keeping the aperture unchanged and changing the pipe diameter.
In the case of unchanged pore diameter, i.e.
sdk＝sdk+1 (0.21)
To keep the suction of the individual holes the same, i.e
ΔQk＝ΔQk+1 (0.22)
From equations (0.3) and (0.21)
vdk＝vdk+1 (0.23)
The flow rates of holes k and k+1 can be expressed as
Thus (2)
pk＝p′k (0.26)
From equations (0.1) and (0.26)
I.e.
From equation (0.7)
The pipe diameter near the top of the inner pipe is larger, and the pipe diameter far from the top of the inner pipe is smaller.
The sponge 5 of the device adopts the VSD sponge, the aperture of the VSD sponge is larger, the attractive force of the near end and the far end of the VSD sponge is basically the same, the using effect of the VSD sponge cannot be influenced due to different positions, the sponge 5 is placed in the inner tube 1, and the porous material of the VSD sponge not only has good water absorption, but also can play a role in filtering, blood cell clusters and blood clots can be adsorbed in the sponge in the outward drainage process without entering a tube, the blockage of the tube cannot be caused, foreign matters are prevented from being formed, red blood cells, fibrin and the like can be blocked and left in the wound by the filtering blocking effect of the sponge, scar tissues are further formed by mechanization, and therefore the healing of the wound is promoted.
The bottom end of the inner tube 1 can be a straight tube vertically arranged in a wound as shown in fig. 3, and can also be a bent tube horizontally arranged in the wound as shown in fig. 1, the outer tube 2 is of a double-layer sleeve structure, and the inner diameter of the outer tube 2 is smaller than that of the inner tube 1, so that the sponge 5 can be fixed in the inner tube 1 and cannot run out in the working process of the drainage device.
As shown in fig. 4, the outer tube 2 may be designed into a structure with the same inner diameter as the inner tube 1, a baffle 4 is horizontally disposed at the joint of the outer tube 2 and the inner tube 1, the baffle 4 is in a ring structure, and the outer edge of the baffle 4 is respectively integrated with the inner tube 1 and the outer tube 2, so that the sponge 5 cannot pass through the baffle 4 under the action of pressure.
The end of the outer tube 2 far away from the inner tube 1 is a hose, and a switch clamping device is arranged on the hose to avoid the suck-back phenomenon generated when not in use.
The invention has the working processes that the invention comprises a wound inner tube 1 for feeding liquid and a wound outer tube 2 for discharging liquid, one end of the outer tube 2 is connected with a negative pressure suction port, a negative pressure suction device is started, body fluid such as pus, blood, liquid and the like which oozes or accumulates on the wound surface of the human tissue with the surface defect or the uncapped outside the wound or the sinus tract is sucked into the inner tube 1 through the side hole 3, and the wound or the sinus tract outside is guided out through the outer tube 2, and normally, the wound or the sinus tract outside is not required to be sealed by a film, and a special case can use a sterile sealing film to seal the gap between the drainage tube and the wound surface. The external part drainage tube is finally connected with a ward equipment negative pressure suction port.
The invention improves the existing aspirator, the sponge is plugged into the inner tube structure, the inner tube is provided with the side holes, the aperture of each side hole is arranged according to a certain rule, so that the pressure of the aperture of each side hole is kept consistent, thereby being beneficial to drainage, avoiding the problem that the drainage degree is different at each place in the wound and the whole drainage efficiency is affected due to different attractive force in the drainage process, and the arrangement of the side holes 3 does not have the problems of sponge falling-off and difficult replacement. The invention has simple structure, can completely take out the sponge in a very good way when the sponge needs to be taken out, and avoids the generation of dead space, thereby accelerating the healing of wounds.