JPH0467448B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to a method for manufacturing a medical member with a sensor (for example, a cannula).

B. Prior Art In recent years, progress has been made in the development of artificial hearts for auxiliary and temporary replacement of the functions of the heart outside the body during open-heart surgery and other surgeries. For example, as shown in FIG. 9, a sac-type blood pump device 11 is connected between the right atrium and the pulmonary artery and between the left atrium and the aorta of a living body's heart 10, respectively. Such blood pump devices are being researched in Japan ahead of the rest of the world, and have already been put into clinical use as auxiliary hearts.

This blood pump device 11 is called a sack type, and as shown in FIG. It consists of a flat blood chamber 2 that is airtightly housed. A blood inlet pipe 3 and a blood discharge pipe 4 are connected to the blood chamber 2 and the upper part thereof.
are formed upward and substantially parallel. A flange portion 5 forming a part of the housing is provided around the upper portion of the blood chamber portion, and the blood chamber is hermetically housed within the housing outer case 1 by this flange portion. In addition, artificial check valves 6 and 7 are installed inside each of the blood introduction tube 3 and the blood discharge tube 4 to prevent the blood 17 from flowing back. The blood 17 introduced into the chamber is pumped out from the blood discharge tube 4. Blood is pumped out by alternately introducing and discharging fluid such as compressed air and decompressed air through the port 8 provided at the bottom of the housing outer case 1, and the blood chamber expands and contracts as the external pressure of the blood chamber changes. This is done by repeating. Each cannula 12 connected to the heart of the living body and each blood conduit 3 and 4 on the blood chamber 2 side are inserted from both ends of each connector 13 to the position of a ring-shaped flange 14 provided at the center thereof.

C. Background of the Invention When performing surgery using the blood pump device 11 as described above, if the blood pressure (real pressure) at the insertion point in the heart or blood vessel is directly measured, necessary treatment (for example, catecholamine and administration of peripheral vasodilators) can be effectively and appropriately administered. For example, there is a monitoring method in which a long catheter with a pressure sensor installed at the tip is inserted from outside the body through a blood vessel to a predetermined position within the heart or blood vessel, and has been used alone or in combination with a cannula or the like. However, in surgical cases using a cannula, in order to perform measurements accurately and easily,
It is effective to incorporate a sensor into the cannula as described above. In any case, the reality is that there is currently no method for easily and accurately mass-producing medical components with sensors as described above.

D. Object of the Invention An object of the present invention is to provide a method for mass-producing sensor-equipped medical components easily and accurately.

E. Structure of the Invention That is, the present invention includes the steps of: fixing a second mold for forming a sensor accommodation space on a first mold having a shape corresponding to the main body of a medical member (for example, a cannula); forming a coating film on each outer surface of the first mold and the second mold; and releasing the first mold and the second mold, respectively, thereby forming a medical member main body and a sensor integrated therein. The present invention relates to a method for manufacturing a medical component with a sensor, which includes a step of molding a housing portion; and a step of attaching a sensor (for example, a pressure sensor) into a housing space of the sensor housing portion.

F. EXAMPLE Hereinafter, an example of the present invention will be described in detail with reference to FIGS. 1 to 8.

First, for ease of understanding, an example of the cannula obtained in this example will be explained with reference to FIGS. Although it is almost the same as that shown in the figures and FIG. 10, a major feature is that a pressure sensor 20 is built-in or embedded in the tip portion 22a. A lead wire 21 is led from the pressure sensor 20 through the cannula wall and connected to a monitor and display (not shown) via an external amplifier. Note that the lead wire 21 is covered with a small diameter tube 23 for protection.

The sensor 20 is embedded in the cannula tip 22a, as shown in the enlarged view in FIG.
A pressure sensor chip portion (diffused silicon semiconductor or piezoresistive element portion) 25 provided as an electrical conversion element on a silicon substrate 24 faces the atmospheric pressure (ie, external pressure) side through a small passage 26. Further, the substrate 24 is fixed in a recessed part of a stainless steel block 27 to form a pressure receiving diaphragm, and the pressure receiving part side is further hardened with adhesive silicone rubber 28, and furthermore, this silicone rubber 28 faces into the cannula through the opening 31. ing. Therefore, when the cannula tip 22a is inserted into the target blood vessel 29, for example, as shown in FIG. performs the original blood extraction or introduction action (see FIGS. 5 and 6), and at the same time, the blood pressure (real pressure) in the blood vessel 29 can also be directly measured by the sensor 20 at its tip.

In this way, according to this embodiment, the cannula 2
Since the device 2 itself has a blood pressure measurement function, there is no need to insert a separate catheter with a sensor as in the past in order to obtain particularly accurate biological information. Therefore, blood pressure can be measured accurately and at the same time, the work is also very easy.

Next, the above-described method for manufacturing the cannula 22 is carried out in a first manner.
The diagram will be explained.

First, as shown in Figure 1A, the cannula 22
A mold 32 having a shape corresponding to the shape of the main body 22b of
and a second mold for forming a space for accommodating the sensor 20 and its lead wires 21.
Metal pins 33 each having a diameter of 0.5 to 2 mm are manufactured.

Next, the mold 32 is preheated to, for example, 180°C, and a metal pin 3 coated with polyvinyl chloride plastisol is inserted.
3 is placed on the mold 32 as shown in FIG. 1B, and the sol is gelled and fixed. Although the fixed gel film 34 is shown in the figure, this film may be present not only at a position not shown but also over the entire surface of the pin 33.
In addition, 35 in the figure is a ring made of polyvinyl chloride that becomes the above-mentioned flange part 30, and the pin 33
It was inserted and fixed after fixation.

Then, the first
As shown in Fig. C, a coating film 22 of polyvinyl chloride is formed on each outer surface of the mold 32 and the metal pin 33.

By repeating the dipping a necessary number of times and selecting the dipping position, the relatively thin main body portion (the tip 22a) of the coating film can be
side) and a relatively thick main body portion (blood pump side) can be formed continuously, and it is also possible to easily provide a distribution of hardness using the above-mentioned plastisols with different amounts of plasticizer.

Next, after the coating film is cured by heating, a part of the coating film is cut off, the metal pin 33 is extracted, and the mold 3 is removed, as shown in FIG. 1D.
2 is also removed. By releasing each mold in this way, a cannula main body is formed corresponding to the mold 32, and a sensor accommodating part 41 having a small diameter elongated hole 36 as a sensor accommodating space is formed corresponding to the metal pin 33. be done.

Next, as shown in FIG. 1E, the above-mentioned sensor 20
Side holes 31 and 37 are formed in the inner wall and outer wall, respectively, by punching 38 at the position (punching).
do. This punching can be performed in the same process as punching the side holes at the tip (not shown).

Next, as shown in FIG.
, and the sensor 20 is pushed into the side holes 31 and 37 as shown in FIG. 1G.

At this time, since the diameter of the elongated hole 36 is formed to be somewhat smaller than the diameter of the sensor 20, the lead wire 21 is smoothly pulled out through the elongated hole 36 to the outside (to the left in the drawing), and then the sensor 20 While the elongated hole 36 is elastically expanded, the sensor 20
It is pushed into the position shown in Figure G. Therefore, in that position, the sensor 20 is firmly held by the elastic force of the coating film. Note that if adhesive is applied to the outer surface of the sensor 20 in advance, the sensor 20
This is advantageous in terms of biological protection, as it can fix the sensor more firmly and at the same time has good insulation sealing properties, and can sufficiently prevent leakage current due to voltage application when driving the sensor.

Next, as shown in FIG. 1H, using a punch piece 38, this punch piece 38 is welded to one of the small holes 37 to close this side hole 37. Instead of this method, the punch pieces 38 may be bonded using sol or adhesive, but heating (curing) is required when using sol. Thereafter, the tip side of the elongated hole 36 is filled with sol, adhesive, silicone rubber, polyurethane, etc. 39. Further, a small-diameter protective tube 23 is inserted from the exposed side of the coiled lead wire 21 and pushed into the position shown in FIG. 1I. At this time, if adhesive is applied to the outer surface of the tube 23 in advance, the strength after insertion and fixation will be increased, effectively protecting the internal lead wire 21, and preventing current leakage from the lead wire 21 and sensor 20. can be prevented.

Further, the opening 31 is formed by the silicone rubber 28 described above.
Keep it closed.

Next, by immersing the entire tip portion 22a in a low-concentration antithrombotic polyurethane solution, it is possible to more completely prevent electrical leakage and also provide antithrombotic properties. Generally, if even 0.1 mA of current leaks into the heart, there is a risk of death, so even during normal use or when high voltage is applied, the leak should be less than 10 μA, and it must be completely sealed.

As explained above, by the method of this embodiment, the cannula with a built-in sensor is attached to each of the molds 32 and 33.
It can be easily manufactured with high precision through a series of processes including the use of , coating, and removal (release) molding, and its productivity is also good.

In the above embodiment, for example, the metal pin 33 shown in FIG. 1A was used, but instead of this, the metal pin 33 shown in FIG.
Alternatively, a metal pin 33 having a larger diameter on the tip side (ie, the fixed position of the sensor 20) as shown in b can be used.

In this case, for example, if the pin 33 shown in FIG. 5a is used, when the pin 33 is fixed to the mold 32 as shown in FIG. Form it. Therefore, after the subsequent dipping shown in FIG. 6B, if a part of the coating film is cut off as shown in the figure and the metal pin 33 is pulled out from the large diameter portion 33a side in the direction of the arrow, the same elongated hole 36 as described above is formed. It can be formed and the step 40
A space is created in the portion where the sensor 20 is smoothly received.

After attaching the sensor 20 and removing the mold 32, one of the punch holes 37 is closed as described in FIG. 1H, and the tip end is closed with adhesive 39, as shown in FIG. Finish the condition.

In addition, in the process shown in FIG. 1F above, the elongated hole 3
If the tip of 6 is packed, the side hole 37
The lead wire 21 and sensor 20 may be inserted from there. Also, another metal pin 33 forming the elongated hole 36
The tip position of the sensor 20 may end at the fixed position of the sensor 20 instead of protruding to the right as shown in FIG. 1B.

Furthermore, if a polyurethane solution is applied inside the long hole 36 or outside the tube 23 in the step shown in FIG. 1H,
Furthermore, sufficient sealing performance can be obtained. However, it is necessary to secure a space within the chillube 23 for communicating the sensor 20 with the outside air. In addition to inserting the tube 23 as shown in Fig. 1H, the tube 23 may be inserted around the lead wire 21 in advance in the process shown in Fig. 1F.
It is also possible to insert the lead wire 21 and the sensor 20 into the elongated hole 36 in a state in which they are glued to each other.
This allows the lead wire 21 to be sufficiently protected and has sufficient tensile strength.

Further, as shown in FIG. 7, the lead wire 21 can be led over almost the entire length to the other end of the cannula 22. However, when clamping the intermediate position of the cannula 22, for example, the position indicated by the dashed-dotted line in Fig. 4, the lead wire 2 should be
It is preferable to derive 1 in terms of not damaging the lead wire. As shown by the dashed line 23 in FIG.
The lead wire may be led out at a position closer to the front than shown in the figure, but this is because when reinforcing a wire coil by embedding it in the wall of the cannula, the lead wire 21 may be led out from a portion where there is no wire coil. be.

Further, the position of the sensor 20 is not limited to the above-mentioned example, and may be built into the flange portion 30, for example, but since the flange portion 30 is originally relatively thick, it is not convenient for fixing the sensor. good.

Furthermore, as shown in FIG. 8, the sensor 20 may be provided at the cannula tip 22a facing outward (that is, the pressure receiving portion faces outward). In this case, the fourth
As can be seen from the figure, the blood pressure within the blood vessel 29 can be measured more directly. To make the structure shown in FIG. 8, only the mold 32 is once dipped in sol before the process shown in FIG. 1B, and then the pin 33 is fixed on the mold 32, and the whole can be dipped again.
However, this second dipping time may be shortened.

Further, the wall thickness below the lead wire 21 can be increased as indicated by the dashed line.

Depending on the purpose, the type of sensor used may be a temperature sensor, gas sensor, PH sensor, temperature sensor, blood sugar level sensor, blood flow sensor, etc. in addition to the pressure sensor, and its fixed (embedded) position etc. It is not limited to the above example. Also, the number of sensors built into the cannula may be 2 or more,
If they are fixed with different functions, a plurality of types of physical and/or chemical quantities can be measured. In addition, cannula is not only the blood vessel and heart mentioned above, but also
It can also be used by bonding to other parts of the body. Moreover, the present invention is of course applicable to other fluid conduits other than cannulae.

G. Effects of the Invention As described above, in the present invention, the second mold is fixed on the first mold, the outer surfaces of both molds are coated, each mold is released, and a sensor is attached. Therefore, sensor built-in type medical components can be manufactured easily and accurately, and mass productivity is good.

[Brief explanation of drawings]

1 to 8 show embodiments of the present invention, including FIGS. 1A, 1B, 1C, and 1D.
1E, 1F, 1G, 1H, and 1I are cross-sectional views showing the method for manufacturing a cannula with a built-in sensor in the order of steps; FIG. 2 is a cross-sectional view of the main parts of the same cannula; and FIG. is an enlarged sectional view of the sensor built into the cannula, FIG. 4 is a sectional view of the cannula in use, FIGS. 5 a and b are sectional views of two other examples of metal pins, and FIGS. 6A and 6B. and FIG. 6C are cross-sectional views showing another example of a method for manufacturing a cannula with a built-in sensor in the order of steps, FIG. 7 is a cross-sectional view of another cannula with a built-in sensor, and FIG. 8 is a cross-sectional view of another cannula with a built-in sensor. FIG. Figures 9 to 10
The figures show a conventional example, in which FIG. 9 is a schematic view showing the state of use of the blood pump device, and FIG. 10 is an exploded perspective view of the same blood pump device. In addition, in the symbols shown in the drawings, 11... blood pump device, 12, 22... cannula, 13...
... Connector, 20 ... Pressure sensor, 21 ... Lead wire, 22a ... Tip, 22b ... Cannula body, 23 ... Small diameter tube, 24 ... Board, 2
5...Sensor part, 28...Silicone rubber, 29
... Blood vessel, 31, 37 ... Opening, 32 ... Mold,
33...Metal pin, 36...Elongated hole.

Claims (1)

[Claims] 1. Fixing a second mold for forming a sensor accommodation space on a first mold having a shape corresponding to the medical component main body; Coating on each outer surface of the first mold and the second mold. a step of forming a membrane; a step of molding a medical component main body and a sensor accommodating portion integrated therein by releasing the first mold and the second mold; A method for manufacturing a medical component with a sensor, the method comprising: attaching a sensor in a housing space.