Emergency detaching apparatus for an extracorporeal blood circuit

Abstract: A new blood circuit detaching apparatus capable of detaching blood circuits under dialysis treatment from a dialyzer swiftly and safely in an emergency of fire or earthquake, which is an apparatus (2) for detaching dialyzing artery and vein plastic tubes blood circuits (1A) and (1B) from a dialyzer in an emergency, including dialyzer side clamping portions (2A) and patient side clamping portions (2B) for clamping the mounted blood circuits (1A) and (1B) and circuit cutting portions (2C) arranged between the two clamping portions (2A) and (2B) as well as a pivotally moving cam mechanism for operating the dialyzer side clamping portions (2A), the patient side clamping portions (2B) and the circuit cutting portions (2C) in which by operating the pivotally moving cam mechanism, cutting at the circuit cutting portions (2C) is carried out successively to clamping at the dialyzer side clamping portion (2A) and clamping at the patient side clamping portion (28) to thereby detach the blood circuits (1A) and (1B) from the dialyzer.

Description: Field of the Invention The present invention relates to a blood circuit detaching apparatus. More particularly, the invention relates to a new improved blood circuit detaching apparatus capable of detaching blood circuits in the midst of dialyzing operation from a dialyzer swiftly and safely in an emergency of fire or earthquake. Prior Art A patient under dialysis is constrained to a dialyzer by blood circuits comprising artery and vein plastic tubes for dialysis and accordingly, there has conventionally been recognized a necessity of swiftly detaching the blood circuits from the dialyzer in an emergency of occurrence of fire or earthquake. Further, in respect of the detaching operation, there must be ensured safety capable of carrying out swift operation and causing no hindrance in the dialyzing operation and it is requested in an emergency that the detachment is operable by a patient per se under dialysis. In order to meet the request as much as possible, conventionally, there has widely been adopted means for clamping (squeezing to close) respectives of artery and vein blood circuits on the side of a dialyzer and on the side of a patient by using pairs of Pean forceps and successively cutting intermediaries between the clamping positions on the side of the dialyzer and the clamping positions on the side of the patient by scissors to thereby detach the blood circuits from the dialyzer. The detaching means comprising a combination of Pean forceps and a scissor is put into a bag and is kept ready at the bed side as an emergency kit. However, in the case of the conventional detaching means comprising Pean forceps and a scissor, since one hand of the patient under dialysis is connected to the blood circuits, the detaching means is operable only by the other hand. An operation of taking out the kit from the bag, clamping the blood circuits by the Pean forceps and cutting them by the scissor, is much troublesome with the patient. Swift operation in an emergency under an upset mental state is extremely difficult practically. Firm clamping may not be attained. Cutting the blood circuits by using the scissor may even be dangerous. In order to resolve such a problem, as detaching means enabling swift one-hand operation, as shown by, for example, Fig. 16, there has been proposed and put into practical use an emergency detacher capable of operating clamping (A) on the side of a dialyzer as well as clamping (B) on the side of a patient and circuit cutting (C) substantially simultaneously. As shown by Fig. 17, the emergency detacher is previously mounted to respectives of artery and vein blood circuits and in an emergency, respective pinching pieces (D) of the emergency detacher are squeezed by one hand to thereby clamp and cut the circuits. In the case of the emergency detacher, there is certainly provided a feature in which the emergency detacher can be operated more conveniently than the combination of Pean forceps and a scissor. However, on the other hand, the detacher is formed in a shape and a size operable even by fingertips of one hand to simultaneously carry out clamping and cutting operation. Therefore, about 7 kg of load is needed in the clamping and cutting operation by squeezing with the pinching pieces (D) and there is a case in which the operation with the load is difficult depending on age, gender or physical condition of the patient. Further, according to the detacher, the squeezing operation must be carried out instantaneously since the operation involves simultaneous clamping and cutting. When the operation is interrupted in the midway of the operation, blood leaks out from partially cut blood circuits, which may be dangerous to the patient or clean feeling may be deteriorated by the leakage of blood. As has been described above, it is an actual situation of the conventional technology that there still is not realized means for emergency detachment in which swift and convenient operation is feasible, safety is ensured, clean feeding is not deteriorated and one hand operation by a patient per se is facilitated. EP-A-0 194 873 discloses an apparatus for making a sterile connection between thermoplastic tubes. SUMMARY OF THE INVENTION It is an object of the invention set least in its preferred embodiments, to provide a new blood circuit detaching apparatus capable of resolving the above-described problems. Hence, according to a first aspect of the invention, there is provided a blood circuit detaching apparatus which is an apparatus of detaching dialyzing artery and vein plastic tube blood circuits from a dialyzer in an emergency, the blood circuit detaching apparatus comprising a dialyzer side clamping portion and a patient side clamping portion both for clamping the mounted blood circuits, a circuit cutting portion arranged between the two clamping portions and a pivotally moving cam mechanism for operating the dialyzer side clamping portion, the patient side clamping portion and the circuit cutting portion, wherein the blood circuits are detached from the dialyzer by carrying out a cutting operation at the circuit cutting portion successively to a clamping operation at the dialyzer side clamping portion and a clamping operation at the patient side clamping portion by operating the pivotally moving cam mechanism. Further, according to this aspect of the invention, the pivotally moving cam mechanism comprises a lever handle, a shaft pivoted by operating the lever handle and cams fixed to the shaft. According to a second, preferred aspect of the invention, there is provided the blood circuit detaching apparatus according to the first aspect, wherein the patient side clamping portion is mounted with forceps members and the forceps members are attached to the blood circuits in a clamped state in the clamping operation. According to a third, preferred aspect of the invention, there is provided the blood circuit detaching apparatus according to any one of the first or second aspects, further comprising a fixedly attaching portion for attaching to a supporter. Further, according to a fourth, preferred aspect of the invention, there is provided the blood circuit detaching apparatus according to any one of the first through the third aspects, wherein the dialyzer side clamping portion, the circuit cutting portion and the patient side clamping portion are arranged in this order in an up and down direction. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a front view of an apparatus according to an embodiment; Fig. 2 is a plane view in correspondence with Fig. 1; Fig. 3 is a side view in correspondence with Fig. 1; Fig. 4 is a sectional view viewing the apparatus in a direction of arrow marks a-a of Fig. 1; Fig. 5 is a side constitution view exemplifying constitutions of cams; Fig. 6 is a rear constitution view of essential portions in correspondence with Fig. 1; Fig. 7 is a plane constitution view of essential portions exemplifying clamping operation at a dialyzer side clamping portion; Fig. 8 is a side constitution view showing motion of the cams up to clamping operation on the side of a dialyzer; Fig. 9 is a rear constitution view of essential portions showing motion of a stopper piece; Figs. 10A and 10B are side constitution views showing motion of the cams up to clamping operation on the side of a patient; Figs. 11A and 11B are plane constitution views of essential portions showing clamping operation in correspondence with Figs. 10A and 10B; Figs. 12A and 12B are front constitution views of essential portions showing motion of the cams in correspondence with Figs. 10A and 10B and Figs. 11A and 11B; Fig. 13 is a plane constitution view of essential portions exemplifying motion of a cutting edge at a cutting portion; Fig. 14 is a rear constitution view of essential portions showing motion of the cams in correspondence with Fig. 13; Figs. 15A and 15B are side constitution views of essential portions showing motion of the cams in correspondence with Fig. 13 and Fig. 14; Fig. 16 is a constitution view of essential portions exemplifying a conventional emergency detacher; and Fig. 17 is a view showing an example of using the emergency detacher of Fig. 16. DETAILED DESCRIPTION OF THE INVENTION A detailed explanation will be given of an embodiment of a blood circuit detaching apparatus according to the invention having the above-described features in reference to the attached drawings. Fig. 1, Fig. 2 and Fig. 3 are a front view, a plane view and a side view showing a constitution example of a blood circuit detaching apparatus according to the invention in respect of the outlook. As exemplified in these drawings, an apparatus (2) of detaching dialyzing artery and vein plastic tube blood circuits (1A) and (1B) from a dialyzer in an emergency, includes dialyzer side clamping portions (2A) and patient side clamping portions (2B) for clamping artery and vein blood circuits (1A) and (1B) mounted in groove portions (2D) installed in the up and down direction on the front side and circuit cutting portions (2C) arranged between the two clamping portions (2A) and (2B). Further, according to the example of the detaching apparatus (2), there is provided a lever handle (2E) to facilitate one hand operation even by a patient per se. The blood circuits (1A) and (1B) can be detached from a dialyzer by pivoting the lever handle (2E) or by pivoting the lever handle (2E) from an original point portion in normal time shown by, for example, Fig. 3 in a direction of an arrow mark d in the drawing. In normal time, a stopper pin (2F) is locked to the lever handle (2E) and accordingly, the lever handle (2E) cannot be pivoted. In an emergency, pivotal operation of the lever handle (2E) can be carried out by drawing the stopper pin (2F) upwardly, that is, in a direction of an arrow mark β of Fig. 3. Further, the detaching apparatus (2) according to the example is provided with a fixedly attaching portion (2G) to be able to be stably fixed to a supporter of a bed side console or the like. The fixedly attaching portion (2G) as well as a mechanism of pivoting and locking the lever handle (2E) and the stopper pin (2F), may be formed in various shapes and structures. Further, needless to explain, according to the above-described example, as shown by Fig. 1, upper sides of the blood circuits (1A) and (1B) are connected to a dialyzer and lower sides thereof are connected to a patient. Further, according to the detaching apparatus (2) of the example, a shaft (2H) is pivoted by pivoting the lever handle (2E) and at the same time, cams fixed to the shaft (2H) are rotated. That is, the detaching apparatus (2) is installed with a pivotally moving cam mechanism for operating the dialyzer side clamping portions (2A), the patient side clamping portions (2B) and the circuit cutting portions (2C). It is a significant feature of the invention that the blood circuits (1A) and (1B) are detached from a dialyzer by carrying out clamping operation at the dialyzer side clamping portions (2A), the clamping operation at the patient side clamping portions (2B) and successively cutting operation of the circuit cutting portions (2C) by the pivotally moving cam mechanism. Fig. 4 shows a sectional view viewing Fig. 1 in a direction of arrow marks a-a and the cams constituting the cam mechanism comprise three kinds of cams (2K1), (2K2) and (2K3). When a position at which the lever handle (2E) is stopped such that the lever handle (2E) cannot be pivoted by locking it by the stopper pin (2F) is referred to as "original point position", Fig. 4 is a sectional view at the original point position and Fig. 5 shows only the three kinds of cams (2K1), (2K2) and (2K3) and the shaft (2H) at the original point position. The cams (2K1), (2K2) and (2K3) may be fixedly attached to the shaft (2H) by fabricating them as respectively separate members or may be fabricated as an integrally formed article. As a relationship among these, according to the example, the cam (2K1) corresponds to operation of clamping the blood circuits (1A) and (1B) at the dialyzer side clamping portions (2A), the cam (2K2) corresponds to operation of clamping the blood circuits (1A) and (1B) at the patient side clamping portions (2B) and the cam (2K3) corresponds to operation of cutting the blood circuits (1A) and (1B) at the cutting portions (2C). When these cams are constituted as respectively separate members, for example, the cams (2K2) and the cams (2K3) are arranged at both sides of the cam (2K1) in a plate-like shape. Now, an explanation will be given to exemplify operation of the cams (2K1), (2K2) and (2K3) as follows. (1) Clamping operation at the dialyzer apparatus side clamping portion (2A) As mentioned above, Fig. 4 is the sectional view viewing Fig. 1 in the direction of the arrow marks a-a and Fig. 6 is a rear view of essential portions of the detaching apparatus (2) according to the example, that is, a view viewing Fig. 4 in a direction of an arrow mark "b". As is seen in Fig. 4 and Fig. 6 showing the arrangement at the original point position, the detaching apparatus (2) is provided with slide bars (2L) at its upper portion and the slide bars (2L) are urged in a direction of an arrow mark γ in Fig. 4 by springs (2L1). Further, the slide bars (2L) are provided with small diameter portions (2L2). The small diameter portions (2L2) are engaged with stopper pieces (2L3) also shown by Fig. 6. At the original point position, slidal movement of the slide bars (2L) in the direction γ are stopped despite urging of the springs (2L1) in the direction γ. As shown also by Fig. 6, the stopper pieces (2L3) are pulled downwardly by springs (2L5) centering on fulcra (2L4). By the pulling force, the stopper pieces (2L3) are brought into a state in which they are fitted into the small diameter portions (2L2) of the slide bars (2L). Therefore, the stopper pieces (2L3) are not moved even when they are urged in the direction γ by the springs (2L1). The slide bars (2L) serve a role for clamping operation at the dialyzer side clamping portions (2A) and the role in this case is achieved by moving the slide bars (2L) in the direction γ by being urged by the springs (2L1). That is, engaging pins (2L6) are erected on the slide bars (2L). As exemplified in Fig. 7, the movement of the engaging pins (2L6) rotate clamp pieces (2M) to thereby firmly clamp the blood circuits (1A) and (1B) in the groove portions (2D). The press force of the engaging pins (2L6) exerted on the clamp pieces (2M) becomes large as urge force of the springs (2L1) exerted on the slide bars (2L) by which the clamping operation at the dialyzer apparatus side clamping portions (2A) is firmly carried out. It is a condition of such a clamping operation to move the slide bars (2L) in the direction γ. The movement is realized by the cam (2K1) mentioned above. That is, as shown also by Fig. 7, the movement of the slide bars (2L) is realized by disengaging the stopper pieces (2L3) from the small diameter portions (2L2) of the slide bars (2L). As shown by Fig. 6, the stopper pieces (2L3) urged downwardly are pushed up in the upward direction of the drawing by pivoting the cam (2K1) in accordance with the pivotal movement of the shaft (2H) in the direction of an arrow mark by operating the lever handle (2E) to thereby rotate in directions δ by which fitted attachment of the stopper pieces (2L3) to the small diameter portions (2L2) is released and movement of the slide bars (2L) in the direction γ is started. Fig. 8 shows motion of the cam (2K1) at this occasion. For example, a corner portion (2K1A) of the cam (2K1) pushes up the stopper pieces (2L3) and fitted attachment of the stopper pieces (2L3) to the small diameter portions (2L2) is released. Fig. 9 shows a height of variation (H) when the stopper piece (2L3) is pushed up. (2) Clamping operation at the patient side clamping portion (2B) When the lever handle (2E) is further turned, the shaft (2H) is pivoted and the cams are also pivoted in accordance therewith. By the pivotal movement, the clamping of the blood circuits (1A) and (1B) is successively carried out at the patient side clamping portion (2B). In this case, the clamping operations are made movable by operating the cams (2K2), as mentioned above. Figs. 10A and 10B show a change in the pivotal state of the cam (2K2) for enabling the clamping operation at the patient side clamping portion (2B) and Figs. 10A and 10B show a change further from the state of Fig. 8. Further, Figs. 11A and 11B and Figs. 12A and 12B show motion of clamp pieces (2N) and projections (2N1) thereof in accordance with the pivotal movement of the cams (2K2). Fig. 10A, Fig. 11A and Fig. 12A show a state before clamping. In this example, the projections (2N1) of the clamp pieces (2N) are moved while being in contact with inclined faces (2K2A) on the lower sides of the cams (2K2) toward peak portions (2K2B) thereof. In accordance therewith, the clamp pieces (2N) are rotated in a direction  and the pins (2N2) push forceps (3) to be attached to the blood circuits on the patient side in the clamped state to thereby push the forceps (3) to the sides of the blood circuits (1A) and (1B). When the projections (2N1) reach the peak portions (2K2B) of the cams (2K2), that is, in the state of Fig. 10B and Fig. 11B, the operation of clamping the blood circuits (1A) and (1B) by the forceps (3) by using the clamp pieces (2N) is completed. Although in the clamping operation on the patient side, it is preferable to use the forceps (3) attached firmly to the circuits in the clamped state in consideration of movement of the patient after the detachment by walk or the like, separate holding means for creating the clamped state may be considered. In any way, according to the detaching apparatus (2), the clamp pieces (2N) are rotated in the direction  by being pushed by strong force by using the cams (2K2) and accordingly, firm clamping operation can be executed. (3) Cutting operation of the blood circuits The blood circuits (1A) and (1B) are cut by further pivoting the lever handle (2E). The cutting is made feasible by pivoting the cams (2K3). The cutting operation is carried out by pivoting cutting edges (2P) exemplified in, for example, Fig. 13 at the cutting portions (2C) shown by Fig. 1. That is, by pivoting the cutting edges (2P) pulled by springs (2P1) in a direction f centering on fulcra (2P2), the blood circuits (1A) and (1B) in the grooves (2D) are cut. According to the example of Fig. 13, the pivotal movement is caused by moving projections (2P3) as contact portions of the cutting edges (2P) by being pushed by the cams (2K3). The motion of the cams (2K3) may be regarded as a change from the original point positions of Fig. 6 to positions in the state of a rear view of Fig. 14, further, as a change in Figs. 15A and 15B. The cutting edges (2P) are pivotally moved in the direction  by movement of positions of the projections (2P3) following the inclined faces of the cams (2K3), that is, by relative movement of positions in an arrow mark direction shown by Fig. 14. By the cutting operation mentioned above, the blood circuits (1A) and (1B) are detached from the dialyzer. (4) Detaching operation after cutting the patient side circuits Further, still more explanation is given to the detaching apparatus (2) exemplified above. When the cutting operation is completed, the blood circuits in the clamped state on the side of the patient can immediately be relieved of the detaching apparatus (2). As shown by Figs. 12A and 12B and Figs. 15A and 15B, the cams (2K2) for executing the clamping operation on the side of the patient, are installed with inclined faces (2K2C) also on the upper sides. The projections (2N1) of the clamp pieces (2N) are moved to follow the upper side inclined faces (2K2C) from the peak portions (2K2B). Therefore, press force for the clamping operation by the clamp pieces (2N) is released at a stroke and the patient side circuits after the cutting operation which have been clamped by the forceps (3) are immediately detached from the apparatus (2). At this occasion, when the apparatus (2) is installed with a bottom plate (2Q) which can be pivoted around a fulcrum (2R), in this example, the cams (2K2) may be brought into contact with the bottom plate (2Q) to thereby push to open the bottom plate (2Q) as shown by Fig. 15B. In this way, even when the bottom plate (2Q) is provided to the apparatus (2), the patient side circuits can be detached smoothly after cutting. (5) Returning operation to the original point position It is easy to again set the detaching apparatus (2) after the emergency state has been resolved. The lever handle (2E) is reversely rotated to return to the state shown by Figs. 1 through 3. Further, front ends of the slide bars (2L) shown by Fig. 1 are pushed in by the stopper pin (2F) to thereby return to a state in which the small diameter portions (2L2) are fitted with the stopper pieces (2L3). As has been explained in details, the following operations are carried out successively and swiftly by only turning the lever handle (2E) owing to the cam mechanism. (1) Clamping operation on the side of a dialyzer (2) Clamping operation on the side of a patient (3) Operation of cutting circuits It is conceivable to adopt electric means such as a motor in place of the lever handle (2E), although this does not fall within the scope of the invention, and it is also conceivable to use the electric means as auxiliary means. In consideration that even in the operation by using the lever handle (2E), the patient per se can swiftly operate the apparatus by one hand with no need of large force, that in the case of the lever handle (2E) the patient can interrupt the operation at a midway and stop the operation in the state where the blood circuits have been clamped in earthquake since rocking is not caused so much and that the manual operation is preferable in view of the cost, the apparatus can be made sufficiently practical by constituting the lever handle or a structure functionally similar thereto in the detaching apparatus in an emergency. When the electric system is adopted, the control poses a problem as an apparatus handled by a patient and a burden in view of the cost must be considered. However, the invention does not exclude the auxiliary, supplementary constitution of the electric system. When the function of the detaching apparatus (2) exemplified in Figs. 1 through 15B is evaluated in view of the operation of a patient, an average value of the operational time period is 4.9±1.5 seconds which is significantly shorter than 52.3±18.1 seconds in the case of a set of Pean forceps and a scissor. Further, in the case of the detacher exemplified in Figs. 16 and 17, the average value is 7.2±2.5 seconds. It is found that the operation can be carried out swifter than in the detacher. Further, although in the case of the operation of the detaching apparatus (2) by the lever handle according to the example, all of patients can handle the apparatus by one hand, whereas in the case of the set of Pean forceps and a scissor and the above-described conventional detacher, there are recognized patients who cannot handle the apparatus by one hand. Further more, in the case of the detaching apparatus (2), the safety is excellent and there is no inconvenience produced by leaking blood. Naturally, the apparatus of the invention is not limited to the description in reference to the drawings. It goes without saying that various modes in implementing the apparatus are pertinently considered in respect of a constitution of the detailed portions, the shape, the size and the structure of the apparatus. As has been explained in details, there is provided a detaching apparatus excellent in swift detachment in dialyzing operation, safety and clean feeling by the invention. According to the apparatus, one hand operation by a patient per se is facilitated and an emergency in the midst of medical treatment of blood dialysis at a facility or at home is dealt with perfectly.

Claims: A blood circuit detaching apparatus which is an apparatus (2) of detaching dialyzing artery and vein plastic tube blood circuits (1A, 1B) from a dialyzer in an emergency, comprising: a dialyzer side clamping portion (2A) and a patient side clamping portion (2B) both for clamping the mounted blood circuits (1A, 1B); a circuit cutting portion (2C) arranged between the two clamping portions (2A, 2B); and a pivotally moving cam mechanism for operating the dialyzer side clamping portion (2A), the patient side clamping portion (2B) and the circuit cutting portion (2C); wherein the blood circuits (1A, 1B) are detachable from the dialyzer by carrying out a cutting operation at the circuit cutting portion (2C) successively to a clamping operation at the dialyzer side clamping portion (2A) and a clamping operation at the patient side clamping portion (2B) by operating the pivotally moving cam mechanism; characterised in that : said pivotally moving cam mechanism comprises a lever handle (2E), a shaft (2H) pivoted by operating the lever handle (2H) and cams (2K1, 2K2, 2K3) fixed to the shaft (2H). The blood circuit detaching apparatus according to claim 1, wherein the patient side clamping portion (2B) is mounted with forceps members (3) and the forceps members (3) are attached to the blood circuits (1A, 1B) in a clamped state in the clamping operation. The blood circuit detaching apparatus according to claims 1 or 2, further comprising: a fixedly attaching portion (2G) for attaching to a supporter. The blood circuit detaching apparatus according to any one of claims 1 to 3, wherein the dialyzer side clamping portion (2A), the circuit cutting portion (2C) and the patient side clamping portion (2B) are arranged in this order in an up and down direction.

Inventors: EGO TOMOMICHI, MAEDA TEIRYO, OTSAKU SHIGERU, EGO, TOMOMICHI, MAEDA,TEIRYO, OTSAKU,SHIGERU, Maeda,Teiryo Maeda Inst.of Renal Res.Musashikosugi, Otsaku,Shigeru Maeda Inst.of Ren.Res.Musashikosugi
Applicants: MAEDA TEIRYO, MAEDA, TEIRYO
Application year: 1999
Main classification: A61M1
IPC codes: A61M1, A61M39