JP5446595B2 - Body fluid treatment device, pressure measuring device, body fluid treatment method - Google Patents

Description

  The present invention relates to a bodily fluid processing apparatus that extracts and processes bodily fluids outside the body, and relates to a bodily fluid processing apparatus that includes a pressure measuring device that measures the pressure of bodily fluids or the pressure of liquids for treating bodily fluids. The present invention also relates to the pressure measuring instrument.

  A hemodialysis apparatus can be exemplified as one of the body fluid treatment devices that derive and treat body fluids outside the body. A hemodialysis apparatus is an apparatus for circulating blood derived from a human body to a blood purifier (dialyzer) to remove excessive water and waste products in the blood. The flow path through which blood derived from the human body circulates is called a blood circuit, is attached to the hemodialysis apparatus, and blood is forced to flow by a blood pump provided in the hemodialysis apparatus, and the blood purification system connected thereto Purified by a vessel. Further, unnecessary substances in the blood separated by the blood purifier are discharged together with the dialysate. The circuit through which the dialysate flows is called a dialysate circuit.

  In particular, when continuous renal support therapy (CRRT) is performed using a hemodialyzer, not only there is a blood circuit for blood circulation, but also a correction measuring mechanism used to adjust the amount and concentration of blood. In addition, since a water refill circuit is required, the number of parts increases. A circuit constructed using these components is very complicated.

  However, mistakes in the installation of parts to be attached to the hemodialysis apparatus, construction errors in the blood circuit, etc. are serious problems relating to the life of the patient to be dialyzed, and no mistakes are allowed. Thus, various proposals have been made for the purpose of reducing the burden on the installation operator while preventing the occurrence of mistakes.

  For example, Patent Document 1 describes a circuit body in which a blood circuit is integrally provided between superimposed resin sheets. According to the circuit body, since it can be attached to a processing apparatus in a state where a blood circuit has already been formed, there are few mistakes in circuit construction, and attachment work is simplified.

  Patent Document 2 describes a blood circuit in which a part is fixed to one sheet. According to the blood circuit, bending and tangle of the tube can be prevented, and the blood circuit can be definitely attached to the hemodialysis apparatus.

Japanese Patent Laid-Open No. 61-113461 Registered Utility Model No. 3082021

  Since the pressure of blood flowing through such a blood circuit and the pressure of dialysate flowing through the dialysate circuit are important indicators related to human life, it is desired that the pressure can be accurately monitored. Therefore, hemodialyzers are equipped with devices that measure the pressure of the liquid flowing in the blood circuit and dialysate circuit, and the components that measure pressure are also connected to the blood circuit in the same way as attaching the blood circuit to a blood pump or the like. It is attached to the equipment which measures pressure as a part.

  However, when accurately measuring the pressure of a liquid flowing through a blood circuit or the like in a stable state, the positional relationship between the pressure measuring device and the blood circuit or the like needs to be constant, and this operation is often difficult. .

  Therefore, in view of the above problems, the inventors of the present application can easily attach and detach a pressure cell provided as a component in a blood circuit or the like to measure the pressure of the liquid, and can accurately measure the pressure. The invention of a measuring device and a body fluid treatment device provided with the pressure measuring device has been filed separately.

  However, the pressure measuring instrument and the body fluid treatment device provided with a mechanism capable of easily attaching and detaching the above-described pressure cell have high workability and can accurately measure the pressure, but are formed by assembling the diaphragm and the casing. It is inevitable that dimensional variations occur in the pressure cell. There are also dimensional variations in the pressure measuring instrument. Such dimensional variations affect the reliability of the measured pressure value.

  This invention is made | formed in view of the said subject, and makes it the 1st objective to improve the reliability of the value obtained from a pressure measuring device or a bodily fluid processing apparatus.

  Moreover, a mechanism for mechanically detecting an attachment error based on a human error is provided in the attachment / detachment mechanism that facilitates the pressure cell. However, although the mechanical detection mechanism has been cleared, there is a possibility that an incomplete connection state that is not securely attached may occur.

  The inventors of the present application have noticed that there is the possibility in the experiment and research aiming at the improvement of the above-mentioned reliability, and furthermore, as a result of earnest experiment and research, the incomplete connection state can be detected. I came to find.

  This invention is made | formed based on the said knowledge, and makes the 2nd objective the detection of a malfunctioning state.

  In the above description, the hemodialysis apparatus has been described as one of the body fluid treatment apparatuses, but the above-described problem is not limited to the hemodialysis apparatus. For example, all devices that derive and process body fluids outside the body, such as blood filtration devices, cardiopulmonary devices, and blood concentration devices, have similar problems.

  In order to achieve the first object, a humor treatment device according to the present invention detachably holds a pressure cell having a liquid storage chamber formed by a housing having an engaging portion and a diaphragm, A body fluid treatment apparatus having a pressure measuring device for measuring a pressure of a liquid stored in a liquid storage chamber, wherein a base and a distance between the housing and the base are regulated by engaging with the engaging portion. And a fixing means for fixing the engagement state between the engaging portion and the restricting means, and a connecting portion connected to the diaphragm, and the displacement of the diaphragm relative to the base is converted into a signal. A value obtained from the first sensor using a first sensor, a second sensor for detecting an engagement state between the engagement portion and the restricting means, and the second sensor detecting an engagement state as a trigger. That calculates the difference between the value and the specified reference value as an offset value It is characterized in that it comprises and.

  This eliminates the inaccuracy of the value obtained from the first sensor based on the dimensional variation of the pressure cell and pressure measuring instrument, and reliably measures the pressure of the liquid flowing in the blood circuit and dialysate circuit. It becomes possible to do.

  In order to achieve the second object, a comparison value that is an absolute value of a difference between an offset value calculated in the past and a newly calculated offset value is compared with a predetermined threshold, and the comparison value is It is preferable to provide an error detection unit that outputs error information when the threshold is equal to or greater than a predetermined threshold.

  As a result, it is possible to detect that the pressure cell is attached in a state different from the conventional state and output error information. Therefore, the error information can be utilized to notify a worker who has a blood circuit or the like attached visually or audibly. Further, it is possible to apply an interlock so that the body fluid treatment device does not operate.

  In order to achieve the first object, a pressure measuring device according to the present invention detachably holds a pressure cell having a liquid storage chamber formed by a housing having an engaging portion and a diaphragm. A body fluid treatment apparatus having a pressure measuring device for measuring the pressure of the liquid stored in the liquid storage chamber, wherein the distance between the casing and the base by engaging with the base and the engaging portion A regulating means for regulating the engagement, a fixing means for fixing the engagement state between the engaging portion and the regulating means, and a connecting portion connected to the diaphragm, and the displacement of the diaphragm relative to the base as a signal The first sensor to be converted, the second sensor for detecting the engagement state between the engagement portion and the restricting means, and the detection of the engagement state by the second sensor are used as triggers. The offset is calculated as the offset value. Characterized in that it comprises a isolation portion.

  As a result, the inaccuracy of the value obtained from the pressure sensor and the first sensor based on its own dimensional variation can be eliminated, and the pressure of the liquid flowing in the blood circuit or dialysate circuit can be measured with high reliability. Is possible.

  In order to achieve the first object, the body fluid treatment method according to the present invention detachably holds a pressure cell having a liquid storage chamber formed by a housing having an engaging portion and a diaphragm. A bodily fluid treatment method applied to a bodily fluid treatment apparatus having a pressure measuring device for measuring the pressure of a liquid stored in the liquid storage chamber, wherein the pressure measuring device is associated with a base and the engagement portion. And a restricting means for restricting the distance of the housing relative to the base, a fixing means for fixing the engagement state between the engaging portion and the restricting means, and a connecting portion connected to the diaphragm. And a first sensor that converts a displacement of the diaphragm with respect to the base into a signal, and a second sensor that detects an engagement state between the engagement portion and the restriction means, and the engagement portion Triggered by the second sensor detecting the engagement state with the restricting means The offset unit calculates a difference between a value obtained from the first sensor and a predetermined reference value as an offset value, and the measurement unit corrects the value obtained from the first sensor based on the offset value. To do.

  This eliminates the inaccuracy of the value obtained from the first sensor based on the dimensional variation of the pressure cell and pressure measuring instrument, and reliably measures the pressure of the liquid flowing in the blood circuit and dialysate circuit. It becomes possible to do.

  In order to achieve the second object, the error detection unit further calculates a comparison value that is an absolute value of a difference between the offset value calculated in the past and the newly calculated offset value, and It is preferable to compare the comparison value with a predetermined threshold and output error information when the comparison value is equal to or greater than the predetermined threshold.

  As a result, it is possible to detect that the pressure cell is attached in a state different from the conventional state and output error information. Therefore, the error information can be utilized to notify a worker who has a blood circuit or the like attached visually or audibly. Further, it is possible to apply an interlock so that the body fluid treatment device does not operate.

  According to the present invention, the reliability of the measured pressure value can be improved by eliminating mechanically generated dimensional errors with software. Further, by using a value used in a software process for eliminating a dimensional error, it becomes possible to detect a pressure cell attachment error.

It is a figure which shows typically the hemodialysis apparatus with which the blood circuit was attached. It is a perspective view which shows a pressure cell, (a) is a front view, (b) is a rear view. It is a side view which shows typically a partial cross section of a pressure measuring device and a pressure cell, and has shown the state before a pressure cell is attached. It is a perspective view which shows the pressure cell and the pressure cell shown by notching a part, and shows a state before the pressure cell is attached. It is a block diagram which shows functionally the control part etc. of a hemodialysis apparatus. It is a figure which shows typically the operation | movement aspect of the clamping body by a cancellation | release means and a cancellation | release means. It is a side view which notches and shows the state of the pressure measuring device to which a pressure cell is attached partially. It is a side view which notches and shows the state of the pressure measuring device to which a pressure cell is attached partially. It is a schematic diagram which deform | transforms and shows the state of the diaphragm in the state in which the pressure cell was attached normally. It is a side view which notches and shows the state of the pressure measuring device from which the pressure cell was removed.

  Next, one embodiment for carrying out the present invention will be described by exemplifying a hemodialysis apparatus which is one of body fluid treatment apparatuses.

  FIG. 1 is a diagram schematically showing a hemodialysis apparatus to which a blood circuit is attached.

  As shown in the figure, a hemodialysis apparatus 100 according to the present embodiment is an apparatus that can perform continuous renal adjuvant therapy with a blood circuit 201 and a filtrate replacement circuit 202 attached, and a pump 101 And a pressure measuring device 150. A pressure cell 210 is attached to the blood circuit 201 and the filtrate replacement circuit 202.

  The hemodialysis apparatus 100 forcibly moves the blood in the blood circuit 201 in one direction by the pump 101, derives blood from the human body 300, and returns the blood purified by the dialyzer 220 to the human body 300 again. In order to detect the pressure of blood from the human body 300 to the pump 101, the pressure of blood before passing through the dialyzer 220, and the pressure of blood after passing through the dialyzer 220, the pressure is applied to the corresponding positions of the blood circuit 201, respectively. A cell 210 is attached.

  On the other hand, the hemodialysis apparatus 100 forcibly moves the dialysate in the filtrate replacement circuit 202 by the pump 101, discharges impurities in the blood extracted by the dialyzer 220, and supplies an appropriate amount of replacement fluid as necessary. (Combined with dialysate) is supplemented to return blood. In order to detect the pressure of the dialysate after passing through the dialyzer 220, a pressure cell 210 is attached to a corresponding position of the filtrate replacement fluid circuit 202.

  As described above, the hemodialysis apparatus 100 continuously draws blood from the human body and purifies the blood, replenishes the components of the blood that are insufficient due to the purification, and returns the blood to the human body 300.

  FIG. 2 is a perspective view showing a pressure cell, where (a) is a front view and (b) is a rear view.

  As shown in the figure, the pressure cell 210 is a device that is incorporated in the blood circuit 201 or the filtrate replacement fluid circuit 202 and changes its state in accordance with the change in the pressure of the liquid flowing in the blood circuit 201 or the filtrate replacement fluid circuit 202. A housing 211, a diaphragm 212, an inlet 213, and an outlet 214.

  The casing 211 is a member having rigidity capable of maintaining a constant form regardless of the pressure of the liquid flowing inside, and a space for forming a liquid storage chamber (not shown) is provided inside. It is a box-shaped member. The housing 211 is provided with an engaging portion 215. In the case of the present embodiment, the housing 211 has a short cylindrical shape with one end closed, and an engaging portion 215 is provided on the peripheral wall so as to project outward.

  The engaging portions 215 are rectangular portions that are formed integrally with the housing 211, and two engaging portions 215 are provided in the diameter direction of the housing 211.

  The diaphragm 212 is a member that has the flexibility to bulge and dent according to the pressure of the liquid flowing inside, and is attached to the casing 211 so as to cover a part of the liquid storage chamber formed by the casing 211. ing. In the case of the present embodiment, a magnetic body (including a metal that can be coupled to a magnet) 216 is attached to the center of the diaphragm 212.

  The magnet 216 is a member for detachably joining the diaphragm 212 and a sensor to be described later. The diaphragm 212 and the sensor are joined via the magnet 216 to detect only the bulging state of the diaphragm 212. In addition, it is possible to detect a state in which the diaphragm 212 is depressed.

  The inlet port 213 and the outlet port 214 are members connected to tubes constituting the blood circuit 201 and the filtrate replacement fluid circuit 202, respectively, and introduce the liquid flowing through the blood circuit 201 and the filtrate replacement fluid circuit 202 into the storage chamber. Moreover, it is a member for taking out from a liquid storage chamber.

  FIG. 3 is a side view schematically showing a partial cross section of the pressure measuring instrument and the pressure cell, and shows a state before the pressure cell is attached.

  FIG. 4 is a perspective view showing a pressure measuring instrument and a pressure cell shown with a part cut away, and shows a state before the pressure cell is attached.

  As shown in the figure, the pressure measuring device 150 is a device that measures the pressure of the liquid stored in the liquid storage chamber 217 inside the pressure cell 210, and includes a base 151, a regulating means 152, and a fixing means 153. A first sensor 154, a release means 155, and a second sensor 165.

  The base 151 is a member serving as a reference for detecting the displacement of the diaphragm 212 as a pressure. In the case of the present embodiment, the housing of the hemodialysis apparatus 100 functions as the base 151.

  The regulating means 152 is a device that regulates the distance of the casing 211 of the pressure cell 210 with respect to the base 151 by engaging with the engaging portion 215 included in the pressure cell 210. In the case of the present embodiment, the restricting means 152 is configured such that the clamping body 157 provided with the second engaging portion 156, the engaging direction in which the engaging portion 215 and the second engaging portion 156 are engaged (in FIG. 3). And a first spring 158 that urges the sandwiching body 157 in a direction (arrow direction in FIG. 3) intersecting with the (left-right direction).

  The engagement direction is a direction of a force generated when the engagement portion 215 and the second engagement portion 156 are engaged and the engagement state is maintained. The direction intersecting with the engagement direction is a direction that is not parallel to the engagement direction. For example, a direction perpendicular to the engagement direction can be listed.

  The sandwiching body 157 is attached to the base 151 by a rotation shaft 159 and is attached to be rotatable about the rotation shaft 159. The sandwiching body 157 is an elongated plate-like member, and a second engagement portion 156 that is a rectangular hole provided in a penetrating manner is provided in the thickness direction of the sandwiching body 157. Further, the tip of the sandwiching body 157 is bent, and when the pressure cell 210 is pressed, a force is generated in a direction against the urging force. The sandwiching body 157 includes a protrusion for rotating the sandwiching body 157 against the urging force applied to the sandwiching body 157. The protruding portion will be described later.

  The first spring 158 is a string-wound spring that is biased in a direction in which the tip of the sandwiching body 157 approaches. The first spring 158 generates an urging force in the vertical direction and the expanding direction shown in FIG. 3, and the urging force is applied to the base end portion of the holding body 157 that is pivotally supported by the base 151. The tip of the sandwiching body 157 is biased in the direction indicated by the arrow in FIG.

  The fixing unit 153 is a device that fixes the engagement state between the engaging portion 215 of the pressure cell 210 and the regulating unit 152. In the case of the present embodiment, the fixing means 153 includes a fixing body 160 and a second spring 161.

  The fixed body 160 is a member that is urged against the base 151 in a direction that intersects the direction in which the clamping body 157 is urged, and in a direction that presses the engaging portion 215 against the second engaging portion 156. Specifically, the fixed body 160 is a plate-like member having a hole in the center, and is urged by a second spring 161 described later in the left-right direction and the direction away from the base 151 shown in FIG. The direction in which the engaging portion 215 is pressed against the second engaging portion 156 is the same direction as the engaging direction.

  The second spring 161 is a string-wound spring that urges the fixed body 160 in a direction away from the base 151. As shown in FIG. 4, in a state where the pressure cell 210 is attached, the urging force of the second spring 161 causes the engaging portion 215 to be moved to the second engaging portion via the fixed body 160 and further via the housing 211. 156.

  The first sensor 154 has a connecting portion 162 connected to the diaphragm 212, and can convert the displacement of the diaphragm 212 into an electric signal by causing the connecting portion 162 to follow the displacement of the diaphragm 212 with respect to the base 151. It is. In the case of the present embodiment, the first sensor 154 includes a load cell 163 and an arm 164 provided with a connection portion 162.

  The load cell 163 is a sensor that converts the displacement of the diaphragm 212, that is, the pressure (force) of the liquid existing in the liquid storage chamber 217 into an electrical signal and outputs it. In the case of the present embodiment, four strain gauges are attached. In addition, a robust load cell 163 is employed. The load cell 163 can detect not only the swelling of the diaphragm 212 of the pressure cell 210 but also the depression. The load cell 163 has a base end attached to the base 151, and a strain gauge is operated by a strain generated by a force applied to the tip of the load cell 163 (left and right direction in FIGS. 3 and 4). Can be sent.

  The first sensor 154 is not limited to the use of the load cell 163. For example, a load cell such as a tension type or a compression type may be employed. Further, not only a strain gauge but also a magnetostrictive effect or a piezoelectric effect may be used.

  The arm 164 and the connection portion 162 are members that move a point at which the load cell 163 is subjected to a load from the tip end portion of the load cell 163 to an arbitrary location. In the case of the present embodiment, the arm 164 is a highly rigid plate-like metal plate, and is arranged in parallel to the load cell 163 at a predetermined distance. The base end portion of the arm 164 is firmly fixed to the tip end portion of the load cell 163, and the tip end portion of the arm 164 extends to the vicinity of the center portion of the load cell 163.

  By arranging the arm 164 as described above, the pressure measuring device 150 can be configured relatively compactly, and can be easily incorporated into the hemodialysis apparatus 100.

  The connecting portion 162 is a columnar member extending in the protruding direction from the tip of the arm 164, and at least the tip is a magnet that can be detachably connected to the magnetic body 216 included in the pressure cell 210 by magnetism. The connecting portion 162 is arranged in a protruding shape without interfering with the sandwiching body 157, the fixed body 160, and the like, and the pressure cell 210 in a state where no liquid is stored in the liquid storage chamber 217 is attached. It arrange | positions so that it may contact | abut with the magnetic body 216 of 210 (without magnetic force). That is, the pressure cell 210 is arranged with respect to the connection part 162 in a state where the diaphragm 212 is not pulled by the magnetic force and conversely the diaphragm 212 is not pushed in by the connection part 162.

  Note that this state is an ideal state, and actually, the diaphragm 212 is slightly pulled or slightly pushed in due to a dimensional error of the pressure measuring device 150 or the pressure cell 210. Yes.

  In the second sensor 165, the position of the fixed body 160 in a state where the engaging portion 215 is pressed against the second engaging portion 156, and the engagement between the engaging portion 215 and the second engaging portion 156 are released ( This is a device for detecting a difference from the position of the fixed body 160 in the state of FIG. In the case of the present embodiment, a micro switch is employed as the second sensor 165.

  FIG. 5 is a block diagram functionally showing a control unit and the like of the hemodialysis apparatus.

  As shown in the figure, the control unit 180 included in the hemodialysis apparatus 100 is software that processes signals obtained from the first sensor 154 and the second sensor 165, and hardware that operates based on the software. , An offset unit 181, an error detection unit 182, an offset value storage unit 183, and a measurement unit 184. In addition, the hemodialysis apparatus 100 includes a display device 189.

  The offset unit 181 calculates an offset value based on a value obtained from the first sensor 154 in a state where the liquid storage chamber 217 is not filled with liquid, triggered by the pressure cell 210 being attached to the pressure measuring device 150. It is a functional part. In the case of the present embodiment, the offset unit 181 constantly monitors the state of the second sensor 165, and the engagement state between the engagement portion 215 of the pressure cell 210 and the regulating means 152 is from the non-engaged state to the engaged state. If the second sensor 165 detects that the change has occurred, a value is acquired from the first sensor 154 using this detection as a trigger, and the difference between the acquired value and a predetermined reference value of 0 is calculated as an offset value. . The offset value can be a positive value or a negative value.

  The offset value storage unit 183 is a functional unit that stores the offset value calculated by the offset unit 181. The offset value storage unit 183 may store data in the short term or in the long term (without consuming power). The number of offset values to be stored may be singular or plural.

  The measurement unit 184 is a functional unit that acquires a value from the first sensor 154 and corrects the value based on the offset value. In the case of the present embodiment, the measurement unit 184 is a functional unit that transmits a value obtained by adding the offset value stored in the offset value storage unit 183 to the value obtained from the first sensor 154 to the display device 189.

  The error detection unit 182 compares the comparison value, which is an absolute value of the difference between the offset value calculated in the past and the newly calculated offset value, with a predetermined threshold, and if the comparison value is equal to or greater than the predetermined threshold, an error is detected. It is a processing unit that outputs information. In the case of the present embodiment, the error detection unit 182 calculates the absolute value of the difference between the offset value stored in the offset value storage unit 183 and the offset value calculated by the offset unit 181 and further calculates the value. Convert to pressure (mmHg) to make a comparison value. On the other hand, the error detection unit 182 stores a value of 10 (mmHg) as a threshold value, and compares the comparison value with the threshold value. As a result, if the comparison value is equal to or greater than the threshold value, the error detection unit 182 creates and outputs error information.

  The display device 189 is an interface that converts values (information) from the measurement unit 184 and error information from the error detection unit 182 into information that can be recognized by human vision.

  In the experiment, when the pressure cell 210 is normally attached to the pressure measuring device 150, the obtained comparison value does not exceed 10 mmHg. For example, 15 mmHg may be adopted as the threshold value. Furthermore, as a result of experiment and research, the threshold that can detect with high probability that the second sensor 165 detects engagement and the pressure cell 210 is not properly attached is not sensitive. It has been empirically obtained that it is preferably employed from the range of 25 mmHg or more and 35 mmHg or less, specifically, 30 mmHg is adopted.

  Note that the threshold value and the comparison value need not be calculated in the state of information indicating pressure, and may be calculated in any state information as long as the information corresponds to the pressure.

  The offset value acquired by the error detection unit 182 from the offset value storage unit 183 may not be the previously calculated offset value, and may be an offset value calculated several times before. Further, the offset value calculated a plurality of times may be statistically processed (for example, average), and the processing result may be used as the offset value.

  FIG. 7 is a diagram schematically illustrating an operation mode of the holding body by the release means and the release means.

  FIG. 9A shows the direction of the force f generated in the holding body 157 by the movement of the releasing means 155 (indicated by the arrow g in FIG. 10B) and the direction d in which the holding body 157 tilts. In addition, description of the cancellation | release means 155 is abbreviate | omitted in (a). FIG. 6B shows the positional relationship between the release means 155 and the sandwiching body 157, which is shown from a different direction from FIG.

  The release means 155 moves the holding body 157 against the urging force of the first spring 158 added to the holding body 157 to release the engagement state of the engagement portion 215 with the second engagement portion 156. Device. In the case of the present embodiment, the release means 155 includes a recess 166 having an inclined portion 167 on one surface in the moving direction. On the other hand, the sandwiching body 157 includes a projecting portion 168 projecting radially from the rotation shaft 159 of the sandwiching body 157 and a cam portion 169 provided at the tip of the projecting portion 168 and engaging with the release means 155. Yes.

  When the release means 155 is pulled in the direction of the arrow in FIG. 7B, the cam portion 169 is pressed by the inclined portion 167, whereby a force f is generated, and the cam portion 169 moves in the left direction in the figure. Move. As a result, the sandwiching body 157 rotates in the direction of the arrow in FIG. Similarly, the tip of the sandwiching body 157 is expanded by rotating the sandwiching body 157 disposed on the opposite side in the same manner.

  Next, how the pressure cell 210 is attached, error detection, offset, and the like will be described.

  As shown in FIG. 7A, the pressure cell 210 is inserted between the sandwiching bodies 157 of the pressure measuring device 150. Next, as shown in FIG. 7B, the pressure cell 210 expands the sandwiching body 157 against the urging force applied to the sandwiching body 157. Further, when the pressure cell 210 is pushed into the pressure measuring device 150, the fixed body 160 is pushed against the urging force applied to the fixed body 160 while expanding the holding body 157 as shown in FIG. 8C. It will be. Finally, as shown in FIG. 8D, when the pressure cell 210 is pushed to a predetermined position, the engaging portion 215 is fitted into the second engaging portion 156 that is a hole provided in the holding body 157, and is sandwiched. The body 157 is closed by the first spring 158 so as to sandwich the pressure cell 210. On the other hand, the second spring 161 presses the pressure cell 210 through the fixed body 160. The biasing force of the second spring 161 is applied in a direction in which the engaging portion 215 is pressed against the second engaging portion 156. As a result, the distance from the base 151 of the pressure cell 210 is fixed.

  In this state, the tip of the second sensor 165 is pushed down to a predetermined position, and notifies the offset unit 181 that the pressure cell 210 is attached to the pressure measuring device 150.

  On the other hand, the magnetic body 216 attached to the diaphragm 212 is connected by a magnetic force, and the connecting portion 162 follows a bulge or depression of the diaphragm 212. Here, when the diaphragm 212 of the attached pressure cell 210 is swollen in a state where no pressure is applied, for example, as shown in FIG. 9A, or as shown in FIG. When it is depressed, it occurs. Therefore, the first sensor 154 outputs some value.

  The offset unit 181 calculates a value from the first sensor 154 in this state as an offset value. That is, this state is 0 points. In the case of (a) in the figure, the offset value is positive, and in the case of (b) in the figure, the offset value is treated as negative.

  As described above, the pressure cell 210 can be attached to the pressure measuring device 150 simply by pressing the pressure cell 210 against the pressure measuring device 150. Further, since the position of the casing 211 of the attached pressure measuring device 150 is regulated by the sandwiching body 157 of the regulating means 152 and fixed by the fixing means 153, for example, the pressure cell 210 is repeatedly attached and detached. Even if this is done, the distance of the pressure cell 210 to the base 151 is constant. When the distance is constant, the distance between the first sensor 154 attached to the base 151 and the diaphragm 212 of the pressure cell 210 is within a very small range. Only a value derived from a generated dimensional tolerance or the like can be set as an offset value.

  In addition, in the case of so-called cantilever where the engaging portion 215 of the pressure cell 210 is engaged with only one of the two sandwiching bodies 157, the second sensor 165 may indicate an attached state. Also in this case, since the positional relationship between the pressure measuring device 150 and the pressure cell 210 in a normal attachment state is stable, the cantilever state can be obtained simply by comparing the offset value calculated by the offset unit 181 with a threshold value. It becomes possible to detect.

  Next, when the hemodialysis apparatus 100 is in operation, when the pressure of the liquid filled in the liquid storage chamber 217 is high and the diaphragm 212 of the pressure cell 210 swells, the connecting portion 162 is pushed in, and the load cell 163 is inserted. Distortion occurs. Further, when the pressure is low and the diaphragm 212 of the pressure cell 210 is depressed, the connecting portion 162 connected to the magnet 216 by the magnetic force is pulled out, and a distortion opposite to that when the pressure cell 210 is pushed into the load cell 163 occurs. The distortion is converted into electrical information by the load cell 163, and the information is corrected using an offset value, whereby a highly reliable value can be shown.

  On the other hand, when the hemodialysis is finished and the blood circuit 201 is removed, as shown in FIG. 10, the holding body 157 spreads by the force f generated by operating the release means (not shown), and the engaging portion The engagement between 215 and the second engagement portion 156 is released. Further, since the urging force applied to the fixed body 160 is released, the urging force acts in the direction in which the pressure cell 210 is pushed out from the pressure measuring device 150.

  As described above, the pressure cell 210 can be easily detached from the pressure measuring device 150.

  The present invention is not limited to the above embodiment. Although the dialysis liquid circuit has been described as an example, the liquid circuit may be a circuit for cardiopulmonary lungs, a circuit for infusion / blood transfusion, or the like.

  In addition, the type and position of the liquid circuit described in the drawings, the arrangement of each substrate, and the like vary depending on the hemodialysis apparatus to be applied, and these variations are also included in the present invention.

  The body pressure treatment device of the present invention and a body fluid treatment device represented by a hemodialysis apparatus equipped with the pressure measurement device can easily attach and detach the pressure cell and stabilize the position of the pressure cell with respect to the pressure measurement device. Therefore, the necessary offset value can be kept in a minute range. Therefore, it is possible to increase the reliability of the measured value even when an operator unfamiliar with the blood circuit or the like is attached. Further, it is possible to detect a slight attachment abnormality of the pressure cell due to the abnormality of the offset value.

DESCRIPTION OF SYMBOLS 100 Hemodialysis apparatus 101 Pump 150 Pressure measuring device 151 Base 152 Restriction means 153 Fixing means 154 First sensor 155 Release means 156 Second engagement part 157 Holding body 158 First spring 159 Rotating shaft 160 Fixed body 161 Second spring 162 Connection part 163 Load cell 164 Arm 165 Second sensor 166 Recess 167 Inclination part 168 Projection part 169 Cam part 180 Control part 181 Offset part 182 Error detection part 183 Offset value storage part 184 Measurement part 189 Display device 201 Blood circuit 202 Filtrate replacement circuit 210 Pressure cell 211 Housing 212 Diaphragm 213 Inlet port 214 Outlet port 215 Engaging portion 216 Magnet 217 Liquid storage chamber 220 Dializer 300 Human body

Claims (4)

A body fluid treatment having a pressure measuring instrument that removably holds a pressure cell having a liquid storage chamber formed by a housing having an engagement portion and a diaphragm, and measures the pressure of the liquid stored in the liquid storage chamber A device,
The base,
A regulating means for regulating the distance of the housing with respect to the base by engaging with the engaging portion;
Fixing means for fixing the engaged state between the engaging portion and the restricting means;
A first sensor that has a connection portion connected to the diaphragm, and converts the displacement of the diaphragm relative to the base into a signal;
A second sensor for detecting an engagement state between the engagement portion and the restricting means;
Using the second sensor to detect an engagement state as a trigger, an offset unit that calculates a difference between a value obtained from the first sensor and a predetermined reference value as an offset value ;
Error detection that compares the comparison value, which is the absolute value of the difference between the previously calculated offset value and the newly calculated offset value, with a predetermined threshold and outputs error information if the comparison value is greater than or equal to the predetermined threshold And a body fluid treatment device. The body fluid treatment device according to claim 1 , wherein a value that can be adopted as the threshold value is 10 mmHg or more. Pressure measurement having a pressure measuring instrument for detachably holding a pressure cell having a liquid storage chamber formed by a housing having an engaging portion and a diaphragm and measuring the pressure of the liquid stored in the liquid storage chamber A vessel,
The base,
A regulating means for regulating the distance of the housing with respect to the base by engaging with the engaging portion;
Fixing means for fixing the engaged state between the engaging portion and the restricting means;
A first sensor that has a connection portion connected to the diaphragm, and converts the displacement of the diaphragm relative to the base into a signal;
A second sensor for detecting an engagement state between the engagement portion and the restricting means;
Using the second sensor to detect an engagement state as a trigger, an offset unit that calculates a difference between a value obtained from the first sensor and a predetermined reference value as an offset value ;
Error detection that compares the comparison value, which is the absolute value of the difference between the previously calculated offset value and the newly calculated offset value, with a predetermined threshold and outputs error information if the comparison value is greater than or equal to the predetermined threshold And a pressure measuring instrument. A body fluid treatment having a pressure measuring instrument that removably holds a pressure cell having a liquid storage chamber formed by a housing having an engagement portion and a diaphragm, and measures the pressure of the liquid stored in the liquid storage chamber A bodily fluid treatment method applied to an apparatus, wherein the pressure measuring device includes a base, a regulating unit that regulates a distance of the housing relative to the base by engaging with the engaging portion, and the engagement A first means for converting a displacement of the diaphragm relative to the base into a signal; a fixing means for fixing an engagement state between the joint portion and the restricting means; a connection portion connected to the diaphragm; A second sensor for detecting an engagement state between the joint portion and the restricting means;
The offset sensor calculates a difference between a value obtained from the first sensor and a predetermined reference value as an offset value when the second sensor detects the engagement state between the engagement portion and the restricting means. And
The measurement unit corrects the value obtained from the first sensor based on the offset value ,
The error detection unit calculates a comparison value that is an absolute value of the difference between the offset value calculated in the past and the newly calculated offset value, and further compares the comparison value with a predetermined threshold value. A body fluid treatment method for outputting error information when a predetermined threshold value is exceeded .

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