ITMO20110063A1 - DEVICE FOR THE MONITORING OF CHEMICAL-PHYSICAL PARAMETERS OF AN ORGANIC FLUID - Google Patents

Description

DESCRIPTION

Field of application

The invention relates to a device for monitoring the chemical-physical parameters of an organic fluid, particularly suitable for being mounted on an extracorporeal circuit in which a patient's blood circulates.

State of the Technique

The monitoring of the partial pressure of Oxygen (hereinafter referred to as p02), the partial pressure of Carbon Dioxide (hereinafter referred to as pC02), the pH and the pressure of biological fluids in circuits for the extracorporeal circulation of an organic fluid, for example blood, is of primary importance in therapies that require the passage of the fluid to be monitored or treated in the pipes that form an extracorporeal circuit for their execution.

In particular, the monitoring of the chemical-physical parameters indicated above is of significant importance especially when, during the execution of the therapies, it is necessary to resort to external support to completely or partially compensate for the respiratory and / or cardiac pump function of the patient. patient, using special machines, so-called heart-lung machines.

Currently, the parameters are monitored using special sensors which are arranged along the pipes of the extracorporeal circuits and which all refer to an electronic data collection and display unit.

Each sensor is made with characteristics such as to be able to monitor a specific parameter and schematically includes a sensory part, which is constituted, for example, by an elastically deformable and hydrophobic membrane intended to be placed in contact with the fluid to be monitored, and an electronic circuit transducer that transforms the stresses applied on the membrane into electronic signals that are sent to the collection and monitoring unit.

The membrane, or an equivalent sensitive element, has hydrophobic characteristics to prevent it from being crossed by the fluid, to avoid on the one hand it can reach and damage the electronic circuit and on the other hand the pollution of the monitored organic fluid.

As previously mentioned, each sensor is specifically designed to detect one of the chemical-physical parameters of the organic fluid.

Thus, for example, the pressure monitoring of a biological fluid is carried out by placing a deformable membrane between the fluid and a sensor that measures the difference between the ambient pressure, considered as a zero reference value, and the pressure incident on a transducer at semiconductor, which, in turn, produces an electrical resistance value generated on the semiconductor itself.

Instead, the variation in the concentration of dissolved oxygen in the biological fluid is determined by means of a technique that measures the attenuation of the luminescence of a luminescent substance as a function of the concentration of oxygen present in the fluid, i.e. a technique that provides that a light, generated by sources light and which has known wavelengths, is reflected by a matrix containing a fluorophore placed in contact with the biological fluid, generating an optical signal which is proportional to the oxygen concentration and is picked up by a photosensitive transistor.

The pH and pC02 measurements are instead commonly obtained in the current state of the art by measuring the quantity of hydrogen ions H + dissolved in the monitored organic fluid and, by calculating the inverse proportion by means of an algorithm concerning the reversible chemical reaction, the quantity of dissolved carbon dioxide.

One of the most innovative methods currently used in these sensors is based on the use of a fluorescent chromophore whose emission intensity is directly proportional to the quantity of H + ions present.

When the fluorescent chromophore is excited with a light that has a predetermined frequency, the chromophores, also called fluorophores, emit a fluorescent light that can be picked up by a transducer and which by means of the latter can be converted into a quantitative electrical signal.

An optical sensor for determining the pH value is known in EP 906.566 According to this document, the optical sensor comprises a membrane on a transparent support material made of polyurethane, polyurea-urethane or a polyurea composition containing a set of pH sensitive fluorescein .

An instrument for the continuous and instantaneous measurement of substances present in a biological fluid is known from the documents FR 2866118.

According to this document, the measuring instrument is equipped with a cavity in which a measuring chamber is defined through which a biological fluid circulates between an inlet and an outlet.

The chamber contains an ISFET chemical sensor, which is the acronym for lon Sensitive Field Effect Transistor, which is sensitive to a substance contained in the biological fluid.

Other optical sensors are known, for example, from WO1996EP04426, US 2004 0003163, US 5,536,783.

This state of the art has some drawbacks.

A drawback consists in the fact that all the sensors that must be used to monitor the overall chemical and physical situation of a patient who is undergoing a therapeutic treatment using an extracorporeal circuit in which the organic fluid to be monitored circulates, such as blood, are positioned in distinct points of the circuit and this determines the need to provide in each corresponding positioning point a specific connection suitable for a specific sensor and a connection cable to transmit the data relating to the parameters collected between the sensor and a destination and display electronic control unit .

It must be thought that these sensors, in order to keep the patient's organic situation completely controlled, must be positioned both on the venous branch of the circuit that comes from the patient, and on the arterial branch that returns to the patient after the organic fluid has been treated. with the therapies to which he must undergo.

Therefore, the total number of connections is significantly high, and the equally high lengths and numbers of the connection cables make the extracorporeal circuit expensive and impractical to use.

Furthermore, if a sensor malfunction occurs, in particular a sensor designed to detect pressure values, this must be disconnected from the connection cable, disassembled and replaced with a new sensor of the same type or, alternatively, the monitoring of the chemical-physical parameter related to it, with the consequence that the conditions of patient are no longer controllable in their entirety.

Presentation of the invention

An object of the present invention is to improve the state of the art.

Another purpose of the invention is to provide a device for monitoring the chemical-physical parameters of an organic fluid which allows to keep the monitoring of the parameters constantly active and to avoid the need to set up a large number of independent connections for each sensor. and distributed along the ducts of the extracorporeal circuits, significantly simplifying their structure. Yet another object of the invention is to provide a device for monitoring the chemical-physical parameters of an organic fluid which, in the event of a failure of one of the pressure sensors, allows it to be quickly replaced or, alternatively, , to place a second sensor of the same type alongside the faulty sensor in such a way as to allow the maintenance of monitoring of the patient's condition without substantial interruption.

According to an aspect of the invention, a device is provided for monitoring the chemical-physical parameters of an organic fluid, in accordance with the characteristics of claim 1.

The invention therefore allows the following advantages to be achieved: - grouping in a single housing and support element a plurality of sensors distinct from each other and connected to units for transmitting the collected data which are also housed in the single element and connected to the electronic control unit with a very small number of connection cables

- quickly restore the best parameters detection conditions even in case of failure of one of the pressure sensors;

- simplify the extracorporeal circuits; And

- reduce the costs and the overall dimensions of the latter.

Brief description of the drawings

Further characteristics and advantages of the invention will become more evident from the detailed description of a preferred but not exclusive embodiment of a device for monitoring the chemical-physical parameters of an organic fluid, illustrated by way of non-limiting example, in the joined drawing tables in which: FIG. 1 is a schematic and front perspective view of a simplified version of a device for monitoring the chemical-physical parameters of an organic fluid according to the invention usable on a single line of an extracorporeal circuit;

FIG. 2 is a schematic and rear perspective view of a second, more complete version of a device for monitoring the chemical-physical parameters of an organic fluid according to the invention, usable on a double line of an extracorporeal circuit;

FIG. 3 is a schematic and front perspective view of the monitoring device of Figure 2;

FIG. 4 is a diagram of an extracorporeal circuit for filtering and oxygenating the blood of a patient on which the monitoring device of Figure 2 is mounted;

FIG. 5 is a schematic and front perspective view of a third version even more complete of a device for monitoring the chemical-physical parameters of an organic fluid according to the invention;

FIG. 6 is a corresponding rear perspective view of the monitoring device illustrated in Figure 5.

Detailed description of a preferred embodiment example With reference to Figure 1, 1 indicates a device for monitoring the chemical-physical parameters of an organic fluid, in the specific case blood, briefly referred to below as a monitoring device, in a simplified version usable for a single line of an extracorporeal circuit 500 known to the skilled person, the device 1 comprises a three-dimensional body 2, in the specific case a body 2 which has a substantially cylindrical shape, which defines a passage section which has an inlet 3 for the organic fluid to be monitored and an outlet 4 for the monitored fluid which flows inside the body 2 in the direction indicated by the arrows "F1" passing through an internal detection chamber which, however, is not visible in the drawings.

In the body 2, in correspondence with the internal detection chamber, seats are obtained in succession for housing corresponding sensors designed to detect parameters of the organic fluid to be monitored.

The seats pass through, that is, they pass through the external wall of the body 2 to put the internal detection chamber and the sensory parts of the sensors positioned in the seats in communication with each other.

Precisely, in the simplified version, the device 1 comprises a raised seat 5 which has a quadrangular profile and in which is housed a blood pressure sensor, venous or arterial, which comes from or returns to the patient "P" and, placed in succession along a longitudinal axis of the body 2, three further seats 6, 7, 8, which have a circular shape and are equipped with attachment and retention elements 10 for corresponding sensors better described below, and a further seat 9 in substantially the same relief to headquarters 5.

All the sensors mounted in the housings 6, 7, 8, are connected to a data collection card from the latter, schematically indicated with 11, which, in turn, is interfaced with a main card that makes the data available and visible. collected on a monitor unit screen.

Similarly, the pressure sensors 5 and 9 are connected with a further own card for collecting the data coming from the latter, indicated schematically by 12, in turn interfaced with a main card which makes the collected data available and visible on a screen of a unit. monitoring.

In detail, the seat 5 and the seat 9, as mentioned, are intended to house a respective pressure sensor, while the seat 6 is intended to house a pH sensor, the seat 7 an oxygen partial pressure sensor (p02) , seat 8 is a carbon dioxide partial pressure sensor (pC02).

With reference to Figure 3, it is noted that the device for monitoring the chemical-physical parameters of an organic fluid, indicated with 100 in the most complete version, comprises two bodies 200 and 201 which have substantially the same shape and which are joined together in parallel position with intermediate connecting ribs, indicated with 120 and which, therefore, form a substantially integral device that can be handled easily.

In this version, the device 100 therefore has two fluid passage lines to be monitored which, as in the previous version, are both equipped with respective inlets and outlets indicated with 150, 151, 152 and 153.

In this way, the device 100 makes it possible to monitor a fluid, such as the blood of a patient "P", both on a venous line 501 that comes from the latter, and an arterial line 502 that returns to the latter, as can be seen schematically in Figure 4.

With reference again to Figure 3, the body 200 is substantially similar to that of the simplified version described above, while the body 201 is equipped with only two raised seats for the same number of sensors.

In detail, the body 200 has a seat 105 and a seat 109 for mounting pressure sensors, in this case of arterial pressure, a seat 106 for an arterial blood pH sensor, a seat 107 for a partial pressure sensor of oxygen (p02) of the arterial blood and a seat 108 for a partial pressure sensor of carbon dioxide (pC02) of the arterial blood.

The body 201, on the other hand, has a seat 112 and a seat 113 for mounting respective pressure sensors of the venous blood arriving from the patient.

Also in this version, all the pressure sensors are connected with a data collection card 212, just as all the other three sensors are connected with a similar data collection card 111, the device for monitoring according to the invention it can also be made in a third, even more complete version, visible in Figures 5 and 6.

As can be seen, the monitoring device, indicated in this case with 600 has a section which is substantially the same as the second embodiment version and indicated with "YES" and a second extension section "S2".

In Figures 5 and 6, the elements common to those of the second version of the monitoring device have been indicated with the same reference numbers for simplicity.

A portion of the extension section "S2" is made of a transparent material so as to be able to visually detect the flow of the organic fluid inside the sensing device 600.

In detail, this portion comprises a plurality of windows 601 which have respective flat surfaces to which it is possible to approach an optical detection unit capable of detecting, for example with the emission of treated light beams, further chemical and physical parameters of the organic fluid.

Indicatively, in the "S2" section it is possible to detect the oxygen saturation, the temperature, the hematocrit and / or hemoglobin value on the venous line coming from the patient, ie on the body 201, while on the body 200, ie on the arterial line directed to the patient, it is possible to detect the oxygen saturation and the temperature of the organic fluid.

The operation of the device for monitoring the chemical-physical parameters of an organic fluid is described below with reference to the most complete version 100, i.e. the one that includes two parallel lines for the passage of the fluid, in the specific case blood, identified by the two bodies 200 and 201.

The device 1 is mounted on an extracorporeal circuit 500 and the two venous lines 501 and arterial 502 are connected respectively to the inlet 153 of the body 201 and to the outlet 150 of the body 200.

A duct 503 for connection to a venous blood treatment device is connected to the outlet 152 of the body 201, which comprises, for example, a filtering unit 504, a pump 508 and a heat treatment and oxygenation unit 505.

A return pipe 506 from the filtering units placed on the arterial branch 507 is connected with the inlet 151 of the body 200.

When in the extracorporeal circuit 500 the blood flow is at steady state, the sensors mounted on the body 200 and 201 allow to detect the chemical-physical parameters during the passage through the internal detection chambers of the two bodies 200 and 201 and to send to the respective boards the collected data.

These collection cards 11, 12 and 111 and 212 are usually connected with a further main card, not visible in the drawings as it is mounted on a display and control unit not shown, with which medical operators can see the parameters of the monitored blood. .

Being grouped in a single device, the sensors for detecting the chemical-physical parameters of both venous and arterial blood (or of another organic fluid) can be quickly connected with the respective boards 11 and 12, or 111 and 212 without a multiplicity of connection cables are scattered disorderly along the ducts of the extracorporeal circuit 500, thus making it less bulky and considerably more practical to handle.

Furthermore, the number of housing seats for the pressure sensors on the bodies 200 and 201 can vary according to the needs and allow the seamless monitoring of the aforementioned parameter, even in the event of a fault, since for each hydraulic duct there are at least two pressure sensors normally engaged by the detection system.

Furthermore, the coupling and retention elements 10 with which all the housing seats of the sensors are equipped, allow a rapid assembly of the latter.

In the third version of the monitoring device, they allow the operators to approach one of the windows 601 with a known optical detection unit which, through the transparent walls of the windows 601, radiates a luminous beam of treated light which strikes the organic fluid. during its scrolling and detects the desired parameters.

Finally, the device for monitoring the chemical-physical parameters of an organic fluid according to the invention, both in the simplified version and in the more complete one, having a substantially monolithic structure, can be easily mounted in special seats provided on therapeutic treatment machinery. , therefore easily identifiable and reachable by medical operators.

In practice it has been found that the invention achieves the intended purposes.

The invention thus conceived is susceptible of modifications and variations, all of which are within the scope of the inventive concept.

moreover, all the details can be replaced with other technically equivalent elements.

in practice, the materials used as well as the shapes and sizes may be any, depending on the needs, without thereby departing from the scope of the protection of the following claims.

Claims (9)

R I V E N D I C A Z I O N I 1. A device (1; 100; 600) for monitoring the chemical-physical parameters of an organic fluid to be monitored which includes: A body (2; 200, 201) which has an inlet (3; 151, 153) and an outlet (4; 150, 152) for the organic fluid; At least one internal detection chamber obtained in said body (2; 200, 201) between said inlet (3; 151, 153) and outlet (4; 150, 152) and in which said organic fluid flows; characterized by the fact that said body includes: at least a first seat (5, 9; 105, 109) for housing a first sensor element for a pressure parameter of said fluid; and at least a second seat (6, 7, 8; 106, 107, 108) for housing a second sensor element of a parameter other than said pressure parameter. 2. A device according to claim 1, wherein said first seat and second seat comprise attachment means (10) of said first sensor element and second sensor element, A device according to claim 1, wherein said body comprises a first flow line (501) for said organic fluid arriving from the patient (P) and a second flow line (502) for said organic fluid returning to the patient (P). A device according to claim 3, wherein said first line (501) and second line (502) of sliding comprise respective internal detection chambers separated from each other. 5. A device according to claim 4 or 5, wherein said first line (501) and second line (502) each comprise a respective inlet and a respective outlet of said organic fluid between which said respective internal detection chambers are arranged. A device according to claim 1, wherein said inlet (3; 151, 153) and outlet (4; 150, 152) are provided with connections for the attachment of corresponding ends of pipes of a sliding circuit (500) of said organic fluid. 7. A device according to claim 1, wherein said first seat comprises a seat (5; 105) for housing a respective pressure sensor and a seat (9; 109) for housing a respective safety pressure sensor. 8. A device according to claim 1, wherein said second seat comprises at least one housing (106) for housing a pH detection sensor of the fluid to be monitored, at least one housing (107) for housing a partial pressure sensor of oxygen, at least one seat (108) for housing a carbon dioxide partial pressure sensor. A device according to claim 1, wherein said body (2; 200, 201) comprises at least one extension section (S1, S2) equipped with transparent detection windows (601).