DESCRIPTION

Technical Field

The present invention relates to an arrangement for monitor¬ ing a patient connected to a respirator, while using to this end an analyzing and/or monitoring device which is coupled by means of a hose to a conduit system connected between the patient and the respirator.

Background Art

Such arrangements are known to the art. These known arrange¬ ments normally include a first device which is operative in analyzing the air of inspiration and/or expiration of the patient, and also a second device which is connected to the first device or structurally combined therewith and which is operative in monitoring the condition of the patient with respect to the composition of the gas analyzed, such as the amount of carbon dioxide present in the gas, the amount of anaesthetizing gases administered through the respirator, pressure and temperature.

Analyzing and/or monitoring devices, often referred to simp- ly as monitors, are connected to one end of a narrow-bore hose, via a filter, the other end of which hose is connected to a first pipe connector on a T-piece, the second pipe con¬ nector of which is connected to a trachea tube or cannula inserted into the patient's mouth, nose or throat, and the third pipe connector of which is connected to a first pipe connector on a Y-piece. The two remaining pipe connectors of the Y-piece are connected to the respirator via hoses. Variants are also known in which the other end of the hose is instead connected directly to the Y-piece.

The aforesaid arrangements are encumbered with serious draw¬ backs.

One drawback is that the air to be analyzed is moist, which can often result in condensation on the inner wall of the narrow bore hose and cause a blockage in the hose or water to run back to the patient. Another drawback is that phlegm, slime and other particles ejected from the patient are liab¬ le to block the narrow bore hose or the filter located between the hose and the monitor. Another drawback is that the con- nection between the narrow bore hose and the T-piece or the Y-piece respectively extends perpendicularly to the flow of inspiration air, which renders its entry into the hose difficult.

Summarv of the invention

One object of the present invention is to eliminate the drawbacks of such prior art arrangements at least partially, and to provide such an arrangement which will ensure that the air analyzed is relatively dry; which will ensure that water condensate is unable to block the narrow bore hose or run back to the patient, which will ensure that particles ejected by the patient are not able to block the narrow bore hose or the filter, which comprises only a few elements thereby rendering the arrangement less expensive and redu¬ cing the risk of elements in the conduit system loosening, and which will ensure that the air of inspiration will be supplied to the narrow bore hose at an advantageous angle thereto at which the air flow is best distributed.

This object is fulfilled by the inventive arrangement, which has the characterizing features set forth in the respective characterizing clauses of the claims.

Brief Description of the Drawing

Figure 1 is a perspective view of an arrangement constructed

in accordance with the invention, and

Figure 2 is a partly cut-away side view of a heat-moisture exchanger incorporated in the arrangement illustrated in Figure 1.

Description of Preferred Embodiments

Fig. 1 illustrates a monitor 1 which comprises a combined analyzing and monitoring apparatus. The monitor 1, which may, for instance, be of the kind sold by Marquette Electro- nics Inc., Milwaukee, Wisconsin, U.S.A. under the trade name Capnograph Series 7050, is used for analyzing the composi¬ tion of the air of inspiration and/or expiration of a patient to be monitored, with respect, for instance, to the oxygen or carbon monoxide content of the air or gas, the amount of anaesthetizing gases administered, and/or the temperature and pressure of said air or gas.

A respirator 2 of known construction is connected to the patient in the manner hereinafter described. The respirator 2 includes an outlet hose connector 2a for delivering gases to the patient, and an inlet hose connector 2b for receiving gases expired by the patient.

The patient is connected to the monitor 1 and the respirator 2 by means of a conduit system, which also incorporates a regenerative heat-moisture exchanger hereinafter described. The conduit system includes a breathing mask or a cannula which is introduced into the throat of the patient, or a trachea tube 3 which is introduced into the nose or the pharynx of the patient. The conduit system also includes two hoses *-) and 5, which are each connected to a respective hose connector 2a and 2b of the respirator 2, a Y-piece 6 having two hose connectors 6a and 6b, each of which is connected to a respective hose ■**. and 5, and a flexible, narrow bore hose 7 having an inner diameter in the order 0.5-**** mm, one end of which hose is connected to the monitor 1.

The heat-moisture exchanger incorporated in the conduit sys¬ tem 3-7 is referenced 9 and is provided with three hose con¬ nectors 9a, 9b and 9c, of which the hose connector 9a is detachably connected to the trachea tube 3, the hose connec- tor 9b is detachably connected to the hose 7 and the hose connector 9c is detachably connected to the third connector 6c of the Y-piece. The hose connectors 9a and 9c define essentially a right angle therebetween, whereas the hose connector 9a and 9b are substantially parallel with one another and extend along an axis line x_ which preferably extends through the centre of the exchanger 9.

The hose connectors 9a-9c are constructed in the same piece as a casing which contains a circular-cylindrical insert 10, said casing preferably being made of a plastics material.

The insert 10 comprises a plurality of mutually concentric, corrugated layers of paper or like material treated with a hydroscopic substance. The layers formed therebetween mutually parallel, through-passing channels along which the expiration gas and inspiration air of the patient are inten¬ ded to flow. The hose connector 9c extends substantially along the full extension of the casing, at right angles to the aforesaid axis line x and the hose connector 9b is pre¬ ferably formed on the hose connector 9c.

When the gas expired by the patient passes through the exchanger 9, via the trachea tube 3 and the hose connector 9a, moisture present in the air is deposited on the insert 10 and the gas is heated at the same time. Any particulate matter ejected by the patient together with the expiration gas remains in the casing upstream of or in the unit 10 when these particles are larger than the diameter of the channels in the insert. Dry gas flows out of the exchanger 9 to the respirator 2, via the Y-piece and the hose ■**.. Dry gas will also flow from the exchanger 9 to the monitor 1, via the hose connector 9b and the hose 7. Despite the small cross-

section of the hose connector 9b and the hose 7, the flow of gas therethrough will be relative large, inter alia because of the aforesaid orientation of the hose in relation to the hose connector 9a and the insert 10. Consquently, a suffi- ciently large quantity of expiration gas, which is also dry and free from large particles, will flow into the monitor 1 for analysis and evaluation purposes, which analysis and evaluation may, for instance, indicate that the setting of the respirator 2 needs to be changed or that a doctor needs to be summoned.

When the patient breaths in, the air delivered by the respi¬ rator 2, via the hose 5, the Y-piece 6, the exchanger 9 and the trachea tube 3, will be moist and is heated by the exchanger 9. The air is not normally analyzed during the inspiration phase. If it is desired to analyze the inspiration air, however, for example in order to supervise the amount of anaesthetizing gases and oxygen contained in the air delivered by the respirator 2, this air will pass through the hose 7 and be analyzed in a similar manner as that described above in conjunction with the expiration phase.

Although the present invention has been described and illu- strated with reference to a single exemplifying embodiment thereof, it will be understood that the invention is not restricted to this embodiment and that the invention is solely limited by the scope of the following claims.