A monitoring probe
The present invention relates to a monitoring probe hav¬ ing means for monitoring and indicating a plurality of given body functions and being arranged to be inserted
4 5 into the oesophagus of a patient and there temporarily orientated during, for example, surgical work.
When carrying out work of a surgical nature, it is extremely important to be able to check certain body functions, including the heart flow curve, heart sound 10 and the body temperature of the patient.
Conventional methods applied for these purposes include the use of breast electrodes for producing an electro¬ cardiogram, an anal thermometer for monitoring the body temperature, and a stethoscope for monitoring heart
15 sound. All of these externally arranged devices con- stitute potential obstacles to the surgeon during the phase of an operation, and require his personal atten¬ tion in continuously following the condition of the patient in the various respects concerned, which is
20 time consuming. Neither are these conventional methods entirely satisfactory, since different surgical acti¬ vities can result in mistakes when assessing heart sound and an electrocardiagraph.
It has also been proposed, among other things, to re- 25 gister an electrocardiagraph through a catheter in¬ serted into the oesophagus of a patient, said catheter being provided on the outside thereof with two elect- rodes and associated conductors, the electrodes en- circling the casing of the catheter. This, however,
. 30 exposes the patient to risk, since the sensitive mocous membrane of the oesophagus may be damaged by mechanical contact with the irregular surface of such a catheter,
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and also as a result of electrical and thermal influ¬ ences when the electrodes are energized. The mucous membrane of the oesophagus can be seriously damaged by even extremely weak, punctiform heat generation.
A catheter similar to that described above but having the additional function of indicating heart sound is also known to the art. In addition to being provided with the electrode arrangement of the abovedescribed catheter, this further catheter is provided at the end thereof with a balloon type device for sensing heart sound. Such a catheter exhibits the same kind of drawbacks as the catheter first described.
With the aforedescribed known technique as a point of departure, the object of the present invention is to provide a monitoring probe which eliminates all the disadvantages associated with known construction and which can be inserted into the oesophagus without danger to the mucous membrane or said oesophagus as a result of mechanical action, and with which dangers created through electrical and thermal influences are also avoided. These objects are realized with a moni¬ toring probe in which the indicator means which indi¬ cate the bodily functions via electric conductors form an inseparable unit with the casing of the probe and are arranged within said probe.
The invention will now be described in more detail with reference to an exemplary embodiment illustrated in the accompanying drawing, which as a partial sectional view of a monitoring probe constructed according to the in- vention.
The probe according to the invention is of tubular con¬ figuration having an outer casing 10 which may be of
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any suitable material, preferably a PVC-plastics mate¬ rial. The probe has a conical, softly rounded end part 11. The probe of the illustrated embodiment is arranged to be inserted into the oesophagus and there to indicate three bodily functions, the means required herefor being hereinafter individually described. In order to enable the heart sound (alternatively also lung sound) of a patient to be sensed, there is arranged within a tubu¬ lar casing 13, i.e. the probe space, in the proximity of the end 11 of the probe, suitably about 10cm from said end, an accelerometer 12 of a kind known per se. The casing 13 may be made, for example, of a metallic material having a thickness a. The accelerometer 12 rests in a movement-damping fluid, for example sili- con oil, and the casing 13 is sealed. 'The casing 13 and the accelerometer form together a unit which is connected to the catheter casing 10 in a manner such as to be inseparable therefrom. In the examplary em¬ bodiment, the metal casing 13 has angular opposing sur- faces which are provided with a suitable granular plastics material and which are fixedly attached to first and second casing parts 14 and 15 respectively of the probe by means of an appropriate adhesive. Consequently, the metallic casing 13 forms a probe casing 10 forming together a bridge part whose outer surfaces are in alignment with the casing part 14, 15. The accelerometer 12 is connected to known insulated conductors 16, these conductors being further shield¬ ed through an outer insulating layer 17.
The illustrated probe according to the invention also exhibits two mutually spaced electrodes 18, 19 arranged within the inner space of the probe. The electrodes are preferably made of silver and are arranged to create a readable electrocariogram (ECG) in a known manner. The electrodes 18, 19 of the illustrated embodiment
have the form of a T, the angular surfaces being pro¬ vided in the described manner with a granular plastics material and connected to the casing parts 15 and 20 of the catheter by means of a suitable adhesive sub- stance. The electrode 19 is connected to the casing parts 20 and 21 of the probe in a similar manner, and the electrodes 18, 19 form bridge parts which connect the said casing parts of the probe. The outwardly fac¬ ing, surfaces of the electrodes 18, 19 are in line with the plastic casing parts of the probe.
Thus, the monitoring probe according to the invention comprises a plurality of mutually, firmly connected parts, which together form an inseparable unit exhibiting smooth outer cylindrical surfaces.
The electrodes 18, 19 are connected to conventional con¬ ductors 22, which are passed through a further shield¬ ing layer 23.
A thermistor 24 of known kind is arranged within the probe space, the function of said thermistor being to indicate the body temperature of the patient.
As will be understood from the description of the illu¬ strated embodiment, the novel monitoring probe is not only unharmful to the patient but also extremely reli¬ able in operation.
Although the illustrated embodiment has been described with reference to certain devices for carrying out de¬ sired operations, it will be understood that other sens¬ ing and detecting means intended for other functions can be incorporated in the probe in a simple and similar- ly reliable manner.