|Title of Invention||
A MULTIFUNCTIONAL ELECTRONIC STETHOSCOPE
|Abstract||Abstract An electronic stethoscope comprises a headpiece (1) , a chest-piece (2) and two earpieces (3). The headpiece is fitted with a display arrangement (13) in the form of a liquid-crystal display. A microphone (21), one or more sensors (15) and fixed electrodes (16) and movable electrodes (17) are mounted in the headpiece (1). The movable electrodes (17) are fixed to pivoted arms (18) which form a contact ring (20). (Figs. 1 and 5)|
The present invention concerns a multifunctional stethoscope according to Claim 1 usable on both ears and preferably fitted with a bow.
Stethoscopes are instruments for investigating sound phenomena or for auscultation of organ functions. Stethoscopes commonly in use are tube stethoscopes usable on both ears and fitted with bows; as the head-piece they have an open bell or a part closed by a membrane. In addition to mechanical tube stethoscopes electronic stethoscopes are also available on the market. By the head-piece of a stethoscope is meant a listening spout which can be placed on the body of the patient being examined. The listening spout is connected to a chest-piece from which two bow sections lead to the ears.
Whereas in the case of the tube stethoscope the acoustic signals are conducted directly from the spout placed on the body via the chest-piece and the two bow sections to the ears of the examining doctor, with the electronic stethoscope the acoustic signals are received by a microphone fitted to the head-piece, converted into electric signals, transmitted to loudspeakers at the ears and amplified there.
In addition to traditional electronic stethoscopes, special models are also known for phonocardiography. A phonocardio-graphically operating stethoscope is known, for example, from US-A-4840183. A further phonocardiographic stethoscope which is connectable to suitable graphic recording units is described in US-A-5025809.
, Whereas in the case of st'.et lioscopes operating phonocardiographically, heart noises caused by heart functioning are received and amplified and, ii required, recorded by suitable means, electrocardiographs plot the curve structure in terms of the temporal progression of the bio¬electric voltages accompanying the increase and decrease of excitation within the heart.
These bio-electric voltages are transmitted by means of electrodes attached to the body surface. The data acquired, displayed in a time sequence, forms an electrocardiogram (ECG) which shows several diagnostically relevant factory.
Finally, an oesophageal stethoscope is known from US-A-5194880 ,-this has a catheter which can be inserted into the oesophagus, within which catheter a cardiophonicall y operating microphone and several sensors are fitted. In particular, a sensor for measuring body temperature and two electrodes for electrocardiographic recording are provided here. The signals received through the catheter are transmitted via an electric lead to a plug socket which enables connection to suitable recording devices.
Whereas traditional electronic stethoscopes and known electrocardiographs are instrument::; which ere in daily use by general practitioners, oesophageal st > -t he cc ;per ere highly sensitive instruments which are used only in the clinical context .
It is the object of the present invention to provide a multifunctional stethoscope which can be used in a mobile way by the general practitioner, and which allows simple electrocardiographic investigations to be made in addition to auscultation.
This objective is met by an electronic stethoscope with the features stated in Claim 1.
'An optimally space- and weight-saving solutions is achieved if the display arrangement located in the head-piece takes the form of a liquid-crystal display. The cheapest solution is achieved if the three electrodes for obtaining the ECG are fixed inside the head-piece.
If only one of the three electrodes is fixed inside the head¬piece while the two other electrodes are attached movably on the stethoscope head-piece, the Einthoven Triangle can be altered or enlarged. The greatest possibility of variation is achieved if all three of the electrodes used to obtain the ECG are made movable.
An especially preferred embodiment has the movable electrodes mounted pivotably in arms fitted to the periphery of the contact surface of the stethoscope head; in the position where they are not pivoted out they form a closed contact ring. This allows a relatively large Einthoven Triangle for the electrodes to be formed despite the use of a relatively small stethoscope head. It also yields a correspondingly informative ECG. This latter solution can be further improved by so forming the pivoted arms that they are in electrical contact with the evaluation unit only in the swivelled-out position. This prevents relatively uninformative data with regard to production of an ECG from being recorded.
The traditional stethoscope, known for approx. the last 100 years, has become the most-used diagnostic instrument: of doctors because it can be used easily, conveniently and without preparation, can be always carried in the pocket or around the neck, and used without loss of time. All other instruments are separate, usually electrical devices which take up space and have to be set up, etc.
The electronic stethoscope according to the invention* enlarges
the previous, simple possibilities of (acoustic) diagnosis by
j simultaneously capturing, with equal simplicity, visually
displaying and evaluating the bio-electrical excitation
involved in heart activity. In this way important information on irregularities in heart frequency, so-called tachycardiae, ventricle flicker and other problems otherwise only detectable later, to be recognised straight away at the first medical examination.
The electronic stethoscope according to the invention can additionally be fitted with sensors for measuring blood pressure and/or temperature. The evaluation unit, also mounted in the head-piece, normally transmits the signals directly to the recording device. However, the signals can also be input into a data memory and only from there transmitted to a static image on the display device.
Accordingly, the present invention provides a multifunctional electronic stethoscope preferably fitted with a bow, with a microphone mounted inside the headpiece and with loudspeakers mounted in the earpieces, characterised in that the headpiece has several sensors located around the microphone, at least three of which sensors are electrodes fixed in an Einthoven Triangle arrangement in order to obtain an electrocardiogram (ECG), and in which a display is incorporated in the head-piece for visual display of the body function values obtained by the sensors, which are collected by an evaluation unit and processed for the display.
In the following description one embodiment of the object according to the invention
is described with the aid of the attached drawings.
Fig. 1 shows a general view of the electronic stethoscope;
Fig. 2 shows a side view of the headpiece of the same stethoscope and
Fig. 3 shows a top view of the headpiece of the stethoscope according to Fig. 2.
Fig. 4 shows a top view of the headpiece of the electronic stethoscope when in use and
Fig. 5 shows the same view of a variant of the stethoscope head.
Fig. 6 shows a top view of a special designed bow-formed arm with its electrode and
Fig. 7 shows a side view of the same arm.
The electronic stethoscope according to the invention has the same general structure as a conventional tube stethoscope. It .ias a stethoscope head or headpiece 1 to be placed on the patient; this is connected to the so-called chest-piece by a connecting lead 4. The two earpieces 3 are connected to the chest-piece 2.
Inside the chest-piece 2 is mounted the feed source 2', which is formed as a plastic housing. The feed source comprises one or more batteries or accumulators which can-" preferably be recharged. The two earpieces 3 are connected to the chest-piece 2. Each earpiece includes a bow 31 which is connected by a flexible joint to the chest-piece 2. An olive-shaped part 32 with a sound aperture 33 is fitted to the end of each bow 31. Within each 'olive' 32 a loudspeaker is mounted.
The embodiment of the electronic stethoscope according to the invention is limited essentially to the structure of the stethoscope head [word omitted in original] 1. The most essential feature of this stethoscope head lies in the integrated display arrangement 11. The display arrangement 11 is formed here as a liquid crystal display. The display arrangement 11 has various display fields 12 which can be activated by pressing the operating keys 13. For example, the display fields 12 can show heart rate, body temperature or an ECG. In the corresponding fields 12 criteria for evaluating the ECG displayed are also shown. From the information shown here it can be seen that a peak height of 10 mm corresponds to one mV.
The progression on the X axis is also shown. In the example illustrated 12.5 mm corresponds to one second. In the side view in Fig. 2 a contact ring 20 can also be seen; this provides the contact surface to the patient.
If one looks at the view of the contact surface shown in Figs. 4 and 5, the operative parts can be seen. At the centre of the stethoscope head 1 is the microphone 21. This is set back
,inwardly from the contact surface formed by the contact ring 20 so that the microphone does not rest:: directly on the skin. However, it is possible, as with known elect: tonic stethoscopes, to provide this microphone with a membrane which is aligned at least very close to the level of the contact: ring 20 so that it rests on the body surface of the patient , The contact ring is normally several millimetres thick, so that it encloses a resonance chamber. In the embodiment according to Fig. 4 the contact ring is made up of three parts. About one-third of the contact ring 20 consists of a ring section 20' fixed to the stethoscope head 1, while the two other sections of the contact ring are formed as arc-shaped arms 18 which can be swivelled outwards about the pivot joints 19.
One electrode 16 is mounted inside the stethoscope head, while
the two other, movable electrodes 17, used to obtain an ECG,
are fixed to the ends of the arms 18. 1 n addition to the tree
electrodes 16, 17, three sensors lb die also liLted to the
stethoscope head 1. These sensors 15 are aligned substantially
in the plane of the surface of the contact ring 20. These
sensors can be used to obtain other Information reflecting body
functioning. For example, one or more sensors can be used to
measure body temperature, or one or more sensors can be used to
measure blood pressure. '
A stethoscope according to Fig. 4 is therefore multifunctional. As long as the arms 18 are not swivelled out, they form the contact ring 20 with the contact ring part 20', and thus enclose a resonance chamber which can be used for auscultation of various body functions. With the arms 18 in this position the microphone 21 can also be used to record a phonocardiogram. By contrast, it is necessary to swivel the arms 18 into position 18' in order to record an electrocardiogram. In the swivelled-out position the fixed electrode 16 and the movable electrodes 17 on the swivelled-out arms 18 ' form a so-called Einthoven Triangle 10.
To avoid erroneous signals, it can be an advantage for f.he pivot joints 19 to be connected by switching contacts v/ith the effect that an electrical connection between the electrodes 17 and the evaluation unit is made only if the arms 18 are in the correct fully swivelled-out position 18'.
In the embodiment according to Fig. 5 the stethoscope head is modified so that on one hand three fixed electrodes 16 are fitted, and, further, the contact ring 20 is formed of three movable arms. In this case, too, a movable electrode 17 is fitted to the end of each arm 18 furthest from the pivot joint 19. In this case the electrodes 16 or 17 are switched so tnat in the non-swivelled-out position of arms 18 only the fixed electrodes 16 operate, whereas after the arms 18 are swivelled out to position 18' only the movable electrodes 17 operate. This arrangement px~ovides a significantly larger Einthoven Triangle 10.
To achieve a firm contact of the electrodes 17 arranged at the movable arms 18 on the body of a patienl, it is of advantage to form the arms 18 flexible. Such an improved embodiment of a swivable arm is shown in figures 6 and 7. In principle such arms could be made in two parts which could be hingeably connected with each other, however, such an arrangement might cause problems when the stethoscope has to be disinfected. Therefore the arm 18 is preferably manufactured in a single piece and injection molded in two stages with two different plastics whereas the electrical parts, namely the sensor 17 and the plug contact 119 that forms at the same time the pivot joint 19 are together with the conducting connection 117 imbedded in the so molded arm. For the injection molded arm-part 181 on which the pivot joint 19 is arranged a harder (less flexible) plastic is elected than for the other arm-part 182 on which the sensor 17 is arranged. This arm-part 182 is molded v/ith a softer (more flexible) plastic. Both arm-parts incline an obtuse angle which changes under pressure on the stethoscope-head.
The electronic components needed for siu-h a .stethoscope art: available on the market. Their programming must be optimised for this application.
The corresponding electronics include essentially a digital-analog converter, amplifier, clock generator for timing and preferably a memory unit in which the measurement results can be temporarily stored and can be called up for display on the display arrangement. In this way a static ECG image can be recorded, which can be studied more closely for diagnosis.
1. A multifunctional electronic stethoscope preferably fitted with a bow, with a microphone mounted inside the headpiece and with loudspeakers mounted in the earpieces, characterised in that the headpiece has several sensors located around the microphone, at least three of which sensors are electrodes fixed in an Einthoven Triangle arrangement in order to obtain an electrocardiogram (ECG), and in which a display is incorporated in the head-piece for visual display of the body function values obtained by the sensors, which are collected by an evaluation unit and processed for the display.
2. The multifunctional electronic stethoscope as claimed in claim 1, wherein the display is a liquid-crystal display.
3. The multifunctional electronic stethoscope as claimed in claim 1, wherein the three electrodes for obtaining the ECG are in a fixed arrangement inside the headpiece.
4. The multifunctional electronic stethoscope as claimed in claim 1, wherein one of the three electrodes is fixed inside the headpiece while the other two electrodes are arranged movably on the stethoscope headpiece.
5. The multifunctional electronic stethoscope as claimed in claim 4, wherein the movable electrodes are arranged pivotably on the stethoscope headpiece and form as at least approximately an Einthoven Triangle in the swivelled-out position.
6. The multifunctional electronic stethoscope as claimed in claim 5, wherein the movable electrodes are fixed to arms attached pivotably to the periphery of the contact surface of the stethoscope head, which arms form at least approximately a closed contact ring when in the non-swivelled-out position.
7. The multifunctional electronic stethoscope as claimed in claim 5, wherein the pivoted arms are electrically connected to the evaluation unit only when in the swivelled-out position.
8. The multifunctional electronic stethoscope as claimed in claim 1, wherein the stethoscope headpiece is additionally provided with at least one sensor for measurement of blood pressure and/or blood temperature.
9. The multifunctional electronic stethoscope as claimed in claim 1, wherein the evaluation unit is effectively connected to at least one data memory from which data can be called up either internally or externally.
10. The multifunctional electronic stethoscope as claimed in claim 9, wherein the data memory is connected to a transmitter.
11. The multifunctional electronic stethoscope as claimed in claim 6, wherein the pivoted arms are made flexible.
12. The multifunctional electronic stethoscope as claimed in claim 11, wherein said flexible arms (18) are formed of two integral connected arm-pieces which are made of two different plastics having two different flectional elasticity properties.
13. A multifunctional electronic stethoscope substantially as herein described with reference to the accompanying drawings.
|Indian Patent Application Number||1013/MAS/1996|
|PG Journal Number||30/2009|
|Date of Filing||10-Jun-1996|
|Name of Patentee||M/S. STRELA DEVELOPMENT AG|
|Applicant Address||SENNWEIDSTRASSE 45, 6312 STEINHAUSEN|
|PCT International Classification Number||A61B-07/04|
|PCT International Application Number||N/A|
|PCT International Filing date|