DE10201904B4 - Method and device for vestibular examination of the inner ear - Google Patents

Abstract

Arrangement for vestibular examination of the inner ear by thermal stimulation of an organ of equilibrium in the auditory canal with a radiation source (2) emitting in the wavelength range from 400 nm to 3000 nm, in a portable housing (1), the radiation of which with a radiation transmission device (3) to form an optical window - a regulated power supply module (7), - an infrared radiation temperature measuring device (4), - a microprocessor-controlled control and evaluation unit, and - a further radiation transmission device (3.3) made of an IR-transmissible material for non-contact recording of body radiation (10) - wherein the beam entrance of the further radiation transmission device (3.3) is located at the optical window, - wherein the further radiation transmission device (3.3) the body radiation (10) via an optical edge filter (4.1) an IR sensor (4), - wherein the IR Sensor (4) provides a radiation temperature proportional output voltage, which is evaluated by means of a microprocessor-controlled detection electronics (5).

Description

The invention relates to an arrangement for Vestibularisprüfung the inner ear by thermal stimulation of the ear canal.

The invention is for Vestibularisprüfung, selective thermal irritation of the organ of equilibrium, for nystagmus testing and for early disease detection.

The balance organ is located in the skull in a bone, the so-called petrous bone near the outer ear. It is paired and together with the cochlea part of the so-called labyrinth. It consists of the semicircular canals and the otolith organs. The semicircular canals record angular accelerations, while the otolith organs (utricle and saccule), which are perpendicular to each other, register linear accelerations. In the organ of balance there are cells in a fluid of the inner ear, the endolymph. Excitations of cells sensitive to balance are transmitted to the brain stem in the eighth cranial nerve, the vestibular nerve (vestibular nerve). From there, among other things, connections to the eye muscles. In 1860 Brown-Sequard et. al., that a flushing of the external ear canal with cold water cause dizziness, a tendency to fall to the rinsed side and rapid eye movements (so-called nystagmus). In 1906 Bárány explained the physical mechanism of this phenomenon: flushing the ear canal with water, the temperature of which deviates from body temperature, leads to a progressive temperature change in the temporal bone and the organ of equilibrium therein. The specific gravity of the endolymph in the semicircular canals changes. If a semicircular canal is vertical, the liquid cooled down in it should sink, and the heated one rise. If there is a temperature difference in the thighs of the semicircular canal, a fluid rotation is supposed to be the adequate stimulus for the organ of equilibrium. For this theory Bárány 1914 was awarded the Nobel Prize. However, the theory can not explain all the peculiarities of the thermal reaction and has been repeatedly criticized in the past.

The flushing of the external auditory canal with a certain amount of water per unit of time at a temperature of 44 ° Celsius and 30 ° Celsius is still used today in clinical practice as the most common and exact method for the qualitative and quantitative assessment of the function of the organs of balance. This leads to rapid eye movements, which are referred to as nystagmus. An irritation at 30 ° Celsius leads to a nystagmus on the same side, an irritation at 44 ° C to a nystagmus to the other side. The ocular movements are observed and counted in the clinical equilibrium diagnostics (Vestibularisdiagnostik) by means of a Frenzelbrille or recorded and evaluated electronically by electrodes. The currently most modern method of evaluating eye movements is the so-called video nystagmography, in which a glasses-like measuring device with video camera detects eye movements, which are evaluated by a computer. The occurrence of nystagmus and the number of eye movements in a given time are the measure of the function of the organs of balance. Normal function, over-, under-function and a loss of function are differentiated.

It is now clear that the thermal stimulation of the ear canal with water only leads to irritation of the organ of equilibrium at the lateral semicircular canal. Slightly the otolith organs should be stimulated. The other semicircular canals are not or negligible stimulated with this method. By mistake, the function of the lateral semicircular canal is extrapolated to the entire organ of equilibrium. One method of isolating the other semicircular canals is currently not available in clinical practice. Although the thermal irritation of the otolith organs is described, it is currently also not possible in isolation. The otolith organs respond primarily to linear accelerations and are irritated by devices such as sledges or lifting chairs.

Also air as an irritant medium is used in the ambulant and clinical practice for the thermal stimulation of the balance organs. The disadvantage is that it is in an irritation with 44 ° C with simultaneous existing eardrum defect and damp middle ear (tympanic cavity) due to evaporative cooling to a cooling of the lateral semicircular canal and thus a paradoxical nystagmus reaction (nystagmus to the same side, so the same reaction as in the irritation with 30 ° Celsius) can come. In addition, the heat capacity of air is too low. The stimulus intensity of a water rinse can be achieved with air at either 44 or 30 ° Celsius. Even minor changes in the auditory canal, such as cerumen (so-called earwax), have a disturbing effect.

In addition, both equilibrium organs can be examined with a swivel chair. Here, eye movements are observed, registered and evaluated in the manner mentioned above. However, a swivel chair examination is unspecific, as both organs of balance and only the horizontal semicircular canals are stimulated: By body rotation in both semicircular arches caused a Endolymphströmung, after change of Turning or stopping the swivel chair, the sensory cells are irritated, and it comes to a nystagmus. A selective statement about the function of an organ of equilibrium is not possible. An advantage of this method is that it can be used in children who can not tolerate water flushing of their ears. The disadvantage is the high cost and the time required. Therefore, this method is not suitable for outpatient practice. But also the technical equipment for a caloric irritation with cold and warm water represent a cost-intensive investment, which can not be used in every outpatient practice.

• – die Methode kann nicht bei Patienten mit Trommelfelldefekten angewendet werden, da unsteriles Wasser zu einer Infektion im Mittelohr führt,
• – die Wasserspülung ist sehr unangenehm, teilweise schmerzhaft, es kann zu vagalen Reflexen durch Irritation des äußeren Gehörganges kommen,
• – es besteht die Gefahr der Trommelfellperforation mit schlechter Heilungstendenz,
• – es entsteht bei der Spülung ein nicht unerheblicher Geräuschpegel,
• – Cerumen kann das Ergebnis der Methode verfälschen,
• – das Gebundensein an eine Wasserquelle ist ungünstig,
• – es kann nur der laterale Bogengang gereizt werden.

Further disadvantages of the water rinse are the following:

• - the method can not be used in patients with tympanic membrane defects, as unsterile water leads to an infection in the middle ear,
• - the water rinse is very unpleasant, sometimes painful, it can lead to vague reflexes due to irritation of the external auditory canal,
• - there is a risk of eardrum perforation with poor healing tendency,
• - There is a considerable noise level during flushing,
• Cerumen can falsify the result of the method,
• - Being tied to a water source is unfavorable,
• - only the lateral semicircular canal can be irritated.

The thermal irritation of the organ of equilibrium in the ear occurs through a heat input via radiation, heat conduction and heat convection. In the case of caloric irritation, this energy is released by conduction of heat from the fluid into the corresponding tissue parts (bone, connective tissue, endolymph fluid). In addition, convection via the air column in the middle ear may also be involved. The heat conduction processes occur via phonons with their relatively slow relaxation times. By contrast, high-energy radiation introduced directly into the tissue, especially in the infrared range, can bring about a much faster heating of the tissue. The effect of such heat radiation is based on the processes of reflection, scattering and absorption of phonons, which propagate within defined, wavelength-dependent penetration depths in the tissue and which are converted into heat in the absorption centers in the tissue. This process takes place much faster than the heat conduction, which is then responsible for a further distribution of heat energy in the tissue. The most important absorber material in human tissue is water with a share of up to 80%. Tissue water has an absorption maximum of its fundamental at 2.7 microns with an absorption coefficient a = 10,000 cm-1; Secondary maxima exist at 1.9 μm and 1.5 μm. But even in the long IR range from 7 to 12 μm a is still around 1000 cm-1. It is clear that conventional tungsten halogen incandescent lamps with a quartz glass bulb can be used as radiation sources in the VIS-NIR range (300 nm to 2.7 μm) for tissue heating.

Radiation-optical methods for heat input into the inner ear and vestibular irritation have not yet become known, although in such a way not only a fast, non-contact and delay-free but also technically simple solution for ENT diagnostics can be realized. Other advantages of infrared stimulation are that this method is sterile compared to flushing water, that it can also be applied to tympanic membrane defects, that no noise is generated, previous subtle auditory canal scavenging is unnecessary, no pain, no vagal response, faster diagnostics Mobility and easy transportability of the device is possible (without being tied to water and other technical equipment) that no paradoxical nystagmus reaction as in the hot air irritation arises and a simple application in children is possible. The method thus represents an alternative to hot water flushing and is quantitatively equivalent to the caloric air irritation currently used in outpatient ENT practice as a screening method, but is qualitatively superior in terms of the advantages mentioned.

Conventional examination devices such as otoscopes for visual observation of the external ear canal with the eardrum have recently been supplemented with an internal light source, sophisticated video optics, associated cameras and recording devices (eg SONY "Video Otoscope with High Resolution Camera with 1/2"). CCD "and external 150 W halogen illumination source). This is especially important for the documentation of diagnoses and therapies. In addition, inexpensive infrared ear thermometers for fever temperature measurement have recently been introduced, which can be widely used in ENT practice as well as in private households. Infrared thermo-vision cameras have already been used to thermographically detect the thermal effect of caloric vestibular examinations on petrous bone specimens. They show that in heat transfer mechanisms, thermal irritation is of great importance at least in the initial phase of irritation of the inner ear (Pau, HW, et , al .: Thermographic detection of heat radiation during the caloric vestibular examination. Laryngo-Rhino-Otol. 78, 217-221, 1999]. The influence of thermal radiation during heat transfer is also due to a simple optical Experiment on ear preparations clearly: If one introduces the radiation of an incandescent lamp into the external auditory canal, not only the eardrum, but also the medial tympanic wall (bone chip!) Light up immediately.

The scientific and technical state of the vestibular infrared examination technique is characterized by publications that deal with the diagnosis of vestibular diseases using infrared video cameras (usually in combination with nystagmography). The eye movements of the patients after the vestibular irritation are recorded via special spectacles with an infrared camera. A connection with an infrared radiant heating of the equilibrium organ is therefore not given. For the clinical thermal stimulation of the organ of equilibrium, the caloric irritation by means of water, but also by means of air, is usually used. A use of radiant heat for thermal irritation of the organ of balance is not detectable in the available literature.

The patent status for heat radiation-based infrared devices for balance diagnostics is mainly due to the following US and US. German patents on infrared thermometry characterized:
U.S. Patent 5,381,796 (Pompei), U.S. Patent 5,411,032 (Esseff) U.S. Patent 5,445,158 (Pompei), U.S. Patent 5,469,855 (Pompei), U.S. Patent 5,479,931 (Mooradian), U.S. Patent 5,487,607 (Makita), U.S. Patent 5,516,010 (O'Hara), US Patent 370,860 (Pompei), U.S. Patent 5,626,147 (Lackey), U.S. Patent 5,628,323 (Pompei), U.S. Patent 5,653,238 (Pompei), U.S. Patent 5,653,239 (Pompei), U.S. Patent 5,673,692 (Schulze), US Patent 388,343 (Yamauchi), U.S. Patent 5,983,128 (Baudonniere).

DE 195 43 096 A1 (Jestaedt) DE 196 00 334 A1 (Beerwerth) DE 197 24 054 A1 . DE 198 15 927 A1 (Beerwerth) DE 198 57 145 A1 (Kraus) DE 198 57 146 A1 (Manne Bach), DE 198 57 148 A1 (Manne Bach), DE 199 13 672 A1 (Kraus) DE 299 00 089 U1 (Cheng).

The IR thermometers described here are designed only for the detection of endogenous radiation in the range of 10 μm. Internal radiation sources are not required. in the U.S. Patent 5,673,692 (Schulze) describes the combination of an IR ear thermometer with an integrated pulse oximeter, which provides additional information about the degree of oxygenation in the earlobe. Otherwise, the above-mentioned patents relate to a variety of technical design options that apply to improve the accuracy of measurement, ease of use and hygienic conditions. In the DE 199 13 672 A1 (Kraus) described heatable measuring tip of an IR thermometer also does not serve a thermal stimulation of a vestibular reaction of the equilibrium organ but the avoidance of measurement errors.

Furthermore, otoscopes, test equipment for the vestibular apparatus and for the detection of vertigo are described, which, however, have no relation to a thermal radiation-related irritation of the organ of balance:
U.S. Patent 5,942,945 (Galiana) U.S. Patent 5,966,680 (Butnaru) US Patent 6,005,955 (Kroll) U.S. Patent 6,063,046 (Allum).

in the U.S. Patent 6,077,237 (Campbell) describes a headset for vestibular stimulation in virtual environments during computer games. In DE 44 28 773 A1 (Müller) is a laser photoscope shown, which contains an IR radiation source of 1.4 microns to 11 microns and a wavelength-selective beam splitter. However, the laser source is only used to perforate the eardrum. In German utility model DE 295 16 394 U1 (Hinze) is for completing an otoscope a lens system for a video camera shown, with which a view through the funnel-shaped tip is to be made possible in the external auditory canal. In German utility model DE 295 07 550 U1 (ABC Elektrogeräte Volz GmbH) a device for provoking nystagmus is presented, which is based on the introduction of vibration energy into the body of the patient via a vibrating stimulation head with a low frequency of 10 to 100 Hz.

Furthermore, it is off WO 99/56826 A1 a device for stimulating the human inner ear, which is used in diseases of the cochlea or the vestibular organ. In this case, a stimulation of the human inner ear takes place with a low-level laser irradiation device, which is arranged in an ear protection device and whose laser beam acts on at least one predetermined area of the ear. The user can thus be irradiated to prevent inner ear damage with laser light.

The invention has for its object to provide an arrangement of the type mentioned above, which allows simple means a safe and rapid diagnosis and therapy, which takes place side by side and with good patient acceptance and is insensitive to changes in the ear canal.

According to the invention the object is achieved with a device which contains the features specified in claim 1.

Advantageous embodiments are specified in the subclaims

The thermal radiation applicator according to the invention is used for vestibular examination and early disease detection in ENT medicine. The temperature increase required for the caloric irritation of the vestibular organ is produced by visible and near-infrared radiation (VIS-NIR radiation). This heat radiation-induced caloric irritation has, in addition to the simple technical solution, other significant advantages with regard to freedom from side effects, patient acceptance and time requirement compared to the usual irritation with water or air rinsing.

The applicator according to the invention advantageously enables the simultaneous or alternating emission of VIS-NIR radiation and the measurement of the remitted heat radiation of the exposed tissue sections. From the remitted heat radiation, the surface temperature of the tissue is determined and the irradiation dose is controlled.

The heat radiation applicator according to the invention is used in the application in the ENT at a predetermined location, for. B. held on the outer ear canal and introduced a corresponding radiation dose of visible and near-infrared radiation in the ear canal of the inner ear. Due to this heat radiation, a temperature increase of several degrees is caused by absorption processes in the bony and soft tissue as well as in the endolymph in accordance with the penetration depth of the optical radiation, which leads to an influence of the equilibrium organ and to the triggering of a nystagmus reaction on the eyes of the patient. From this nystagmus reaction can be drawn important diagnostic and therapeutic conclusions.

The thermal radiation applicator can be used for diagnostic and therapeutic purposes not only in adults but also children and infants as well as patients whose vigilance is disturbed.

The invention will be explained in more detail below with reference to an embodiment.

In the accompanying drawing show:

1 the semicircular canals of the organ of equilibrium with receptor, which is located in the inner ear fluid (endolymph) and

2 a schematic representation of a heat radiation applicator with temperature measuring device.

The heat radiation applicator consists of a portable housing 1 with a radiation source 2 , a radiation transmission device 3 , an infrared radiation temperature measuring device 4 , a microprocessor-controlled control and evaluation unit 5 , an LCD display 6 , a battery-powered, regulated power supply module 7 , as well as an interface 8th for optional pairing with a PC. In the heat radiation applicator, a tungsten-halogen lamp with an electrical power of a few tens of watts is preferably arranged. This provides optical radiation in the wavelength range from 400 nm to 2700 nm. At a wavelength of 800 nm, the maximum radiant power is emitted, which drops to about half at the end of the range. The despite the pulse operation of the radiation source 2 accumulating heat energy by heating the lamp glass bulb and adjacent assemblies is removed via air convection through vents in the housing of the heat radiation applicator. For coupling the largest possible proportion of the radiation of the lamp in the glass fiber optic radiation transmission device 3 serve a condenser optics made of quartz 3.1 as well as an ellipsoidal mirror 3.2 , This warm-light reflector is preferably provided with an NIR-impermeable aluminum layer. Alternatively, it is also possible to use laser radiation sources in the red and near infrared wavelength range for a spatially selective radiation stimulation. Both optical assemblies are made of such a material which resists the thermal shock stresses due to the radiation pulse operation. The radiation energy of the lamp is coupled into a NIR quartz optical fiber bundle, which is arranged in such a form in the heat radiation applicator that the emitted radiation 9 hit the desired section in the posterior external auditory canal or the external skull bone next to the pinna. In 2 For this purpose, the non-axial arrangement of the optical fiber bundles is shown, which is structurally realized by a correspondingly held flexible optical fiber bundle. The optical output of the optical fiber bundle is terminated by a quartz optical window.

At the edge of the quartz fiber bundle or in the middle (not in 2 shown) is another light guide 3.3 or an optical fiber bundle of an IR-transmissible material such as As-Te glass arranged, which forwards infrared radiation in a wavelength range of 10 microns. The optical input of this second optical fiber takes contactlessly the body radiation 10 the targeted tissue section in the ear canal. This radiation is via an optical edge filter 4.1 the IR sensor 4 supplied The IR sensor 4 is built from an integrated thermopile assembly with a thermistor reference and provides a radiation temperature proportional output voltage via the microprocessor-based detection electronics 5 on an LC display 6 is displayed when needed.

Due to the radiant energy input of the halogen lamp into the tissue, there is a temperature increase of a few degrees, which is thus registered in parallel. By an intermittent operation of the radiation source 2 can be set to a predetermined temperature and avoid harmful overheating of body tissue. The adjustment and control of the temporal lamp operating regime is advantageously carried out via the microprocessor unit 5 , The operating parameters such as the target heating temperature of the target tissue are achieved via a simple membrane keyboard or via the interface 8th (eg RS232, IrDa, USB, Bluetooth) of the heat radiation applicator set by a PC program.

• – ein oder mehrere Quarz-Lichtleiterbündel aus Multi-Mode-Stufen-Index-Fasern,
• – ein weiterer Lichtleiter oder ein weiteres Lichtleiterbündel aus einem IR-transmissiblen Material,
• – ein Halbleiterblockfilter;
• – ein Temperaturstrahlungsdetektor, vorzugsweise eine Thermopile-Anordnung,
• – ein optisches System mit Umlenkprismen und/oder -spiegeln sowie wenigstens einem VIS/NIR-teildurchlässigen dielektrischen Spiegel,
• – eine Warmlichtquelle,
• – ein oder mehrere NIR-Laser-Lichtquellen.

In the case 1 one or more of the following components may be arranged

• One or more quartz optical fiber bundles of multi-mode step index fibers,
• A further light guide or a further light guide bundle made of an IR-transmissible material,
• A semiconductor block filter;
• A temperature radiation detector, preferably a thermopile arrangement,
• An optical system with deflecting prisms and / or mirrors and at least one VIS / NIR semi-permeable dielectric mirror,
• A warm light source,
• - One or more NIR laser light sources.

An expedient embodiment provides that As-Te-glass is used as IR-transmissibles material, as semiconductor filter a InSb filter with an edge of 7.3 microns and the optical system is a partially transmitting dielectric mirror made of In-Sn-oxide.

• – für die Bilderfassung mittels Videokamera mit Zoom-Optik oder Bildleiter-System,
• – für die berührungslose Abstandserfassung mittels NIR-Remissionssensor,
• – mit konventionellem Otoskop oder Laser-Otoskop
• – mit herkömmlichen technischen Einrichtungen zur Nystagmus-Erfassung wie Frenzel-Brille, Videonystagmografie, EMG-Elektroden, Dehnungsmessstreifen sowie
• – mit einem berührenden/nichtberührenden VIS/NIR-Remissionsspektrometer zur Messung der Hb-Oxigenierung der Cochlea, des Wassergehalts oder der mikrovasculären Durchblutung.

The application of the arrangement can take place

• - for image acquisition by means of video camera with zoom optics or image guide system,
• - for non-contact distance detection using NIR reflectance sensor,
• - with conventional otoscope or laser otoscope
• - with conventional nystagmus detection equipment such as Frenzel goggles, video nystagmography, EMG electrodes, strain gauges and
• - with a non-contacting VIS / NIR remission spectrometer for measurement of Hb oxygenation of the cochlea, water content or microvascular perfusion.

LIST OF REFERENCE NUMBERS

1

casing

2

radiation source

3

Radiation transfer device

4

Infrared radiation and temperature measuring device

5

Control and evaluation unit

6

LCD display

7

Power supply module

8th

interface

9

emitted radiation

10

body radiation

Claims (5)

Arrangement for vestibular examination of the inner ear by thermal stimulation of an organ of equilibrium in the auditory canal with a radiation source emitting in the wavelength range from 400 nm to 3000 nm ( 2 ), in a portable housing ( 1 ) whose radiation is transmitted by a radiation transmission device ( 3 ) is directed to an optical window, - a regulated power supply assembly ( 7 ), - an infrared radiation temperature measuring device ( 4 ), - a microprocessor-controlled control and evaluation unit, and - a further radiation transmission device ( 3.3 ) of an IR-transmissive material for non-contact absorption of body radiation ( 10 ), - wherein the beam entrance of the further radiation transmission device ( 3.3 ) is located at the optical window, - wherein the further radiation transmission device ( 3.3 ) the body radiation ( 10 ) via an optical edge filter ( 4.1 ) an IR sensor ( 4 ), whereby the IR sensor ( 4 ) provides a radiation temperature proportional output voltage, which by means of a microprocessor-controlled detection electronics ( 5 ) is evaluated. Arrangement according to claim 1, characterized in that on the housing ( 1 ) an interface ( 8th ) is arranged for optional coupling with a PC. Arrangement according to one of claims 1 or 2, characterized in that as a radiation source ( 2 ) A tungsten-halogen lamp is arranged. Arrangement according to one of claims 1 or 2, characterized in that as a radiation source ( 2 ) at least one NIR laser light source is arranged. Arrangement according to one of claims 1 to 4, characterized in that in front of the radiation source ( 2 ) a condenser optics ( 3.1 ) is made of quartz and behind the radiation source ( 2 ) one ellipsoidal mirror ( 3.2 ) provided with an NIR impermeable aluminum layer.

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