DE202022104255U1 - Measuring device for daylight PDT - Google Patents

Abstract

Measuring device (1) for daylight PDT, wherein the measuring device (1) has a sensor element (2) for receiving a discrete wavelength range of incoming radiation and wherein the measuring device (1) has a control and evaluation unit (5) which is used to determine a Intensity of the incoming radiation from a measured value recorded by the sensor element (2), and / or for detecting an exposure time interval, if a target value for an intensity of the incoming radiation has been exceeded, is set up.

Description

The present invention relates to a measuring device for daylight PDT.

The so-called PDT - photodynamic therapy - is divided into daylight PDT and conventional PDT. The patient is first instructed to wear long clothing and to protect the uncovered skin areas with sunscreen. A cream containing active ingredients is then applied to the corresponding lesion. These lesions occur, for example, on the head, particularly bald areas, and on extremities and are usually the result of exposure to light in the ultraviolet wavelength range.

The skin then metabolizes the absorbed active ingredient. After the application, radiation takes place. The metabolites are stimulated by the light and free radicals are released, with mutant cells accumulating more metabolites than normal cells. The agent therefore has a targeted effect on mutated cells. The excitation is carried out by light of a discrete wavelength, which can be applied artificially, but which is also contained in normal daylight or sunlight.

However, the irradiation variants are different. Conventional photodynamic therapy (c-PDT) uses a lamp at a discrete wavelength, e.g. 632 nm, and is very painful (VAS pain scale approx. 7/10).

Daylight PDT, i.e. daylight therapy, is not painful at all or at least significantly less painful. According to guidelines, it will not be carried out in the winter months and is limited to midday in sunny to slightly cloudy weather. The therapy involves sun exposure of approximately 2 hours, which does not take into account the exact weather conditions, the lighting conditions or the individual behavior of the patient during this time.

In practice, many patients go for a walk during daylight PDT and stay in places that are too shady, despite instructions not to do so. Typically, patients are uncomfortable with direct sunlight because they become too warm. Rather, people enter buildings or sit under a parasol. The risk of underexposure is therefore high.

Conversely, the patient can also be overexposed.

Based on the previous preliminary consideration, the object of the present invention is to provide the patient with a measuring device for daylight PDT, which supports the patient in the treatment during the application of a radiation dose to daylight.

The present invention solves this problem by a measuring device with the features of claim 1.

A measuring device according to the invention for daylight PDT has a sensor element for receiving a discrete wavelength range of incoming radiation. The discrete wavelength range relates to a range of preferably less than 20 nm, particularly preferably less than 12 nm. The background is that a corresponding active ingredient suitable for PDT only releases radicals that attack a lesion when exposed to radiation of a certain wavelength. Therefore, the detection of precisely this wavelength range is of interest. Typically, a measured value recorded by the sensor element can be a voltage-equivalent signal that must first be converted.

For this purpose, the measuring device has a control and evaluation unit, which is set up to determine an intensity of the incoming radiation from a measured value recorded by the sensor element, and/or to detect an exposure time interval if a target value for a dose of the incoming radiation has been exceeded. For this purpose, the control and evaluation unit can, in particular, have a data memory on which one or more corresponding computer program products are stored for conversion and/or setpoint comparison. The control and evaluation unit can also have a computing unit which can be used to execute the computer program products. In addition, a timer can be provided which determines the exposure time interval. The computer program product is able to calculate the metabolic parameters, especially the minimum and maximum intensity, which contribute to dose accumulation.

Advantageous embodiments of the invention are the subject of the subclaims.

It is advantageous if the sensor element has a diode and an optical filter for filtering the wavelength. This means that the measurement of the diode is not disturbed by radiation components outside the relevant wavelength range.

The diode can preferably be designed as a photodiode. A photodiode has the advantage over other diodes, such as an LED proven to be particularly suitable for the present purpose, as shown, among other things 2 from the description of the figures.

The control and evaluation unit can have a storage unit with an external storage medium. The external storage medium is therefore replaceable. It can be, for example, a USB storage medium, an SD card or something similar. The aforementioned data memory can then be part of the storage unit, but in contrast to the external storage medium, it is a non-replaceable part of the measuring device.

The optical filter can advantageously be designed to filter radiation beyond a wavelength range between 630 - 635 nm and/or 405 - 415 nm.

The measuring device, in particular the control and evaluation unit, can have a signal generator, preferably an acoustic signal generator. The signal generator can, for example, be an acoustic signal generator which indicates when the PDT patient is outside an area with an effective radiation dose.

Furthermore, both an upper setpoint for the radiation intensity and a lower setpoint for the radiation intensity are stored on the storage unit for displaying and/or initiating a time measurement of an effective or ineffective radiation dose.

The sensor element is separated from the control and evaluation unit of the measuring device, i.e. spatially separated. Lesions can occur in different parts of the body. It is therefore advantageous to position the spatially comparatively small sensor element as flexibly as possible and, if necessary, in such a way that the radiation does not necessarily hit the lesion perpendicularly. The spatial separation between the sensor element and the control and evaluation device offers a particular advantage here.

The sensor element can have a fastening means for fixing the sensor element separately from the control and evaluation unit.

Likewise, the control and evaluation unit can have fastening means for separately fixing the control and evaluation unit separately from the sensor element.

The control and evaluation unit can be set up to continuously detect one or more input signals generated by the sensor element, which are dependent on a detected radiation intensity per unit of time. This has the advantage that several sensor elements can be connected, each of which can be attached to different locations or measure different wavelength ranges.

A sensor housing can also have an amplifier to optimize the output signal generated by the sensor element. Accordingly, the amplifier is positioned on the signal input side in front of the computing unit in the sensor housing.

The measuring device can also have a display for outputting the radiation intensity, the exposure period of an effective radiation dose and/or the settings of the therapy parameters. Furthermore, operating parameters of the device such as the battery or memory status can be called up.

The measuring device is energy self-sufficient and is therefore designed as a portable, battery-powered measuring device.

• 1 Schematischer Aufbau des Messgeräts;
• 2 Signal zu Wellenlängen-Diagramm für verschiedene Dioden und Dioden und Filterkombinationen; und
• 3 Messdiagramm über die Aufnahme einer Therapiesitzung durch das Messgerät.

The invention is described in detail below using an embodiment variant:

• 1 Schematic structure of the measuring device;
• 2 Signal to wavelength diagram for various diodes and diodes and filter combinations; and
• 3 Measuring diagram about the recording of a therapy session by the measuring device.

1 shows the structure of a measuring device according to the invention with a sensor element 2 comprising a measuring sensor housing and a transmitter housing 4 spatially separated therefrom. The measuring device 1 is portable and the sensor element 2 is typically attached to the patient in the immediate vicinity of the area to be treated.

In a variant of the invention, the sensor element can be arranged within the housing of a control and evaluation unit, the measuring device being miniaturized in such a way that all elements of the measuring device can also be positioned at the location to be treated within a single housing.

Alternatively, only the sensor element 2 can also be used, as in 1 .shown, be attached in the immediate vicinity of the area to be treated and can transmit a signal wirelessly or with a cable 3 to a remote housing 4, the so-called transmitter housing, a control and evaluation unit 5. The housing 4 can be worn on a strap or attached to a belt, for example.

Furthermore, the housing 4 of the control and evaluation unit 5 has a display 6 and input elements 7, for example buttons, as well as a computing unit 8. Furthermore, the sensor element 2 or the sensor housing of the sensor element 2 has an output-side amplifier or amplifier 9 for signal amplification. The transmitter housing 4 in turn can have a storage unit on which, among other things, setpoint information for a minimum and a maximum exposure time is stored. Thus, on the one hand, the measuring device according to the invention warns when the intensity falls below the threshold value and calculates when the effective dose reaches the therapeutic value, which also triggers a warning in order to avoid overexposure.

This prevents over- and under-exposure and optimizes and personalizes therapy.

The storage unit preferably has a storage element 13 which is replaceable, for example an SD card or another storage medium. This means that the dosage of radiation can be specified for each patient and/or patient data can be saved and extracted. This means that the measuring device can be used by a large number of patients without the patient data being mixed up. The storage unit can also have a non-replaceable data memory, for example a ROM.

The computing unit processes the incoming signal detected by the sensor element. The intensity of the detected radiation is defined for each area, the extent of which is determined by an upper and lower limit value, which represent the biochemical reaction of the metabolism. The intensity is integrated into the dose taking metabolism into account. The input elements 7 for control and the display are located in or on the housing 1.

The sensor element 2 can preferably include a photodiode 10. Furthermore, the sensor element can have a filter 11 in front of the photodiode, which only allows light with a specific wavelength to pass to the photodiode 10.

The measuring device 1 measures the intensity of the incident light in the wavelength range around 633 nm, or between 630 - 635 nm. The filter 11 is configured accordingly.

Alternatively or additionally, an extension or an alternative in the range of 410 nm, or 405-415 nm, would also be an extension for the therapy of actinic keratoses. For this purpose, the filter 11 and/or the photodiode 10 can be adapted to the wavelength.

It is also possible to use other filters to monitor UV therapies, for example, and to use the device for study purposes.

The wavelength-specific intensity range starts at 0 W/m2, the addition of the dose value starts at 130 W/m2, the measuring device can measure an intensity of up to around 1,000-1,200 W/m2.

The summation can be limited, in particular by the theoretically maximum possible concentration of the target molecule, in particular protoporphyrin 9. However, this is only formed in the reaction. What has not yet emerged cannot react.

1. I. Auftrag einer auf die Haut-abgestimmte Sonnencreme
2. II. Applikation einer wirkstoffhaltigen Creme auf die Läsion
3. III. Aussetzen von Tageslicht, wobei der Zeitraum der Sonnenlichtexposition durch das erfindungsgemäße Messgerät überwacht wird.

A daylight PDT method according to the invention can also be carried out as follows:

1. I. Apply a sunscreen that is tailored to your skin
2. II. Application of a cream containing active ingredients to the lesion
3. III. Exposure to daylight, the period of sunlight exposure being monitored by the measuring device according to the invention.

As mentioned at the beginning, radical formation occurs by means of the active ingredient, more precisely by activating the metabolite of the aforementioned, which requires light of a discrete wavelength for the activation mentioned. A broadband measurement of solar radiation across all wavelengths is therefore too unspecific. Accordingly, the measuring device should be equipped to measure one wavelength or a narrow wavelength range. This is achieved through the combination of photodiode and filter.

2 shows recording curves between LED 101, photodiodes 102, 103 and photodiodes with filters 104, 105. A sharp and comparatively high-resolution input signal was achieved for the combination of photodiode and filter compared to the other variants.

If under-exposure is detected, the measuring device triggers an alarm. For this purpose, a signal transmitter 12 can be specified in the measuring device. This can be a buzzer, for example.

The received signal is preferably detected continuously - i.e. not intermittently. If under-exposure occurs, the time with this under-exposure is not counted towards the dosing time. If over-exposure occurs, the time given by the The maximum value defined at the upper threshold is added to the dosing time. Anything beyond that is ineffective.

3 shows a real curve recorded by a corresponding measuring device according to the invention. Curve 202 shows the recorded intensity. You can tell when the person was in the shade by interruptions in intensity. However, the effective dose is important for the success of the therapy. This is represented by curve 201. It is determined whether a sufficient dose was reached within a time interval, for example 1 second. This dose is limited because the accumulation of the light dose is itself limited by the accumulation of the active ingredient.

At the beginning, curve 201 initially rises steeply because there is no solar radiation, but the active ingredient is metabolized without the metabolite being consumed. This increase is due to the deposit of a so-called metabolic factor, which reflects the speed of formation of the metabolite.

As the therapy progresses, so much intensity is always achieved that the metabolite is consumed immediately, meaning metabolism is the limiting factor. In this respect, curve 201 shows approximately the optimal course of therapy.

Only in the middle range, e.g. at arrow 203, was there a dose accumulation that was below the maximum possible accumulation, limited by the speed of metabolism. Here the user may have been in the shade for a short time with insufficient intensity.

The 3 shows that the monitoring of the success of therapy by the measuring device according to the invention works excellently. The measuring device opens up, among other things, greater treatment potential for therapy. Until now, this therapy was only used in summer when the weather was good because it was necessary to ensure that there was sufficient intensity of radiation from the sun. With the measuring device according to the invention, the therapy can be carried out safely and reliably independently of environmental factors but also the individual behavior of the patient, since the intensity and thus the success of the therapy can be better quantified.

Reference symbols

1

measuring device

2

Sensor element

3

Cable

4

Housing

5

Control and evaluation unit

6

display

7

Input elements

8th

Computing unit

9

Amplifier/amplifier

10

photodiode

11

filter

12

Signal transmitter

13

storage medium

Claims (14)

Measuring device (1) for daylight PDT, wherein the measuring device (1) has a sensor element (2) for receiving a discrete wavelength range of incoming radiation and wherein the measuring device (1) has a control and evaluation unit (5) which is used to determine a Intensity of the incoming radiation from a measured value recorded by the sensor element (2), and / or for detecting an exposure time interval, if a target value for an intensity of the incoming radiation has been exceeded, is set up. measuring device Claim 1 , characterized in that the sensor element (2) has a diode and an optical filter (11) for filtering the wavelength. measuring device Claim 2 , characterized in that the diode is designed as a photodiode (10). Measuring device according to one of the preceding claims, characterized in that the control and evaluation unit (5) has a storage unit with an external storage medium (13). Measuring device according to one of the preceding claims, characterized in that the optical filter (11) is designed to filter radiation beyond a wavelength range between 630 - 635 nm and/or 405 - 415 nm. Measuring device according to one of the preceding claims, characterized in that the measuring device (1), in particular the control and evaluation unit (5), has a signal generator (12), preferably an acoustic signal generator. Measuring device according to one of the preceding claims, characterized in that on the storage unit (13) there is an upper setpoint for the radiation intensity to avoid overexposure and a lower setpoint for the radiation intensity intensity is stored for displaying and/or initiating a time measurement of an effective or ineffective radiation dose. Measuring device according to one of the preceding claims, characterized in that the sensor element (2) is separated from the control and evaluation unit (5) of the measuring device (1). Measuring device according to one of the preceding claims, characterized in that the sensor element (2) has fastening means for separately fixing the sensor element (2) relative to the control and evaluation unit (5). Measuring device according to one of the preceding claims, characterized in that the control and evaluation unit (5) has fastening means for fixing the control and evaluation unit (5) separately from the sensor element (2). Measuring device according to one of the preceding claims, characterized in that the control and evaluation unit (5) is set up for the continuous detection of an input signal generated by the sensor element (2), which is dependent on a detected radiation dose per unit of time. Measuring device according to one of the preceding claims, characterized in that the sensor element (2) has an amplifier (9) for optimizing the input signal generated by the sensor element (2). Measuring device according to one of the preceding claims, characterized in that the measuring device (1) has a display (6) for outputting the radiation intensity, the exposure period of an effective radiation dose and/or the settings of the therapy parameters. Measuring device according to one of the preceding claims, characterized in that the measuring device (1) is designed as a portable battery-powered measuring device (1).

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