Measuring and testing – Testing of apparatus
Reexamination Certificate
2001-06-01
2004-10-26
Raevis, Robert (Department: 2856)
Measuring and testing
Testing of apparatus
Reexamination Certificate
active
06807876
ABSTRACT:
FIELD OF THE INVENTION
The invention relates to a testing or setting device for a PDD or PDT system or for training on such a system, as well as to a process for testing or setting a PDD or PDT system and to a tissue phantom and a process for producing a tissue phantom.
BACKGROUND OF THE INVENTION
Photo-dynamic diagnosis (PDD) or therapy (PDT) systems are widely used in medical practice to detect and/or to treat malignant as well as benign tissue degenerations. These practices make use of photo-sensitizers, which accumulate specifically in the tissue to be examined and luminesce with light stimulants (photo-dynamic diagnosis) or alternatively at high photo-sensitizer doses and high illuminating strength they lead to a photo-toxic effect, through which the diseased tissue is destroyed (photo-dynamic therapy). In particular, for photo-dynamic diagnosis, luminescent substances occurring in the body can be brought into play. A combined fluorescence/auto-florescence PDD system is described in the publication Endo World THOR No. 27-E, 1999, by the Karl Storz GmbH & Co. KG.
PDD and PDT systems include a lighting system, whose light serves to stimulate luminescence, that is, fluorescence or phosphofluorescence substance for instance. In addition, PDD systems as well as many PDT systems are provided with an observation system, with which the tissue area to be examined or treated can be observed, or it is also possible to conduct only an intensity measurement of the luminescent light. Since the luminescence tends to be considerably weaker than the reflection of the light stimulant, a filter system is usually provided to permit observation of the luminescent effect. If the process takes advantage of the fact that the luminescent light has different wavelengths from the stimulant light, then a wavelength-selective filter system is used. On the other hand, if the process with pulsed stimulant light employs a luminescent light emission that is delayed with respect to the reflection, then a time-selective filter system is used. The filter system, which also includes the radiation or time sensitivity of the detector system, can be designed in such a way that reflected light can also be used to observe the relevant tissue area, as is described for instance in WO 97/11636 and in WO 98/43534; the lighting unit can also provide for an additional broadband illumination.
PDD and PDT systems include components that can age or become damaged, such as lamps, light cables, filters, or lens systems, as well as components that require initial or repeated setting or adjustment, such as the light source or the camera, for which the brightness or color balance may have to be adjusted. The optimal setting in each case can also depend on the particular application or on the user. If this testing or setting is not carried out until the system is actually in use, this can unwittingly place a burden on the patient. The same is true for the training of the user that may be required because of the complexity of such systems and their specific application.
It is advisable therefore for a PDD or PDT system to be tested and, if necessary, adjusted prior to use, with the help of a device. Such a device, which can also be used for training, as well as a related process, is known from WO 98/11945. That invention provides for a target that reflects the illuminating light of the PDD or PDT system, and includes a light source that emits light in the wavelength range of the fluorescent spectrum of the particular photo-sensitizer. In order to test or set a PDD or PDT system, it is placed in the device, the illumination intensity of the light stimulant is received by a photo element, and a control unit controls the light source according to a predetermined function in order to duplicate the luminescent effect.
This device is costly because of the need for a light source and a control unit, and the reproduction of the luminescent effect can have only a limited fidelity.
One task of the present invention is to provide a device for testing and/or setting a PDD or PDT system or for training on such a system, a device which is as simple in construction as possible, is easy to handle, and allows for the most realistic possible imitation of the luminescent effect, as well as a related process for testing and/or setting a PDD or PDT system.
The invention fulfills this task through the characteristics of claims
1
and
13
. A tissue phantom, which has at least one luminescent area, is arranged in a housing in which the PDD or PDT system can be at least partially accommodated, in such a way that it can be at least partially illuminated by the lighting system of the PDD or PDT system. As a result, a realistic depiction of the luminescent effect becomes possible without the need for additional devices for producing the luminescent light.
In an advantageous application of the invention, the housing includes a hollow space in which the PDD or PDT system for testing, setting, or training can be at least partially accommodated. The housing can be designed as described in U.S. Pat. No. 5,820,547. It is particularly advantageous, in this case, if the hollow space is closed off and if there is an aperture equipped with a preferably light-sealed closing to accommodate one part of the PDD or PDT system, to simulate the lighting conditions during an intervention inside the body. This is particularly advantageous when the PDD or PDT system includes an endoscope or an operating microscope, through which the illumination is directed to the tissue or through which the tissue can be observed. There can also be several apertures of various diameters for endoscopes of different diameters, or apertures arranged at an angle to one another for endoscopes with various viewing angles. In addition, other apertures or devices may be provided, through which surgical instruments can be introduced for instance, or through which independent lighting or observation is possible, or through which rinsing can take place since work is frequently carried out in practice in common salt solution.
To permit the use of the invention's device in a sterile area or with sterile implements or instruments, it is also advantageous if a sterile foil can be placed in the housing to protect the sterile part from contamination each time it is introduced. This foil can also encase the entire device, possibly along with additional substitute tissue phantoms, to permit unrestricted use in a sterile area. On the other hand, the device can be designed so that the PDD or PDT system can be accommodated in the housing with a sterile foil which protects the inserted sterile part from contamination. It is thereby possible to test the PDD or PDT system during an operation as well, without affecting its sterility. Of course the device can also be designed so as to be sterilizable as a whole; in this case the tissue phantom can be equipped with a hermetically sealed casing. The device or the tissue phantom itself can also be produced for one-time use.
In another advantageous application, the tissue phantom is secured on an adjustable, for instance sliding, mounting. This has the advantage that the tissue phantom can be moved into the focal area of the lighting or observation system and then out of it again, without the need to displace the PDD or PDT system itself. As a result, the conditions of actual use can be simulated in a simple manner.
In another advantageous application, the tissue phantom is replaceable. Thus, by exchanging the tissue phantom, it is possible to use the invention's device for various PDD or PDT systems, for various application cases, for instance for various tissue types or organs, or else with various photo-sensitizers or luminescence modes. Likewise it is possible, as a result, to replace a damaged, soiled, non-sterile tissue phantom, or one that has become unusable through fading of the photo-sensitizer.
In another advantageous application, several tissue phantoms are provided. This makes it possible, for instance, to observe simulations of different tissue
Beck Gerd
Erhardt André
Irion Klaus M.
Karl Storz GmbH & Co. KG
Raevis Robert
St. Onge Steward Johnston & Reens LLC
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