technical aspects of telepathology with emphasis on future...

107

Technical aspects of telepathology withemphasis on future development

P. Schwarzmann, B. Binder and R. KloseInstitute of Physical Electronics, University ofStuttgart, Stuttgart, Germany

Pathology undergoes presently changes due to new develop-ments in diagnostic opportunities and cost saving efforts inhealth care. Out of the wide field of telepathology the paperselects three prototype applications: telepathology in teleed-ucation, expert advice for preselected details of a slide and fi-nally telepathology for remote diagnosis. The most challeng-ing field for remote diagnosis is the application in the frozensection scenario. The paper starts with the mental experimentto map conventional procedures to counterparts in telepathol-ogy.

Technical opportunities and economical restrictions oftelepathology equipment are discussed with respect to thecomponents: electronic camera, display devices, haptic sen-sors and displays, available telecommunication channels andtelepathology software.

As an example and for illustration of the state of the artfor an advanced telemicroscopy system able to perform re-mote frozen section diagnosis, the HISTKOM equipment ispresented in more details.

The section concerning future developments regards theaspects of the acceptance by tentative users, legal aspects,costs and affordability of equipment, the market for equip-ment components and the adequate telecommunication ser-vices. Further is regarded the mutual influence of propertiesof existing systems and application experiences gained withthem on the next generation of equipment and applicationsoftware. Conclusions and references close the paper.

Keywords: Telepathology, telepathology networks, artificialhand, teleeducation, virtual slide, telemedicine market

1. Introduction

The field of pathology presently undergoes world-wide changes as a result of new scientific experiencesand tools [3,5], as well as from cost saving efforts:

– Pathology splits more and more into specialfields, which make it difficult for the pathologistto overlook still the complete field. This requires

an increased number of expert consultations toprovide the patient with a the state of the art diag-nosis. It requires also adequate opportunities forcontinuing education to provide pathologists withthe results of new developments.

– Due to cost saving efforts, more and more smalland medium hospitals lose their own departmentsof pathology and have to rely on services fromoutside the hospital.

Both trends make telepathology an attractive tool forrequesters and providers of services in pathology tomeet the indicated challenges. Accordingly the orig-inal motivation for the introduction of telepathologyprocedures was just to replace the deficiencies men-tioned above by the new tool. The basic attraction weretwo features: (i) to avoid the physical transportation ofslides and tissue and (ii) to allow a local separation ofthe investigated sample and the investigator. The chal-lenge for the developers of telepathology equipmentwas to consider the new situation and to fit their instru-ments into the existing workflow in pathology. Laterconsiderations were made, not only to reestablish thetraditional workflow, but to exploit additionally newopportunities offered by telepathology.

The present paper will be restricted to the technicalaspects of telepathology equipment. It starts in para-graph two with a presentation of different modes oftelepathology and their requirements to equipment. Inpart three, technical solutions together with econom-ical restrictions are discussed and part four demon-strates an example of today’s state of the art equipment.Part five finally discusses new opportunities and possi-ble trends. A short section with conclusions and refer-ences ends the paper.

To avoid misunderstanding of the term “slide”,throughout the paper “slide” will be used only for theglass slides with the prepared tissue for inspection un-der the microscope, “slides” of photographic films willbe called “diapositives”.

Analytical Cellular Pathology 21 (2000) 107–126ISSN 0921-8912 / $8.00 2000, IOS Press. All rights reserved

108 P. Schwarzmann et al. / Technical aspects of telepathology with emphasis on future development

2. What is telepathology?

The item “telepathology” includes a variety ofvery different procedures and functionalities in pathol-ogy. In principle, it includes everything, provided atelecommunication step is part of a service. A collec-tion and an overview with definitions may be foundin a report [4,14] of the EUROPATH project of theEU promoting telepathology and in [8]. For simplic-ity reasons, we will select three representative telepa-thology applications and the corresponding equipmentcovering almost the whole field. These prototypes oftelepathology services may be characterized accordingto their application:

– Education and continuing education;– Expert advice and 2nd opinion consultation on the

basis of a few preselected images of a case;– Primary telediagnosis including 2nd opinion in

the sense of a complete remote diagnosis.

As the item 2nd opinion is used for different pro-cedures: opinion on the basis of a few selected detailsand opinion in the sense of a 2nd diagnosis, this itemis avoided and replaced in this paper by the item expertadvice and telediagnosis for the two procedures.

It should be mentioned here, however, that there is alot of overlapping between these idealized applicationsand the real existing equipment functionalities. Alsoapplications not included in the three prototypes are inoperation. As an example shall be mentioned the telee-valuation and telequantification of images with imageprocessing methods and tools.

Requirements to the corresponding equipment of thethree prototypes will be formulated first just in the lightof their aim to replace an already existing service bya counterpart applying telecommunication technology.In a later section of the paper new opportunities emerg-ing from telepathology and their requirements will beregarded separately. In the next section it will be triedto map the existing conventional services identicallyto their telepathology counterparts. The description ofthe three prototype services cited will be structured ac-cording to the following scheme: description of the ap-plication scenario, motivation to apply a telepathologycounterpart, technical parameters to map the existingservice identical to his telepathology counterpart.

2.1. Telepathology in education

In lectures, continuing education and self-educationwell selected images from microscopic investigations

of tissue and cells are presented for illustrations and in-terpreted by the teacher or the students. Telepathologymeets these scenarios, if the images and the auditoriumare locally separated. Not regarded within this scenariois the inspection of slides under the microscope, northe performance of ring experiments with real slides.These scenarios will be covered by the telediagnosis inSection 2.3.

The motivation for telepathology in teaching is toavoid the handling and above all the mailing of diapos-itives. Instead, the images are collected with an elec-tronic camera by the teacher and stored on an elec-tronic medium within a data base or in a Web-basedserver data bank. From this server, images may be re-trieved via networks of any type and from any locationto be displayed to an audience somewhere. This tech-nology makes diapositive collections, their administra-tion and mailing obsolete.

Coming back to the scenario; the only requests to thetelepathology technology applied are: the images shallhave the same quality as the presentation with the con-ventional diapositives and the images shall be presentfor the audience sufficiently fast.

The steps to realize such a scenario include:

– Collection and perhaps annotation of the imagesby an expert and their digitization;

– Storage and administration in a data bank;– Facility to transmit retrieved images via networks;– Receiving and displaying of the images to an au-

dience or to an individual.

To map the diapositive world to the telepathologyworld, there is only one necessity: to maintain thesame image quality as is provided by diapositives.Fortunately the resolutions and field dimensions ofcolor slides correspond approximately to those of mod-ern fields of view in a microscope. According to thetechnical report of the Zeiss Company (Zeiss, Axio-Cam, table of technical data of microscope, objec-tives) a modern microscope objective (e.g., Zeiss Fluar10× NA 0.5) requires about 4000× 3000 image pix-els in a rectangular format to cover the full resolu-tion and field of view. This resolution correspondswith 12 Mbyte/frame data. In principle this resolu-tion should be maintained for all three basic colorsred, green and blue. But due to the characteristics ofthe human visual system, in which color resolutionmay be reduced compared to the brightness resolution,12 Mbyte may be equally distributed to the pixels ofthe three basic colors (for details see Section 3.3 forcameras). For the image contrast a ratio of 1 : 256 cor-responds to that of diapositives.

P. Schwarzmann et al. / Technical aspects of telepathology with emphasis on future development 109

This amount of data/image has to be regarded forthe whole chain: image acquisition, storage, transmis-sion and final display to an observer. The effect of datacompression will be regarded separately.

Deviating from the diapositive concept, also a con-cept known as “virtual slide” is investigated: the aim isto image the whole slide in full resolution to a digitaldatabank, creating a virtual or electronic slide, whichmay be handled on a display screen similar to a realslide under a microscope. Because the storage of acomplete slide in maximum resolution would overloadthe storage capacities, strategies are applied to store thecomplete slide only for low magnifications and to re-strict the application of high magnifications to areas ofspecial interest, a procedure, which is well adapted toeducation.

2.2. Telepathology in expert advice for preselectedslide details

The classical 2nd opinion procedure, which is bet-ter described as 2nd diagnosis method, is the send-ing around of histological slides to colleagues. For thisprocedure the adequate counterpart is telemicroscopyas described in Section 2.3. Within the context oftelepathology, expert advice for preselected slide de-tails is practiced on a larger scale only since netconnected computers became available. The classicalcounterpart was to make some diapositives and to sendthem to a colleague. This procedure also often is called“passive” telepathology. It should be mentioned how-ever, that if “enough”, and, before all, the “adequate”slide details are presented, a diagnosis may be renderedas well.

In this telepathology mode a pathologist selects rel-evant images of a slide under his microscope and, inadvanced versions, collects them in an electronic casefolder. Then he sends this folder via electronic mail oranother transmission protocol to a colleague. On bothsides is a pathologist and the procedure may be com-pletely offline. For this scenario there is no counter-part of a conventional procedure (with the exceptionof diapositive transfer), as this mode is a child of thecomputer age. Therefore this telepathology mode is al-ready based on today’s standard equipment for cam-eras, monitors, networks and computers.

The motivation of this procedure is the possibilityto ask colleagues for their opinion concerning selecteddetails in a slide and to get their opinion within one ortwo days.

The technical requirements to these applicationshave been restricted from the beginning to TV-frametechnology, in low quality solutions with FBAS 1-chipcameras and in high quality solutions with 3-chip CCDcameras; only very recently, resolutions beyond theTV-standard become affordable and are considerablefor application.

2.3. Telepathology for telediagnosis

Telediagnosis offers pathologist an opportunity todiagnose a slide in the same way and quality as if theslide would be under the microscope on their desk.

The most challenging, but also the most attractive,scenario for small and medium hospitals without anown pathologist is frozen section telediagnosis. In thiscase, during a surgical intervention, tissue for immedi-ate diagnosis is removed as usual. In the conventionalprocedure the tissue is prepared and diagnosed in largehospitals by the in-house pathologist, or the material istransported to the next pathologist somewhere else, ora pathologist was asked to come to the hospital for thefrozen section diagnosis.

The motivation for hospitals without an in-housepathology department to apply telepathology is toavoid the transportation of tissue and the resulting de-lay in surgery.

The new scenario relying on telemicroscopy avoidsthis delay: the removed tissue is immediately preparedfor frozen section diagnosis in the surgery department,put under the remotely operable telemicroscope. Thena distant pathologist is called by phone and asked forhis assistance. If he agrees and owns a display stationfor telemicroscopy, he is connected to the microscopestation, and he may operate it as it would be on his deskand inspect the field of view on a monitor instead ofin an eyepiece. He renders his diagnosis and informsthe surgery team of the result. Then the connection isreleased and the pathologist is free to work for anothersurgery team.

In the case of frozen section service by telepathol-ogy however, the change in workflow, compared to theconventional procedure, has to be considered with re-spect to the distribution of tasks, responsibilities andliabilities. Figure 1 illustrates the workflow for frozensection diagnosis in the conventional procedure (1a)and with the application of telepathology (1b). Themain difference is, that the frozen section preparationis now made by the surgery team and no more by thepathologist.

To map the conventional procedure identically to atelepathology scenario the following requests to equip-ment and technology would be necessary:


(a)

(b)

Fig. 1. The difference in workflow in frozen section diagnosis, aconventional and applying telemicroscopy; (a) is the conventional procedure and(b) applies telepathology.


– A fully remotely operable microscope (roboticmicroscope) at the surgery site.

– An online image transmission of the microscope’sfields of view to the remote display station of thepathologist to provide the impression of a com-fortable interactive workflow with the remote mi-croscope. This is achieved with about 25 framesper second.

– A resolution and field of view of the transmittedimages according to those of section 2.1 (4000×3000 pixels/frame).

– A presentation device for the removed tissue as anoptical connection during “telepreparation”. Thisis an important component in the frozen sectionscenario with respect to the main critizism to theintroduction of such a service: the preparation ofthe frozen section slide is made by the surgeryteam and not by the pathologist. For the patholo-gist such a macro presentation device is presentlythe only opportunity to supervise and guide thesurgery team in the preparation procedure.

– A haptic device (robotic hand) to feel the tissuefor malignant features and for the definition of theposition of the frozen section. Additionally, a de-vice to code and transmit the haptic impressionand the positions of the robotic finger tips to theremote station of the pathologist.

– A device at the pathologists site to present thehaptic information and the finger positions ade-quately.

– A teleknife to perform the section at the remotetissue.

The complete realization of the above list would pro-vide a “tele frozen section” scenario identical to theconventional procedure.

It is obvious that equipment incorporating all theabove features will also be well suited for all othermodes of telepathology as, e.g., described in Sec-tions 2.1 and 2.2 – it would become a gold standard.

3. Technical opportunities and economicalrestrictions

Section 3 discusses already existing technical toolsto meet the requirements of Section 2. The three pro-totypic applications will be discussed with respect tothree main considerations:

– Technical components and systems available tomeet the requirements.

– Economical considerations for the selection of al-ternatives.

– Technology applied in today’s equipment on themarket.

Table 1 outlines a list of key components for thethree telepathology system types. Also a rough esti-mation of the availability and affordability is includedin the table. The estimation is subdivided into 5 cate-gories:

+ Components in principle available, but makeno sense at the moment due to affordability orother reasons; compromises or suboptimal so-lutions should be accepted.

++ Components available and economically ac-ceptable.

- Solution at the moment not available, but de-velopments are in progress.

- - Solutions not known, and also not visible forthe near future.

nr Not relevant.

The remaining part of Section 3 will discuss pres-ently existing solutions for components of Table 1 inmore detail with respect to the technical limit, the eco-nomical feasibility and the actually implemented so-lutions in telepathology equipment of the three types.Due to space limitations, only the most challenging

Table 1

Key components of telepathology systems, their availability andaffordability

Component Teleeducation Expert Telediagnosis

advice

Microscopes ++ ++ ++

Microscope stages nr nr ++

Cameras ++ ++ +(-)

Display screens -(+) -(+) -(+)

Host computer equipment ++ ++ ++

Archiving and memory

capacity ++ ++ ++

Haptic equipment (artificial

hand and feeling sensor) nr nr -(+)

Haptic “display” nr nr - -

Teleknife nr nr +

Telecommunication

channels ++ ++ +

System software ++ ++ ++

Telepathology software ++ ++ +++, in principle available; ++, available and affordable; -, not avail-able but development in progress; - -, no solution yet known, nr, notrelevant.


components are discussed, all other components arewithout problems, available off the shelf and wellsuited for telepathology applications.

3.1. Cameras

The camera is the first member of the image trans-mission chain: camera – telecommunication link – dis-play device. It determines together with the other mem-bers the quality and therefore also the aptitude fortelepathology. As already mentioned in Section 2, thefield of view and the resolution of modern microscopesand that of diapositives determine the gold standardfor a telepathology scenario, which is fully compati-ble with the conventional procedure in education anddiagnosis. Expert advice telepathology makes an ex-ception, as this mode had no equivalent with a con-ventional procedure and the quality of TV-images wasaccepted from the beginning. Therefore the requeststo expert advice telepathology are satisfied with highquality TV-color cameras of the 3-chip-type. Only re-cently it was suggested to use cameras with higher re-solution and field of view. The aim of these effortsis to reach the xsame resolution and field of viewthat modern computer screens (about 1600× 1200 pi-xels/image) provide.

The other modes teleeducation and telediagnosis,however, orient themselves at the microscope and thediapositive resolution and end up at 4000× 3000pixels/frame. For images with such pixel resolutions,

today’s camera technology offers several opportuni-ties:

(1) Cameras with sensor chips of such a resolutionand field of view. Upper end electronic photo camerasmeet these requirements. These cameras can thereforedirectly replace the diapositive photocamera on the mi-croscope, because their sensor has also about the for-mat of a diapositive and because these sensors are em-bedded in standard photo camera cases. A critical pointfor the user is to know, to which degree the images atthe output interface of the camera are not only com-pressed but potentially also reduced in the informationcontent. Such reduction procedures are applied oftento save memory capacity! In our application the full in-formation should be available at the camera–computerinterface.

Another point to be regarded is the handling of thecolor information. Only 3-chip cameras or sequentialcolor filtering of 1-chip cameras provide RGB-dataof the identical object location. Masks in front of thesensors with color patterns (RGB or ComplementaryColor Mosaic) provide a reduced spatial color resolu-tion. Figure 2 illustrates the main concepts of color rep-resentation for cameras used presently.

The grey value resolution (contrast) corresponds tothat of the color diapositives 1 : 256 (256 grey levels)and is determined by the signal to noise ratio (SNR)of the CCD-pixels. The contrast may be increased bycooling the sensor or by applying averaging to improvethe SNR.

Fig. 2. The main concepts presently used to represent colors in electronic cameras. Top panel: 3-chip-RGB representation (corresponds to thesequential acquisition of three color images), middle panel: RGB color mosaic mask, bottom panel: complementary color mosaic.


Other technologies with even higher spatial resolu-tions are scanning line cameras, in which one coordi-nate direction is scanned with a scanning mirror.

The new upcoming CMOS-sensor technology withits attractive opportunities to integrate image prepro-cessing steps on the sensor chip to realize, e.g., non-linear characteristics and to realize contrast figures be-yond 1 : 100 000 are announced by the Foveon Com-pany in the year 2000, but not yet on the market forcapacities larger than 1024× 1024 pixels/frame [9].These cameras are interfaced to the computer via spe-cial digital interfaces, new versions will use the stan-dard USB (Universal Serial Bus).

(2) Sensor-Shift-Technology cameras. This technol-ogy applies conventional TV-CCD sensors with re-duced fill-factors of the light sensitive area. Betweena series of sequentially acquired images the completesensor chip is moved within subpixel distances and atthe end of the image acquisition procedure all subim-ages are combined (see Fig. 3 for illustration).

Applying normal TV-CCD-sensor chips with 768×576 pixels/frame and a reduction of the sensitive pixelaperture to 1/5 of the pixel distance, the combinationof 25 subimages results in a combinatorical image ofabout 4000× 3000 pixels/frame. Representatives ofthis camera type are the ProGes camera from Jenop-tik, Jena, the AxioCam from Carl Zeiss, Oberkochem,and the Nikon DXM 1200, Nikon, Tokyo. The princi-ple and the system theoretical aspects of which havebeen published by Lenz [7]. Color is introduced by acolor mask in front of the sensor chip. The drawbackof this technology is a reduced light sensitivity due tothe low fill-factor and a relative long image acquisitiontime due to the necessity to get a series of images forone result image.

Fig. 3. The shift-chip technology to achieve high resolution withstandard TV-technology sensors.

(3) The tiling of images. Histological slides arestatic objects and can therefore be scanned as subim-ages (tiles), which later can be combined appropriatelyto one single large image. This technique can be per-formed with the standard TV-cameras acquiring TV-images with 768×576 pixels/frame. After acquiring animage the scanning stage of the microscope is movedby one image distance. To get a perfect fit at the tileborders either the scanning stage has to be moved withpixel accuracy or overlapping image tiles must be col-lected, which are then fused to the combination image[11]. With this technology in principle any dimensionof images can be achieved.

In conclusion: there are several technologies avail-able to collect images with the characteristics of dia-positives as far as the image format and resolution isconcerned.

For online telediagnosis additional to the image for-mat the frame rate is an important key feature. As al-ready stated, the gold standard for an online transmis-sion would be the video frame rate – 25 frames/sec – toprovide a comfortable impression for moving objects.

All high resolution cameras mentioned above do notmeet the online requirement. For the digital photo cam-eras we find normally a transfer interval of several sec-onds between two full frame images. The product fam-ily for online image acquisition is not the digital photoline but the video camera sector. For online video ap-plications we find here presently video cameras forHDTV applications. High quality 3-chip CCD videocameras for full resolution RGB-signals are on themarket with about 1600× 1200 pixels/frame and 25frames/sec. This technology is below our gold standardfor lateral resolution but fits to the data of modern highresolution computer monitors (see also Section 3.2).We will see later (Section 3.6) that even this format willrequire transmission capacities not affordable today.

The question is, which of the solutions are ac-ceptable and affordable for the different telepathol-ogy modes. For teleeducation and expert advice, on-line capabilities are not relevant and only the resolu-tion must be regarded. The extremely high resolutioncameras with 6000× 4000 pixels are very expensive(>20 000€) and therefore only affordable for a fewapplications but not for making slides in pathology.The shift-chip cameras also cost about 10 000€ andcome near to High Density TV-oriented cameras as,e.g., the JVC type KYF-70 from the Victor Company,Tokyo (1360×1024pixels). The cheapest solution pro-vides the tiling of large images, if there are no otherreasons not to use this technique. But remember for a


tiling without image fusion at the image borders, highprecision scanning tables must be installed.

As most of the systems used in education have beendesigned by the users themselves, who are normallynot willing to invest too much labor in design and con-struction of systems, which would also fit the necessi-ties of a broader market, we find only a few commer-cial systems on the market today, fulfilling the slidequality request. In most cases the users restrict them-selves to the application of the normal TV-camera re-solution. There is a tendency today to use digital photocameras as they become more and more introduced inthe consumer market with decreasing costs and risingquality.

For telediagnosis, due to the limited capacity ofthe transmission channels, exclusively 3-chip CCDTV-format cameras are implemented (about 5 000€).Only for in-house applications with own broadbandTV-networks HDTV cameras make sense.

3.2. Display devices

The counterpart to the camera equipment is the im-age display facility at the location of the remote part-ner. Presently two technologies are commonly used:

– The conventional tube monitors;– LCD monitors (Liquid Crystal Display).

Other technologies are found only in niche applica-tions:

– Plasma display screens;– LED-screens;– Video beamers for a greater audience;– Laser scanner displays.

For the well known and long introduced tube tech-nology we find today resolutions until 2000 pix-els/line and for LCD displays the limit presently isat 1600 pixels/line. Both types allow frame rates be-yond 25 frames/sec but do not meet the request for4000× 3000 pixels/frame; they are however compati-ble with the HDTV camera format. Both technologiesoperate with a contrast ratio beyond 1 : 100, which isadequate for 8-bit data.

Presently the image quality of tube displays for nat-ural image scenes is regarded still better concerning theviewing angle and the linearity of the intensity. On theother side LCD displays have a tremendous advantagewith respect to geometrical distortions, weight, dimen-sions and power consumption.

Image dimensions beyond those mentioned abovecan be realized with laser scanning monitors and, asthe counterpart of the tiling technology at the acquisi-tion site, by the presentation of the image simultane-ously on several monitors side by side. Unfortunatelythe borders of tiles stay visible.

Due to the limited potential to reduce further the sizeof the image pixels on the screens, an adequate dis-tance of the observer to the screen is mandatory, not tosee artifacts from the screen structure, a recommenda-tion, which is often violated.

3.3. Haptic equipment

This and the next two sections are only relevant fortelediagnosis and especially for the frozen section sce-nario. Until now the haptic information, which is im-portant to locate the section in a tissue correctly, isthe only information which is presently not transmit-ted with telepathology equipment to the remote pathol-ogist. This fact is the main reason for hesitations tointroduce telepathology services on a broader basis.Presently, the surgeon is responsible to determine thelocation for the section. He may be guided by the re-mote pathologist in this task with a telecursor in themacro-image of the removed tissue in the “presen-ter”, a module, which is offered by most of moderntelepathology systems.

We find surgeons in a similar situation, when theyswitch from conventional surgery to minimal invasivesurgery – they also miss the direct haptic contact tothe tissue they operate on. It is therefore also a ba-sic concern of surgeons to get a tool for “telefeeling”.Another stimulation to develop such instrumentationcomes from the industry, when robots have to workwith delicate objects in for humans hazardous environ-ments.

Having in mind these other applications, the “tele-feeling” aspect becomes much less futuristic, as thepressure to promote this field is strong enough to pushsuch developments.

Today prototypes of artificial hands with the samekinematics and geometry as the human hand alreadyexist [13]. Such devices grab objects in a similar man-ner as humans do. Figure 4 illustrates such a device.Presentations to grab a raw egg look very promising.The way to market for such devices should not be toolong from now.

Quite different is the situation for the sensory partof such a module, where not only forces have to betransmitted but feelings as, e.g., surface characteristics


Fig. 4. Example for a prototype of an artificial human hand (by courtesy of S. Schulz, Forschungszentrum Karlsruhe).

like: rough, smooth, dry, soapy, etc. In this case weare by far more away from solutions for technical sen-sors with similar qualities as human fingers, than in thekinematics model.

The necessity for haptic equipment is discussed con-troversially in different circles of pathologists. Onefraction asks for such equipment to keep the frozensection procedure under the full control of the pathol-ogist, and the other fraction agrees to delegate the taskto the surgery team under visual control of the patho-logist.

3.4. Haptic displays

The counterparts of the haptic actors and sensors arethe corresponding tools at the remote site as an inter-face to the human hand. Like stated above some ac-ceptable solutions for the kinematics capabilities of thehand using a force feedback exist (manipulators, elec-tronic gloves) and are applied in handling machines forhot cells in nuclear fuel plants. They allow an excel-

lent handling of bottles, tools, etc. and allow the re-mote classification of hard and soft objects. But in totalthey are far from the more complexcapabilities of thehuman hand. The technology is applied in telesurgeryand the related minimal invasive surgery.

Nearly no solutions exist to the authors knowledgeto reestablish feelings as indicated in 3.3 by a mecha-nical presentation device to the human skin of the fin-gers. What is known is a solution for blind people tofeel letters or symbols acquired by a camera and trans-formed into a topologic object by an array of small dif-ferently vibrating pins.

3.5. Teleknife

To allow the remote pathologist to make the frozensection cut of the tissue, he needs a tool calledteleknife. As already indicated in Sections 3.3 and 3.4solutions exist and are in operation in robotics and intelesurgery. Under visual control the comfort of thesetools is acceptable.


3.6. Telecommunication channels

The characteristics of the telecommunication chan-nel determine to a high degree the operational comfortof a telepathology system. This is obvious for all onlineservices, but also influences expert advice and teleedu-cation services. To get an impression of the scale of in-formation content and the corresponding intervals fordata transmission, we regard 3 mile stones:

– Assuming our ideal image format of 12 Mbytes/image and an online frame rate of 25 images/s, weend up with a data flow rate of 2.4 Gbit/s!

– Assuming only a color TV-image format of 768×576 pixels and a ISDN telephone line with 64kbit/s, the transmission time for one frame con-sumes about 2.7 min.

– Telecommunication service providers charge cus-tomers with respect to several criteria:

∗ Amount of data transmitted;∗ Connection time and connection distance;∗ Channel capacity requested;∗ Quality of service requested (e.g., online or

offline connection).

From a technical point of view 2.4 Gbit/s are stateof the art and are easily transmitted by modern glassfiber connections. The bad news are that 2.4 Gbit/s cor-respond to about 37 000 telephone channels with thecorresponding fees, which become really unaffordableif requested from public service providers. The situa-tion may be much more favorable, if glassfiber linesare available within an institution.

Economically realistic concepts will therefore haveto consider limitations in the data transmission capa-city. Another limitation will be the restriction to ser-vices, which are available everywhere and also usedfor different purposes than telepathology. In principlewe have to restrict to following services:

– Analog telephone (ca. 3.5 kHz bandwidth).– ISDN lines with 2× 64 kbit/s.– ATM connections (rarely available for end users).– UMTS mobile phones with 2 Mbit/s (a new, not

yet available but coming network).– Internet connections (normally limited by the ser-

vice provider to the telephone channel capacity).– xDSL services from ISDN-data rate to about

1 000 kbit/s download bandwidth, but the connec-tions are asymmetric: download is normally about5 times faster than upload.

– In-house connections.

For expert advice telepathology the data rate andthe online capacity are of minor interest as store andforward operation is performed. For these servicesthe cheap Internet is the preferred network. The sameholds for teleeducation services, if images are retrievedfrom remote data bases in advance of a presentation. Ifthey are retrieved from a remote database online dur-ing a presentation, delay times of more than 5–10 s be-come unacceptable. As indicated above telephone linesare too slow for this application.

For online telediagnosis in frozen section scenariosn × ISDN connections (n = 6–10) are the most ap-propriate selection today, which may be replaced in thenear future by the upcoming UMTS device generation.This is a reasonable compromise between comfort andaffordability. To reach a sufficient speed in telediag-nosis workflow considerable efforts are necessary tomanage the data flow appropriately. The most impor-tant procedures to reduce the data flow and a rough es-timation of the data reduction effect are listed below:

– Reduction of the image format from a diapositiveto a color TV-frame format: 50×;

– Data compression without visible loss: 5×;– Reduction of frame rate: 3×;– Transmission of only novel image details: 10×;– Introduction of local intelligence, e.g., for autofo-

cus, autoillumination: 3×;– Permanent slide overview image for orientation:

3×.

Accumulating the performances of the procedurescited, we get a data reduction of about 70 000×. Ap-plying this reduction to the 2.4 Gbit/s data flow, resultsin a reduced data flow of under 0.5 Mbit/s. This meetsabout the capacity of 8 bundled 64 kbit/s ISDN chan-nels. Data reduction procedures are discussed in thesoftware Section 3.7.

Another aspect of the data transmission channel isdata security and data confidentiality. These functionsmay be part of the network or may be part of the systemsoftware. Network providers offer solutions based onintranets requesting identification as well as authentifi-cation for the access to the net. Cheap but not very se-cure means are simple passwords, better solutions relyon chipcards and keys of certified trust centers for en-cryption.

In conclusion: The state of technology imposes norestrictions to the data flow requested. Limitations re-sult from economic reasons. The limited data rates can-not provide the workflow speed of conventional frozensection services but they provide an acceptable level,


offering a routine application even in the most chal-lenging telepathology mode – the online frozen sectionservice.

3.7. Telepathology software

The telepathology software integrates computerequipment and peripheral devices into a telepathologytool. It determines the quality and the comfort of atelepathology application.

As already indicated in the introduction, teleeduca-tion and expert advice telepathology are present witha wide spectrum of software with different degrees ofquality and operating comfort. Commercial softwarefor these applications meets requirements concerningsafety of operation and adaptation to the workflow inthese fields. Compared to hardware investments in ad-dition to already present equipment, these softwaremodules are expensive and therefore often self writtenmodules are applied between two users.

Quite different is the situation in telediagnosis. Inthis case the investment for new equipment is high(computer controlled microscope, camera, framegrab-ber, network modules, etc.) and the software neces-sary to operate adequately such equipment is com-plex. Telediagnosis is therefore dominated by certi-fied commercial software systems. All manufacturersof equipment provide their own software, but neverthe-less some basic modules more or less common to mostsystems can be identified:

– System software integrating and supervising allhard- and software modules.

– The user interface, which provides the tools tooperate the system and which displays image andother information in an adequate manner to theuser.

– The data management module is responsible foradequate data reduction, transmission and presen-tation.

– The documentation and archiving module meetsrequirements of legal necessities and exchange ofcase oriented patient folders.

– Macrofacilities provide means for the pathologistto guide the surgery team during the frozen sec-tion procedure.

– Teleconference modules improve telepresence du-ring sessions.

– In future, image evaluation tools and expert sys-tem modules will further improve the diagnosticprocedure.

Good software concepts allow with acceptable ef-forts the adaptation to new applications and workflowsin telemedicine.

4. HISTKOM as an example for an advancedtelediagnosis system

A collection of examples documenting the state ofthe art of today’s telepathology technology and ap-plications in general may be found in [6]. Telepatho-logy systems on the market iclude CORABI fromApollo Systems, USA, HISTKOM from the DeutscheTelekom AG, Germany, MIGRA from Olympus, To-kyo, Japan, TPS from Leica Microsystems, Germany,the Zeiss LINK from Tripath Imaging+ Carl Zeiss,Germany, or ZEM from Nikon, Japan. his sectionpresents representative also for other developments[21] of telemicroscopy equipment an overview of theHISTKOM [5] telepathology system for telediagno-sis. The key design criteria are similar, and can be de-scribed for the HISTKOM system as followshave been:

– The system must be able to perform all modes oftelepathology, especially online frozen section di-agnosis.

– The device must meet legal necessities as docu-mentation of sessions, safety and confidentialityof data.

– The system must rely on networks everywhereavailable and affordable.

To keep this section short, the functional descriptionof the system is condensed in the agenda of Fig. 7 forthe user interface and Fig. 5 presents the equipmentin the surgery department, the microscope station. Fig-ure 6 illustrates the equipment at the pathologists site,the display station.

The functionality of the HISTKOM equipment hasbeen evaluated in more than 10 fieldtests. These field-tests were designed to test the diagnostic quality withretrospective representative embedded and frozen sec-tion material, in routine online clinical frozen sectionoperation and in tests for telecytology (PAP-smears).

5. Future development

From today’s point of view it is difficult, if not im-possible at all, to make reliable prognostications forthe future development of telepathology and its equip-ment. With some assumptions nevertheless at least


Fig. 5. HISTKOM microscope station with the remotely controllable microscope with scanning table and color TV-camera, the macro deviceto present the removed tissue before section and to guide the surgery team in frozen section preparation; The host computer; the two monitorsdisplay the user interface and the field of view of the microscope; the monitors display identical information as those at the pathology displaystation and are used also in conference mode.

Fig. 6. The remote display station in the pathologists lab consists of 2 monitors displaying the identical information as on the surgery site, thehost computer and a joy stick to operate alternatively to the mouse the scanning table.

some general considerations can be made. Importantaspects identified already, which will influence the fu-ture development, will comprise different fields:

(1) The acceptance by and the requests of the com-munity of tentative users of telepathology ser-vices.

(2) The alterations in routine workflow and the legalaspects derived from it.

(3) The tradeoff between requested type and qua-lity of telepathology equipment and the costs ac-cepted for equipment and fees.

(4) The development of the component market fortelepathology equipment and of the market oftelecommunication services.

(5) The progress of equipment and service qualitydue to mutual influences resulting out of opera-tional telepathology services.


Fig. 7. The user interface in detail with the description of the functionality. Out of the complete functionality a subset is listed below using thelabels in the image. 1: Large overview of the total slide in high quality and resolution. 2: Window indicating the position and the scale of theactual microscope field of view displayed on the other screen. 3: Overview of positions of all screen shots of key scenes made and archivedin the investigation protocol during the diagnostic session. 4: Buttons to select the objectives respectively the magnification of the microscope.5: Control to set the microscope illumination. 8: Buttons to call other image material (e.g., US-imagery) of the patient folder or of anothercamera (e.g., video conference camera) on the screen. 9: Field displays information of presently active functions on the remote microscope andtheir status (e.g., busy (wait) or ready to accept new instructions). This field also accepts and displays text as patient information, diagnoses andrecommendations. 10: Button to request an autofocus procedure on the microscope. 11: Interactive control of the focus position (e.g., for focusingthrough a nucleus). 12: Button to request a zoom activity at the microscope (change of objective by one step and request of an autofocus activity).

Future development considerations will be discussedin the following according to the list above, but will notrepeat considerations already made in Section 3.

5.1. The acceptance of telepathology by an interestedcommunity of users

Today two motivations with completely different in-tentions to apply telepathology are found:

– An exchange of experience between pathologists,who know each other well. Expert advice consul-tation and store and forward technology are the

characteristics of this type of telepathology. Theprocedure normally is not included in a normalroutine workflow.

– The other motivation results from a request ofnon-pathologists for services in pathology. Theservice asked for is telediagnosis including itsmost challenging mode of online frozen sectionservices for institutions without an own patho-logist. The initiative for this applications oftencomes from surgery teams and hospital adminis-trations and not from pathologists.The service is intended for the routine daily work-flow of patient treatment and therefore contains


considerable economical aspects. Such servicescan only be operated with certified professionalequipment, a high quality of service and the ac-ceptance of the corresponding costs.

The motivation for the second type of telepathology(telediagnosis) will promote the development of net-works with participants requesting and participants of-fering services in pathology or probably even all typesof services in telemedicine. Figure 8 illustrates this sit-uation.

Such networks, one day when they exist, will alsohost the expert advice and continuing education ser-vices but with professional and standardized hard- andsoftware to maintain interoperability between all part-ners in the network. In the very beginning, islands willform as is the case today, but if a critical number ofparticipants and telepathology applications exist, theseislands will condense to more general telepathology ortelemedicine networks. They will provide an electronicmarket place for telemedicine services and documents

(e.g., electronic patient folders of investigations, ac-counting documents, protocols of remotely performedevaluations of image material, etc.), which allows thefull exploitation of the opportunities of telemedicine.

An example to test the acceptance of a routinetelepathology service is the EUROQUANT serviceserver of the University of Dresden, which has been de-veloped by financial support of the EUROPATH Euro-pean Union, project (DG XIII-Project HC 1038). EU-ROQUANT is a subproject within the EUROPATH.This service provides clients, which send in imagesof Feulgen stained cells of cytological imprints, withDNA histograms and their interpretations includingquality check of the material sent. It is an example ofa new upcoming service interpreting remotely imageswith image processing tools. The service is one of theoutcomes of the EUROPATH project of the EU.

The tendency to start professional telemedicine net-works becomes already visible by several start-upcompanies which offer today at least a limited amount

Fig. 8. Future telemedicine networks which will also host telepathology services.


of service content in their networks, for example, in theDGN (Deutsches Gesundheitsnetz, Bostonnetwork, orthe Global Health Care by the Deutsche Telekom AG.The first task for such networks is to overcome themissing interoperability of today’s equipment of dif-ferent manufacturers. It is by far too late to start a for-mal standardization, to which all manufacturers shouldcomply, because a lot of telepathology equipment is al-ready on the market. A solution to overcome the sit-uation will be to develop interfaces between propri-etary software and protocols on the one side and gener-ally accepted standards, which already exist like Web-software and protocols, on the other side of the soft-ware interface. Candidates for such standards may be:

– Image formats (DICOM, Tiff, PDF, GIF, etc.);– Platform independent software (JAVA, JAVA ap-

plets);– Internet protocols (TCP/IP, Email, FTP, etc.);– Net interfaces for ISDN, UMTS, Phone, XDSL,

Encryption, etc.

The application of components off the shelf reducesthe costs for equipment and promotes at least a qua-sistandardization. Finally there is no doubt that com-ing telepathology and telemedicine networks will crossnational borders at the earliest convenient opportunity

5.2. Legal aspects of telepathology

The legal aspects of telepathology have been dis-cussed since 1992 [1,12] and are, in addition, compiledin another contribution of thisACPissue [1,12] and aretherefore beyond the present contribution with the ex-ception of the influences of legal aspects on the deve-lopment of telepathology equipment. For designers anddevelopers of telepathology equipment some consider-ations of the outcome of the discussions of the legalnecessities will be of importance:

Quality, security and safety aspects for equipment:If telepathology equipment becomes operational, inwhich not each participant is fully informed on all de-tails of the equipment of his partners in a network, hehas to rely on a warranty of a minimum standard onthe other side of his connection. This is with respect tospecimen quality, image quality, transmission and dis-play quality. Means to meet such requirements couldbe annotation information for the data similar to theDICOM standard in radiology, where images are ac-companied by detailed data of the image generationprocedure.

New features and developments in telepathologymay be initiated by legal recommendations. A candi-date could be in the frozen section service telepathol-ogy the introduction of haptic sensors and actors – thevirtual hand with the virtual telefeeling.

5.3. What is necessary and what is affordable intelepathology equipment?

Like in other fields the requirements to telepathol-ogy equipment are limited on one side by the state ofthe art in technology and on the other side by the esti-mation of the potential users of the affordability of thenew technology. In the case of telepathology this willbe with respect to the components of the equipment,software, maintenance and fees for telecommunicationchannels.

Equipment of the store and forward type (expert ad-vice) as well as for teleeducation will rely on alreadyexisting microscope, camera and computer equipment;a potential for innovations will be well adapted soft-ware.

In telepathology for telediagnosis the communityof pathologists more or less unison prefers telemi-croscopy to maintain both diagnosis steps: searchingfor relevant areas in a slide and the diagnosis of foundrelevant objects.

Components for telemicroscopy add up today toabout 50 000–70000€. These costs can only be jus-tified if the telepathology application is included intoa routine workflow, generating a corresponding cash-flow in the pathology department by serving additio-nally customers, in the surgery department by savingexpensive time of the surgery team or in the hospi-tal administration with an increased throughput of pa-tients.

Another consideration for the future acceptance ofequipment in daily routine in medicine is the easy (foolproof) operability of a service, because most users areconcentrated on the medical problems and not on themachine operation.

5.4. Market for future components andtelecommunication services for telepathology

Telepathology equipment manufacturers and admin-istrators of telemedicine networks will rely more andmore on already existing and especially already ac-cepted and introduced solutions off the shelf. As mostof these components have been or are developed notexplicitely for the telepathology market, telepathology


with its only minor economical volume will not influ-ence the technical features of these components. Thecomponents will develop according to guidelines ofother market segments.

Only components whose market success dependsalso on telepathology will be influenced by requestsfrom the telepathology community. Examples of thistype may be the computer controllable microscopes,scanning stages, telehaptic instruments and teleknifes(if the last two at all are requested by pathologists!).Strong influences however will concern the telepathol-ogy software with the user interface and the library offunctionality.

Nevertheless some assumptions concerning the fu-ture development of key components of telepathologyequipment can be made today:

Microscopes. For store and forward telepathology(expert advice) the standard microscope of the pathol-ogist on his desk will be applied also in future; the de-sign of this microscope will reflect the requests of rou-tine pathology. For telemicroscopy presently all inter-national microscope manufacturers offer devices fromthe upper end of universal microscopes incorporatingall modes of microscopy. These instruments includefunctionality and universality far beyond the necessi-ties of pathology. They are therefore very expensiveand cover the main part of equipment costs. From mostmicroscope companies below this level by far less ex-pensive microscopes are offered, which miss just oneor the other function necessary for full telemicroscopy.It can be assumed that once the number of telepathol-ogy systems ordered reaches a distinct limit, thesecompanies will upgrade these microscopes to the fullfunctionality for telemicroscopy to penetrate the mar-ket. Efforts to standardize the computer interface tothe microscopes (VMI – Virtual Microscope Interface)[14] will promote the installation of computer control-lable equipment.

Scanning stages.Telemicroscopy equipment installspresently scanning stages of the upper end to ensurebea good positioning and repositioning quality and toavoid artifacts at the border of composite images fromtiles. As in the microscope case these universal devicesare overdesigned for telepathology. Therefore also inthis case by far less expensive scanning stages with re-duced universality will appear on the market once itsvolume reaches a lower limit. An alternative would beto use inexpensive and more inaccurate stages and tocompensate the handicaps (coarser steps, limited posi-tioning accuracy) with more intelligent but also moreexpensive software like substep border fitting of tiles.

Electronic cameras. The development of electroniccameras is currently driven by two markets: TV-relatedonline video cameras with high frame rates and on theother side digital photo cameras with high pixel num-bers.

For store and forward applications with no video as-pects, the second type is the best selection, because in-expensive digital photo cameras with very high reso-lutions are already on the market and fit like a normaldiapositive camera onto the microscopes. Presentlycameras with 4 megapixels are state of the art as,e.g., Megaplus ES:4.0 from Roper Scientific BV, Via-nen, The Netherlands; cameras with 16 megapixelsenter the market, for example the 4096× 4096 pix-els CMOS-chip type KAF-16801 from Foveon Inc.California, USA, or the MegaPlus 16.80i from RoperScientific BV, Vianen, The Netherlands.

In future telemicroscopy will rely also on the TV-related camera technology. As pathologists requesthigh quality images, cameras of the 3-chip type areadequate, as each pixel represents all three colors.Presently the 3-chip cameras for normal TV-frames(e.g., 768× 576 pixels TV 3-chip cameras (the DCX930P from Sony, Tokyo, Japan)) are state of the art, butalso cameras with higher resolutions but still maintain-ing video frequency or near-video frame rates are al-ready on the market (KYF-70 from Victor Company,Tokyo, Japan). They fit and exploit the present reso-lution of good computer monitors with 1600× 1200pixels.

Completely new image sensor concepts are inves-tigated and promise also realization in a near future.They rely on semiconductor technology with electron-ically controllable spectral sensitivity [10]. These sen-sors will exhibit the advantages of 3-chip cameras(ideal registration of the pixels of the 3 colors) and ofthe 1-chip cameras (costs, avoidance of the dichroiticmirrors) and will be manufactured in CMOS technol-ogy with a superior contrast compared to CCD-typesensors.

Haptic instrumentation. Minimal Invasive Surgeryfosters the development of telefeeling to provide thesurgeon again with a direct haptic impression of tissue.The technology is in the state of science and still needssome more time to realize products. Devices with thekinematic features of a hand to grip objects are rela-tively good developed already [13], whereas the sen-sor part to reproduce not only the forces but also whatwe call feeling is yet in the beginning. Good ideasto present the signals of the hand and particularly thefeeling to the remote partner adequately, meaning to


provide him with a similar impression, as if he wouldtouch the object himself, are still missing.

It will be the outcome of a longer period of applica-tion of today’s telemicroscopy equipment to decide ifpathologists will request “telesensation” or if the sur-geon will overtake this part in the telepathology sce-nario.

Teleknife. Teleknife technology for the pathologist tomake the section remotely (without any telesensation)could be installed today already as the technology isavailable from telesurgery activities. Since it is a spe-cial development for surgery, the costs would be fairlyhigh at the moment, and like in the case of haptic in-strumentation only a longer period of application oftelemicroscopy can answer the question, if teleknifesshould be installed or the activity can be performed bysomebody in the surgery team adequately. The ques-tion will become more important when new prepara-tion technologies would become state of the art.

Network technology and network services.Store andforward telepathology can already be practiced withtoday’s networks without any restrictions.

The situation is quite different for telemicroscopy,as here the telecommunication channel is the bottle-neck for a comfortable working environment. Pathol-ogists ask and will ask in future for higher capacitiesto transmit online images of highest resolution and de-tail richness. From other applications will also comestimuli for broader and less expensive telecommuni-cation channels. Only the costs will determine the se-lection of the adequate telecommunication channels.Service nets in telepathology will be installed as earlyas pathologists emphasize their interest by purchasingmore telepathology systems.

Telepathology software.This paragraph considersonly telepathology dedicated software; general PC-software like operating system and periphery driversare standardized products off the shelf.

The software specifically developed for telepathol-ogy is and will in the future be the component whichis influenced by customers and will decide over suc-cess and failure of a telepathology device (see also Sec-tion 4.5).

The main challenges for software developers intelepathology can be summarized in following aims:

– Optimization of ergonomy to handle a system.– Development of intelligent strategies to handle

the limited data transmission capacity and to min-imize the consequences of it for the operator.

– Considerations of legal requirements like docu-mentation of sessions and supervising of correctsystem operation.

– Documentation of software for maintenance pur-poses.

For the three prototype applications of this paperwe find three different situations to cover the costs:In teleeducation only a small number of customers isnecessary to justify the development costs. Softwarecosts in this case can be kept low if on the clients siteonly standard browser software is requested. Then onlyfor the server site special software has to be developed.Clients can contribute to the server service by sendingcontributions (e.g., by email) to the server institution,where it will be integrated in the already existent serverenvironment for access to all other participants.

In interactive telemicroscopy the software will bethe most important part. In this application the aspectsof ergonomy, handling of the telecommunication chan-nel and in the near future special software to evalu-ate images are the most prominent. The software willinclude blocks for the remote microscope operation,slide handling, data transmission, data and image pre-sentation and finally add-on services like image pro-cessing and interpretation.

Interoperability between telemicroscopy systems ofdifferent manufacturers will become a challenging ef-fort for general telepathology networks; today only fora few blocks interoperability steps are under develop-ment [14].

5.5. Mutual influences of system properties andapplication experiences on future developments

Besides the technical improvement of componentsand of telepathology system software, mainly the mu-tual influences between existing operational systemsand experiences gained using them in daily routineworkflow, together with ideas to install new servicetypes will drive the development and the catalog of fa-cilities of next generation devices. Figure 9 may illus-trate this cycle.

Present generation equipment especially of the tele-microscopy type and the experiences gained in longeroperational periods revealed a collection of requestsand suggestions for the next generation devices for thethree prototypes:


Fig. 9. Mutual influence of existing equipment and experiences gained with it on the development of next generation devices.

5.5.1. TeleeducationMost relevant for the continuing development of this

type of telepathology will be:

– How many pathologists are interested in continu-ing education and how many students will accepttelepathology as a training tool? May telepatho-logy become a tool for quality control programsin pathology? If the interest in participation is suf-ficiently large, the next step will be to install re-levant data bases with annotated image materialand case documentation well suited for education.The format of this information has to meet a ge-neral accepted standard.

– The technology of such education networks shouldbe of the client server type. For the clients stan-dardized every where already installed softwareshould be applied as for instance Web browsersand Java applets transmitted from the server.

– On the server location sufficient efforts should beundertaken to develop new didactic concepts welladapted to telelearning. Sufficient resources mustbe planned to operate and maintain such teleedu-cation centers.

– The hard- and firmware components will comestill from the PC-market.

– Pioneers in the field already have begun to installsuch data bases for several fields in pathology,e.g., for cytology and for hematology.

5.5.2. Store and forward telepathology for expertadvice applications

In this category the impulses for the next generationof hard- and software will be influenced from the out-come of the experiences of operational equipment:

– As before, the main influence will be the accep-tance and requests for expert advice telepathology

on a sufficiently large scale. If this is the case pro-fessional and certified software for a broad rou-tine application will appear on the market.

– The hard- and firmware will consist of compo-nents from the general computer and microscopemarket.

– Experiences for the development of the next ge-neration devices will come from more or less al-ready official operational services as, e.g.,

∗ The AFIP network of the American Army.∗ The experiences of the EUROQUANT server

in Dresden for DNA histogram measurementand interpretation of cytologic cell specimens.∗ The starting network of the UICC for expert ad-

vice telepathology in oncology operated by theCharité in Berlin [2].∗ Software has to be designed to glue together

single images to case folders in a standardizedstructure adequate for the tissue involved. Alsothis software should be compatible with con-cepts of other telemedicine applications like ra-diology and hospital information systems.∗ Screening of cytological slides can be per-

formed with store and forward equipment. Fordiagnosis in this case all fields of view contain-ing cells have to be transferred. Normally (e.g.,in PAP-screening) this will lead to tremendousamounts of data and to the corresponding un-acceptable transfer times. A way out for PAP-screening is the employment of a cytotechni-cian or the installation of a prescreening ma-chine, which selects automatically diagnosticimportant cells and transfers only those to thecytopathologist.


5.5.3. TelemicroscopyTelemicroscopy requires fairly complex equipment

and software and must be designed also for the mostchallenging application in pathology, the intraopera-tional frozen section service. Therefore the develo-pers of next generation devices will be confronted withmany suggestions and requests from the users commu-nity:

– As before the acceptance and introduction oftelemicroscopy services in telepathology will pro-vide the main argument for investments in newsoftware versions. Especially the frozen sectionservice comprises a high economical potentialand will drive the field. Therefore the main in-fluences will come from recommendations of na-tional professional chambers and legal issues im-posed on the properties of future equipment fortelediagnosis. Another problem of this type is theredistribution and definition of tasks in pathology,if frozen section preparations are produced in thesurgery department without the physical presenceof a pathologist as already discussed in the begin-ning of the paper.

– Related to the point above is the question, towhich extent frozen section diagnosis serviceswill change, when they become available moreeasily at the surgeons operation theatre and whennew intraoperational diagnostic opportunities willdevelop.

– New aspects in telepathology in future may beservices providing image processing and evalu-ation facilities remotely (as, e.g., the DNA his-togram service of the Dresden group).

– What will be the effect of increasing specializa-tion in pathology? Will 2nd diagnosis become arelevant service?

– From a technical point of view, as well as from theusers, the bottleneck of data transmission rates ofaffordable telecommunication services will stay acontinuing challenge for developers.

– The item above is a key for the application oftelemicroscopy in screening cytology applica-tions. Due to huge numbers of fields of view (fullinspection of a slide with high magnification) thetime needed for routine screening, e.g., of PAP-smears is prohibitive. The way out is only the ap-plication of broadband telecommunication chan-nels or a preselection of objects of interest at theconsulting partners location as in the case of ex-pert advice devices (e.g., prescreening machines).Obviously this argument is not valid for slideswith only few cells.

– First tests for a new application of telemicroscopyin quality control of services in pathology havebeen carried out. In this test pathologists in theUK, who have to undergo a biannual test in diag-nosing test preparations in histology, were askedto make their test in a telemicroscopy environ-ment to avoid in future sending around slides witha high risk of loss and damage plus an extremelylong time to get the results. If such an applicationis accepted, this would be the entrance of telemi-croscopy in realistic teleeducation for diagnosingslides with both activities: searching for relevantevents and diagnosing the found objects.

– How big will be the pressure to form larger com-petent telepathology networks? This would in-crease the efforts to develop tools to make equip-ment and services interoperable between institu-tions and equipment manufacturers. This dependson tendencies in pathology to form small islandsof networks between cooperating colleagues onone side and to join large service networks on theother side.

– The introduction of telemicroscopy in a dailyworkflow in pathology will request immediatelytools to interface pathology to the hospital infor-mation system (HIS) and to other departments in ahospital involved in treatment of the same patientgroup.

6. Conclusions

Today’s telepathology equipment has reached a statein technology enabling an integration in routine work-flow. This holds perfectly for teleeducation and expertadvice equipment, where all requests of pathologistscan be met. In teleeducation the only problems left areadequate contents and didactic forms for large and effi-cient education programs. In expert advice telepathol-ogy, many pathologists accept even equipment belowthe state of the art.

In online telediagnosis two problems for ideal de-vices still remain: the haptic telepresence of the pathol-ogist and an increased cheap data transmission channelto further improve the online impression.

Especially in the frozen section scenario some legalquestions, which arise due to the change in workflow,have to be settled between surgeons and pathologists.

For all types of telepathology, operational equip-ment is commercially available. The near future de-cides upon the acceptance of the new tools.


After a first operational period with existing equip-ment, experiences gained in daily workflow will initi-ate the next software generation, which will run on thesame equipment.

The first generation of telepathology users also willdecide, if telepathology will be applied in the futurebetween partners or within general telemedicine net-works offering an open market for services offered andrequested in pathology.

The degree of integration of further services into theplatforms of telepathology equipment, the forming ofnetworks and the integration of pathology workstationsand telepathology devices may become an interestingdevelopment in the near future.

References

[1] C. Dierks, Legal aspects of telepathology; in the sameACPissue.

[2] M. Dietel, P. Hufnagl and T.N. Nguyen-Dobinsky, The UICCtelepathology consultation center – a global approach to im-proving consultation for pathologists in cancer diagnosis,Can-cer 89 (2000), 187–191.

[3] K. Kayser, G. Kayser and S. Zink, New technical aspects intelepathology,Elec. J. Pathol. Histol.6(3) (2000), No. 003-04.

[4] K. Kayser and G. Kayser, Basic aspects of and recent devel-opment of telepathology in Europe with specific emphasis onquality assurance,J. Anal. Quant. Cytol. Histol.21 (1999),319–328.

[5] K. Kayser, Telemedizin,Wiener Klin. Wschr.108 (1996),932–940.

[6] K. Kayser, J. Szymas and R. Weinstein,Telepathology, Elec-tronic Communication, Education and Publication in Pathol-ogy, Springer-Verlag, Berlin, Heidelberg, 1999.

[7] R. Lenz, Digitale Kamera mit CCD-Flächensensor und pro-grammierbarer Auflösung bis zu 2994× 2320 Bildpunk-ten pro Farbkanal; Informatik Fachber, in:Proc. 11. DAGM-Symposium 1989, Springer-Verlag, Hamburg, 1989.

[8] J. Leong, A. Graham, T. Gahm and J. McGee, Telepathol-ogy: Clinical utility and methodology,Recent Advances inHistopathology18 (1999).

[9] MountainViewTM , CMOS camera 1024×1024 pixel,MessTec& Automation(1 Sept. 2000), 26.

[10] T. Neidlinger, C. Harendt, J. Glöckner and M.B. Schubert,Novel device concept for voltage-bias controlled color detec-tion in amorphous silicon based CMOS cameras,Mat. Res. Soc.Symp. Proc.557(1999).

[11] H.S. Sawhney, S. Hsu and R. Kumar, Robust video mosaic-ing through topology inference and local to global alignment,in: Computer Vision – ECCV’98, Freiburg, June 1998, LectureNotes in Computer Science, Vol. 1407, Springer, pp. 103–119.

[12] M. Schiffer, Legal aspect of telepathology,Zetralbl. Pathol.138(1992), 393–394.

[13] S. Schulz, Ch. Pylatiuk and G. Bretthauer, A new class of flexi-ble fluidic actuators and their applications in medical engineer-ing, Automatisierngstechnik47(8) (1999), 390–395.

[14] P. Schwarzmann, Interoperability report (version 3.3), May1999, European Union, project EUROPATH (DG XIII-ProjectHC 1038).

Submit your manuscripts athttp://www.hindawi.com

Stem CellsInternational

Hindawi Publishing Corporationhttp://www.hindawi.com Volume 2014


MEDIATORSINFLAMMATION

of


Behavioural Neurology

EndocrinologyInternational Journal of



Disease Markers


BioMed Research International

OncologyJournal of



Oxidative Medicine and Cellular Longevity


PPAR Research

The Scientific World JournalHindawi Publishing Corporation http://www.hindawi.com Volume 2014

Immunology ResearchHindawi Publishing Corporationhttp://www.hindawi.com Volume 2014

Journal of

ObesityJournal of



Computational and Mathematical Methods in Medicine

OphthalmologyJournal of


Diabetes ResearchJournal of



Research and TreatmentAIDS


Gastroenterology Research and Practice


Parkinson’s Disease

Evidence-Based Complementary and Alternative Medicine

Volume 2014Hindawi Publishing Corporationhttp://www.hindawi.com

technical aspects of telepathology with emphasis on future...

Documents