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At least 109 records · Page 6Linked to original sources

PubMed2000

An evaluation of telemedicine in surgery: telediagnosis compared with direct diagnosis.

HYPOTHESIS: Telemedicine for real-time transmission of clinical documents and interactive remote telediagnosis allows accurate clinical application in surgery. DESIGN: Prospective cohort study in which 2 hospitals, 120 miles apart, were connected via integrated services digital network (ISDN) teleconferencing units, and each evaluated clinical cases in real time. SETTING: A tertiary care university hospital and primary care county hospital. PARTICIPANTS: Between May 1, 1998, and June 30, 1998, 112 patients undergoing digestive or endocrine surgery were evaluated by teletransmission (study group) and direct vision (control group). Diagnosis had to be known by the viewer, and either conventional magnetic resonance imaging or computed tomographic scans were available. MAIN OUTCOME MEASURES: Picture quality, organ structure, and pathologic finding viewed on telemedicine documents were evaluated by radiologists and surgeons blind to diagnosis. Accuracy of remote 128-kilobit (kb)/s transmission-rate diagnoses and results were compared with those obtained directly. RESULTS: Picture quality was "good" or "excellent" in 92.9% of transmitted documents and 95.5% of live images (P>.4). The target organ was always recognized, structure and pathologic finding were analyzable in 98.2% of transmitted documents and 99.1% of live documents, and fine structures were assessable in 89.3% of transmitted pictures and 95.5% of live pictures (P>.05). Diagnosis was made in 84.8% of transmitted cases and 93.8% of live cases (P = .02). CONCLUSIONS: Low bandwidth (128 kb/s) telemedicine application in surgery is reliable in evaluating remote cases. Loss of image quality through teletransmission occurred in 2.7% of cases, and diagnosis was not possible in 15.2% of transmitted vs 6.2% of live cases, suggesting factors other than technical quality (choice of radiological studies, additional clinical information required, etc). This underscores the importance of real-time interactive discussion during surgical teleconferences.

Cohort Studies↗

PubMed1995

Telepathology: frozen section diagnosis at a distance.

Telepathology may be used to provide a frozen section service to hospitals without a department or institute of pathology. We have developed a telepathology system using the commercially available Integrated Services Digital Network (ISDN). The main software and hardware elements of our system are: Apple Macintosh workstations, a program for simultaneous transfer of image, voice and data, and a data bank for storage of patients' data and microscopic images. A picture instrument manager (PIM) makes remote control of microscopes or other instruments possible. The system connects the Department of Pathology of the University of Basel with the Regional Hospital of Samedan, 250 km away, and the Regional Hospital of Burgdorf, 100 km away. During a period of 20 months, frozen sections with the hospitals in Samedan and Burgdorf were performed in 53 patients. Between 54 and 58 s were required for the transfer of a diagnostic 8-bit grey level image containing 341 +/- 26.1 (standard error) kbytes (n = 13) or a diagnostic 24-bit colour image containing 165 +/- 16.9 kbytes (n = 40). Frozen section diagnosis was completed in 20-40 min. True-positive diagnoses of malignant tumours were achieved in 85.7% of cases (sensitivity = 0.857). No false-positive diagnosis was made. In 3 of the 53 cases telepathological diagnosis was not possible for technical reasons.

Frozen Sections↗

PubMed1997

Picture archive and communication systems implementation in a community medicine practice.

In order to gain experience with vendor-supplied picture archive and communication system (PACS) products, a Vantage PACS from Lockheed-Martin was installed in a Mayo community medicine practice in Rochester. This practice produces about 45,000 radiology examinations annually. The PACS includes central long- and short-term storage devices, 10 image display workstations, and a dedicated high-speed image distribution network. Digital images are produced using two Fuji computed radiography readers. Custom worklists were created to facilitate efficient system usage. Currently, all radiographic examinations for this practice are acquired digitally, and interpreted and distributed using the PACS. Remote softcopy interpretation via PACS has decreased the turnaround time for both routine and urgent examinations, and has allowed subspecialty interpretation or consultation for pediatric examinations. These results have significantly improved the radiology component of this community medicine practice.

Community Health Centers↗

PubMed2000

[Telemedicine in otorhinolaryngology. Basic principles and possible applications].

Telemedicine includes all medical activities involved in diagnosis, therapeutics or social medicine undertaken by an electronic transfer medium. This technique requires the transmission of visual and acoustic information over long distances and does not require the specialist to be personally present at the requested consultation. In the last few years, the digital data transmission, e.g., ISDN (ISDN (Integrated Service Digital Network), has become available and has facilitated the use of telecommunication. Recently, the real-time transmission of acoustic and visual signals will be improved by use of asynchronous transfer mode (ATM). Advanced telecommunication applications in minimally invasive ENT surgery are experimental in most cases. We can distinguish three different telesurgical developments: surgical teleconsultation, surgical teleassistance, and surgical telemanipulation. The different applications and transmission media are explained and discussed.

Forecasting↗

PubMed2001

Teleeducation in surgery: European Institute for Telesurgery experience.

The information age is revolutionizing the practice and education of surgery. The use of video-conference systems through Integrated Service Digital Network (ISDN) teletransmission connects surgeons around the world without the limits of distance. Teleeducation, teleteaching, teletraining, telementoring, and teleaccreditation have been clearly demonstrated and are now common practice. Pre- and perioperative surgical advice may be obtained from expert networks. Patient data can be reconstructed as virtual tridimensional images analyzed by computers, and the surgical procedure can be simulated to obtain an optimal surgical decision. Finally, the use of the Internet will provide access to this information, whenever and wherever necessary, through dedicated websites. It remains to be adequately demonstrated that these means will allow improvement in patient care.

Computer Simulation↗

PubMed1998

Is image selection a useful strategy to decrease the transmission time in teleradiology? A study using 100 emergency cranial CTs.

This study examines the suitability of working with a selection of images in a teleradiology consulting system in neurological or neurosurgical emergency situations. The teleradiology system was based on IBM-compatible personal computers, video digitization for data acquisition, and data transmission by Integrated System Digital Network. Forty normal and 60 abnormal emergency cranial computed tomograms were shown to a radiologist on call who presented all cases he regarded as pathologic to a neuroradiologic expert by teleradiology. To reduce transmission time, only a selection of images from the CT study was presented (up to four images per case). For each case the on-call radiologist's diagnosis (D(on-call)), the expert's diagnosis on the teleradiology screen (D(monitor)), and the expert's diagnosis on the original film (D(original)) was documented, together with an estimation of the agreement between those diagnoses. There was clinically relevant disagreement between the on-call radiologist's diagnosis and the neuroradiologist's diagnosis based on the image selection on the teleradiology monitor in 23% of cases. A clinically important discrepancy between the neuroradiologist's diagnosis based on the image selection and his diagnosis using the original films was found in 30% of cases. This was due to the presence of clinically relevant information on images not transferred by the on-call radiologist. Image quality of the transferred images was sufficient in all cases. Drastic selection of images from a complete CT study leads to a high rate of incorrect diagnoses and is not appropriate to reduce transmission time in teleradiology.

Humans↗

PubMed1992

JPEG compression for PACS.

In the medical field, especially in diagnostic radiology, there still remains controversy over how and whether or not to compress X-ray images for storage and transmission. The joint Photographic Expert Group (JPEG) standard which has recently been agreed upon is the very attractive technique to archive and to transport images in medical fields. This technique is based on 'lossy' compression of images, which can handle not only X-ray images but also full-colored images, and is suitable for introduction into picture archiving and communicating systems (PACS). The images can be handled after compression as quite small clusters of data. For example, a single 2000 x 2000 x 12 bits chest X-ray image which is an 8 Mbyte image compressed at a 10:1 ratio could retain virtually all the visible quality of the original version, and would take 100 s to transmit at 64 kbits/s using the Integrated Services Digital Network (ISDN, 800 kbytes compressed file, 8 kbytes/s transmission theoretically). An important factor in the design of this technique is that this format relies on no specific hardware or software if using JFIF (JPEG File interchange Format). Soon this algorithm will be able to run on any workstation or on any PC in the world. Highly compressed images may be unsuitable for diagnostic purposes. However, they may be sufficient for reference images which will be needed in clinical fields.

Algorithms↗

PubMed1996

Teleradiology: state of the art in clinical environment.

Teleradiology may even be a tautology since communication is an essential part of radiology. The value of a radiological report is strictly dependent on how fast and clearly it is transmitted to the referring physician. The radiologist has therefore learnt to combine imaging expertise with communicator's skills. However, the term teleradiology is usually reserved to define the instances in which computers and digital networks help to reduce the limitations imposed by the physical distance between radiologists and between radiologist and referring physician. In this paper the main clinical applications of teleradiology will be presented, distinguishing between intra-institutional teleradiology (that involves more units belonging to the same department or to the same hospital) and inter-institutional teleradiology (more classically aimed at primary interpretation and subspecialty consultation). Finally a brief mention will be made concerning the potential for Internet to provide radiologists with new professional and educational opportunities.

Computer Communication Networks↗

PubMed2005

Seven years of clinical experience with teleconsultation in craniomaxillofacial surgery.

PURPOSE: In this work the experiences from 50 telemedically supported treatments in craniomaxillofacial surgery are summarized and different setups for their technical realization are described. Furthermore, for the first time the innovative UMTS (universal mobile telecommunication system) is applied for the transmission of arthroscopic videos of the temporomandibular joint and other craniomaxillofacial structures. MATERIALS AND METHODS: The combination of computer-assisted navigation technology in augmented reality environments with telecommunication is used for execution of interactive stereotaxic teleconsultation. Furthermore, treatments without navigation are telemedically supported. This study is composed of 4 technical system configurations: 1) integrated services digital network (ISDN)-based videoconferencing without remote control of the navigation computer; 2) transmission control protocol/internet protocol (TCP/IP)-based interactive teleconsultation via bundled ISDN lines (including remote control of the navigation computer); 3) TCP/IP-based interactive teleconsultation via network; 4) combination of TCP/IP-connection and ISDN-based videoconferencing. The telemedically supported treatments are: orbitozygomatic osteotomies, positioning of the mandibular condyle in orthognathic surgery, insertion of implants, positioning of the maxilla in orthognathic surgery, distraction osteogenesis, arthroscopies of the temporomandibular joint, and operation simulations on stereolithographic models. The surgical interventions are evaluated on a 5-level system performance scale from the technical point of view. In a separate trial 20 videosequences of arthroscopies of the temporomandibular joint are transmitted via UMTS cellular phones and independently evaluated by 3 experts (ie, a total of 60 streamings) to investigate feasibility of this technology in the field of craniomaxillofacial surgery. RESULTS: In the years from 1996 to 2002 a total of 50 treatments were telemedically supported. All intraoperative applications were successfully finished; 48 of 60 UMTS transmissions were finished without any interruptions in constant quality, slight interruptions were observed in 8 tests, and a complete breakdown was observed during 4 streamings that required a restart of the transmission. Resolution was sufficient to diagnose even tiny anatomic structures inside the temporomandibular joint, but orientation was hardly recognizable. CONCLUSION: In many applications telecommunication technology can contribute to a quality improvement in cranio- and maxillofacial surgery because of the global availability of specialized knowledge. The required technical expenditure for teleconsultation crucially depends on the infrastructure that is already available at the clinic and the remote site. UMTS is a promising technology with the potential to be valuable in numerous craniomaxillofacial applications.

Arthroscopy↗

PubMed1998

[Robotics in neurosurgery: current status and future prospects].

Neurosurgery is in essence a field of application development for robots, based on multimodal image guidance. Specific motorized tools have already been developed and routinely applied in stereotaxy to position a probe holder or in conventional neurosurgery to hold a microscope oriented towards a given target. The potentialities of these approaches have triggered industrial developments which are now commercially available. These systems use databases, primarily coming from multimodal numerical images from X-ray radiology to magnetic resonance imaging. These spatially encoded data are transferred through digital networks to workstations where images can be processed and surgical procedures are pre-planned, then transferred to the robotic systems to which they are connected. We have been using a stereotaxic robot since 1989 and a microscope robot since 1995 in various surgical routine procedures. The future of these applications rely mainly on the technical progress in informatics, about image recognition to adapt the pre-planning to the actual surgical situation, to correct brain shifts (for instance), about image fusion, integrated knowledge such as brain atlases, as well as virtual reality. The future developments, covering surgical procedure, research and teaching, are sure to be far beyond our wildest expectations.

Forecasting↗

PubMed1997

Telemedicine and fetal ultrasonography: assessment of technical performance and clinical feasibility.

OBJECTIVE: Our aim was to determine the performance and clinical feasibility of telesonography for the interpretation of fetal anatomic scans sent from a remote location compared with those obtained at a tertiary care prenatal ultrasonography center. STUDY DESIGN: Routine ultrasonographic studies from 35 patients were remotely interpreted. Evaluation included a blinded comparison of the sonographer's assessment of 38 fetal structures with that of the physician at the tertiary care center. Technical evaluation included system reliability and the number of digital telephone lines required for adequate real-time visualization. RESULTS: The mean gestational age at the time of the ultrasonography was 25.84 +/- 6.8 weeks (range 14 to 38). There was complete consistency of interpretation for 25 of 38 (66%) fetal structures. Thirteen structures had discrepancies in visualization, reflecting a difference in the adequacy of visualization, not the normalcy or identity of the structures. Three digital (integrated switching digital network, ISDN) telephone lines were required for real-time visualization. CONCLUSION: Our preliminary experience supports telesonography as a clinically useful tool for remote interpretation of fetal ultrasonographic examinations. Further studies are warranted for the continued evaluation of this emerging technology.

Female↗

PubMed2002

Real-time transmission of pediatric echocardiograms using a single ISDN line.

We tested the adequacy of a videoconferencing system using a single integrated systems digital network (ISDN) line (128 kilobits per second) for the remote diagnosis of children with suspected congenital heart disease (CHD). Real-time echocardiogram interpretation was compared to subsequent videotape review in 401 studies with concordance in 383 (95.5%) studies. A new diagnosis of CHD was made in 98 studies. Immediate patient transfer was arranged based upon a real-time diagnosis in five studies. In 300 studies, a normal diagnosis obviated further evaluation. A single ISDN line is adequate for transmission of pediatric echocardiograms and it allows for remote management of patients with CHD.

Adolescent↗

PubMed2004

Tele-endoscopy: a way to provide diagnostic quality for remote populations.

BACKGROUND: Flexible endoscopy plays an important role in digestive health. However, access to endoscopy is limited in many rural areas throughout the world. Training non-physician personal to perform diagnostic endoscopy and to transmit images to a central hospital, where experienced endoscopists can review the procedures, may improve digestive health for patients in remote areas. The aim of this study was to evaluate the diagnostic quality and accuracy of upper-GI tele-endoscopy. METHODS: Fifty patients scheduled for EGD underwent upper-GI tele-endoscopy. The procedures were observed simultaneously by the endoscopist and a gastroenterologist observing from a remote station connected by 4 integrated services digital network telephone lines. The interpretation of the findings by both were compared and concordance for diagnosis of major and minor lesions was analyzed. RESULTS: Tele-endoscopic image quality was adequate to support diagnosis of abnormal lesions by the remote observer. Technical issues included worsening image quality caused by mild pixelation during rapid endoscope movement and rare loss of the telephone lines. The endoscopist identified 47 different major and 44 minor findings in the 50 patients. The observer missed one major lesion (columnar-lined esophagus) because of suspected inflammation and described 10 non-existing major lesions (sensitivity 98%: 95% CI[89%, 99%], specificity 80%: 95% CI[66%, 90%]). Some of the differences were because of interobserver variability. CONCLUSIONS: Upper-GI tele-endoscopy by using telephone lines has good diagnostic quality and is highly sensitive with regard to major findings. The misinterpretation of certain findings (esophageal ring, gastric erosions) may be caused by interobserver variability. The data strongly suggest that endoscopist and observer see similar endoscopic views.

Adult↗

PubMed1984

Logical elements in living cells.

Recognition processes with enhanced accuracy (as performed by structures like enzymes or ribosomes) are investigated using elementary ideas of statistical mechanics and related concepts of thermodynamics. The analysis starts from a formal definition of recognition and provides a correspondence with appropriate physical properties of the macromolecular logical elements. Transitions of the recognizing system between different modifications are a necessary feature of a more exacting recognition process. Rearrangement steps provide the process with higher accuracy by performing two physical operations: (1) rearranging the phase space of the system so that the "correct" states be better separated from the "wrong" states and the probability of occupation of the "correct" states be enhanced, (2) directing the process toward the more favourable modifications thus formed. Both operations are related to changes in the physical properties of the recognizing system. These changes can be expressed as differences of macromolecular Gibbs energy levels; if ligand binding or release participate in a step, directivity of the step depends also on the actual chemical potentials of the ligands in solution. The two operations just mentioned resemble two basic operations known to be necessary in electronic digital networks: directivity of control and signal standardization. An analysis of the entire reaction catalysed by a macromolecular logical element takes into account the requirements imposed by the logical functions as well as the need that the chemical potential of the product be not restricted to very low values. To satisfy these conditions, the reaction must be supported by a so-called non-specific reaction, usually implemented by the cleavage reaction of a nucleoside triphosphate.

Catalysis↗

PubMed1998

A telemedicine consultative service for the evaluation of patients with urolithiasis.

OBJECTIVES: A 6-month pilot teleconsultative project linking Georgetown University Medical Center (GUMC) in Washington, DC, and City Hospital in Martinsburg, West Virginia, 90 miles away, was designed to assess the effectiveness of telemedicine on the clinical decision-making process for patients with urolithiasis. METHODS: The telemedicine system designed and tested for this project was based on a PC-based platform. Videoconferencing and review of the patient's imaging studies were performed over an Integrated Service Digital Network (ISDN) with 3 Basic Rate (BRI) ISDN lines providing a 336-kilobytes/s bandwidth through an Inverse Multiplexor (IMUX). Treatment options were recorded for the clinical trial group and a simulated study group by the consulting urologist after the initial telephone consultation, after the telemedicine consultation, and after examination of those patients transferred to GUMC. RESULTS: A total of 32 telemedicine consultations were performed: 14 in the clinical trial group and 18 in the simulated study group. The recommendation of the consulting urologist at the tertiary center was altered in 12 patients (37.5%) after the telemedicine consultation compared with the recommended treatment after the initial telephone consultation. CONCLUSIONS: In the evaluation of patients with urolithiasis, this telemedicine application enhanced the clinical decision-making process by allowing for improved quality of care through immediate access and effective transfer of information between the referring urologist, the patient, and the stone center specialist.

Adult↗

PubMed2000

Teleophthalmology: the use of real-time telementoring to remove an orbital tumor.

OBJECTIVE: To determine whether current telemedicine technology can support real-time surgical telementoring to remove an orbital tumor. DESIGN: Interventional case report METHODS: An orbital specialist guided a general ophthalmologist in the removal of a lateral orbital tumor from a site 210 miles away on another island. A 3-mm endoscope connected to a three-chip digital video camera attached to a Concorde 4500 Picture-Tel videoconferencing system was used to transmit images at a rate of 384 kb per second over integrated service digital network lines. MAIN OUTCOME MEASURES: Successful performance and outcome of the telementored procedure comparable to hands-on orbital surgery. RESULTS: The surgical procedure was successfully telementored with uncomplicated removal of the orbital tumor. CONCLUSIONS: Current telemedicine technology can support real-time telementoring to remove an orbital tumor.

Adolescent↗

PubMed2001

Telemedicine in ultrasound: new solutions.

The transport of dynamic ultrasound (US) pictures as video files or streams no longer presents a problem. Despite teleconferencing, this method of transfer provides no active influence on the data sent for the receiving expert. We are evaluating a software-based 3-D US system that provides the new opportunity of an active US re-evaluation of a virtual patient. The 3-D volumes can be reanalyzed, time- and examiner-independent, wherever the device is installed. To test the clinical feasibility of this virtual US investigation, we installed the device in a peripheral hospital and in our US unit. The transfer of the volume (about 10 to 15 MB) could be done with two parallel Integrated Services Digital Network (ISDN) lines with a conduction capacity of 128 KB/s. In this basic assessment, the transmission of US volumes of patients proved to be easy in the acquisition, quick in off-line transmission and reliable in off-line re-evaluation of the data.

Computer Communication Networks↗

PubMed2001

Advances in information technology.

Advances in digital technology have vastly increased the speed and content of information transfer. Equine practitioners of the future should be in contact with their office and other information resources at all times through an array of digital networks. Patients and practitioners alike should benefit from better information access.

Animals↗