Using digital watermarking to enhance security in wireless medical image transmission.

OBJECTIVES: During the last few years, wireless networks have been increasingly used both inside hospitals and in patients' homes to transmit medical information. In general, wireless networks suffer from decreased security. However, digital watermarking can be used to secure medical information. In this study, we focused on combining wireless transmission and digital watermarking technologies to better secure the transmission of medical images within and outside the hospital. METHODS: We utilized an integrated system comprising the wireless network and the digital watermarking module to conduct a series of tests. RESULTS: The test results were evaluated by medical consultants. They concluded that the images suffered no visible quality degradation and maintained their diagnostic integrity. DISCUSSION: The proposed integrated system presented reasonable stability, and its performance was comparable to that of a fixed network. This system can enhance security during the transmission of medical images through a wireless channel.

Using HSPA to improve the telemedical links on a moving ambulance.

As the demand for faster and more effective health care increases, there is a growing need to establish mobile, high-speed communications between a moving ambulance and a consultation point (usually a hospital). The recent addition of HSPA (HSDPA and HSUPA) into the UMTS suite provides higher bandwidth and reduced delays, making this choice ideal for real-time telemedical applications. In this paper, we will describe a set of scenarios that took place in a typical large city area, along with their equivalent results: a moving ambulance was linked with a consultation station using HSPA and several videoconferencing sessions were initiated. Best-case, worst-case and average scenarios were recorded. Furthermore, in areas where the UMTS reception was marginal, a repeater was placed on top of the vehicle to boost up the signal power and thus maintain the higher bandwidth. Finally, treating doctors were asked to evaluate the effectiveness of this system's outputs, based on a variety of objective and subjective criteria.

Mobile consultant: evaluation of additional services.

As the need for mobility in the medical world increases, newer systems and applications came to light; many of them based on wireless and mobile networks. PDA based systems were presented in the past, capable of videoconferencing and transmitting high quality images between a roaming consultant and a fixed point in the hospital. These systems not only had desirable characteristics but also incorporated additional services that were found of value: paging, Voice over IP calling, Internet, email, intranet, patient record update, etc This paper presents an engineering and clinical evaluation of those additional services based on both objective and subjective criteria. It concludes that such complementary services can be desirable as they increase personnel mobility, utilize the hospital resources more efficiently while at the same time increase productivity and decrease the cost of hardware and communications.

Performance of a wireless telemedicine system in a hospital accident and emergency department.

We developed a mobile, wireless videoconferencing system suitable for use in a hospital accident and emergency (A&E) department. Four consultants, eight junior doctors and 11 nurses working in the A&E department tested the system. Transmission of three types of data (audio, still images and video) was tested. The audio for the breath and heart sounds was judged to have some disturbance. One consultant rated the diagnostic quality as good and one rated it as fair. The quality of the still images was judged to be from fair to excellent. The quality of the video was rated as good. Possible interference between the wireless local-area network and various medical devices in the A&E department were examined, but none was detected. The four consultants who tested the system were very positive in their initial comments. Eight of the 11 nurses remained sceptical about its use. Of a total of 20 patients who answered a survey, 13 were slightly anxious about the use of the system to transmit their data to a distant point. Overall, the performance of the system was satisfactory for use in the A&E role.

Use of 3G mobile phone links for teleconsultation between a moving ambulance and a hospital base station.

We developed a mobile teleconsultation system based on third-generation mobile phone links. The system comprised a laptop computer and a digital camcorder. It was installed inside an ambulance to allow video-conferencing between the moving vehicle and a doctor at a base station. In addition to video and voice, high-quality still images could also be transmitted. A series of 17 trial runs with real ambulance patients was conducted in the city of Athens. In general, the videoconferencing sessions produced relatively clear video. The bandwidth was high enough for a satisfactory video of 10-15 frames/s. During a total testing period of 23 h and in an area of about 180 km2, there were nine instances of signal loss, amounting to a total of 17 min. The general opinion formed by the doctors was that the system produced good results. All initial diagnoses made using the system agreed with the final diagnoses of the patients. The study showed that the mobile system could reduce the time before an ambulance patient is seen by a doctor.

Mobile consultant: combining total mobility with constant access.

Minimizing the time required for a medical consultant to offer his/her expert opinion, can be viewed as a life-saving procedure. We have designed and tested an integrated system that will allow a medical consultant to freely move either within, or outside the hospital, while still maintaining constant contact with the patients via videoconferencing and high-resolution imaging. The above system is explained in this paper, along with its advantages and its potential limitations. Conclusively, we demonstrate that such a system further increases the mobility of the medical consultant, while improving the healthcare service.

Ambulance 3G.

Minimising the time required for a patient to receive primary care has always been the concern of the Accidents and Emergency units. Ambulances are usually the first to arrive on the scene and to administer first aid. However, as the time that it takes to transfer the patient to the hospital increases, so does the fatality rate. In this paper, a mobile teleconsultation system is presented, based primarily on third generation mobile links and on Wi-Fi hotspots around a city. This system can be installed inside an ambulance and will permit high-resolution videoconferencing between the moving vehicle and a doctor or a consultant within a base station (usually a hospital). In addition to video and voice, high quality still images and screenshots from medical equipment can also be sent. The test was carried out in Athens, Greece where a 3G system was recently deployed by Vodafone. The results show that the system can perform satisfactory in most conditions and can effectively increase the patient's quality of service, while having a modest cost.

Mobile e-health: the unwired evolution of telemedicine.

The movement of telemedicine from desktop platforms to wireless and mobile configurations may have a significant impact on future health care. This paper reviews some of the latest technologies in wireless communication and their application in health care. The new technologies can make the remote medical monitoring, consulting, and health care more flexible and convenient. But, there are challenges for successful wireless telemedicine, which are addressed in this paper.

Social presence in telemedicine.

We studied consultations between a doctor, emergency nurse practitioners (ENPs) and their patients in a minor accident and treatment service (MATS). In the conventional consultations, all three people were located at the main hospital. In the teleconsultations, the doctor was located in a hospital 6 km away from the MATS and used a videoconferencing link connected at 384 kbit/s. There were 30 patients in the conventional group and 30 in the telemedical group. The presenting problems were similar in the two groups. The mean duration of teleconsultations was 951 s and the mean duration of face-to-face consultations was 247 s. In doctor-nurse communication there was a higher rate of turn taking in teleconsultations than in face-to-face consultations; there were also more interruptions, more words and more 'backchannels' (e.g. 'mhm', 'uh-huh') per teleconsultation. In doctor-patient communication there was a higher rate of turn taking, more words, more interruptions and more backchannels per teleconsultation. In patient-nurse communication there was relatively little difference between the two modes of consulting the doctor. Telemedicine appeared to empower the patient to ask more questions of the doctor. It also seemed that the doctor took greater care in a teleconsultation to achieve coordination of beliefs with the patient than in a face-to-face consultation.

The accuracy of length and angle measurement in videoconferencing teleradiology.

Telemedicine was used to make measurements on a series of radiographs. The first group consisted of 25 radiographs of the cervical spine; four lengths were measured on each. The second group consisted of 100 wrist radiographs showing Colles fractures; the degree of backward angulation of the distal fragment was measured on each. Measurements were made via a videoconferencing link. The consultant used the shared white boarding facility to indicate where on the film the measurements were to be made. The videoconferencing link was used to check that the measurements were being made correctly and a nurse measured lengths and angles. In addition, the consultant used the link to read the scales on the measuring instruments for himself. Four different methods of measuring length were tested and three methods of measuring angle. A transparent plastic ruler was best for measuring length-the emergency nurse practitioner and the consultant made almost all measurements to an accuracy of 1 mm. A protractor with pen marker was best for measuring angles; all were made to within 2 degrees. Simple methods can be used to measure lengths and angles in videoconferencing teleradiology.

Four years' experience of telemedicine support of a minor accident and treatment service.

In 1996 we studied patients attending a minor accident and treatment service in London, some of whom were the subjects of teleconsultations with a main hospital emergency department. In the subsequent four years, 56,139 patients were seen at the minor accident and treatment service unit. Teleconsultations were performed in 2032 cases (3.6%). Most of the teleconsultations (58%) concerned patients with fractures. The main reason for teleconsultation was to review and discuss radiographs (46%). In comparison with the 1996 study, both the emergency nurse practitioners and the consultant had improved the accuracy of their teleradiology diagnosis, although the difference was not significant. Most of the telemedicine patients (90%) did not need a transfer to the main department. Thus telemedicine allowed local decision making in the majority of cases. In the 1996 survey, 75% of patients were sent to their general practitioner or to the main hospital department; in the present survey, this proportion had halved, to 38%. The present study showed that teleconsultations are an effective way of preventing patients being transferred unnecessarily from a minor accident and treatment service to the main hospital accident and emergency department.

Level of diagnostic confidence, accuracy, and reasons for mistakes in teleradiology for minor injuries.

The objective of this study is to determine whether eliminating uncertainty in diagnosis improves accuracy in teleradiology for remote trauma management and to assess the correlation between the probable reason for the mistake and the level of confidence. An emergency physician interpreted 2133 radiological series transmitted from a community hospital to an emergency department using videoconferencing equipment. He marked his level of confidence as 1 = sure positive; 2 = fairly sure positive; 3 = unsure; 4 = fairly sure negative; 5 = sure negative. The emergency physician also entered free-text comments, e.g., feeling tired, to enable a better understanding of what was happening. The accuracy, sensitivity, and specificity were 97.3% (98.6%), 94.48% (96.72%), and 98.63% (99.42%), respectively. Figures in brackets represent the 93.5% of cases in which the level of confidence was graded as sure. Boredom and hurry were the main reasons identified for mistakes. Reducing uncertainty in diagnosis may improve the accuracy of screen interpretation. This first series must be reproducible by others before any general use of such systems can be made for primary diagnosis. American College of Radiology standards must be met.

ENP review clinics.

As public expectations of the health service progressively increase, there will be greater pressure to increase the staffing of A&E. departments. An additional expectation is that the public wants the provision of local services. An option is to ask ENPs to do review clinics. This paper looks at the feasibility of this innovation.