Secure Teleassistance towards endless medical litigations: identification of liabilities through a protocol using Joint Watermarking-Encryption Evidences.

Teleassistance is defined by the help provided through a telemedicine network by a medical practitioner to one other medical practitioner faced to a difficult case. One of the main limiting factors of its development is the fear of the practitioners to be involved in a litigation. In such a situation, the main issue is to determine as quick and as certain as possible if the damage is in relation with the tort of negligence and the liabilities of each involved physician. After a brief summary of the legal context, we present a protocol combining joint watermarking-encryption and a third party to enforce exchange traceability and therefore to bring valuable electronic evidence in case of teleassistance litigations.

Combination of watermarking and joint watermarking-decryption for reliability control and traceability of medical images.

In this paper, we propose a novel crypto-watermarking system for the purpose of verifying the reliability of images and tracing them, i.e. identifying the person at the origin of an illegal distribution. This system couples a common watermarking method, based on Quantization Index Modulation (QIM), and a joint watermarking-decryption (JWD) approach. At the emitter side, it allows the insertion of a watermark as a proof of reliability of the image before sending it encrypted; at the reception, another watermark, a proof of traceability, is embedded during the decryption process. The scheme we propose makes interoperate such a combination of watermarking approaches taking into account risks of interferences between embedded watermarks, allowing the access to both reliability and traceability proofs. Experimental results confirm the efficiency of our system, and demonstrate it can be used to identify the physician at the origin of a disclosure even if the image has been modified.

Development of a cardiac acoustic mapping system.

The authors describe a cardiac acoustic mapping system designed to acquire, analyse, and display the amplitude distribution of a phonocardiogram (PCG) recorded from 22 sites on the thorax. A new PCG envelope detection approach, implemented by analogue circuits, enables simultaneous sampling of PCG envelopes from the 22 sites at a rate of 250 Hz/channel. A calibration procedure removes channel-to-channel gain variations, and a coherent averaging of each PCG envelope over several cardiac cycles improves the signal-to-noise ratio. Time congruent samples from the 22 averaged PCG envelopes are then interpolated in 2D to generate the isoamplitude maps. Preliminary results show that the acoustic maps can help locate the source of heart sounds and murmurs, and characterise their radiation and propagation patterns. Cardiac acoustic mapping opens up new avenues for the study of the propagation of heart sounds and murmurs through the heart-thorax acoustic system. This technique could contribute to improvements in the diagnosis of valvular dysfunctions.