The personal internetworked notary and guardian.

In this paper, we propose a secure, distributed and scaleable infrastructure for a lifelong personal medical record system. We leverage on existing and widely available technologies, like the Web and public-key cryptography, to define an architecture that allows patients to exercise full control over their medical data. This is done without compromising patients' privacy and the ability of other interested parties (e.g. physicians, health-care institutions, public-health researchers) to access the data when appropriately authorized. The system organizes the information as a tree of encrypted plain-text XML files, in order to ensure platform independence and durability, and uses a role-based authorization scheme to assign access privileges. In addition to the basic architecture, we describe tools to populate the patient's record with data from hospital databases and the first testbed applications we are deploying.

Glucoweb: a case study of secure, remote biomonitoring and communication.

As the Internet begins to play a greater role in many healthcare processes, it is inevitable that remote monitoring of patients' physiological parameters over the Internet will become increasingly commonplace. Internet-based communication between patients and their healthcare providers has already become prevalent, and has gained significant attention in terms of confidentiality issues. However, transmission of data directly from patients' physiological biomonitoring devices over the Web has garnered significantly less focus, especially in the area of authentication and security. In this paper, we describe a prototype system called Glucoweb, which allows patients with diabetes mellitus to transmit their self-monitored blood glucose data directly from their personal glucometer device to their diabetes care provider over the Internet. No customized software is necessary on the patient's computer, only a Web browser and active Internet connection. We use this example to highlight key authentication and security measures that should be considered for devices that transmit healthcare data to remote locations.

Impact of anatomic closure on somatic growth among small, asymptomatic children with secundum atrial septal defect.

We retrospectively identified 92 children aged

Temporal expressiveness in querying a time-stamp--based clinical database.

Most health care databases include time-stamped instant data as the only temporal representation of patient information. Many previous efforts have attempted to provide frameworks in which medical databases could be queried in relation to time. These, however, have required either a sophisticated database representation of time, including time intervals, or a time-stamp-based database coupled with a nonstandard temporal query language. In this work, the authors demonstrate how their previously described data retrieval application, DXtractor, can be used as a database querying application with expressive power close to that of temporal databases and temporal query languages, using only standard SQL and existing time-stamp-based repositories. DXtractor provides the ability to compose temporal queries through an interface that is understood by nonprogramming medical personnel. Not all temporal constructs are easily implemented using this framework; nonetheless, DXtractor's temporal capabilities provide a significant improvement in the temporal expressivity accessible to clinicians using standard time-stamped clinical databases.

Scaling a data retrieval and mining application to the enterprise-wide level.

Most medical institutions have had difficulty in adopting practices that use stored clinical and administrative data effectively. This stems in part from the lack of available tools to easily and accurately retrieve datasets of interest. In this work, we describe the development of a data retrieval and mining application, Goldminer, which allows authorized personnel at our institution to query clinical and demographic data stores through a graphical, non-programmer interface. It builds upon DXtractor, our previously described tool that retrieves data from a smaller, more specialized dataset. We discuss the difficulties encountered in scaling this application to the enterprise-wide level, and our solutions.

Data mining by clinicians.

Clinical databases are becoming commonplace in healthcare environments. However, clinicians have been unable to readily explore these information sources, because currently available data retrieval tools require substantial technical skill, as well as knowledge of the underlying database structures. To address this, we have defined a group of "atomic" queries, including both population-based and temporal predicates, to enable the extraction of clinically meaningful information form these databases. DXtractor is an application that incorporates this functionality, and allows clinicians to simply combine these atomic queries. In doing so, arbitrarily complex data retrieval and exploration becomes possible for the non-programming clinician.

ATRAS: a decision support application layered on the W3-EMRS architecture.

The creation of portable decision support systems (DSSs) remains an important goal in medical informatics. The Adrenal Test Retrieval and Analysis System (ATRAS) has been developed as an example of a simple yet highly effective decision support application which runs in a system-independent way. It is the first implementation of a decision support application layered on the World Wide Web Electronic Medical Record System (W3-EMRS) architecture, which allows for unified access to remote heterogeneous electronic medical record system (EMRS) databases.

Patient-interactive, computer-controlled neurological stimulation system: clinical efficacy in spinal cord stimulator adjustment.

Over the past 20 years, continuing technical advances have rendered spinal cord stimulation an easily implemented low-morbidity technique for the management of chronic intractable pain in properly selected patients. Percutaneous methods for the insertion of arrays of multiple epidural electrodes, which are driven by noninvasively programmable "multichannel" implanted devices, have been among the most important of these technical improvements. The same implanted electronics may be used with peripheral nerve or intracerebral electrodes. If the capabilities of this new hardware are to be used to full advantage, a major investment of time and effort is required to adjust the system postoperatively for optimum effect. Ideally, these adjustments should be based upon psychophysical data, obtained in a manner that minimizes influences such as potential operator bias or stimulus presentation-order effects. These requirements have been met by the development of a computerized system designed for direct patient interaction and for greater ease of operation than the standard external devices used with these implants. The system has been tested clinically in 25 patients with spinal cord stimulation for pain. It rapidly tests the available electrode combinations and stimulus pulse parameters at a rate comparable to or greater than that of a skilled human operator using the standard device. It records detailed graphic data and patient analog ratings at varying thresholds and implements "pain drawing" methods with novel input and analytical techniques. This patient-interactive computerized system has proved to be safe and effective clinically. The time required by the average patient working with this system to adjust the stimulator is comparable to or less than the time required by the same patient working with a physician's assistant. Psychophysical data collected by the system may be correlated with clinical observations. Ongoing development will permit delivery of novel pulse sequences and protocols to assess the mechanisms by which stimulation affords relief from pain.