Overview

The Medical-Objects® messaging system uses a distributed n-tier architecture. Any number of nodes can join the network and these nodes can be anywhere in the world. A VPN is not required as all traffic is signed and encrypted. Any TCP/IP connection can be used to establish connectivity. There are centralised Provider directory, Routing, Registration and Terminology servers but these functions can also be decentralised if desired and they are only centralised for ease of configuration and setup. All communication is via encrypted HL7, either in classic encoding or XML. PIT is also fully supported, both ingoing and outgoing although it is usually wrapped in HL7 for transport. Encryption is either PGP (V2.6 natively supported) or HIC PKI. Currently most specialists are using an ASP arrangement but several specialists without ADSL access use a local server and permanent dial-up. There are a wide variety of clients available to solve specific problems we have come across and all use the same framework. The software that enables a GP to receive messages is either a single 2.7mb download on the windows platform (95+) or a single click into a Java WebStart application (PKI only) that runs, and has been tested on, Windows (98+) , Linux or Mac OS X. Setup is automated, for PGP, key generation is local, and the installation can be done over the phone in less than 10 minutes in most cases.

Architecture

The Medical-Objects® messaging system consists of the following major components.

Magellan, the lightweight download client that runs on windows systems. It connects to one or several internet based servers and downloads new results when they become available. It fully supports PGP(V2.6) and PKI and all traffic is in HL7. The results are placed in your application "in" directory and are imported the same way you import pathology. No user intervention is required. It has the ability to split results into several queues and convert results to PIT or images if HL7 is not supported. It uses standard HL7 ACKs to ensure guaranteed delivery. It meshes with the Medical-Objects twain interface to allow images to be ‘scanned’ into GP applications. The images are of course transported in standard HL7 format. It runs as a service for reliable unattended operation, or can run as a tray icon or scripted/scheduled or interactive application. This flexibility allows for many varied modes of operation rather than locking you into a single inflexible scheduling mode. All Magellan installations functionality is monitored by medical objects to detect connection problems early. PGP key generation is performed at the installation site as part of the install process. Once installed its operation is invisible to the user. It includes automatic upgrade technology.

J-Client, is the cross platform version of Magellan. Written in Java and available as open source in the near future it uses HIC PKI to deliver reports in HL7 or PIT format to applications running on Windows, Linux or Mac OS/X. It operates in a similar manner, sending a HL7 query to an internet bases server and receiving results as HL7. The delivery is ensured by sending a HL7 ACK back to the server. It has an inbuilt scheduler and can be installed if you have a site certificate. Installation is a snap with the process being initiated by a single click on the Medical-objects web site (Java Web Start Technology).

Trinity, the lightweight referral client is a freely available, “No registration required” client that captures GP referrals which can be sent to any other connected user. It even allows the use of a USB key while running on terminal services. It is designed to be as unobtrusive as possible and many referrals can be sent with 2 clicks! It uses medical-objects developed PKI signature technology to make referrals sent this way a legal referral that complies with the Electronic Transaction Act. It runs in the background popping up when u need it. All you need is a PKI key and one driver off the HIC disc. There is no need to try and install all the PKI drivers or configure any Email clients to use PKI. It uses PKI signatures as your electronic identity. There is no charge for GP referrals or record transfers sent this way. It also includes an interface into the Medical-Objects provider directory. You can lookup address and contact information on other users and create and edit your own entries. If your address or contact information is out of date you can fix it yourself without picking up the phone.

Eclipse, is the standalone routing tool that can be used to solve the complex messaging problems that are likely in a large organisation. It can watch for files in directories, or download messages and perform convert/encrypt/decrypt/upload/download/Email /etc operations on them. It can also upload email and perform any combination of transformations on them. It has several Email options that clone the functionality of existing Email applications making it a flexible solution for complex situations. It uses decorator technology to achieve this. The message transformations can be interactively chained to achieve a large variety of objectives. The message transformations are easily extendable for specific requirements an organisation may have, including interface engine functionality. If you have a difficult message routing/transformation problem then eclipse can probably solve it.

Medical Objects Explorer, is the specialist clinical application that makes report creation and data analysis a breeze. While not complete as yet it has been in active use internally for several years and includes advanced data analysis and graphing technology as well an ability to allow access to clinical data from any internet connected location on the planet. It is what is sometimes called a “rich thin client”. It uses 100% HL7 messaging between itself and the HL7 Server and works well even on low bandwidth connections. Medical Objects Explorer has an offline mode in which all clinical data can reside on the client as encrypted HL7 which can be accessed offline. Given the terse nature of HL7 this is amazingly efficient with over 100,000 pathology tests/letters fitting into 75mb of encrypted HL7. If you loose your notebook then don’t worry, the data is encrypted and remains private, and you can reinstall Medical Objects Explorer on a new notebook and get another copy! Medical Objects Explorer is still under active development as a clinical tool but even now can make Specialist GP communication a snap. It makes sending quick updates about patients as easy as sending an email. The GP however receives the report as simply as he reviews new pathology, with no manual intervention. Report delivery is near real-time to Magellan users and real-time to other Medical Objects Explorer users. Medical Objects Explorer also provides provider lookup, Digital signature evaluation and generation as well as evolving access to decision support and drug information data. It also has access to message tracking where every reports delivery and routing history is available. You can tell when the report has been downloaded by a GP and even when other Medical Objects Explorer users have viewed it!. Access to reports is restricted at the individual report level as well as supporting the HL7 confidentiality markers.

Medical-Objects, is the “Word Plug-in” to HL7-enable commonly used word processors. This is a COM server that can be accessed by Microsoft Word or WordPerfect to enable the sending of Text based reports directly from the word processing application. It uses the same framework and has inbuilt provider lookup and intra message digital signature production. Word Documents that have been created can be saved and reopened without loss of the HL7 data. This allows corrections to be sent which will replace the document in the GP software, rather than duplicate it. Installing medical objects adds a “Send” button to word or WordPerfect. Extensive trails involving local Specialist secretarial staff have succeeding in making this a painless way be transmit text reports in internet time. As with all the medical-objects applications simple token based installs and automatic updates make installations a breeze. The underlying COM server is potentially accessible to a wide range of other windows applications to enable tight integration with any existing applications. Reports sent with the this application are available for viewing and further editing from Medical Objects Explorer.

Equator, is the workhouse of the suite of applications. It’s the server end of the equation and comes in several forms. There is a standalone tray icon server, a Service application or a Apache module or IIS ISAPI DLL. It can also be compiled into a single tier application although this is not recommended. Equator is the middle tier of the suite, processing a wide array of HL7 messages and storing the Data in the database tier. It uses an open source SQL server called Firebird (formally InterBase). The database is usually run on Linux servers but call run on the same machine. All access to functionality is based on public key authentication, there are no passwords. The server can use PGP or PKI encryption. On a Pentium class server it can easily persist 10,000 ORU messages an hour and process over 50,000 an hour. It fully supports HL7 2.3.1 queries which is how Magellan and Medical Objects Explorer obtain data. It has inbuilt result indexing and free text "Google" like searches are available. It already contains support for HL7 order messages. The server supports replication (using HL7 of course) to enable remote data backup in the event of natural disaster. It has an open API which supports delivery of PKI signed and encrypted HL7 without pre registration (It has inbuilt HIC LDAP server lookup) Remote configuration is possible using a HL7 based RPC mechanism. The servers use push rather than pull technology wherever possible and there is automatic discovery and routing to newly connected users. Reports entered today to non connected users will route when the recipient comes online. If desired routing of messages over encrypted email transport is also implemented. The preferred transport is encrypted/signed HL7 over HTTP but HL7 LLP is also supported. All routing uses the HL7 ACK (acknowledgement) protocol to ensure delivery and handles lost connections and internet outages without difficulty or data loss. The server has interface engine functionality and is capable of fixing many common errors and upgrading messages to V2.3.1. It also has message decorators capable of modifying outgoing messages for specific applications. Adherence to standards has made this less necessary but some modification to headers and batch numbers can be done to improve the ability of other applications to import documents and dynamically remove parts of a message they cannot process.

We also have a simple file based version of equator which can accept HL7 traffic from the internet, ACK it and save it in a directory. This would allow real time delivery of results to GPs but would require opening the GP firewall, something we don’t feel is appropriate for most practises at the current time. In the long term however, this may be achievable.

Hosting, is also available for specialist users and is the preferred mode of operation. Medical-Objects has a class C network on the internet and has its first hosting facility at PIPE Networks in Brisbane. This is a state of the art data centre with excellent security, environmental protection and redundant high speed internet connections. We have high quality, high end, servers with SCSI RAID arrays/redundant power supplies/switches, and redundant CISCO routers, along with multilayer firewalling. There is even a dial-up connection available for those GP users without an internet connection. PIPE networks use BGP (Border gateway Protocol) for the fastest, least costly direct connections to many ISPs. We have redundant 300Mb connections to the internet backbone and can deliver data at near network speeds. For specialist practises this reduces the need for expensive servers and on site maintenance. Upgrades can be performed easily and cheaply and backup can be done centrally. GP users do not need to consider this as message delivery is free and distribution servers are provided. It is possible to use these distribution servers as a data repository and make it browsable, if desired. (This is similar to the vision presented by Charles Parisot at a messaging meeting in Melbourne in December 2004) Some of the current trial GP users do this and run Medical Objects Explorer to view new results in real time, as well as downloading data into their existing applications. Currently we have servers running at 4 physical locations. One location on permanent dial-up, 2 locations on 1500/256 ADSL and the other at Pipe networks in Brisbane.

Message Validation

Messages are extensively processed and validated, although given the lack of support by many message sources for handling a reject ACK, generally an attempt is made to correct obvious errors rather than reject the messages. Some messages will fail validation and an internal notification message is used to allow manual intervention and re-submission. By trying to standardise messages to HL7 2.3.1 format we have had minimal import problems with over 300 connected users.

Strength and Weaknesses

The main strength of Medical-Objects is adherence to standards and an open architecture. The server API is an open standard which can be implemented by any vendor or user. Data in the system is always in a standard format which allows its transfer to an alternate application at any time. It has a distributed connectionless architecture with no single point of failure. As development has been aimed at this market from the start every component is designed for the job in mind and not adapted from another domain. Real users have been involved from the start and an extensive trial has been done to iron out unforseen problems and ensure there are no gaps and good user and staff acceptance. The internal use of messaging has led to extensive use of this rather than an external add on interface to the world. This has led to a much more rapid maturation of the messaging and encryption technology than would have otherwise have occurred. Result delivery is just another message in a system that passes millions of messages every week. A focus on quality and good cutting edge technology along with good domain knowledge of both the medical, standards and software world have allowed Medical-objects to produce a package that satisfies the wants of people who live entirely, or mostly in one of these spheres. As the project was funded by a busy Day surgery and Medical Practice there has not been a strong push to get it to market, but instead a commitment to real R&D, iterative development and quality technology rather than marketing and vapourware. Medical-Objects is used by its creators every day in the real world care of patients and while its by no means finished, its hard for it to get off track when every week the latest version is under trial and minor annoyances are immediately brought to light by practising clinicians.

Users

Medical Objects is under active use by over 300 individual Doctors, Psychologists, Physios, Nursing homes and Dieticians on the Sunshine Coast. There are 2 radiology practices and one Nuclear Medicine practice using it as the sole means of electronic delivery and in all over 30 specialists are online. Expansion outside the Sunshine Coast, as a continuation of the trial is underway with a site on the Gold Coast active for 12 months and sites in Brisbane, Toowoomba and Cleveland planned. It is under active trial with the Sunshine Coast Division of General Practice, delivering psychology assessments to Gympie GPs. Wider trials include Radiology, Nuclear Medicine, Cardiology, Gastroenterology, ENT, Surgeons, Dieticians, Pharmacists, Nursing Homes, Obstetrics & Gynaecology, and IVF clinics. Over 90% of local GPs with a computer are online.

Support

Medical-Objects has been conscious of the need to keep support costs and the need for onsite assistance to a minimum. Installation is automated with the use of a setup PIN and a registration server to allow easy secure installation with user generation of PGP keys where needed. All the software supports automated upgrade and the only real requirement for operation is a working TCP/IP connection and fire-walling issues which can be dealt with by local IT support personal. Server upgrades can also be automated but the use of hosting for specialists reduces the need for onsite visits. Because of the built in offline access internet outages are less of a concern. The hardware requirements for specialists are reduced as are support costs. Phone and Email support is available and we tend to use messaging for queries about functionality as its built into the system. One huge advantage of the messaging environment is the lack of server/client version sensitivity. Obviously functionality can be limited by version mismatch but in general old versions of the client work with newer servers and vice versa. This allows for extensive server upgrades without upgrading clients. In fact the first service version of Magellan is still running after 12 months even though the server it talks to has been through a regular cycle of server upgrades. Without a messaging standard this would not be possible.

Costs

We are committed to free clients to enable any health care professional to receive messages as it encourages the use of HL7 messaging. We also feel that a per message fee discourages the use of quick notes and comments, something that the trial has shown to be of enormous benefit in the trial. It is possible for a specialist to write a comment about a pathology test or notify a GP of an admission with less effort than a quick Email. It’s a practice we want to encourage. We believe that a subscription based cost structure with some adjustment for message and storage volumes is the best option, with the price being cost neutral with respect to other savings on hardware and consumables. We have already seen many practices request that paper no longer be sent, despite our statement that in trial phase both should be sent. Part of the ongoing trial is to assess support, staff and hardware/internet costs so that an appropriate fee structure can be set for specialist users.

Summary

Medical-Objects is a purpose built messaging environment for medical practice. Despite still being in trial phase its is a mature and tested product that leapfrogs the common single tier medical applications to provide a distributed, scalable solution that works with existing applications to achieve the goal of electronic report distribution now, while having its eye on the future where much more semantic interoperability is possible.