Sir William Osler, a great clinician was of firm belief that a medical trainee requires convenient access to authoritative information to aid them in their learning process. He said: " The student begins with the patient, continues with the patient, and ends his studies with the patient, using books and lectures as tools, as means to an end ". What he so eloquently said has always remained true and the only thing that could be added to this one hundred year old statement would be 'using books and lectures and PDA as tools, as means to an end'.

For the past two decades, healthcare informatics has gone through a long and slow gestational period of development and evolution. The learning curve at times has been very painful and expensive; however for the past five years there are now encouraging signs of its acceptance by the medical fraternity and at the same time the development platforms have shown the much required flexibility among various interfaces to talk to one another. These evolutionary developments have been rapid in the last five years and we are now noticing changes in the way healthcare professionals learn, exchange and store information. These changes will surely in time to come have a beneficial effect on the patient care and make healthcare systems more efficient. The overall benefit of these changes will only be apparent when we are able to effectively show that the use of information technology has actually brought down the healthcare costs and decreased the number of errors that takes place. Those who accept and change will greatly benefit and those who do not will slowly perish and fade away. The clinicians who are reluctant to learn must learn to accept the changes and slowly learn to adapt to these. As Alvin Toffler put it - ' The illiterate of the 21st century will not be those who cannot read and write, but those who cannot learn, unlearn, and relearn '.

Internet, e-mail, PDA are the three major thrust areas that have helped the clinicians to accept information technology in the field of healthcare. Today, the majority of the healthcare professionals have used e-mail service and have done some research on the World Wide Web. Clinician sees one patient every 7- 9 mins with 2 mins travel between the patients and to them mobile computing makes more sense. The PDA hence has been an instant success among the doctors and nurses. One study has found that almost 40% of clinicians in US are now using PDA in their daily routine. There are other reasons why PDA's make sense in healthcare industry.

>> PDA's are Lightweight, durable, Safe, Low power equipment that do not interfere with medical equipment.
>> For every 10 patients seen, 1-5 questions arise requiring information that can be easily accessed on PDA'
>> There is no monthly usage charges·
>> Protocols to guide with standard management decisions can be quickly reviewed on the PDA by clinician or a nurse.

Medical errors also happens to be one of the US's biggest causes of preventable death. As per the 'British Medical Journal' editorial (March, 2001) Preventable healthcare errors cost the economy an astonishing $17-$29 billion p. a and medical errors lead to 3 million extra bed days per year in England and Wales, costing £1bn. The few area that are most prone to errors include drug prescribing, their dosage and treatment administration especially for an uncommon conditions. A computer with its vast memory capability in the form of a PDA that can easily store and give information at a click of button. This process is hence more appealing to a trainee, a nurse or a clinician. This is one reason for their popularity in this field that is so information intensive and complex. The PDA has now found a place in the pocket of the white-coat, the appeal is even more since it is lightweight, small, easy to carry around, it does not interfere with the various medical equipments functioning and it can talk to the desktop computer with ease. It seems like the most wonderful device to have as it fits all the requirements. No wonder that the usage of PDA doubled in 1999-01 and a survey done by ACP American Society of Internal Medicine in 2001 showed that 47% of their members were using PDAs and this was expected to be 67% by the end of 2002. The most popular software's were the drug reference software, medical calculators and messaging service to Pharmacy to order prescriptions. 

The idea of making small hand held computer for storing addresses and phone numbers , taking notes and keeping track of daily appointments originated in the 1980’s.

1980 - Psion defined the PDA .

1984 - Psion launched its first organizer, it was slightly longer and thicker than a large pack of cigarettes .

• -         Psion 1 was followed by Psion II
• -         Psion II was followed by a 3a series , which was the first to link to desktop PC for data transfers.
• -         The Series 5 followed up the success of the 3a , Largest screen (640 X 240 pixel) and keyboard to date.

1993 - Apple tried to copy Psion's success,Apple launched the Newton MessagePad One of the first to use touch-sensitive screens and handwriting recognition software .

1995 - US Robotics acquired Palm Computing leading to the launch of the Palm Pilot

1996 - The Pilot was introduced by US Robotics , Data entry was made using a stylus and Graffiti handwriting system (a simplified alphabet for handwriting recognition )

1997 - Apple produced eMate, a new PDA , but handwriting recognition software was not fast enough or reliable enough hence in 1998 Apple discontinued its PDA development.

1997 - US Robotics was bought by 3Com and Palm Pilots became major players in the PDA market , Palm introduced even smaller devices.

1999 - Palm was leading the industry with the Palm V and its Graffiti software, The Palm VII added wireless access to the Internet .Palm Computing's sales for 2001 are estimated at 13 million devices making it the industry's leader .

PDAs fall into two major categories: hand-held computers and palm-sized computers. The major differences between the two are size, display and mode of data entry.

Hand-held computers: Compared to palm-sized computers, tend to be larger and heavier. They have larger liquid crystal displays (LCD) and use a miniature keyboard, usually in combination with touch-screen technology, for data entry.

Palm-sized computers: are smaller and lighter. They have smaller LCDs and rely on stylus/touch-screen technology and handwriting recognition programs for data entry.

Regardless of the type of PDA, they all share the same major features:

• microprocessor
• operating system
• solid-state memory
• batteries
• LCD display
• input device - buttons in combination with touch-screen or keyboard
• input/output ports

Microprocessors

Like standard desktop and laptop computers, PDAs are powered by microprocessors. The microprocessor is the brain of the PDA and coordinates all of the PDA's functions according to programmed instructions.

The Operating system

The operating system contains the pre-programmed instructions that tell the microprocessor what to do.

Memory

A PDA doesn't have a hard drive. It stores basic programs (address book, calendar, memo pad and operating system) in a read-only memory (ROM) chip, which remains intact even when the machine shuts down. The data and any programs that are added later are stored in the device's RAM. This approach has several advantages over standard PCs.

When the PDA is turned on , all the programs are instantly available. One does not have to wait for applications to load. When changes are made to a file, they're stored automatically, hence a Save command is not required. And when the device is turned off, the data is still safe, because the PDA continues to draw a small amount of power from the batteries. PDAs usually come with 2 MB minimum of memory. However, many application programs take up memory space, so more advanced models usually have more memory (5 to 32 MB). Also, Pocket PC takes more memory space so PDAs with this operating system usually have 16 or 32 MB. In some PDA models, the amount of memory is upgradeable.

Batteries

PDAs are powered by batteries. Some models use alkaline (AAA) batteries, while others use rechargeable batteries (lithium, nickel-cadmium or nickel-metal hydride). The battery life depends on what kind of PDA one has and what it is used for.

LCD Display

PDAs have some type of LCD display screen. Unlike the LCD screens for desktop or laptop computers, which are used solely as output devices, PDAs use their screens for output and input. The LCD screens of PDAs are smaller than laptop screens, but vary in size. Hand-held computers generally have larger screens than palm-sized computers.

Input Device

PDAs vary in how the mode of inputting data and commands. Hand-held computers typically use a miniature keyboard in combination with a touch screen. Palm-sized computers use a stylus and touch screen exclusively in combination with a handwriting recognition program .Eventually, most PDAs will incorporate voice recognition technology, where one speaks into a built-in microphone while software converts voice waves into data.

Input/Output Devices

Because PDAs are designed to work in tandem with a desktop or laptop, they need to work with the same information in both places. If an appointment is made on the desktop computer, it needs to be transferred to the PDA; likewise if a phone number is noted on the PDA, it should be uploaded to ones PC. Everything on the PDA has to be saved to a desktop computer in case the batteries go dead in the PDA. So, any PDA must be able to communicate with a PC. The communication between PDA and PC is referred to as data synchronization or syncing. This is typically done through a serial or USB port on the PDA.

• Sony
• Palm
• Compaq
• Handspring
• HP
• Microsoft
• Casio

Sony is making some of the most innovative and feature-rich Palm OS PDAs.

Announced Oct.1st, 2003, this is Sony's latest entry level PDA. It runs Palm OS 5.2.1 on a 200 MHz processor with 16 megs of RAM and has a high res color display. It targets business users and doesn't offer advanced multimedia features. Est. $199 US.

• Sony Clié TJ35

Announced Oct.1st, 2003, this and the TJ25 are Sony's latest entry to mid level PDAs. It runs Palm OS 5.2.1 on a 200 MHz processor with 32 megs of RAM and has a high res color display. It has an MP3 player. Est. $249 US.

• Sony Clié UX50 & UX40

These groundbreaking new units have landscape 480 x 320 displays, comfy keyboards, integrated WiFi and Bluetooth (Bluetooth only on the UX40) and will fit in your pocket. They look like super-miniaturized notebook computers. And don't forget Palm OS 5.2 and a VGA camera. Est. $599 for UX40 and $699 for UX50.

• Clié NX80V

Released early July, 2003. The new top of the line NX. Palm OS 5, an XScale processor running at 200 MHz, hi-res transreflective display, MP3, 1.3 megapixel CCD digicam, integrated backlit keyboard, swiveling design and more. Est. $599 US

• Clié NX73V

Released late June, 2003. The new breed of NX series PDAs. Palm OS 5, an XScale processor running at 200 MHz, hi-res transreflective display, MP3, VGA digicam, integrated keyboard, swiveling design and more. Est. $499 US

• Clié TG50 Color

Released March, 2003. Sony's first tablet design PDA with a built-in thumb keyboard and integrated flip cover. Palm OS 5, an XScale processor running at 200 MHz, hi-res transreflective display, MP3 and more. It has Bluetooth. Est. $399 US

• Clié NZ90 Color

Announced Jan. 9, 2003, shipping mid-Feb. Think of this as an NX70V plus more toys. This new model has everything the NX70V offers, including Palm OS 5, an XScale processor running at 200 MHz, an amazing hi-res transreflective display, and more. It adds Bluetooth, a 2 megapixel digicam with flash, a better keyboard and a versatile cradle. Est. $799 US

• Clié SJ33 High res color

MP3 player, 66 mhz Dragonball processor, Palm OS 4.1, 16 megs of RAM. Compact and attractive. Est. $299 US

• Clié SJ22 High res color

33 mhz Dragonball processor, 16 megs of RAM, Palm OS 4.1, compact. Sony's follow up to the sucessful SJ30, but priced $100 less than the SJ30. Est. $199 US

• Clié SJ20 Monochrome

Came out just after the SL10 listed below and is the next step up.. It has a hi-res grayscale paper-white display, 16 megs of RAM and a rechargeable battery at a very reasonable price. Est. $199 US.