PDA adapted to control intravenous pain-relief

A US company has linked up an intravenous medication pump to a handheld computer that allows patients to control the amount of painkiller they receive, recording the dosage amounts and times for analysis by clinicians.

Medtronic, whose Personal Therapy Manager (PTM) is based on a Palm Handspring, developed the device after suggestions from doctors. The device (right) is connected via a wireless link to a drug infusion system, called SynchroMed, that delivers medication via catheter to the spinal cord. It is aimed at patients who experience chronic pain, and costs up to $50,000 (£25,000).

"Pain is very subjective," Dr Stephen Oesterie, senior vice-president for medicine and technology told BusinessWeek magazine. "Only the patient is the best judge of chronic pain intensity."

"We hadn’t thought of a patient controller for the SynchroMed previously," added Tom Valine, senior product manager at Medtronic. "But the physicians overwhelmingly urged us to create one."

Software on the PTM invites the patient to indicate what level of pain she is feeling, either by entering it on a scale of 0 to 10 or by selecting a happy or a sad face. Any medicine that is delivered is recorded.

In order to prevent overdose, the patient’s doctor can set a maximum number of extra doses that can be given above what they have already been prescribed. Data can also be downloaded wirelessly to a doctor’s computer so that the patient’s dosage pattern can be monitored.

The Palm device was chosen by Medtronic because it was in common usage and familiar. It has been altered by the installation of the dosage software and a wireless transmitter at the top of the unit, and no longer functions as a PDA. However, Medtronic believes that functioning mobile devices that can interface with medical devices are not far off.

Kevin Young, director of industrial design at Design Continuum, a healthcare device development company, told the magazine: "Before, serious medical tools had the feel and look of ‘Don’t touch me, because you don’t have the background or education to use this equipment’."

Medtronic, a 50-year old international medical technology company, were responsible for inventing the world’s first wearable pacemaker in, based on a metronome, at a paediatrics clinic in Minnesota in 1957. The company is active in the UK, and manufactures cardiology devices.