Newborn children hospitalised in an Intensive Care Unit frequently experience pain as a result of medical interventions. This makes adequate pain treatment very important. Assessing the level of pain in these very young children (0-1 years), however, is difficult. Although many assessment scales have been developed over the years, they are generally subjective, time consuming and discontinuous. Recent developments in long-term ambulatory monitoring [1,2] may, however, also be useful for objective pain assessment in young children.

The aim of this study was therefore to examine the feasibility of a so-called 'Continuous Pain Monitor', based on continuous, ambulatory and objective measurement of pain indicators. First, the most relevant indicators of pain were selected on the basis of existing pain assessment scales, the literature [3,4] and experts' opinions. Facial expressions, movement patterns of the extremities, muscle tension in the extremities and heart rate were all considered to be relevant and measurable parameters.

Second, based on explorative measurements in eight children during the post-operative period, a sensor configuration and analysis program was developed. EMG, accelerometry and ECG were monitored during these measurements.

Subsequently, the most appropriate configuration and analysis program was tested in six children to determine whether it was possible to continuously and objectively measure post-operative pain. The preliminary results show that signal variability and frequency content are both important signal characteristics. Validation measurements have been performed, and data will be presented.

References

1. Bussmann, J.B.; Martens, W.L.; Tulen, J.H.; Schasfoort, F.C.; van den Berg-Emons, H.J.; Stam, H.J. (2001). Measuring daily behavior using ambulatory accelerometry: the Activity Monitor. Behav Res Methods Instrum Comput, 33(3), 349-56.
2. Schasfoort, F.C.; Bussmann, J.B.J.; Stam, H.J. (in press). Ambulatory measurement of upper limb usage and mobility-related activities during normal daily life with an Upper Limb-Activity Monitor: a feasibility study. Med Biol Eng Comp.
3. van Dijk, M.; de Boer, J.B.; Koot, H.M.; Tibboel, D.; Passchier, J.; Duivenvoorden, H.J. (2000). The reliability and validity of the COMFORT scale as a postoperative pain instrument in 0 to 3-year-old infants. Pain, 84 (2-3), 367-77.
4. Peters, J.W.; Duivenvoorden, H.J.; Grunau, R.V.E.; Boer, J. de; Druenen, M.J. van; Tibboel, D.; Koot, H.M. (submitted). The value of the neonatal facial coding system for assessing post-operative pain in children.

Paper presented at Measuring Behavior 2002 , 4^th International Conference on Methods and Techniques in Behavioral Research, 27-30 August 2002, Amsterdam, The Netherlands

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