JMIR Publications

ABSTRACT

Background:

Continuous vital sign monitoring postoperatively may facilitate earlier detection of postoperative patient deterioration, but conventional cable-based systems can restrict mobility. Wearable monitoring devices may overcome some of these limitations, however, they still require a sensor to be attached to the patient´s skin, which may reduce comfort and acceptance.

Objective:

This study aimed to evaluate patients’ acceptance of continuous contactless radar-based vital sign monitoring after elective total hip and knee arthroplasty.

Methods:

In this prospective single-center study, adults undergoing primary elective total hip or knee arthroplasty were monitored throughout their inpatient stay using a wall-mounted radar-based system in addition to standard clinical monitoring. The investigational system was used solely for observational purposes and did not inform clinical decisions. Patients completed questionnaires assessing satisfaction, trust, perceived usefulness, personal acceptance of continuous monitoring, and device-related disturbances. Outcomes were analyzed descriptively.

Results:

120 patients were included and complete questionnaires were available for 111. Mean age was 67.6 years, mean BMI 29.6 kg/m², and mean ASA score 2.4. Overall satisfaction with radar-based monitoring was 8.3 ± 2.0 on a 0–10 scale. 68% rated the system as very or somewhat trustworthy, whereas only 1.8% provided a negative trust rating and 92.8% considered continuous radar-based monitoring useful. Overall, 94.6% stated that they would accept radar-based vital sign monitoring during medical treatment. Most patients (81.5%) reported no noticeable disturbance; the most frequently reported issue was the sensor light at night (7.6%), followed by slight noise (1.7%).

Conclusions:

Continuous contactless radar-based vital sign monitoring was well accepted by patients following elective joint arthroplasty and caused few perceived disturbances. Its contactless approach may be particularly suitable for postoperative patients, as it does not require skin-attached sensors or active patient interaction. Before routine clinical implementation, however, technical reliability, measurement accuracy, and integration into clinical workflows require further validation. Clinical Trial: German Registry for Clinical Trials, ID: DRKS00038082, date of registration: 09.10.2025.