Bodytrak® Feasibility Study

Bodytrak® is a wireless earpiece which can monitor the user's vital signs such as tympanic (ear) temperature and heart rate. The earpiece is non-invasive and should fit comfortably within the right ear, similar to an earphone with an over-the-ear hook. Bodytrak is currently in a prototype stage. The purpose of this study is to assess the feasibility of conducting a trial investigating the integration of Bodytrak in an NHS (National Health Service) environment at Chelsea and Westminster Hospital; to collect patient vital sign data for the development of Bodytrak algorithms to detect the transition point of recovery/deterioration of health, as well as the level of consciousness; and to obtain nurse and patient feedback regarding their user experience of Bodytrak.

BACKGROUND Sepsis claims many lives annually, and poses a substantial drain on NHS (National Health System) resources. The use of a 'track-and-trigger' monitoring system, or the National Early Warning System (NEWS) has reduced mortality rates in recent years, by detecting the early onset of Sepsis. However, the acquisition of vital signs, required as part of NEWS, is a manual, error-prone, and time consuming process. Therefore, scope exists for improvement in the care pathway by automation and subsequent improvements in reliability, staff productivity, and patient treatment outcomes. Post-operative patients are typically monitored for a period of time before they are discharged. Potentially, patient safety can be further improved, and earlier discharge can be enabled by means of a continuous vital signs monitoring device, with algorithms that can track deterioration/recovery rate. This complementary information, together with the NEWS score, can then provide objective metrics to aid the attending physician. The primary objectives of this study are to assess the effectiveness of Bodytrak in monitoring patient health. In addition, within the set of vital signs monitored by NEWS, it is most difficult to automate the measurement of the Level of Consciousness/Alertness (LOC). Therefore, one objective of the proposed project is to investigate the feasibility of developing an unobtrusive method for automatically measuring LOC, of patients who are not under the influence of general anesthesia, which leads to the introduction of Bodytrak. Bodytrak® is a non-invasive, wireless ear-based device which can continuously monitor physiological parameters including tympanic temperature, photoplethysmography (PPG) derived heart rate and heart rate variability and accelerometer based motion metrics. The earpiece should fit comfortably within the right ear, similar to a earphone. To this end, the physiological and biomechanical signals required for LOC algorithm development will be acquired using Bodytrak®. Automating the measurements of two other vital signs - Tympanic temperature and heart rate, will be carried out using Bodytrak® as well. Since these vitals are important predictors of Sepsis, and because they are currently part of the NEWS framework, providing reliable means of measurement, and automating the acquisition process is consistent with the goal of improving patient safety and staff productivity. As an important part of the study, these primary vital signs will be evaluated against validated medical devices. Further, critical to eventual improvement of the care pathway by means of Bodytrak® is the feedback that can be gathered from both patients and clinical staff, since they are the end users of the system. If this application is approved, Inova intends to work closely with its partner, Chelsea and Westminster Hospital, in order to gather information necessary for the integration of Bodytrak® into the NEWS framework. TRIAL DESIGN The trial is a non-blind, non-randomised single group feasibility study. 8 participants will be recruited who have scheduled elective surgery and aftercare in the HDU (high dependency unit). Patient participation will include 2 visits: a screening visit during a pre-clinic visit; and an intervention visit which will last approximately 2.5 days during their elective surgery in-patient stay in the high dependency unit. During their in-patient stay, participants will wear a Bodytrak earpiece during the day (for approximately 8 hours per day during the working hours of the research nurse), alongside continuous vital sign monitoring from hospital standard equipment (Philips Intellivue MP50 Monitor). The research nurse will carry out hourly checks on the patient to ensure the earpiece is not causing any discomfort. Patients will be asked to complete a feedback questionnaire regarding their experience of wearing Bodytrak. Research nurse's will also complete a feedback questionnaire regarding their use of Bodytrak. While the sample size is admittedly small, note that the purpose of this study is NOT to validate Bodytrak® as a medical device, but rather to determine if it is feasible to devise reliable algorithms for reliably detecting the LOC and patient status, as well as to carry out a preliminary evaluation of the vital signs derived from Bodytrak®. A power analysis test will be carried out after the data collection has completed, in order to ascertain the validity of the statistical tests used and to determine if the sample size is sufficiently large. This would provide useful information for further studies that need to be carried out.