Jacobs Journal of Anesthesiology and Research

Novel Method for Continuous Long-Term Monitoring of Animals Via Multispectral Photoplethysmography

*Julia T. Rettberg
Department Of Aquatic Animal Medicine, TUM School Of Medicine, Munich, Germany

*Corresponding Author:
Julia T. Rettberg
Department Of Aquatic Animal Medicine, TUM School Of Medicine, Munich, Germany

Published on: 2018-11-19


Objectives: To investigate the reliability of vital sign parameters in different animal species measured with a Biovotion vital sign monitor (vsm-1; Biovotion AG, Switzerland) and to introduce a novel method for continuous long-term monitoring of freely moving animals using different medical indications. Study Design: All measurements were performed in animals anesthetized in the context of different preclinical studies. The interventions included anesthesia and intubation exercises, endoscopies, abdominal surgeries, ophthalmic surgeries, and cardiac studies. Animals: Eleven domestic pigs, ten minipigs and sixteen sheep. Methods: Heart rate (HR) and blood oxygenation (SpO2) were simultaneously measured under general anesthesia with conventional monitoring systems 1-3 using the vsm-1 at eight different positions. Data from both parameters were then compared statistically. Real-time values of various additional vital signs, including skin temperature, skin blood perfusion index, blood pulse wave, and motion/ acceleration, were transmitted from the vsm-1 to a laptop computer via Bluetooth and interpreted with the appropriate engineering tool (pyWatch; Biovotion AG, Switzerland). Results: The HR values measured using the vsm-1 (HRVSM) did not significantly differ from those measured simultaneously using conventional monitoring systems 1-3 (HRConventional). No relevant systematic differences (Δ HR) regarding the animal species or the position of the vsm-1 and no association with the magnitude of the measurements (Mean HR) were detected. The distribution of the differences showed no notable trends. The extent of the differences in the means (Δ Mean HR) related to individual positions was not consistent among the species. SpO2 measured using the vsm-1 provided reliable mean values in only one-third of the measurement cycles. Conclusions and Clinical Relevance: Parameter visualization via a user-friendly, real-time interface provides important information for potential applications using the vsm-1 for long-term monitoring. Further development of the investigated parameters, particularly SpO2, and others will improve both the monitoring and assessment of an animal’s well-being.


Heart Rate; Monitoring; Cardiovascular; Photophletysmography; Infrared; Microcirculation; Intensive Care; Pain Assessment; Stress; Animal Welfare


The primary diagnostic challenge in veterinary medicine compared with human medicine is the fact that animals cannot speak. Adequate knowledge about the patient depends on the anamnesis given by its owner and on a thorough clinical examination. Furthermore, stress, anxiety and aggressiveness not only make the examination more difficult but also disguise symptoms and may induce false investigative results. This observation was exemplified by Bragg et al, who compared measurements of panting and different vital sign parameters in healthy dogs in a veterinary clinic with measurements taken in a familiar environment.