You will be shown an abstract from a biomedical research paper. Given this abstract, your task is to extract all unique entities of the following types: ["HealthCareActivity", "InjuryOrPoisoning", "BodySubstance", "IntellectualProduct", "AnatomicalStructure", "SpatialConcept", "Chemical", "Bacterium", "MedicalDevice", "Organization", "BiomedicalOccupationOrDiscipline", "Finding", "BiologicFunction", "Virus", "ResearchActivity", "ClinicalAttribute", "PopulationGroup", "Eukaryote", "BodySystem", "Food", "ProfessionalOrOccupationalGroup"].

Please return the output as a JSON object of the format: {"Virus": ["HIV", ...], "Bacterium": ["MRSA", ...], "AnatomicalStructure": ["Lung", ...], "BodySystem": ["CNS", ...], "BodySubstance": ["Serum", ...], "Finding": ["Headache", ...], "InjuryOrPoisoning": ["Fracture", ...], "BiologicFunction": ["Death", ...], "HealthCareActivity": ["Biopsy", ...], "ResearchActivity": ["Clinical trial", ...], "MedicalDevice": ["Lenses", ...], "SpatialConcept": ["Camps", ...], "BiomedicalOccupationOrDiscipline": ["Forensic medicine", ...], "Organization": ["WHO", ...], "ProfessionalOrOccupationalGroup": ["Provider", ...], "PopulationGroup": ["Swimmers", ...], "Chemical": ["Gold", ...], "Food": ["Rice", ...], "IntellectualProduct": ["RPAM", ...], "ClinicalAttribute": ["Biomarker", ...], "Eukaryote": ["Dogs", ...]}. The keys should be entity types and values should be lists of extracted entities belonging to the corresponding type. If you cannot find entities belonging to a specific type, the value should be [].

Only output the JSON object and do not include any additional text.

Abstract:

Comparison of pulse wave velocity derived from accelerometer and reflective photo-plethysmography signals placed at the carotid and femoral artery Carotid - femoral pulse wave velocity is an established measure to assess cardiovascular risk and an interesting surrogate parameter towards non-invasive continuous blood pressure inference. Due to progress in sensing technologies for wearable wrist worn sensors, there are low cost sensor combinations of photo-plethysmography and high fidelity accelerometer s available offering access to pulse information from larger arteries complemented by blood volume changes in the superficial tissue. In this work we compare pulse wave velocities derived from accelerometer and reflective photo-plethysmography signals placed at the carotid and femoral artery. We discuss the different underlying physiological processes for the two sensing principles and present experimental results obtained in a study with healthy subjects.
{"AnatomicalStructure": ["larger arteries", "Carotid", "femoral artery", "superficial tissue", "femoral", "carotid"], "Bacterium": [], "BiologicFunction": ["physiological processes"], "BiomedicalOccupationOrDiscipline": [], "BodySubstance": [], "BodySystem": [], "Chemical": [], "ClinicalAttribute": ["blood volume", "non-invasive continuous blood pressure inference"], "Eukaryote": [], "Finding": ["experimental results"], "Food": [], "HealthCareActivity": ["pulse information", "photo-plethysmography", "reflective photo-plethysmography signals"], "InjuryOrPoisoning": [], "IntellectualProduct": [], "MedicalDevice": ["high fidelity accelerometer s", "accelerometer"], "Organization": [], "PopulationGroup": ["healthy subjects"], "ProfessionalOrOccupationalGroup": [], "ResearchActivity": ["study"], "SpatialConcept": [], "Virus": []}