New optical device aims to detect dangerous neutropenia without needles

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: 1. Able to understand the purpose and risks of the study and to provide signed and dated informed consent and authorization to use confidential health information in accordance with national and local subject privacy regulations. 2. Male or Female aged 18 years or above. 3. Diagnosed with a hematological (e.g., lymphoma, myeloma) or breast cancer. 4. Scheduled active treatment with cytotoxic chemotherapy with an associated high/intermediate risk of neutropenia. 5. Able (in the Investigators opinion) and willing to comply with all study requirements Exclusion Criteria 1. Participants with amputations, congenital malformations, or any severe abnormalities of the hands as determined by the investigator. 2. Participants with a history of vasculitis, Raynaud syndrome, scleroderma, mixed connective tissue disease or any other rheumatologic systemic condition that could produce microcirculatory changes in the nailfold. 3. Participants with circulating tumour cells in previous or current lab determinations. 4. Participants with leukemia. 5. Participants with any condition producing significant tremor (e.g., essential tremor, Parkinson´s disease, dystonic tremor). 6. Inadequately medically controlled hypotension (systolic blood pressure \<90 and diastolic blood pressure \< 60mmHg). 7. Participants whose gold standard blood differential was obtained more than 120 minutes after the last evaluation with the medical device. 8. Any other significant disease or disorder which, in the opinion of the Investigator, may either put the participants at risk because of participation in the study, or may influence the result of the study, or the participant's ability to participate in the study. 9. Other unspecified reasons that, in the opinion of the Investigator or Sponsor, make the subject unsuitable for enrolment.