Ambulatory monitoring of physiological variables is important in following the health status of individuals in non-hospital controlled situations. The investigators are developing a non-invasive sensor based on dynamic light scattering that is able to measure pulse, blood flow and coagulability. Oxygen saturation can also be detected with minor modification of the apparatus. The investigators plan to validate the investigators sensor by applying it to patients in the intensive care unit, or to patients undergoing cardiac stress tests. The results of the investigators sensor will not be utilized for any therapeutic decisions, but will be collected for later comparison with conventional monitoring of pulse and oxygenation with standard monitors. The monitor is worn like a wrist watch, and will collect data into a small data storage disc for later analysis.

Subjects to be studied will be either individuals undergoing routine cardiac stress tests, or patients admitted to the pulmonary ward of Meir Hospital who are being monitored in conventional manner. Normal volunteers will also be tested, under the following conditions: at rest, while running, while performing calisthenics, and while crawling on the ground. If non-inferiority of the new sensor is established compared to the standard clinically used sensors, then additional studies will be performed on acutely ill patients, such as patients admitted with multi-trauma.

Inclusion Criteria:

• Patients who are able to sign informed consent.
• Patients undergoing standard cardiac stress tests who are able to sign informed consent.
• Patients with pulmonary disease who are being monitored in a routine manner who are will ing to sign informed consent.

Exclusion Criteria:

• Children
• Patients unable or unwilling to give consent

Normal volunteers will be studied. Individuals undergoing routine cardiac stress testing will be studied. Stable patients admitted to the pulmanary ward who are being monitored routinely for oxygen saturation and pulse will be studied.