The Continuous Blood Pressure Device (CBPD) is a noninvasive beat-to-beat blood pressure, heart rate, and electrocardiogram (ECG) measurement device for use by crewmembers in microgravity.Facility Manager(s)
Johnson Space Center, Human Research Program, Houston, TX, United States
National Aeronautics and Space Administration (NASA)Expeditions Assigned
13,14,15,16,17,18,19/20,21/22Previous ISS Missions
The Continuous Blood Pressure Device (CBPD) is a noninvasive measurement device that measures blood pressure continually at the finger using plethysmography (which measures the change in volume of the finger due to blood flow). Finger cuffs, which have a small bladder and an infrared spectral measurement transmitter and receiver, are placed around the fingers. A basic three-lead electrocardiogram (ECG) amplifier is also provided for measurement of ECG data from the subject.
The CBPD is configured in a waist belt with three pouches to allow for individual (but electrically connected) stowage of the pump, microprocessor, and direct-current power adapter, which is replaced by batteries for ambulatory use. The waist-pouch configuration supports the front-end servo-controller, which operates attached to the back of the forearm and interfaces to the microprocessor and pump through electrical and air tube connections. The front end controls the pressure and data interface to the finger cuffs being used for arterial blood pressure monitoring. The front-end unit sends pressure feedback from infrared light-emitting diodes (LEDs) to the microprocessor for pump control and data acquisition purposes. The microprocessor has an internal flash memory card that can store up to 40 MB of blood pressure and heart rate data. The CBPD power and data interfaces reside in the microprocessor unit. The CBPD can, via software, interface to the Human Research Facility (HRF) laptop and workstation to download, display, and archive data. The data interfaces are RS-232 for personal computer monitoring and control, input for analog ECG, heart rate, and respiration timing; and output for analog blood pressure, ECG, and height correction.
The CBPD can be used to monitor beat-to-beat blood pressure for a wide range of investigations. The hardware (excluding the frontend unit which goes on the forearm) can be worn around the crewmembers' waist for extended periods of time, or it can be attached to a handrail or other Human Research Facility (HRF) hardware depending on the application.
To use the CBPD, the crewmember retrieves the hardware from its stowage location and dons the waist pack and frontend unit. The CBPD front-end unit is worn on the wrist or lower forearm and the main unit is inside a belt assembly worn around the waist. Alternatively, the belt assembly can be tethered to a hand rail during certain experiment scenarios. The finger cuffs are then applied. The CBPD can operate in two modes.