PulSAR MD is an ultrasonic Doppler blood flow measurement system developed by Indus Instruments specifically for preclinical small animal research. The system integrates dual-channel simultaneous acquisition, multiple ultrasound measurement modes, and automated data analysis to measure blood flow velocity, vessel diameter, volumetric flow, and cardiac functional parameters, enabling comprehensive assessment of hemodynamics and cardiovascular function. Its slender, pen-style ultrasound probes support noninvasive repeated measurements, making the system suitable for disease model studies, evaluation of pharmacological interventions, and longitudinal studies.

The integrated electronics unit combines a pulsed Doppler transceiver, a Doppler signal digitizer, and a physiological signal digitizer. Together with automated analysis software, it enables signal acquisition, waveform display, and parameter analysis. The system provides two independent Doppler channels, A and B, each supporting switching between 10 MHz and 20 MHz probe frequencies to accommodate different animal models and measurement requirements.

Pulsed Doppler technology measures aortic outflow, mitral inflow, and peripheral vascular blood flow velocities to assess cardiac systolic and diastolic function and changes in vascular hemodynamics. The two channels simultaneously acquire blood flow velocity waveforms at two measurement sites. Pulse wave velocity (PWV) is calculated from the pulse transit time between the sites and the distance separating them, enabling assessment of arterial stiffness.

The automated analysis software rapidly calculates blood flow velocity, pulsatility index, resistive index, and other parameters, reducing manual analysis workload and inter-operator variability. The system also accepts external physiological signals, including electrocardiography and respiration, and can be used with an RSM+ or RSM oX small animal physiological monitor for integrated monitoring of hemodynamics and vital signs.

• Simultaneous dual-channel acquisition of blood flow velocity waveforms at two measurement sites supports in vivo pulse wave velocity measurement.

• Slender, pen-style probes facilitate adjustment of the angle between the ultrasound beam and the direction of blood flow, allowing measurements at multiple vascular sites in small animals.

• Integrated M-mode ultrasound, pulsed Doppler, and color Doppler M-mode enable measurement of blood flow velocity, vessel diameter, and dynamic cardiac changes.

• Automated analysis software calculates blood flow velocity, pulsatility index, resistive index, and cardiac functional indices.

• External physiological signals, including electrocardiography and respiration, can be acquired and recorded synchronously to support comprehensive assessment of cardiovascular function.

• Noninvasive ultrasound measurement supports repeated measurements and longitudinal studies in the same animal.

Technical Specifications

• Doppler Channels: Two independent channels (A and B), supporting simultaneous acquisition of blood flow signals at two sites.

• Ultrasound Frequencies: Independently selectable 10 and 20 MHz on each channel.

• Maximum Blood Flow Velocity: 770 cm/s (10 MHz, 100 kHz PRF, and a 0° angle between the ultrasound beam and the direction of blood flow).

• Pulse Repetition Frequency: 10/20 MHz: 25, 50, and 100 kHz; 30 MHz: 25 and 50 kHz.

• Physiological Signal Inputs: Four inputs: EKG, Aux1, Aux2, and Aux3.

Applications

• Studies of cardiac systolic and diastolic function and cardiac remodeling in small animals.

• Assessment of arterial stiffness, vascular elasticity, and pulse wave velocity.

• Studies of peripheral vascular blood flow velocity, vessel diameter, and volumetric flow.

• Hemodynamic assessment related to myocardial, renal, cerebral, and other organ perfusion.

• Studies of coronary flow velocity reserve and myocardial ischemia.

• Studies using cardiovascular disease models, including transverse aortic constriction (TAC), hypertension, and atherosclerosis.

• Longitudinal monitoring of pharmacological interventions, vasodilatory responses, and cardiovascular disease progression.

Inhibition of glycosphingolipid synthesis ameliorates atherosclerosis and arterial stiffness in apolipoprotein E-/- mice and rabbits fed a high-fat and -cholesterol diet. Chatterjee S, Bedja D, Mishra S, Amuzie C, Avolio A, Kass DA, Berkowitz D, Renehan M. Circulation, 129:2403-2413, (2014). PMID: 24710030

RhoBTB1 protects against hypertension and arterial stiffness by restraining phosphodiesterase 5 activity. Mukohda M, Fang S, Wu J, et al. J Clin Invest, 129:2318-2332, (2019). DOI: 10.1172/JCI123462

A surgical mouse model of neonatal pressure overload by transverse aortic constriction. Malek Mohammadi M, Abouissa A, Heineke J. Nat Protoc, 16:775-790, (2021). DOI: 10.1038/s41596-020-00434-9

Doppler velocity measurements from large and small arteries of mice. Hartley CJ, Reddy AK, Madala S, Entman ML, Michael LH, Taffet GE. Am J Physiol Heart Circ Physiol, 301:H269-H278, (2011). PMID: 21572013