Reducing blood viscosity with magnetic fields

Blood viscosity is a major factor in heart disease. When blood viscosity increases, it damages blood vessels and increases the risk of heart attacks. Currently, the only method of treatment is to take drugs such as aspirin, which has, however, several unwanted side effects. Here we report our finding that blood viscosity can be reduced with magnetic fields of 1 T or above in the blood flow direction. One magnetic field pulse of 1.3 T lasting ∼1 min can reduce the blood viscosity by 20%-30%. After the exposure, in the absence of magnetic field, the blood viscosity slowly moves up, but takes a couple of hours to return to the original value. The process is repeatable. Reapplying the magnetic field reduces the blood viscosity again. By selecting the magnetic field strength and duration, we can keep the blood viscosity within the normal range. In addition, such viscosity reduction does not affect the red blood cells’ normal function. This technology has much potential for physical therapy.

Figure 1

The relationship between blood viscosity and hematocrit.

Figure 2

Aggregated red-cell clusters have the shape that favors the flow dynamics, leading to further viscosity reduction.

Figure 3

(a) Without magnetic field applied, the red blood cells were randomly distributed in the plasma. (b)After a strong magnetic field of 1.33 T was applied for 1 min, short red-cell chains are formed. (c) After a strong magnetic field of 1.33 T was applied for 12 min, the red blood cells aggregated to form long cluster chains.

Figure 4

The kinetic viscosity of a blood sample at 37 °C dropped from 5.7 to 4.35 cS after applying a magnetic field of 1.33 T for 1 min. The viscosity then gradually increased to return to the original rheological state.

Figure 5

The viscosity of a blood sample at 37 °C dropped from 7.0 to 4.75 cP after applying a magnetic field of 1.33 T for 1 min. The viscosity then gradually increased to return to the original rheological state.