Study type: Medical/biological study (experimental study)

Thermal haemolytic threshold of human erythrocytes med./bio.

By: Checcucci A, Olmi R, Vanni R
Published in: J Microw Power Electromagn Energy 1985; 20 (3): 161-163
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Aim of study (acc. to author)

To perform a systematic study of the thermal threshold for human blood.

Background/further details

Microwave heating is used in therapeutic treatment of several diseases. It is therefore useful to know the thermostability of red blood cells.

Endpoint

Exposure

Exposure Parameters
Exposure 1:
Exposure duration: intermittent* during the growth phase
  • SAR: 250 mW/g mean (cf. remarks) (when the blood samples were heated upto 50°C)
Exposure 2:
Exposure duration: intermittent* during the steady state temperature phase for at least 30 min
  • SAR: 250 W/kg mean (cf. remarks) (when the blood samples were heated up to 50°C)

General information

*Heating of samples were divided into 2 phases: Growth phase in which irradiation is applied when the temperature is below a given function in time. Steady state temperature in which irradiation is applied when the temperature falls below the preset value

Exposure 1

Main characteristics
Exposure duration intermittent* during the growth phase
Additional info Microwave irradiation Reference article: Bacci M, Bini M, Checcucci A, Ignesti A, Millanta L, Rubino N and Vanni R (1981) J. Chem. Soc. Faraday Trans. 77: 1503-1509.
Modulation
Modulation type unspecified
Exposure setup
Exposure source
Setup The heating system consisted of a resonant cavity with sample positioned at the point of maximum coupling to the electric field.
Additional info The sample was contained in a Plexiglas cuvette (10 x 10 x 45 mm³) which was inserted in a section of an S-band waveguide filled with lossless thermal insulating material.
Parameters
Measurand Value Type Method Mass Remarks
SAR 250 mW/g mean determined by power loss cf. remarks when the blood samples were heated upto 50°C

Exposure 2

Main characteristics
Exposure duration intermittent* during the steady state temperature phase for at least 30 min
Additional info Microwave irradiation
Modulation
Modulation type unspecified
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
SAR 250 W/kg mean determined by power loss cf. remarks when the blood samples were heated up to 50°C

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

Temperatures between 50 and 55°C are necessary to produce an initial haemolysis of red blood cells in the whole blood, while the thermal threshold drops to 37°C for erythrocytes suspended in buffered saline.

Study character:

Study funded by

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