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TARGET REGION TEMPERATURE HISTORY APPROACH FOR INCREASING ACCURACY

OF CRYOEXPOSURE DOSE PROVIDING

Alexey V. SHAKUROV, Aleksandr V. PUSHKAREV, Anatoly A. ZHERDEV, Dmitry I. TSIGANOV

Bauman Moscow State Technical University

3th IIR conference on cold applications in life sciences – cryotherapy and cryopreservation, Saint Petersburg, Russia, 2018

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Acknowledgements

The study was supported by Russian Science Foundation grant (Project 16-19-10567).

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Outline

Short cryoexposure classification.

Target region of cryoexposure.

Problem: Low accuracy of dose providing.

Cryoexposure dose providing stages.

Target region temperature history approach.

An example: fluid hypothermia predicting.

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SHORT CRYOEXPOSURE CLASSIFICATION

Aim

Cryopreservation refrigerators, freezers Anabiosis

(protection against

destruction)

Cryosurgery hand-held portable,

stationary cryosurgical

devices

Cryonecrosis

(destruction)

Cryotherapy

(whole body & local)

cryochambers,

local therapy devices

Cryostimulation

(intensification of

biological activity)

Hypothermia hypothermia systems Protection against damage

(slowing down of

biological activity)

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TARGET REGION (TR) OF CRYOEXPOSURE

Before During After

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PROBLEM: LOW ACCURACY OF DOSE PROVIDING

physicians assigns the dose requirements for this TR;

the dose is provided as a result of heat transfer (between the equipment and the biotissue);

low correlation between the assigned and the actual dose (low accuracy of dose providing);

it is necessary to apply measures to improve the accuracy;

it is possible to create a universal indicator of successful cryoexposure.

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CRYOEXPOSURE DOSE PROVIDING STAGES Measures to improve the accuracy may take place at stages: Each stage has its own limit (saturation). However, if they are promoted all until saturation, then perhaps the problem will be solved using modern level of the technologies.

before (prediction);

during (control);

after (analysis) cryoexposure.

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TARGET REGION TEMPERATURE HISTORY APPROACH

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1\3 ПТО для МПГГ

10

TR analysis: - the depth of the TR is 2 mm; - TR volume increases during the operation; - initial temperature 37 ° C; - temperature of thermostating 5..15 ° C - for up to 10 minutes; - heating does not require exact limitations; - uncertainty should not exceed 2 ° C.

1

2

3

AN EXAMPLE: FLUID HYPOTHERMIA PREDICTING

min

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"prostate" (1), "urethra" (2), "bladder" (3), "rectum" (4), "urogenital diaphragm" (5),

"pelvic bone" (6), "fat" (7),"connective tissue" (8) and "fluid"(9).

Software - Ansys 18.

(1)

(2)

(3)

(7)

(4) (5)

(8)

(9) (6)

AN EXAMPLE: CRYOEXPOSURE SIMULATION PROGRAM

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AN EXAMPLE: CRYOEXPOSURE SIMULATION ANALYSIS

Safety check (TR & surrounding) Efficiency check (TR)

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AN EXAMPLE: TEMPERATURE HISTORY OF LIMIT POINTS

min sec

mm

mm

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CONCLUSIONS

The indicator of safety and efficiency for (1) any cryoexposure, (2) full sequence of stages of its implementation is proposed;

Other approaches that provide an increase in the accuracy of cryoexposures are also possible…

Further the applicability of the described approach should be practically tested for various types of cryoexposures and various types of equipment.

The most promising directions for testing are: (1) cryosurgery, (2) cryopreservation (especially for macroscopic structures, tissue engineering), (3) local and whole body cryotherapy.

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INSTITUT INTERNATIONAL DU FROID | INTERNATIONAL INSTITUTE OF REFRIGERATION

www.iifiir.org | iif-iir@iifiir.org | | | | #refrigeration

Alexey V. SHAKUROV

shakurov@bmstu.ru

Bauman Moscow State Technical University

THANK YOU Questions?