**2. Reduction of adhesion of coagulated blood on a tip of radio knife**

Radio knife is a common operation tool for surgery to avoid intense bleeding. However, there is severe trouble of severe adhesion of coagulated blood on the tip of radio knife during operation. The non‐conductive coagulated blood stops electric current and the radio knife can

© 2013 Umehara et al.; licensee InTech. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2013 Umehara et al.; licensee InTech. This is a paper distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

not work. In order to avoid this issue, nurses have to remove the coagulated blood from the tip of the radio knife frequently with abrasive clothes.

(a)

(c)

0

1

2

Adhesion force

*F* , N

3

4

5

5 mm

5 mm

Frequency : 6.8 kHz Amplitude: 7 - 19 m Power : 50W Cutting time : 20 s Sample : bovine blood Specimen : SUS304

(b)

(d)

**Figure 2.** Observation results of coagulated blood on the tip without and with vibration (a) No vibration as conven‐

0 5 10 15 20 Vibration amplitude *a* , mm

**Figure 3.** The relationship between vibration amplitude and adhesion force of conventional and vibrated tips

tional, (b) vibration amplitude:7 μm, (c) vibration amplitude:14 μm and (d) vibration amplitude:19 μm

5 mm

Tribology for Biological and Medical Applications 223

5 mm

Conventional Vibrated

Inordertoovercomethisissue,weconfirmedtheadhesionmechanismofbloodduringtheusage of a radio knife and proposed two types of new tips forradio knife as vibration‐cooled type and water‐cooledtype.Water‐cooledtype showedgoodresults [1,2].Figure1shows the experimen‐ tal setupto obtainsurface temperature ofradio knife by thermo camera. Highfrequency electric voltage was appliedfromelectricpower source as showninFigure 1 afterthe radioknife tip was dipped into bovine blood. During operation with electric power, temperature distribution aroundthetipwasmeasuredwithinfraredthermocamera.Alsoaftertheoperation,theadhesion force of coagulated blood on the tip was measured with s scratch test. At first we observed the coagulated blood on the tip with vibration by a bimorph‐typed piezoelectric actuator. Figure 2 shows the observation results of coagulated blood on the tip without and with vibration after test. It can be seen that amount of coagulation of blood decreased with increasing of ampli‐ tude. Afterthe observation, adhesion force was measured for each coagulated blood on the tip by a scratchtest of apinstylus.Themaximumscratchingforcewasdefinedas anadhesionforce. Figure 3 shows the effect of amplitude of vibration on the adhesion force. It can be seen from Figure 3 that the adhesion force decreased with the increasing of vibration amplitude gradual‐ ly. When the amplitude was reached to 19 μm, the adhesion force with vibration was 1/3 of that withoutvibration.Ontheviewpointoftemperaturesurroundingaradiotipwithelectriccurrent, the vibration decreased temperature of surface of blood. We supposed that the temperature reduction is the essence to reduce the coagulation of blood. Therefore we made a proto‐type of a tip with water cooling. Figure 4 shows the observation results of coagulated blood on the tip without and with water‐cooling after test. Water was circulated inside a radio knife tip under various flow rate of cooling water. It can be seen that amount of coagulation of blood de‐ creased with temperature. Figure 5 shows the relationship between adhesion force of coagulat‐ ed blood and flow rate of water. It can be seen that water‐cooling with 120 ml/min of flow rate provided 1/4 of adhesion force comparing to the conventional tip. On the basis of the well achievement of proposedtip, surface temperature shouldbe essentialto controlthe adhesion of coagulated blood.

**Figure 1.** Schematic diagram of experimental setup for blood coagulation to a radio knife tip

not work. In order to avoid this issue, nurses have to remove the coagulated blood from the

Micro-Nano Mechatronics — New Trends in Material, Measurement, Control, Manufacturing and Their Applications in

Inordertoovercomethisissue,weconfirmedtheadhesionmechanismofbloodduringtheusage of a radio knife and proposed two types of new tips forradio knife as vibration‐cooled type and water‐cooledtype.Water‐cooledtype showedgoodresults [1,2].Figure1shows the experimen‐ tal setupto obtainsurface temperature ofradio knife by thermo camera. Highfrequency electric voltage was appliedfromelectricpower source as showninFigure 1 afterthe radioknife tip was dipped into bovine blood. During operation with electric power, temperature distribution aroundthetipwasmeasuredwithinfraredthermocamera.Alsoaftertheoperation,theadhesion force of coagulated blood on the tip was measured with s scratch test. At first we observed the coagulated blood on the tip with vibration by a bimorph‐typed piezoelectric actuator. Figure 2 shows the observation results of coagulated blood on the tip without and with vibration after test. It can be seen that amount of coagulation of blood decreased with increasing of ampli‐ tude. Afterthe observation, adhesion force was measured for each coagulated blood on the tip by a scratchtest of apinstylus.Themaximumscratchingforcewasdefinedas anadhesionforce. Figure 3 shows the effect of amplitude of vibration on the adhesion force. It can be seen from Figure 3 that the adhesion force decreased with the increasing of vibration amplitude gradual‐ ly. When the amplitude was reached to 19 μm, the adhesion force with vibration was 1/3 of that withoutvibration.Ontheviewpointoftemperaturesurroundingaradiotipwithelectriccurrent, the vibration decreased temperature of surface of blood. We supposed that the temperature reduction is the essence to reduce the coagulation of blood. Therefore we made a proto‐type of a tip with water cooling. Figure 4 shows the observation results of coagulated blood on the tip without and with water‐cooling after test. Water was circulated inside a radio knife tip under various flow rate of cooling water. It can be seen that amount of coagulation of blood de‐ creased with temperature. Figure 5 shows the relationship between adhesion force of coagulat‐ ed blood and flow rate of water. It can be seen that water‐cooling with 120 ml/min of flow rate provided 1/4 of adhesion force comparing to the conventional tip. On the basis of the well achievement of proposedtip, surface temperature shouldbe essentialto controlthe adhesion of

Z stage

PIEZO Driver (Amplifier)

Blood

**Figure 1.** Schematic diagram of experimental setup for blood coagulation to a radio knife tip

Specimen

Vibrator

Specimen holder

Stainless steel case

Radio knife power source (High-frequency power source)

Function generator

tip of the radio knife frequently with abrasive clothes.

coagulated blood.

Biomedical Engineering

222

**Figure 2.** Observation results of coagulated blood on the tip without and with vibration (a) No vibration as conven‐ tional, (b) vibration amplitude:7 μm, (c) vibration amplitude:14 μm and (d) vibration amplitude:19 μm

**Figure 3.** The relationship between vibration amplitude and adhesion force of conventional and vibrated tips

T0 T1

ional)d)

Cooling temp : 23 Υ Flow rate: 0 ~ 120 ml / min Vibration frequency : 6.8 kHz Vibration amplitude : 7 ~ 19 Pm

Tribology for Biological and Medical Applications 225

C,

Power : 50W Cutting time : 20 s Sample : bovine blood

30 40 50 60 70 80 90 100 110 Temperature *T* , 䉝

**Figure 6.** Relationship between adhesion force of coagulate blood and surface temparature on the tip of convention‐

Therefore we obtained the relationship between surface temperature of tip on adhesion force as shown in Figure 6. It can be seen from this figure that adhesion force of blood was constant

C during temperature rising. It was clarified that this temperature dependence of adhesion force of blood was similar to the temperature dependence of blood deterioration at tempera‐ ture rising. Also it was found that we can realize high temperature at the tissue surface even if the temperature of a tip is lower that sever adhesion temperature with both proposed tips.

**3. Reduction of adhesion between steel and grilled fish protein with Ultra‐**

When you grill fish, you probably have experiences that skin and meat of the fish has adhered to some metal grids. This issue is still unsolved on the adhesion of the denatured fish body by heating. Conventional grids of grill are coated with Fluorine resin to avoid the severe adhe‐ sion of grilled fish to the grids. If the maximum temperature of grilling room is less that 300 <sup>o</sup>

the coatedgridwithFluorine resincanworkwell.Howeverwhenthe temperature inthegrilling

because Fluorine resin should disappear by heat decomposition. The recent grilling equip‐ ment heats both from top side and bottom side, and extra heating is applied to the grilling rods

C, conventional grill rods with Fluorine resin coating can not work well,

C even if the temperature on contact part between grid and fish is at about

C, rose up and reached to the large value if the temperature of blood was more than

0

al, vibrated and water-cooled tips.

**Hydrophobic DLC**

room rises up to 500 <sup>o</sup>

thatrise it up to 500 <sup>o</sup>

150 <sup>o</sup> C.

under 65o

80 <sup>o</sup>

2

Adhesion force

*F* , N 4

Heated specimen

Radio knife tip (Conventional) Radio knife tip (Vibrated) Radio knife tip (Cooled)

**Figure 4.** Observation results of coagulated blood on the tip without and with water-cooling (a) No water-cooling as conventional, (b) flow rate: 0 ml/min, (c) flow rate: 60 ml/min and (d) flow rate: 120 ml/min

**Figure 5.** The relationship between flow rate and adhesion force of conventional and water cooled tips

(a)

Biomedical Engineering

224

(c)

0

1

2

Cooling temp. : 23 ℃ Power : 50 W Cutting time : 20 s Sample : bovine blood Specimen : SUS304

Adhesion force

*F* , N

3

4

5

5 mm

5 mm

conventional, (b) flow rate: 0 ml/min, (c) flow rate: 60 ml/min and (d) flow rate: 120 ml/min

(b)

Micro-Nano Mechatronics — New Trends in Material, Measurement, Control, Manufacturing and Their Applications in

(d)

**Figure 4.** Observation results of coagulated blood on the tip without and with water-cooling (a) No water-cooling as

0 20 40 60 80 100 120 140 Flow rate *Q* , ml/min

**Figure 5.** The relationship between flow rate and adhesion force of conventional and water cooled tips

5 mm

5 mm

Conventional

Cooled

**Figure 6.** Relationship between adhesion force of coagulate blood and surface temparature on the tip of convention‐ al, vibrated and water-cooled tips.

Therefore we obtained the relationship between surface temperature of tip on adhesion force as shown in Figure 6. It can be seen from this figure that adhesion force of blood was constant under 65o C, rose up and reached to the large value if the temperature of blood was more than 80 <sup>o</sup> C during temperature rising. It was clarified that this temperature dependence of adhesion force of blood was similar to the temperature dependence of blood deterioration at tempera‐ ture rising. Also it was found that we can realize high temperature at the tissue surface even if the temperature of a tip is lower that sever adhesion temperature with both proposed tips.
