THERMOMETRIC CALIBRATION OF THE HEATING EFFECTS BY 27.12 MHz
METTLER DIATHERMY SYSTEM FOR USE IN HYPERTHERMIA SYSTEM FOR
TREATMENT OF CANCER
Abdul Muqeet Syed
B.E., Osmania University, India, 2006
Atif Ahmed Syed
B.E., Osmania University, India, 2006
PROJECT
Submitted in partial satisfaction of
the requirements for the degree of
MASTER OF SCIENCE
in
ELECTRICAL AND ELECTRONIC ENGINEERING
at
CALIFORNIA STATE UNIVERSITY, SACRAMENTO
FALL
2009
THERMOMETRIC CALIBRATION OF THE HEATING EFFECTS BY 27.12 MHz
METTLER DIATHERMY SYSTEM FOR USE IN HYPERTHERMIA SYSTEM FOR
TREATMENT OF CANCER
A Project
by
Abdul Muqeet Syed
Atif Ahmed Syed
Approved by:
, Committee Chair
Dr. Preetham B. Kumar, Ph.D.
, Second Reader
Prof. Russ Tatro, MS EE.
Date
ii
Name of the Students:
Abdul Muqeet Syed
Atif Ahmed Syed
I certify that these students have met the requirements for format contained in the
University format manual, and that this Project is suitable for shelving in the Library and
credit is to be awarded to this Project.
____________________________, Graduate Coordinator
Dr. Preetham B. Kumar, Ph.D.
Department of Electrical and Electronic Engineering
iii
____________________
Date
Abstract
of
THERMOMETRIC CALIBRATION OF THE HEATING EFFECTS BY 27.12 MHz
METTLER DIATHERMY SYSTEM FOR USE IN HYPERTHERMIA SYSTEM FOR
TREATMENT OF CANCER
by
Abdul Muqeet Syed
Atif Ahmed Syed
This project will focus on the thermometric calibration of the heating
effects by the 27.12 MHz Mettler Diathermy system on non-hardening clay with digital
thermometer of plastic probe for use in Hyperthermia system for the treatment of cancer.
The non-hardening clay is chosen so that the electrical properties are identical to the
biological human tissue. The experimental study on the Mettler diathermy system will
include the adjustments of the head of the applicator and different sizes of clay medium.
Our goal would be to achieve the temperature of the treatment within the desired time
and to improve the conditions of the experiment and to be more efficient and accurate
with the temperature measurements with respect to time.
, Committee Chair
Dr. Preetham B. Kumar, Ph.D.
_______________________
Date
iv
ACKNOWLEDGEMENTS
We would like to take this opportunity to convey our sincere regards to Dr. Preetham
Kumar, faculty Member, EEE department and Graduate Advisor, for valuable guidance,
giving us the opportunity to take on this project and being very helpful throughout this
project. It was his support and encouragement that helped the project to start and end at
the right time. We thank him again for his constructive feedback throughout the course of
our fieldwork.
We would also like to acknowledge and thank Professor Russ Tatro, Faculty Member,
EEE department for being part of the review committee and extending his guidance for
better formulation of our project. We also thank him for his review and comments on the
project report.
Our sincere appreciation goes to all our family members and friends for their love and
support during the entire duration of our coursework and this project.
v
TABLE OF CONTENTS
Page
Acknowledgements……...………………………………………………………………...v
List of Tables…………………………………………………………… ……………….ix
List of Figures…………………………….……………….……………………………...x
Chapter
1. INTRODUCTION……..…………...…………….…………………………...…………1
2. BACKGROUND RESEARCH ON MICROWAVE HYPERTHERMIA IN
CANCER TREATMENT…………………………………3
2.0 Description on Hyperthermia Radiation ……………………………………………3
2.1 Types of Hyperthermia ……………………………………………………………..3
2.1.1 Local Hyperthermia ………………………………………………..……….4
2.1.2 Regional Hyperthermia ……………………………………………………..5
2.1.3 Whole Body Hyperthermia …………………………………………….…...7
2.2 Effects and Working Methodology of Hyperthermia ….…………………………..8
2.3 Benefits of Hyperthermia ………………….……….......………………………....10
2.4 Risks Involved in Hyperthermia..…………………………………………………12
3. DIATHERMY SYSTEMS FOR HYPERTHERMIA APPLICATIONS ………..……14
3.1 Hyperthermia Application Systems………………………………………………...14
3.1.1 Hot Packs ………………………………………………………………….14
3.1.2 Electrical Heating Pads ………………..….……………………………….15
vi
3.1.3 Heat Lamps …………………………………………………………………..15
3.1.4 Paraffin baths…………………………………………………………………15
3.1.5 Ultrasound…………………………………………………………………….16
3.1.6 Infrared Heating Pads……………………………….……...………………...16
3.2 Diathermy…………………………………………………………………………16
3.2.1 Shortwave Diathermy………………………………………………………17
3.2.1.1 Dielectric Diathermy………………………………………..……….17
3.2.1.2 Inductive Diathermy……………...…...…………………………….17
3.2.2 Microwave Diathermy ……………………………………………………..18
3.3 Absorption of Microwaves………………………………………………………..19
3.3.1 Effect of Hyperthermia in the Flow of Blood …………...………………...21
3.3.2 Features of Diathermy Devices…..…..………………………………….…22
4. METTLER AUTOTHERM EQUIPMENT DESCRIPTION………………………...25
4.1 Mettler Autotherm Equipment Details ………..…………………………………26
4.2 Mettler in Heat Therapy ……………..…………..………………………………27
4.3 Technical Specifications of Mettler Autotherm Equipment ……………….……28
4.4 Advantages of Mettler Shortwave Diathermy Unit …..…………………………29
4.5 Precautions While Using Autotherm ..…..………………………………………29
4.6 Digital Thermometer with Plastic Probe ….…………………………………….32
5. EXPERIMENTAL RESULTS USING DIATHERMY ON CLAY MEDIUM…...….34
5.1 Measurements with the Probe on the Top of the Clay….……..………………...35
vii
5.2 Measurements with Probe Inserted 1 Inch From the Surface…….…..…….……37
5.3 Measurement with the Sliced Clay……….……..….……………………………38
5.4 Measurements Using a Reflector……………….…...…………………………...40
5.5 Measurements with the Applicator Touching Clay………….…….…..……..….41
5.6 Measurement with the Probe Inserted one Inch From the Surface…….…...……43
5.7 Measurements with the Sliced Clay Toucing the Applicator Head….………….44
5.8 Measurements of the Clay with Water………….…….…..….………………….47
6.CONCLUSION………………………………………………………………………..50
References ……………………………………………………………………………….52
viii
LIST OF TABLES
Page
Table 3.1 Penetration Depths of Tissues in cm with High and Low
Water Content Tissues………………………………………….19
Table 4.1 Electromagnetic Heating Comparison .………….…………...………………..30
Table 5.1 Variation of Temperature Rise in Thick Clay with Time
(Probe on Top of Thick Clay)………………………………….36
Table 5.2 Variation of Temperature Rise in Clay with Time
(Probe Inch below Clay Surface)………………………………37
Table 5.3 Variation of Temperature Rise in Sliced Clay with Time
(Probe on Top of Clay)…………………………………………39
Table 5.4 Variation of Temperature Rise in Clay with Time Using Reflector
(Probe on Top of Clay)…………………………………………40
Table 5.5 Variation of Temperature Rise in Clay with the Applicator Touching
(Probe on Top of Clay)…………………………………………42
Table 5.6 Variation of Temperature Rise in Clay with the Applicator
Touching the Surface…………………………………………..43
Table 5.7 Variation of Temperature Rise in Sliced Clay with the Applicator
Touching the Surface…………………………………………..45
Table 5.8 Variation of Temperature Rise in Clay at Different Depths with the
Applicator Touching the Surface……………………………….46
Table 5.9 Variation of Temperature Rise in Clay with Time
(One Inch below Clay Surface with Water)………………….…48
ix
LIST OF FIGURES
Page
Figure 2.1 Scheme for Local Hyperthermia ……….……………………………………...4
Figure 2.2 Applicator Types for Local Hyperthermia, such as (a) Waveguide
Applicator; (b) Spiral Applicator; and (c) Current Sheet Applicator……………..………5
Figure 2.3 Sigma-60 Applicator……………………………………………..……….…….6
Figure 2.4 Schematic for Aquatherm System ……………………………….…………….8
Figure 2.5 Density Measurements From Stained Tissues ….…..………….....…...……...9
Figure 3.1 Rate of Heat Penetration in Fat, Muscle and Bone Tissues……....….…….….20
Figure 3.2 Range of Intensities of Stray Magnetic Fields around
the Diathermy Cables………………………………….….23
Figure 3.3 Range of Intensities of Stray Magnetic Fields around
the Diathermy Cables……………………………………..24
Figure 4.1 Mettler Autotherm Diathermy Unit………………………………….………..25
Figure 4.2 Control Knobs on Mettler Autotherm…….……….…………………………..26
Figure 4.3 Patient Input Meter for Autotherm………….….……………………………...27
Figure 4.4 Relative Absorption of RF Power Generated by the
Autotherm Equipment…………………………………….28
Figure 4.5 Plastic Probe Digital Thermometer…………....………………………………32
Figure 5.1 Graphical presentation of Temperature Vs Time
(Probe on Top of Thick Clay)……………………………..36
Figure 5.2 Graphical Presentation of Temperature Vs Time
(Probe Inch below Clay Surface)………………………….38
Figure 5.3 Graphical Presentation of Temperature Vs Time
(Probe on Top of Clay)……………………………………39
x
Figure 5.4 Graphical Presentation of Temperature Vs Time
(Probe on Top of Clay)……………………………………41
Figure 5.5 Graphical Presentation of Temperature Vs Time…….….……………………42
Figure 5.6 Graphical Presentation of Temperature Vs Time
(Probe One Inch below the Surface)……………..………..44
Figure 5.7 Graphical Presentation of Temperature Vs time
(Probe on Top of the Clay)……………………………….45
Figure 5.8 Graphical Presentation of Temperature Vs time
(for all three Depths)……………………………….……47
Figure 5.9 Graphical Presentation of Temperature Vs Time
(One Inch below Clay Surface)………………………….48
xi
1
Chapter 1
INTRODUCTION
In this phase of experiment our aim is to focus mainly on several aspects to
improve the accuracy and the understanding of hyperthermia treatment using Mettler
Autotherm. However, we want to improve the experimental procedure in such a way that
we can get consistent measurements. Our goal is to get accurate and efficient
measurements so that these can become the basis for further study and research in
treatment of hyperthermia. There are certain changes that could be done to achieve
desired temperature at different depths so that it comes closer to the real time treatment of
hyperthermia.
We are using the Mettler Autotherm 300 to generate microwaves for heating the
clay. Clay is chosen as it closely mimics the properties of human tissue or skin. The
modern hyperthermia equipments used these days are highly complicated, bulky and are
very expensive. This makes the treatment confined and accessible to very small number
of centers. On the other hand the Autotherm 300 is portable, flexible and inexpensive.
This is the reason even small treatment centers can take advantage of it.
In this experiment we will be replacing the metal probe thermometer with plastic
probe digital thermometer. In the first phase of measurements [1] the temperature
readings taken by metal probe thermometer were inaccurate as the calibrations were
affected by interference between the incident wave energy and the metal probe. As stated
earlier, our aim is to obtain higher temperature similar to the temperature used in real
2
time treatment. We will vary the medium of transmission for some measurements. We
will also be using the reflector in different positions in order to increase the heating
effect. The process of consistent heating will be done to observe the differential heating
effect, so that we can understand the variations with respect to time in a better manner.
More number of variations in the temperature calibrations is expected throughout the
experiment.
According to Food and Drug Administration (FDA) the patient should not be
exposed to heat more than 20 minutes. This regulation is set to avoid the pain threshold in
human during the treatment. The experiment will also involve the ways to achieve this
temperature rise (more than 100° F) within 20 minutes of the treatment time. This
variation can be achieved if we succeed in reducing the heat loss during the experiment.
Our main goal in this experiment hence is to improve the experimental conditions
from the first phase and also to understand more efficient and accurate temperature
variations with respect to time. The first chapter of this report is an introduction to
cancer and the treatments used. Chapter II gives background knowledge and research on
hyperthermia for the treatment of cancer. We will also be discussing the benefits and
applications of microwave hypothermia. Chapter III explains the dielectric properties and
the types of diathermy. Chapter IV looks at the details of Mettler Diathermy equipment
and Plastic probe thermometer. Finally Chapter V details the experimental results that
were obtained using the Mettler Autotherm unit, followed by the conclusions and
References.
3
Chapter 2
BACKGROUND RESEARCH ON MICROWAVE HYPERTHERMIA IN
CANCER TREATMENT
2.0 Description on Hyperthermia radiation
Hyperthermia is a type of treatment in which body tissues under treatment are
exposed to high temperatures. Research has shown that high temperatures can damage
and kill cancer cells, usually causing minimum injury to the other normal tissues. It is
proposed that by killing cancer cells and damaging proteins and structures within the
cells, hyperthermia may shrink tumors [2]. The heat may destroy two types of tumor
cells, the first being those that are making deoxyribonucleic acid (DNA) in preparation
for division and the second type of cells being those that are acidic and poorly
oxygenated. These cell types tend to be resistant to radiation [3]. It is suggested by
proponents that heating makes cells more sensitive to radiation and prevents radiationdamaged cells from repairing themselves [4].
2.1 Types of Hyperthermia
There are different kinds of hyperthermia that are under study
1. Local Hyperthermia
2. Regional Hyperthermia
3. Whole Body Hyperthermia
4
2.1.1 Local Hyperthermia
In local hyperthermia the cells affected with cancer are heated to at very high
temperatures 106° F by using heating elements such as microwave, antennas, heating
rods, ultra sound. In this treatment the heat is applied to small areas on the body and
when the cancerous cells are exposed to high temperatures continuously they get
destroyed. Two factors play a major role in this treatment: the temperature of the cell and
the volume of area exposed. The temperature of 106º F for a period of 60 min is used
here [5]. There are several applicators are used for the treatment of local hyperthermia
such as waveguide, horn, spiral, current sheet and compact applicators. The temperature
during the treatment can be controlled either by positioning the applicator or using a
power generator. We can see the components used in the hyperthermia system in the
Figure 2.1, 2.2.
Figure 2.1 Scheme for Local Hyperthermia [6]
5
Figure 2.2 Applicator Types for Local Hyperthermia, such as (a) Waveguide Applicator;
(b) Spiral Applicator; and (c) Current Sheet Applicator [6]
2.1.2 Regional Hyperthermia
Regional Hyperthermia is used for specific body organ such as hands, legs. It is
very popular for the treatment of cancers like sarcomas and melanomas. Deep tissue,
regional perfusion and Continuous Hyperthermic Peritonial Perfusion (CHPP) are the
different ways that are followed in regional hyperthermia.
Deep tissue cancer treatment is done mainly for lung, liver and ovarian
carcinoma. The tumor is treated with devices that can produce high energy waves
directed to specific areas [7]. In Regional perfusion affected body part is isolated from
the rest of the body. Pump oxygenator is used to pump the blood from the isolated region
6
into the heating device. Once the blood is heated to certain temperature the blood is
pumped back.
Continuous Hyperthermic Peritonial Perfusion (CHPP) is type of regional
hyperthermia which is used to treat abdominal cavity cancers such as intestines and
digestive organs. The drugs are injected into the cancerous cavity during this treatment
and the temperature is maintained up to 108º F.
Regional hyperthermia treatment uses the Sigma-60 applicator which is shown
below in Figure 2.3
Figure 2.3 Sigma-60 Applicator [6]
7
2.1.3 Whole Body Hyperthermia
Whole body hyperthermia (WBH) is utilized when the cancer has spread
throughout the body (metastatic cancer) [5]. It is achieved with either radiant heat or
extracorporeal technologies, and elevates the temperature of the entire body to at least
105.8° F. In radiant WBH, heat is externally applied to the whole body using hot water
blankets, hot wax, inductive coils, or thermal chambers.
The patient is sedated throughout the WBH procedure, which lasts approximately
four hours. The patient reaches target temperature within approximately 1.3 hours, is
maintained at 107.2° F for one hour, and one-hour cooling phase. During treatment, the
esophageal, rectal, skin and ambient air temperatures are monitored at 10-minute
intervals. Small probes may be inserted into the tumor under a local anesthetic to monitor
the temperature of the affected tissue and surrounding tissue. Heart rate, respiratory rate,
and cardiac rhythm are continuously monitored. It is always recommended to use
temperatures below 111° F otherwise the normal tissues may also get affected [5].
The Aquatherm system is used for the whole body hyperthermia. It is an isolated
moisture-saturated chamber which ha steamed tubes (122 – 140 °F) on its inner sides in
which the patient is positioned. The whole body is exposed to long-wavelength infrared
wave emission. The cabins contain hot water tubes where the patient is kept and the
temperature of (140° F) is maintained inside. After a systemic temperature of 107.2° F
has been achieved, the patient is thermally isolated with blankets.
8
Figure 2.4 Schematic for Aquatherm System [6]
2.2 Effects and Working Methodology of Hyperthermia
Hyperthermia has its own beneficial effects in several ways on the body. Several
studies have shown that this treatment increases apoptosis in the body in response to heat.
Hyperthermia damages the membranes, cytoskeleton, and nucleus functions of malignant
cells and thus kills the tumor cells. There is irreversible damage to cellular perspiration of
the cells. Heat above 105.8° F also pushes cancer cells toward acidosis that is decreased
cellular pH in body where there is decrease in the cells’ viability and transplantion
ability.
Hyperthermia when used activates the immune system of the body tissues. From
one of the source we get to know that "Heat has a well known stimulatory effect on the
immune system causing both increased production of interferon alpha, and increased
immune surveillance." [8] Another source mentions the release of lysosomes [7].
9
Tumors have an effect on the vessels carrying blood to them. The blood vessels
grow in such a way that these vessels are unable to dilate and dissipate heat as normal
vessels respond to heat. So tumors take longer to heat, but concentration of heat on to
them has immense effect on the cells. Tumor blood flow is increased by hyperthermia.
The blood flow increases as normal vessels are incorporated into the growing tumor mass
and are able to dilate in response to heat, and to channel more blood into the tumorous
cells. The figure 2.5 shows the density measurements of blood vessel for different
processes.
Figure 2.5 Density Measurements From Stained Tissues [9]
Tumor masses contain oxygen deprived cells within the inner part of the tumor.
These oxygen deprived cells provide resistance to radiation and are very sensitive to heat.
This is the reason hyperthermia is considered to be ideal companion to radiation. While
radiation kills the oxygenated outer cells, hyperthermia destroys the low oxygenated
10
cells. The hyperthermia oxygenates these cells and makes them more susceptible to
radiation damage. It is also thought that hyperthermia’s induced accumulation of proteins
stops the malignant cells from repairing the damage done by radiation.
We get to know from a source that "It can be hypothesized that hypoxic cells in
the center of a tumor are relatively radio resistant but thermo sensitive, whereas wellvascularized peripheral portions of the tumor are more sensitive to irradiation. This
supports the use of combined radiation and heat; hyperthermia is especially effective
against centrally located hypoxic cells, and irradiation eliminates the tumor cells in the
periphery of the tumor, where heat would be less effective." [7] [8].
Hyperthermia when used with radiation is very effective. Studies [8] reveal that
combination of hyperthermia and radiation therapy results effective and better treatment,
the response rate for radiation without heat was 35% and the response rate of
hyperthermia combined with radiation was 75% [8]”. As the research gains momentum,
more reasons for the use of hyperthermia are continuously being identified.
2.3 Benefits of Hyperthermia
Hyperthermia, when used alone, results in impressive shrinkage sometimes has
complete eradication (10-15%) of tumors. These results usually don’t last, and the tumors
grow again. Hyperthermia raises the body temperature above normal of 98.6° F as this
reduces the foreign organism presence and the impurities in the body. When compared to
the body tissues, the invading foreign organisms cannot survive in the high temperatures.
11
This is a certain benefit as the temperature can be increased above certain level which kill
the unwanted organisms, bacteria and virus, and thereby killing the cancer cells.
Increase in body temperature above normal levels consistently for a period of time
helps in drawing out toxins out of the body, cleaning clogged pores, killing of harmful
bacteria and viruses, increasing circulation and enhancement of immune system. It is also
used in treatments such as healing the muscle aches, pains and injuries which is treatment
after accidents [10].
There are several applications of the Hyperthermia in the field of medical
sciences. Many diseases can be treated by using this. Hyperthermia and radiation
combined together in the treatment has been reported to yield higher and durable
responses than radiation alone. In deep seated tumors, the effect of this combined
treatment is under research for deep seated tumors. Though it is difficult to increase
human tumor temperature, recent clinical trials has shown that radiation with
hyperthermia is far more successful in controlling many human tumors radiation alone.
Hyperthermia is used in the treatment of upper and lower respiratory tract infections,
bladder problems, bronchitis, pneumonia, urinary tract infections such as cystitis,
sinusitis and other conditions of the lungs and body cavities. It is also helpful in
controlling the bleeding; improve conditions in prostatic hypertrophy and psoriasis [7].
Hyperthermia may also provide additional advantage in drug delivery, being
specific hyperthermia is good choice for delivery of drugs with relatively large carriers.
Several studies have shown that the delivery of monoclonal antibodies is enhanced by
12
using hyperthermia, particularly to the tumors with resultant improvement in anti tumor
effects. The spread of carried chemo drugs into the tissues of liposome is increased
considerably with higher temperature when compared to that under normal temperature.
Much of the information and research has emerged from hyperthermia studies in
several other treatments that may become valuable in the future. Hyperthermia improves
the therapeutic index of TBI (total body irradiation), not only by increased neoplastic cell
kill, but also by inhibiting the expression of radiation induced damage to the normal cell
population.
2.4 Risks Involved in Hyperthermia
The side effects of hyperthermia are external methods includes pain, unpleasant
sensations and burns in a small percentage of patients. The situation is more complicated
in the case of the internal pyrogens. Sometimes there are fatal reactions in humans, as
bacterial toxins released during treatment can induce serious imbalances to the tissues,
depending on dosage. Ultrasound hyperthermia will cause bone pain in areas where the
tumor is over a bone. Whole body hyperthermia can result in neuropathies.
Extracorporeal systemic hyperthermia is another mode, where the blood is routed
from the body as in dialysis and is heat is applied before returning to the body. It has few
benefits such as higher possible temperatures, and more homogeneous heating. The side
effects are considerable such as frequent persistent peripheral neuropathies, abnormal or
lethal blood coagulation, damages to liver tissues and kidneys, and brain hemorrhaging
and some seizures. We get the reason from a source which says that the role of perfusion-
13
induced hyperthermia may be doubtful. There are few risks involved with whole body
hyperthermia and these risks include problems such as cardiac and vascular disorders,
diarrhea, nausea and vomiting. Extracorporeal systemic hyperthermia can give side
effects such as frequent persistent neurophites, damages to liver or kidneys, abnormal
blood coagulation, and brain hemorrhaging and few seizures. [11] [12]
All these risks and side effects involved with hyperthermia are very rare,
negligible and can be avoided by being careful and precise during treatment. The
reactions can be avoided by controlled clinical procedures.
14
Chapter 3
DIATHERMY SYSTEMS FOR HYPERTHERMIA APPLICATIONS
3.1 Hyperthermia Application Systems
Hyperthermia is any process that uses heat to cure a disease or in order to kill
tumors in the human or animal body. This process helps in relaxation of the muscle
tissues and also helps in the metabolic process and also in the induction of reflex
vasodilatation. Hyperthermia could be the process to kill on the skin or inside the skin.
[13] There are different processes that have been used as a process of Hyperthermia,
some of which are mentioned below:
3.1.1 Hot Packs
In this process of hyperthermia, canvas bags filled with silicon dioxide are used
that absorbs more times its own weight. These canvas bags are immersed in hot water for
good amount of time and are taken out whenever required. These canvas bags are
covered with seven to eight layers of towels before applying to the surface and they are
even made sure that the excessive water is taken out. These hot packs stay warm for 30
minutes and have advantage over heat lamps as the heat dries the skin and leaves the skin
of the patient moist.
15
3.1.2 Electrical Heating Pads
These are used as an alternate to the hot packs, and as these are electrically heated pads,
they remain warm for a longer time than the hot packs as the water keeps circulating in
this process. As the pads do not cool down by themselves, they should be set on a timer
that stops the process within 20 minutes or it would burn the skin.
3.1.3 Heat Lamps
The process of heat lamp works on the process of conversion of radiant energy
into heat. This process uses 250W incandescent bulb as these bulbs produce large
amounts of infrared energy which is good for the process. The heat of this process is
adjusted by varying the distance between the bulb and the body. Usually the ideal
distance between the bulb and the body is 40 to 50 cm. These are much easier to use than
the hot packs for the patient as well as the therapist. For the patient as there is no pressure
to be handled as in the case of hot packs.
3.1.4 Paraffin Baths
This process is done by using a mixture of mineral oil and paraffin in a container
which is heated from 122-129° F. The paraffin soluble can also be heated in small
containers or home stoves. It is easier in usage too and can be used by the patient either
by immersing the portion to be treated continuously for 30 minutes or even in intervals.
16
3.1.5 Ultrasound
This is process in which conversion of the energy helps in producing heat unlike
the process of Heat Lamps. In Ultrasound the sound energy is required to process the
heat, and this process is usually beneficent with the deep tumors in the skin. This can be
even placed on the skin or the application part can be immersed in the ultrasound treated
liquid. As this process requires constant check by a therapist, it is not recommended for
homes.
3.1.6 Infrared Heating Pads
These heating pads use infrared waves in order to generate heat as the infrared
rays contains the mechanisms such as arsenide and tungsten. In spite of the greater cost
involved with the process, the hot packs and electric heating pads remain much better
than the infrared heating pads. [13]
3.2 Diathermy
In this process of heating, high frequency electric currents increase the blood flow
in the body resulting in acceleration of the repair of the tissue. The heat generated also
helps in reducing the nerve fiber sensitivity and also in increasing the threshold of the
pain. This process is even used to treat arthritis, painful joints, pelvic infections and
sinusitis. [14]
There are two types of diathermy which are being used today: Shortwave diathermy and
Microwave diathermy.
17
3.2.1 Shortwave Diathermy
This diathermy is also known as radio frequency diathermy or high frequency
diathermy. This process works on the operating frequency of 27.12 MHz which is
assigned by the Federal Communications Commission. The part to be treated in this
process is mainly the one that contains thick tissues like the ones at the hip and breast.
The part is placed between two capacitor plates and high frequency wave is passed
between the plates that treat the part [15].
There are two methods of applying shortwave diathermy, one is dielectric diathermy and
the other is inductive diathermy.
3.2.1.1 Dielectric Diathermy
The electrodes that are used for the dielectric diathermy produce alternating
electric field which is kept either on one side or on both ends of the part to be treated. The
electrodes are usually small plates or wire mesh which are covered with cushion or
inserted inside the pillow. The electric charge that develops between the plates causes the
movement of the molecules, the friction and collision among the molecules generates
heat in the tissues.
3.2.1.2 Inductive Diathermy
This type of diathermy uses coil for the treatment of the tissue to generate circular
electric and magnetic fields into the tissues causing heat in them. These are usually used
at the lower RF regions. The coil is normally wound inside the applicator so that the coil
18
could produce reversing magnetic fields. The applicators are usually designed in such a
way that it could be easily adjusted and moved to be placed over the area or near to the
area to be treated.
Shortwave Diathermy has its own contraindications such as malignancy, sensory
loss, metallic implants, pregnancy, phlebitis, metal containing intrauterine contraceptive
devices, etc.
3.2.2 Microwave Diathermy
As the name denotes it, this diathermy treatment uses microwaves to heat the
body tissues. The applicator is usually a horn shaped or a direct beam gun that could be
utilized to direct the heat to the concerned area. The variation in the heat to be applied is
varied by the positioning the space between the applicator and the treated area. The shape
of the applicator is usually designed considering the area where it would be used for
treatment [15].
This diathermy deals with the frequency from 300 MHz to 300 GHz and this
spectrum is after the radio frequency spectrum. These high frequency waves are usually
used to cure the tumor on the tissues deep inside the human body. These microwave
frequencies help in the repair of the tissues and reduces the stiffness in the joints and
muscles.
The microwave diathermy unit works on the frequency spectrum of 2.45 MHz
and it is not just the frequency which is taken into consideration for the treatment but also
19
the other specifications such as time and power induced for the treatment. The table
below shows the penetration depths of microwaves in the human tissues with respect to
the water content present in it.
Table 3.1 Penetration Depths of Tissues in cm with High and Low Water Content
Tissues [6]
The penetration of the microwaves depends on the dielectric constant as these
both properties are directly proportional to each other. From the above table 3.1 we can
see that there is more energy absorbed with high content of water.
3.3 Absorption of Microwaves
The percentage of the radiation of the microwaves varies from the range of 50-75
percent depending on the thickness of the skin. All other lower frequencies than the
microwaves reach up to the level of 60 percent of penetration. The figure below shows
the amount of heat penetration in fat, muscle and bone tissues.
20
Figure 3.1 Rate of Heat Penetration in Fat, Muscle and Bone Tissues
The absorption of the microwaves usually works on the Grotthus law which states
that “When any radiation meets the surface of a different medium it may either be
reflected or penetrate. Those radiations that do penetrate will only have an effect if they
are absorbed; thus they will be ineffective if they pass right through”. The heating of the
tissues depends on the absorption of the microwaves and rate of heat transfer between the
tissues. So, this process of heating is mostly used for heating the tissues of the muscle to
increase the flow in blood. [16]
21
3.3.1 Effect of Hyperthermia in the Flow of Blood
The process of Hyperthermia is mainly used to kill cancer cells by heating the part
to the treated keeping in consideration the pain threshold of the patient. For most
treatment in the cure of cancer, hyperthermia only does not help in destroying the tumor
and killing the cancer cells but it is usually used in addition with other process like
chemotherapy and radiotherapy. [17]
The use of heat for the process of curing the tumor of cancer is for the reason that
cancer cells react more to heat than the normal cells in the human body. With the tumor
in the tissues of the human body, it causes severe abnormalities in the structure of the
tissue. As the tumor tissues react more to the increase in the heat, there is more structural
damage to the cells which causes the increase in body temperature to about 104 degrees
Fahrenheit.
As there is structural damage to the tumor tissues, it gets acidic and gets deprived
of nutrients. As the acidic conditions increase in the tumor area, the radiations are more
effective on these tumors and it causes more effect if it is given with the drugs used for
chemotherapy. Therefore, hyperthermia is usually combined with other processes in the
treatment of cancer. [17]
In both kinds of diathermy, shortwave and microwave, the heating of the tissues is
done by the electromagnetic energy radiated from the head of the applicator. Usually in
shortwave diathermy devices, the RF field exists around the cable that carries the
electrical waves from the generator to the head of the applicator whereas in microwave
22
diathermy there is very little radiation as it is well shielded between the generator and the
head. As it absorbs less RF energy from the surroundings, there is very little heat around
the cables of the applicator.
There are a few factors that are being considered including the generator setting
and even the area where the energy is concentrated. Heating either with shortwave or
microwave has never caused any harm as the maximum damage that can be done with
that heat is that it causes smoke and melting of some materials. [18]
3.3.2 Features of Diathermy Devices
The diathermy device uses the radio frequency spectrum to cure the tumor of the
human body with heat produced. This process uses an applicator, a generator and a
console to check the rise in temperature of the treated part. The power is transmitted from
the generator to the head of the applicator and is concentrated on the part where the
treatment is to be done. Proper care and supervision should be done so that the
temperature should not increase the pain threshold or should not increase to the extent to
cause burns on the human skin. The temperature should be elevated to 113° F and should
be confined to not more than 30 minutes.
There are two kinds of applicators used for the process of diathermy, one is
capacitor type electrode and the other is inductor type electrode. In the capacitive type
electrode the heating of the tissues is done by the RF electric field. In the inductive type
electrode, the heating is done by the eddy currents induced by the magnetic field. In the
23
inductive type of electrode, there is high intensity magnetic field around the cables. The
figure below shows the range of intensities around the diathermy cables in electric field
and magnetic field. [19]
Figure 3.2 Range of Intensities of Stray Magnetic Fields around the Diathermy
Cables [19]
24
The figure below shows the range of electric field intensities around the cables
of shortwave diathermy device for different types of electrodes and for different
power settings. The intensity depends on the distance from the electrode.
Figure 3.3 Range of Intensities of Stray Magnetic Fields around the Diathermy
Cables [19]
25
Chapter 4
METTLER AUTOTHERM EQUIPMENT DESCRIPTION
In this project, all the measurements of the experiment were conducted with the
Mettler Autotherm equipment shown in the Figure 4.1. The Autotherm is a equipment
which possesses unique induction field circuitry which produces a short wave frequency
of 27.12 MHz. This wave can penetrate into muscle tissue with negligible heating in the
fatty layer or bone [18].
Figure 4.1 Mettler Autotherm Diathermy Unit
26
4.1 Mettler Autotherm Equipment Details
The Autotherm 300 is a continuous shortwave diathermy unit which is designed
to be economical and light weight. It is capable of automatic tuning which ensures
proper frequency response of the equipment. It is portable with a roller coaster base and
is flexible. The arm is made adjustable, so that it can reach different parts of the body and
can heat accordingly. This equipment is mainly used where deep heat is required such as
the low back, shoulder, neck and hip. This equipment is economical and is easy to
operate since it only has two controls, a timer knob and an intensity control knob as
shown in figure 4.2 respectively
Figure 4.2 Control Knobs on Mettler Autotherm
27
The Autotherm has a timer which is designed to the variation of 0 to 30 minutes.
The timer helps to know the timing of treatment. The power meter, as shown in Figure
4.3, displays the energy levels absorbed by body surface. It also monitors the current
from the power supply and displays the energy absorbed.
Figure 4.3 Patient Input Meter for Autotherm
4.2 Mettler in Heat Therapy
Mettler Autotherm is used when deep heat therapy has to be done for any part of
the body. It operates with short wave diathermy and is a safe for subcutaneous body
tissues. The electro-magnetic field is generated between the equipment and the body. The
heat penetrates deep into muscle tissue and eases the tensions and brings relief. This
therapy is mainly used for back pain, chronic arthritis, bursitis and other musculo-skeletal
conditions [20]. The heat therapy modality is shown below in figure 4.4.
28
Figure 4.4 Relative Absorption of RF Power Generated by the Autotherm
Equipment [19]
4.3 Technical Specifications of Mettler Autotherm Equipment
Input: 100–240 VAC, 50-60Hz
Frequency: 27.12 MHz (Wavelength λ= 11.06 meters)
RF output: Continuous mode 100 W Average Power, Pulsed mode 200 W Peak Power
Continuous mode: 100 Watts Average Power
Pulsed Mode: 200 Watts Peak Power
Pulse frequency: 10 Hz, 20 Hz, 50 Hz, 100 Hz, 400 Hz
Pulse duration: 65 μs, 100 μs, 200 μs, 300 μs and 400 μs
Treatment time: 1–30 minutes [20]
29
Weight: Unit: 30 pounds
Dimensions: 40 in (H) x 18 in (W) x 18 in (D), (100 cm (H) x 46 cm (W) x 46cm (D))
4.4 Advantages of Mettler Shortwave Diathermy Unit
1. Simple to use.
2. Economical
3. Flexible and gives easy access to all body areas
4. Timer switch for treatment lengths
5. Maximum portability
6. No damages are done to the adjacent tissues and bones
7. Light weight
8. A dosage intensity control regulates the power demand
4.5 Precautions While Using Autotherm
The use of Autotherm for shortwave and microwave diathermy treatment, tissues
are heated by use of electromagnetic energy. This induces or radiates from the head of
diathermy unit. This is absorbed in the electrically conductive tissues of the human body
and is converted to heat [11]. In most of the shortwave diathermy units, a radio-frequency
field exists around the cables in the equipment and carries electrical energy from the
source generator to the equipment head. Microwave diathermy units have well-shielded
leads within the equipment between the generator and head of the applicator. The
30
generator and applicator head are integrated, and there is normally very little radiation
from other source except that of the applicator. There is very little or no heating of the air
surrounding the cables since it absorbs little energy from the radio-frequency fields.
Table 4.1 shows the variation pattern of electric and magnetic fields in the diathermy unit
as a function of distance within the treatment volume.
Table 4.1 Electromagnetic Heating Comparison [11]
Heating occurs only when conductive or partially conductive material is located
within the electric or magnetic field produced by the cables or applicator. The Canadian
Bureau of Medical Devices mentions in its data that certain plastics and synthetics such
as nylon, polyvinyl chloride, and polyethylene terephthalate and some fabric blends
which are usually regarded as good insulators, can also be heated certain temperatures by
shortwave and microwave diathermy units [7]. However, two other synthetics widely
used in medical practice for several applications, silicone and polytetrafluoroethylene
usually called teflon are relatively very less affected by electromagnetic fields.
The amplitude of heating depends on a number of factors, including the output
setting of the generator and the degree to which the electromagnetic energy waves are
31
concentrated in a small area of the body. A very high density field exists because of three
reasons: When a cable is located near a grounded or conductive object, when the cables
are positioned at a very less distance. There are some recommendations which will
minimize the risk involved in equipment damage and injury and can also reduce the risk
of fire associate with equipment [18].
When generator is activated leaning on the equipment or holding the cables may cause
unwanted heating or radiation to the body. If done so the cable might break and expose
the user to high voltages or radiation.
Cables should be spaced apart for each other. We should not keep anything in between
these cables to avoid the damage of cables.
We should keep all line cords away; there should be no contact between diathermy unit
cables. The operating diathermy unit should be kept away from coil line cords.
The cables should be kept at least several inches away from any objects or material.There
should be no contact between cables and metal or grounded objects. There may be some
synthetic or plastic objects which may be nonconductive but may be heated by the
diathermy unit.
32
4.6 Digital Thermometer with Plastic Probe
Figure 4.5 Plastic Probe Digital Thermometer [23]
In the first phase of this project the thermometer with metal probe was used. In
this phase of the project we have used the digital thermometer with plastic probe as
shown in above figure 4.5. This digital thermometer has easy to read LCD which displays
temperature in Fahrenheit or Celsius and its plastic probe accurately senses the
temperature. This thermometer gives the readings in 0.1° F and in range of -10° F to 140°
F with accuracy of ±1.5° F. [23] This thermometer includes suction cups, replaceable
battery, and 39" long temperature probe cord. We can mount this digital thermometer for
this experiment by following instructions as follows.
Attach suction cups and place the probe in desired location. Press power button to
activate the digital thermometer. Slide Fahrenheit/Celsius selector switch to Fahrenheit.
Metal probe thermometer was acting as antenna as metal is conductor of electromagnetic
energy. The temperature reading shown by this thermometer was fluctuating as it was
effected by the interference caused by the microwaves. On the other hand the
33
thermometer with plastic probe is not affected by any interference as the plastic is not a
conductor of any electromagnetic waves. The readings shown by this plastic probe are
more accurate and are not fluctuating.
34
Chapter 5
EXPERIMENTAL RESULTS USING DIATHERMY ON CLAY MEDIUM
As we have discussed about the Mettler diathermy system in the earlier chapter, in
this chapter we outline the experiments that were taken by considering many
specifications. In the first phase of experiments, [1] clays of two different types were
used, one with more water content and one with less water content in it. In all our
experiments, we would be using clay with more water content in it as we noticed better
results with the non-hardening and that matches more close to the properties of the
human body.
The clay with more water content resembles to the human skin in many properties
such as plasticity, absorbency and cohesion. As with the part of absorbency, oxygen,
nitrogen and carbon dioxide can diffuse into the epidermis in small amount constituting
to high content of water in the skin. [22] The similar is the case with the clay that it
contains 40% of natural water that fills up all the minute pores between all the mineral
grains. [21] The plasticity of the clay and the human skin depends on the proportion of
water content in them which makes them exhibit similar properties.
Another variation from the first phase of experiments [1] is that in this project all
the readings have been taken with the plastic probe thermometer. In the set of
experiments done in the first phase where the metal probe was used, there were
fluctuations in the thermometer display as the probe experienced significant interference
from the incident RF radiation from the Autotherm unit. We tried to cover the part of the
35
metal probe that was exposed to the microwaves but that did not help to stop the
fluctuations with the thermometer. So, it was decided to use a probe which should not act
as an antenna to the thermometer. We researched and got a digital thermometer with the
plastic probe which should not fluctuate with the microwaves from the Autotherm unit.
The readings were taken by making a closed circuit so that the microwaves
remain in the finite area. The system was covered on all sides with absorbers. All the
readings were taken with utmost accuracy taking in consideration the time and the
distance of the applicator’s head from the clay. All the readings were taking with high
intensity on the Autotherm unit.
5.1 Measurements with the Probe on the Top of the Clay
This set of measurement was taken by keeping the probe on the top of the clay of
about 5 inches thickness and the head of the applicator a one-half inch away from the
surface of the clay. The intensity of the Autotherm was kept on maximum throughout the
experiment. The readings were taken every 15 minutes and were taken for 2 hours. All
the readings were taken in Fahrenheit. Table 5.1 shows the reading taken with the probe
on the top of clay medium.
36
Time in
Minutes
Temperature in
Fahrenheit
0
68
15
70.5
30
72.6
45
73.4
60
74.8
75
75.5
90
76.5
105
76.9
120
76.9
Table 5.1 Variation of Temperature Rise in Thick Clay with Time
(Probe on Top of Thick Clay)
Fig 5.1 shows the graphical presentation of Table 5.1
Temperature in Fahrenheit
Probe on top of thick clay
78
76
74
72
70
68
66
64
62
0
15
30
45
60
75
90 105 120
Temperature in
68 70.5 72.6 73.4 74.8 75.5 76.5 76.9 76.9
Fahrenheit
Figure 5.1 Graphical presentation of Temperature Vs Time
(Probe on Top of Thick Clay)
37
The graph shows that the temperature rises quite rapidly initially over the first 60
minutes, and then tapers off to a peak value.. As we can see there was a gradual change
in the temperature with time, but after 90 minutes of the heating, not much change in the
temperature could be seen.
5.2 Measurements with Probe Inserted 1 Inch From the Surface
This set of readings were taken with probe inserted an inch below the surface of
the five inch thick clay. With this set of readings, the head of the applicator was placed
half inch above the surface of the clay. All the readings were taken with interval of 15
minutes for 2 hours. Table 5.2 shows the readings taken with the probe an inch under the
surface.
Time in
Minutes
Temperature in
Fahrenheit
0
72.9
15
83.4
30
85.1
45
86
60
86.4
75
86.5
90
88.1
105
88.3
120
88.3
Table 5.2 Variation of Temperature Rise in Clay with Time
(Probe Inch below Clay Surface)
38
Fig 5.2 shows the graph of the readings from the Table 5.2
Temperature in Fahrenheit
Probe inserted 1 inch under the surface of the clay
100
90
80
70
60
50
40
30
20
10
0
0
15
30
Temperature in
72.9 83.4 85.1
Fahrenheit
45
86
60
75
90
105
120
86.4 86.5 88.1 88.3 88.3
Figure 5.2 Graphical Presentation of Temperature Vs Time
(Probe Inch below Clay Surface)
As we can see from the graph that the change in tempertaure was only seen in the
first 15 minutes of the experiment. After 30 minutes of heating the clay medium, there
was a difference of only 3° F for the next 90 minutes.
5.3 Measurement with the Sliced Clay
These set of readings were taken with the sliced clay that was just an inch in
thickness. This step was taken as there was no much increase in the temperature after 30
minutes of heating. These readings were taken by keeping the probe on the surface of the
clay and the head of the applicator not more than an inch away from the surface. These
readings were taken with an interval of 15 minutes for 150 minutes. Table 5.3 shows the
readings taken with the sliced clay.
39
Time in
Minutes
Temperature in
Fahrenheit
0
69
15
69.5
30
71.2
45
72.5
60
73.2
75
73.9
90
74.9
105
75.7
120
75.7
135
76.3
150
76.3
Table 5.3 Variation of Temperature Rise in Sliced Clay with Time
(Probe on Top of Clay)
Temerature in Fahrenheit
Readings with sliced clay
78
76
74
72
70
68
66
64
0
15
30
45
60
75
90 105 120 135 150
Temperature in
69 69.5 71.2 72.5 73.2 73.9 74.9 75.7 75.7 76.3 76.3
Fahrenheit
Figure 5.3 Graphical Presentation of Temperature Vs Time
(Probe on Top of Clay)
40
From the above graph, we can see that there was gradual change throughout the
process till 135 minutes then there was no temperature increase.
5.4 Measurements Using a Reflector
We even tried taking the readings having a reflector so that we could have the
incident wave as well as the reflected so that the time required to reach the desired
temperature could be reduced. In this set of readings, we have used the thick clay of 5
inches and the probe was placed on the surface of the clay. All the readings were taken by
keeping the head of the applicator an inch above the surface of the clay. Table 5.4 shows
the readings taken with the reflector.
Time in
Minutes
Temperature in
Fahrenheit
0
69
15
69.5
30
71.2
45
72.5
60
73.2
75
73.9
90
74.9
105
75.7
120
75.7
Table 5.4 Variation of Temperature Rise in Clay with Time Using Reflector
(Probe on Top of Clay)
41
Temerature in Fahrenheit
Reading with the reflector
77
76
75
74
73
72
71
70
69
0
15
30
45
60
75
90
105 120
Temperature in
71.5 72.9 74 75.5 75.7 75.7 75.7 75.7 75.7
Fahrenheit
Figure 5.4 Graphical Presentation of Temperature Vs Time
(Probe on Top of Clay)
There was no much difference seen with the reflector. There was increase for 45
minutes then it stopped and there was no difference seen for the next 75 minutes.
5.5 Measurements with the Applicator Touching the Clay
These set of readings were taken with the head of the applicator touching the clay
medium. In real time scenario, the autotherm unit is used in such a way that the head of
the applicator touches the human body so that there is no heat loss. Rather than having a
vacuum medium, a cloth or a towel is used so that the heat could be transferred to the
area to be treated without causing skin burns.
42
Time in
Minutes
Temperature in
Fahrenheit
0
69.3
3
91.6
15
98.7
30
103.9
45
110.2
60
115.2
75
119.4
90
122.4
105
125
120
128.3
Table 5.5 Variation of Temperature Rise in Clay with the Applicator Touching
(Probe on Top of Clay)
Readings with applicator touching the clay
Temperature in Fahrenheit
140
120
100
80
60
40
20
0
0
3
15
30
45
60
75
90
105
120
Temperature in
69.3 91.6 98.7 103.9 110.2 115.2 119.4 122.4 125 128.3
Fahrenheit
Figure 5.5 Graphical Presentation of Temperature Vs Time
43
As we can see that there was a large increase of temperature as it reached form
69.3° F to 91.6° F in just 3 minutes. And we have even seen that, the temperature reached
100° F in just 20 minutes which is the requirement of the FDA ( Food and Drug
Administration ) that it should not increase the pain threshold of the patient.
5.6 Measurement with the Probe Inserted One Inch From the Surface
These set of readings were taken to check the depth of the heat with the applicator
head touching the surface of the clay. Table 5.6 shows the readings taken by inserting the
probe one inch under the surface of the clay.
Time in
Minutes
Temperature in
Fahrenheit
0
71.3
15
72.6
30
75
45
76.9
60
77.8
75
78.5
90
79.8
105
80.4
120
80.9
Table 5.6 Variation of Temperature Rise in Clay with the Applicator Touching
the Surface
44
Temperature in Fahrenheit
Readings with probe inserted an inch from the surface
82
80
78
76
74
72
70
68
66
0
15
Temperature in
71.3 72.6
Fahrenheit
30
75
45
60
75
90
105
120
76.9 77.8 78.5 79.8 80.4 80.9
Figure 5.6 Graphical Presentation of Temperature Vs Time
(Probe One Inch below the Surface)
From the above graph we can see that there is not much significant increase in
temperature at a depth of one inch from the surface of the clay even after having the
applicator head touching the surface of the clay.
5.7 Measurements with the Sliced Clay Toucing the Applicator Head
These set of readings were taken with the sliced clay instead of a thick clay to
observe the difference in the temperature rise with the thickness of the medium. Table 5.7
shows the readings taken by inserting the probe under the surface of the clay and having
the applicator head touching the surface of it.
45
Time in
Minutes
Temperature in
Fahrenheit
0
74.2
15
75.6
30
78.3
45
82.7
60
96.5
75
98.5
90
103.4
105
122.3
120
125.6
Table 5.7 Variation of Temperature Rise in Sliced Clay with the Applicator
Touching the Surface
Temperature in Fahrenheit
Readings of the sliced clay with applicator head
touching the clay
140
120
100
80
60
40
20
0
0
15
30
45
60
75
90
105
120
Temperature in
74.2 75.6 78.3 82.7 96.5 98.5 103.4 122.3 125.6
Fahrenheit
Figure 5.7 Graphical Presentation of Temperature Vs time
(Probe on Top of the Clay)
46
From the above graph we can see that we have achieved the desired temperature
but it took 80 minutes to reach the mark of 100° F.
As we have achived the desired temperature with the applicator touching the
surface of the clay, we will analyze it further by plotting the readings taken at different
depths of the probe in the clay.
Time in
Minutes
Temperature
in Fahrenheit
Probe on clay
Temperature
in Fahrenheit
Probe an inch
Temperature
in Fahrenheit
Sliced clay
0
69.3
71.3
74.2
15
98.7
72.6
75.6
30
103.9
75
78.3
45
110.2
76.9
82.7
60
115.2
77.8
96.5
75
119.4
78.5
98.5
90
122.4
79.8
103.4
105
125
80.4
122.3
120
128.3
80.9
125.6
Table 5.8 Variation of Temperature Rise in Clay at Different Depths with the
Applicator Touching the Surface
47
140
120
100
Temperature in
Fahrenheit (Probe
touching the clay)
80
60
40
20
Temperature in
Fahrenheit (probe 1
inch inside the clay)
0
Temperature in
Fahrenheit
(applicator on sliced
clay)
Figure 5.8 Graphical Presentation of Temperature Vs time (for all three Depths)
From the above graph we can see that the temperature rise in the thick clay and
the sliced clay when the probe is inserted under the surface of the clay reaches the same
mark of 125° F. But the probe when inserted an inch under the surface of the clay reaches
not more than 90° F in 120 minutes.
5.8 Measurements of the Clay with Water
These set of experiments were taken by adding more water to the clay to check
the difference in rise of temperature having water as a medium. Table 5.8 shows the
readings taken by having the applicator head one inch away from the surface of the clay
and the probe inserted under the surface.
48
Time in
Minutes
Temperature in
Fahrenheit
0
70.5
15
71.3
30
73.9
45
75.4
60
76.9
75
78.5
90
79.2
105
79.8
120
80.9
Table 5.9 Variation of Temperature Rise in Clay with Time
(One Inch below Clay Surface with Water)
Fig 5.8 shows the graph of the readings from the table 5.8
Temperature in Fahrenheit
Readings with water on the clay
82
80
78
76
74
72
70
68
66
64
0
15
30
45
60
75
90
105 120
Temperature in
70.5 71.3 73.9 75.4 76.9 78.5 79.2 79.8 80.9
Fahrenheit
Figure 5.9 Graphical Presentation of Temperature Vs Time
(One Inch below Clay Surface)
49
We can see from the above graph that there was no significant increase in
temperature by having more water content in the medium. Though there was a gradual
change in temperature with the increase in time, the desired temperature was not
achieved.
From the readings that were taken in this phase of experiment, we have noticed
that we achieved the desired temperature twice during the process.
50
Chapter 6
CONCLUSION
The hyperthermia treatment system and its effects were thoroughly studied and
analyzed. The aspects and the ways hyperthermia is used in the treatment of tumor were
reviewed. The applications and benefits of hyperthermia alone and along with radiation
in cancer treatment is studied. All simulations were performed using 27.12 MHz Mettler
Diathermy Equipment. The duration and intensity of the system were constantly
monitored during the experiments. Measurements were successfully taken at intervals of
15 minutes without allowing the clay to cool down so that to avoid the heat loss. The
conditions close to hyperthermia treatment in real world were created.
The replacement of hardening clay with non-hardening clay was better idea, as it
made us understand the effect of the heat on the object which resembled more to the
human body. The digital thermometer of the plastic probe gave us more accurate reading
than the previously used thermometer of the metal probe.
Initially we faced difficulties as the reading on the thermometer was fluctuating
because of the interference caused by the microwaves with the metal probe of the
thermometer. Though we took intense care in collecting the data the interference had a
major effect on the measurements. This problem was addressed as we came to know that
the treatment is done in real time by using cloth as medium between the applicator and
the patient’s body and not the air. We took various measurements by varying the medium
of transmission such as air, water and by variation of length of the clay. We also used
51
reflector in different positions. These measurements we took gave us varied responses as
we were not able to generate the high temperature required for hyperthermia.
The major success in this project came from two changes: Firstly, we changed the
thermometer with the metal probe to another thermometer with a non-metallic probe, and
secondly when we heated the clay directly without any medium. The temperature
variation was very high as the measurements reached 128.3° F. This also satisfied the
regulation set by the Food and Drug Administration (FDA) as the temperature reached
100° F in 23 minutes.
Though we were not be able to replicate exactly how the human body responds to
heat, we concluded that we made a considerable progress in understanding the way the
heat can be effectively transmitted using the autotherm. Further research on this topic
can include a different medium between the applicator and the clay so that it can transfer
most of the heat.
This was all part of the research to get an insight in this treatment. As we work
towards the goal of cure for cancer, this effort will help understand the use of Mettler
Autotherm in the treatment of hyperthermia.
52
REFERENCES
1. Beena Roshini John William, “Experimental Study of Heating effects of 27.12
MHz Diathermy unit on clay models for Hyperthermia applications in cancer
treatment”, Summer 2009; 37-45.
2. http://www.cancer.gov/clinical_trials/
3. Hyperthermia” http://www.geocities.com/hotsprings/villa/5443/alts/hytherm.html
4. National Cancer Institute (NCI) Resources, ‘Hyperthermia in Cancer Treatment:
Questions and Answers’, 2004.
5. http://www.cancercenter.com/glossary/local-hyperthermia.cfm
6. Wust P et al., ‘Hyperthermia in combined treatment of cancer’, The Lancet
Oncology, 2002; 3: 487–497
7. http://www.cancer.org/docroot/ETO/content/ETO_1_2x_Hyperthermia.asp
8. http://www.redblufftumor.com/hyperthermia.htm\
9. http://spie.org/x31557.xml?ArticleID=x31557
10. http://www.steamsaun.com/hyprthr.html
11. http://bmb.oxfordjournals.org/cgi/content/full/83/1/379\\
12. Hildebrandt B, Wust P, Ahlers O, et al., ‘The cellular and molecular basis of
hyperthermia’, Critical Reviews in Oncology/Hematology, 2002; 43:33–56.
13. http://www.aetna.com/cpb/medical/data/500_599/0540.html
14. http://www.encyclopedia.com/doc/1G2-3435100264.html
15. High - Frequency Electrical Equipment in Hospitals; 1970, NFPA No. 76CM,
Part III, Section 31, National Fire Protection Association, Boston, Massachusetts
53
16. http://www.scribd.com/doc/6130660/Microwave-Diathermy
17. Gian Franco Baronzio, E Dieter Hager .,’Hyperthermia in cancer treatment a
primer’, Georgetown, Tex. : Landes Bioscience, 2006: 79-83
18. http://www.hc-sc.gc.ca/ewh-semt/pubs/radiation/83ehd-dhm98/fields-rf-champseng.php
19. http://www.mdsr.ecri.org/summary/detail.aspx?doc_id=8276 precautions Health
and Welfare Canada. Health Protection Branch. Guidelines for microwave
diathermy devices. Information Letter, No. 585; Sep 19, 1980. Fire hazard from
shortwave and microwave diathermy units. Alert-Medical Devices 1979, No. 24;
Aug 24.
20. http://www.mettlerelectronics.com/Brochures/300brochure.pdf
21. http://www.es.ucl.ac.uk/schools/UCL/clays.htm
22. Connor, Steven: The book of skin, Cornell University Press, 2003, pg. 176
23. http://www.drsfostersmith.com/product/prod_display.cfm?pcatid=12089