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INVASIVE METHODS 1. Mechanical and chemical1. Mechanical and chemical

Are widely used in surgery and stomatology (scalpels, tweezers, peans)

1. Rotary and elevator instruments

2. Water scalpel

Instruments used in stomatology

• cuts tissues by narrow water torrent ( isotonic solution of NaCl)• device consists of: pressure pump, high pressure hose and water engine• cuts are smooth

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Are used for deep freezing of tissues (from 25°C to -190°C) – liquid N2 is used. If the cooling is slow , than water mole-cules change into the ice crystals and these may damage the cells during rewarming.Advantage: anaesthetic effect of cold, small destruction of the tissue, no bleedingUsing: ophthalmology, gynecology, urology, oncology

3. Cryocauthery instruments

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• ultrasound (US) with high intensity (50 – 1000 W/cm2)• selective destruction of tissues

High frequency focusing US (1 – 3 MHz) Low frequency US (20 – 50 kHz)

Ultrasound is produced by piezo-electric crystal and conducted by special wave- conducting system, that amlifies the amplitude by 10 times. US scalpel oscilates in re-sonance with transformer´s fre-quency. It is widely used in oto-laryngology and neurosurgery.

2. Ultrasound2. Ultrasound Methods Methods

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PhacPhacoemulsifioemulsificcatorator

This device is utilised for This device is utilised for extracextrac--tiontion of cloudy lenseof cloudy lense (cataract). (cataract). Method is based on Method is based on low frequency low frequency ultrasound applicationultrasound application, which , which destructs the cloudy lensedestructs the cloudy lense.. LLense ense is then is then coagulatedcoagulated and sucked off. and sucked off.

3. Electric3. Electrical Methodsal Methods

Electrotomy and electrocoagulation

extraction of cloudy lense

• use effect of HF electric currents > 100 KHz• production of heat by contact of different electrode with tissue - water is evaporated and cells are dest- ructed. This results in tissue coagulation and clos- ng of vessels – cuts do not bleedcuts do not bleed

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4. Methods of vital organ support4. Methods of vital organ support

1. Breathing support – artificial respiration

• is used when no spontaneous respi-ration is present apnoe, or by pulmo-nary insufficiency- partial presure ofoxygen in arterial blood is < 5kPa, pH<7.25 VENTILATORSVENTILATORS

•pressure controled ventilators-switch inspiration to expiration by setting of pressure of inhaled air•volume controled ventilators-can set inspiratory volume of breathing and ts frequency - optimal value of pulmo- nary ventilation

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Parameters which can by setParameters which can by set up up on the ventilator on the ventilator::

• respiratory exchange ratio (1:1.5 or 1:2)respiratory exchange ratio (1:1.5 or 1:2)• respiratory frequency (8 – 24 respiratory frequency (8 – 24 //min)min)• inspiratory oxygen concentration (20 – 100inspiratory oxygen concentration (20 – 100%%))• inspiratory pressure (maximal value is 7 kPa)inspiratory pressure (maximal value is 7 kPa)• postinspiration time (between end of inspiration postinspiration time (between end of inspiration and start of expirationand start of expiration )) control of control of PaOPaO

22 (by (by

oxymetry) and oxymetry) and PaCOPaCO

22 (by capnogram)(by capnogram)

Special type: CPAP (continuous positive airway pressure)

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2. Substitution of Substitution of Heart function Heart function –– EExtracorporaxtracorporal l CCirculationirculationBlood pump – elastic tube and rotor with 2 sheaves – they rotate, compress the tube and drive the blood before them Amount and pressure of blood is regulated by turning the pump rotationOxygenator – substitutes the lung function, blood is eliminated from from CO2 and is saturated by O2

Warmer device – modifies the temperature of oxygenated blood which returnes to the body to 37.5 °C

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2. Extracorporeal Circulation - scheme

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2. Heart substitutions

artificial artificial heartheart

• transplatantion of human´s heart• implantation of artificial heart dri-ving of pump is provided by pressure ofcompressed air, suitable non-iritable material is used (imunology)• surgery substitution of coronary ar- teries (bypass) and heart valves (be- cause of stenosis or insufficiency) PACEMAKING – uses DC current to treat the „sick sinus syndrom“ therapy

pacemakepacemakerr

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3. Artificial kidney - hemodialysisArtificial kidney - hemodialysis

Basic parts of this device:• Extracorporeal blood circulation - see the previous chapter• Dialysing circulation – circle which provides flow and preparation of dialysing solution – by mixing water and NaHCO3,pH is changed to 7.36 and osmolarity to 5300

mOsm/l (as in blood plasma). Integrity of dialysing membrane is controled by detection of hemoglobine amount. Temperature of dialysing solution is kept on the same value.

Enables to treat the intoxications or disorder affecting the function of kidney– filtration, resorbtion

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• Dialyser – is divided into 2 parts (blood part and dialy-sing part) by dialysing membrane. Blood flows by laminary streaming (200 – 300 ml/min) on the one side of the membrane and passes the dialysing membrane. Dialysing solution flows in opposit direction by turbulent streaming (500ml/min) on the other side of the membrane.

It results in increasing of concentration gradient, which leads to rapid diffusion of low weight molecules-toxic substances (urea, aceton) from blood to dialysing solution. Velocity of ultrafiltration and amount of redundant water can be regulated by transmembrane pressure .

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3. Artificial kidney-scheme of hemodialysis and peritoneal dialysis

Peritoneal dialysis– peritoneum works as a filter for hemo-perfusion, hemofiltration ( intoxication treatment and liver failure disorders)

Hemodialysis Peritoneal dialysis

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4. Artificial lenses4. Artificial lenses

are implanted because of eye injuries or the cataract Composition of lens:

• optic part – increases refractive power of the eye• haptic part – for mechanical fixation in the eye ball

Types:• solid and hard (polyme- tacrylate)• soft ( hydrogels)

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5. Cochlear electrode implants

Multiple electrode stimulating sys-tem consists of 2 parts: External part• sound processor• sensitive microphone amplifier• transmitterInternal part• receiver implanted under the skin• electrode system -is inserted into Scala media of the Cochlea near to basilar membrane in the vicini-ty of the acustic nerve

for deaf patients whose conduction of APs through the acoustic nerve retained intact

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6. Prothesis of limbs6. Prothesis of limbs

• Mechanical prothesisMechanical prothesis – mobile only in knee and ankle, – mobile only in knee and ankle, enable walking with assistenable walking with assistaance (lower extremities) or nce (lower extremities) or partial grip functionpartial grip function• Bioprothesis Bioprothesis – biosignals conducted by needle electro– biosignals conducted by needle electro--des into preserved muscles. There is a lack feedback des into preserved muscles. There is a lack feedback between afferent and efferent signals. Mechanism of between afferent and efferent signals. Mechanism of unit can be electricunit can be electric and and hydraulic. hydraulic.• BiomanipulatorBiomanipulator – bioprothesis of new generation – – bioprothesis of new generation – more complicated functionsmore complicated functions with feedback from sensors with feedback from sensors • EndoprothesisEndoprothesis – artificial joints – artificial joints being being made from made from special steel (knee, hip joint)special steel (knee, hip joint)

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7. Injection pumps7. Injection pumps•enable to assure an exact timetable for drug´s application into the blood circulation•to speed a dose, quantify it and apply a solution, its time of application, all functions can be seen on display•operation of the pump is controlled by PC microprocessor, with ability to choose the mode

Trombolytic pumpsDrug (which dissolve the thrombus or prevents its formation) is applied into the blood by a pulse of compressed air

Insulin pumpsAutomatic programmable insu-lin applicator device with auto-matic control of sugar level in blood

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Nanotechnology in Treatment of CancerNanotechnology in Treatment of Cancer

Nanotechnology in treatment of cancer

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Thanks For Your Attention!