POWERED EQUIPMENT

DEFIBRILLATOR

Emergency equipment needed in the OT for restoring normal heartbeat


This equipment allows an electric shock to be applied to the heart to correct ventricular or atrial fibrillation.
- It may be mains or battery operated and can apply the shock through the chest wall or via electrodes placed directly in contact with the walls of the heart.
- When switched on, the defibrillator charges a condenser to a maximum energy of 320 J external application, and 100 J using internal electrodes.
- The level of stored energy output can be continuously controlled between 5 and 320 J and this energy is released in a pulse lasting about 3 milliseconds.
- In the case of atrial fibrillation the defibrillator is coupled with an electrocardiograph so that the defibrillation discharge is delivered in synchronization, normally 40 milliseconds delay after the peak of the R wave of the patient’s ECG.
- Although different makes of defibrillator vary slightly in the method of operation, basically the same technique is used.
- The cardiac recorder defibrillator when used in an emergency the instruction are printed on the side of the box.
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POWERED SURGICAL INSTRUMENTS

SURGICAL ULTRASONIC EQUIPMENT
Instrument using high energy source for surgery.
It works through ease of dissection, and aspiration of soft tissue

- Ultrasonic techniques are well established in neurosurgery for rapid and efficient removal of intracranial and spinal cord tumors.
- This instrument is also used in resection, and dissection applications of:

(a) Liver,
(b) Kidney, and
(c) Spleen.

- Their application is also gaining popularity in pancreatic and urologic surgery.
Ultrasonic surgery is carried out with the aid of a special instrument known as the CUSAtm (Cavitron TM Ultrasonic Surgical Aspirator).
- This is an acoustic vibrator which consists of three distinct components.

• Transducer: A device, that converts electromagnetic energy into mechanical vibrations. The transducer is composed of a stack of nickel alloy plates. A magnetic field is produced by a coil placed around the plates and causes mechanical motion of approximately 300 microns.
• Connecting body: Mechanically conveys the motions of the transducer to the surgical tip. It also amplifies the vibration motion of the transducer.
• Surgical tip: Completes the amplifications of the motion and also contacts the tissue. For this reason the tip is relatively long compared to its diameter and this provides adequate motion amplification.

- The electric coil which is permanently fitted in the hand piece surrounds the transducer.
- This coil receives 23,000 cycles per second (hertz) alternating electric current from the console and activates the transducer.
- The hand piece is connected to the console by a cable which includes the tubing for circulating fluid between the cooling water canister in the console and the hand piece.
- Since the electric coil has a current flowing through it heat is generated and absorbed by the water circulating within the hand piece.
- This keeps the hand piece at a comfortable temperature for the surgeon.
Any questions be sent to drmmkapur@gmail.com
All earlier posts are stored in archives for access and review.
Vistors that follow the site may post contributions to the site.
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HIGH INTENSITY LIGHT

LASERS

Lasers are an equipment that use high energy to destroy, or seal tissue

- A laser is an instrument equipped to produce a fine parallel beam of high intensity light, which can be focused on a very small spot.
- The development of surgical lasers, during the last decade, has made a significant contribution to microsurgery.
- Used with an operating microscope or fiberscope a wide range of microsurgical procedures have now become possible, for example, suture less micro vascular anatomists.
- Excision of the posterior capsule of the lens through the transparent cornea.
- Coagulation of bleeding peptic ulcers using a flexible gastro scope.
- In laser surgery, the light beam heats the target tissue and causes:

• Thermal(heat) tissue destruction, first with local edema and then by denaturing of proteins.
• Contraction of tissue due to alteration of fibrous tissue protein and finally boiling of cell water and vaporization.
• Generally, low energy exposure results in coagulation of blood vessel.
• Higher energy exposure produces a precise incision by vaporization of the tissue at the focal point.
Any questions be sent to drmmkapur@gmail.com
All earlier posts are stored in archives for your access and review.
Visitors that follow the site may post contributions to the site.
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COOL POWERED INSTRUMENT

CRYOSURGICAL SYSTEMS

Cryosurgical is the application of extreme cold to tissues and is a useful technique for the destruction of tissues.
It is characterized by minimal bleeding, or pain, in the post-operative period.
Cryosurgical procedures are well established in many specialties including:

• General surgery,
• Dermatology,
• Neurology, and
• Urology.


The first practical equipment for the control and maintenance of extreme low temperature in surgery was produced in 1962.
The apparatus was not very sophisticated and used liquid nitrogen to achieve low temperature in the region of – 196°C.
This very low temperature was subsequently found to exceed requirements.

A more simple apparatus which used nitrous oxide or carbon dioxide to achieve temperature in the region of – 70°C.
The design principles established, are still used in modern cryosurgical equipment which employs high-pressure, non-siphon cylinders of N2O, or CO2.

- Cryosurgical systems consist of a flexible tubing, connecting the gas flow control unit, to a cryoprobe or working tip, this unit comprises of two concentric tubes.
- The inner tube delivers nitrous oxide or carbon dioxide at pressures between 4,000 and 6,000 kpa to a narrow orifice in the end.
- The sudden expansion of this gas, through the Joule-Thompson orifice, produces a rapid drop in temperature of the probe surface, forming an ice ball.
- The expanded gas is then returned at atmospheric pressure along the outer tube.
- Some cooling along the shaft of the probe occurs, which can be a disadvantage, for example in neurosurgery.
- To overcome this, manufactures designed a probe which employs a reversed gas flow.
- This design enables the incoming gas, to be carried to the probe tip, via the outer of the two concentric tubes; it is allowed to expand through an annular orifice, being finally returned through the central tube.
- The incoming gas acts as an insulating barrier and the cooling is confined to the probe tip.
Any questions be sent to drmmkapur@gmail.com
All earlier posts are stored in archives for your access and review
Visitors that follow the site may post contributions to the site.
Click on image to see details.