Surgery – Instruments – Electrical application
Reexamination Certificate
2000-02-24
2002-10-15
Dvorak, Linda C. M. (Department: 3739)
Surgery
Instruments
Electrical application
C606S037000, C606S038000
Reexamination Certificate
active
06464696
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an electric surgical operating apparatus which performs medical treatment to organism tissue and the like such as excision and coagulation, using high-frequency electric power.
2. Description of the Related Art
In recent years, electric surgical operating apparatuses which perform medical treatment to organism tissue and the like such as excision and coagulation by using high-frequency electric power have come to be known. Generally, such electric surgical operating apparatuses are configured having a high-frequency cauterization electric power source device for generating high-frequency electric current, and a high-frequency cauterization treating instrument provided with an active electrode for coming into contact with the area of the patient to be treated, and executing medical treatment with high-frequency electric current.
Regarding the types of the high-frequency cauterization treating instrument, monopolar treating instruments and bipolar treating instrument are known.
Monopolar treating instruments are configured having an active electrode which is connected to one output terminal of the high-frequency cauterization electric power source device and comes into contact with the area of the patient to be treated, and a feedback terminal portion which is connected to the other output terminal and is in plan contact with the body surface of the patient at a portion other than the area of the patient to be treated. The high-frequency cauterization electric power source device generates high-frequency electric power, this high-frequency electric power is concentratedly introduced into the organism tissue via the active electrode which is in contact with the area to be treated, and this high-frequency electric current is dispersed and recovered by the feedback electrode, thus enabling medical treatment to be performed on the organism tissue, such as excision, coagulation, and the like.
Conversely, bipolar treating instruments do not have a feedback electrode, with the line portion from which the active electrode extends being connected to both output terminals of the high-frequency cauterization electric power source device. There are various forms of the active electrode, according to use. For example, the is a loop-shaped loop electrode such as shown in
FIG. 1A
, a band-shaped band electrode such as shown in
FIG. 1B
, a roller-shaped roller electrode such as shown in
FIG. 1C
, and so forth.
Generally, once the supply of high-frequency electric power from the high-frequency cauterization electric power source device to the active electrode begins, heat is transferred to the organism tissue from the active electrode which has generated heat due to this high-frequency electric power. This generated heat causes transpiration of the organism tissue resulting in tissue degeneration, and as shown in
FIG. 2
, load impedance increases with time. Then, voltage drop owing to load impedance increases, and the output voltage of the electric surgical operation apparatus increases. When the output voltage reaches the predetermined voltage VE, arc discharge from the active electrode to the organism tissue is started. This arc discharge starts the excision operation on the organism tissue.
Incidentally, the reference symbols a, b, and c in
FIG. 2
indicate that the properties of the active electrodes differ according to the electrode form, size, volume, material, and so forth. Also, in addition to the excision operation performed on the organism tissue, a coagulation operation can be performed, by modulating the waveform of the high-frequency current into a intermittent waveform, or lowering the output voltage in comparison with the voltage at the time of excision, thus facilitating hemostasis.
The output power of such an electric surgical operating apparatus exhibits properties such as shown in
FIG. 3
as to the load impedance which is the impedance of the organism tissue.
That is, in the event that the load impedance is within a predetermined range from the rated load impedance, the rated output electric power necessary for performing the treatment to the area to be treated can be obtained, but in the event that the load impedance is smaller or greater than this range, the output voltage decreases, and output electric power necessary for performing the treatment to the area to be treated cannot be obtained.
Incidentally, the organism tissue prior to supply of high-frequency electric power to the active electrode normally contains a great deal of moisture, so the load impedance is small, and the rated output power cannot be obtained.
Also, the output power reaches the maximum value when the load impedance is near the predetermined rated load impedance value. The farther the load impedance value is from the rated load impedance, the smaller the output power is. Thus, the load impedance changes according to the state of the above-described tissue deterioration, consequently allowing the output power to change, so optimal output voltage for performing excision or coagulation cannot be obtained.
For example, in the event that the output voltage at the time of performing the excision operation is great, high-density discharge energy is transferred to the organism tissue when conducing the arc discharge. Conversely, in the event that the output voltage is small, there is no arc discharge. Consequently, trouble similar to that in excision occurs for performing coagulation as well, in the event that optimal output voltage for coagulation cannot be obtained. This means that the speed and so forth of tissue deterioration differs from that which the operator intends, due to optimal output voltage not being obtained.
Accordingly, means are provided in the First Embodiment of the high-frequency electric scalpel apparatus disclosed in Japanese Unexamined Utility Model Publication 4-30509 measures the output voltage value so that the stability of excision and coagulation operations can be improved by setting an appropriate target value, thereby comparing the output voltage value with the set target value and increasing or reducing the gain of the output circuit to maintain the output voltage value at the target value by performing constant-voltage control, whereby change in the output voltage is reduced as to change in the load impedance. Also, means for performing constant-voltage control and constant-power control are described in another embodiment disclosed in this Japanese Unexamined Utility Model Publication 4-30509, but these cannot be applied to the object of stabilizing the output voltage.
Also, with the electric surgical operation apparatus such as shown in
FIG. 2
, there is the problem of a delay in time occurring from the point of starting output of the electric power to the time of starting the excision or coagulation operation to the area to be treated. Also, increasing the output current in order to accelerate the deterioration of the organism tissue speeds up the increase of load impedance, but there has been a problem in that excessive power is output even after the load impedance reaches the necessary value.
Accordingly, the high-frequency electric scalpel apparatus in Japanese Patent No. 2542058 for example discloses means which enables control to be made such that the output current increases for a predetermined amount of time following starting of power output, wherein power with increased current is output during the period immediately following starting power output when the load impedance is small so as to accelerate tissue deterioration, following which appropriate power output can be made after a certain amount of time. This shortens the amount of delay in time from starting power output to the start of the excision/coagulation operation.
Further, the treating instrument of the above-described electric surgery operating apparatus is generally provided with an insulating covering at places other than the electrode. However, in the event that this insulating covering is damaged and insula
Harano Kenji
Hijii Kazuya
Oyama Masahide
Takahashi Hiroyuki
Dvorak Linda C. M.
Olympus Optical Co,. Ltd.
Ostrolenk Faber Gerb & Soffen, LLP
Schopper Kenneth G
LandOfFree
Electrical surgical operating apparatus does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Electrical surgical operating apparatus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Electrical surgical operating apparatus will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2932220