GB2105196A - Endoscopic surgical apparatus - Google Patents

Abstract

Endoscopic surgical apparatus (10) comprises an endoscope (12) with and an arrangement (50) fitted thereto in order to sample gas in region (1318) at the free end (12A) of the endoscope. Sampled gas is delivered to a detection means (51) which preferably effects a chemical-species analysis and the result is delivered to a read-out device (52). Means (51) may alternatively drive a comparator so that the analysis is compared against a check-list to permit machine interpretation of the analysis. The detection means may comprise a detection head (20) for measuring the potential explosivity of the sampled gas and disabling means (16) may be provided for disabling a surgical device (11) fitted to the endoscope (12) in the event that the explosivity of the sample exceeds a preset level. <IMAGE>

Description

SPECIFICATION Endoscopic surgical apparatus This invention relates to endoscopic surgical apparatus.

Endoscopic surgical procedures currently utilise fibre optic and other instruments extending through an endoscope to perform or monitor a surgical procedure in an internal tract ofthe body. For example it is possible to remove growths such as polyps from the human bowel utilising such procedures whereas previously such growths were removed by a transabdominal operation.

Recent studies have shown that potentially explosive gaseous mixtures (methane and/or hydrogen) esist in certain internal tracts ofthe human body such as the large intesting and whereas with transabdominal operations the gases escape to atmosphere, with endoscopic procedures the gases tend to remain in the tract concerned and there is an attendant risk of these gases becoming ignited in an explosive fashion, for example due to the energy utilised in an electro-surgical procedure or due to frictioninduced sparking. In known cases serious injury has resulted to a patient and in certain instances the injury has progressed to fatality.

Furthermore studies have shown that the chemical nature of the gaseous mixtures existing within the tracts ofthe human body is indicative ofthe condition of the body and indeed such gases may be a byproduct of a diseased condition in the body.

There is therefore a need to monitor the existence and nature of gaseous mixtures present within the human body.

It is an object of the present invention to provide an improved form of endoscopic surgical apparatus for monitoring the existence and nature of gaseous mixtures existing within tracts of the human body.

According to the present invention there is provided endoscopic surgical apparatus comprising sampling means capable of being fitted to an endoscope for sampling gases at the free end of the endoscope, and gas detection means connected via the endoscope to the sampling means for detecting the nature of the sampled gas.

The detection means may be arranged to effect a chemical analysis on the sampled gas and provide a read-out or display of the analysis so that a medical practitioner may interpret the analysis as part of a diagnostic routine. Alternatively the chemical analysis may be compared automatically against a predetermined check-list held by a computer memory and the apparatus may therefore be organised to provide a machine interpretation of the analysis in human-readable form. It will be evident that in this arrangement the computer memory requires to be pre-programmed with a range of standard analyses indicative of standard diseases.

In an alternative form the detection means may be arranged for detecting the potential explosivity ofthe sampled gas in which case disabling means is provided for disabling the surgical device fitted to the endoscope in response to the detected potential explosivity exceeding a first preset level.

Conveniently in this form the apparatus further comprises pump means fitted to the endoscope and said detection means is arranged to control operation of said pump means below said first preset level intermittently to extract said sample. Preferably the pump means is operable in a first mode to extract said sample intermittently and otherwise to be inoperative, and in a second mode to extract said sample intermittently and otherwise to pump a cleansing gas along the endoscope to the free end thereof said first and second modes being established automatically according to the potential explosivity being respectively below or above a second preset level. The pump means may comprise separate pump devices respectively for extracting the sample and for insufflating the cleansing gas.

Preferably said detection means comprises a gas detector head upstream of which there is located a moisture removal and temperature normalising device. Moisture removal may be by way of a mechanical trap and a condenser unit, and temperature normalising may be by way of a heat exchanger unit.

Embodiments of the present invention will now be described by way of example with reference to the accompanying drawings in which; Figure 1 schematically illustrates endoscopic surgical apparatus according to the present invention; Figure 2 illustrates a detail of Figure 1; Figure 3 illustrates a second embodiment in diagrammatic form; and Figure 4 illustrates a modification of Figure 3.

lnthefirstembodimenttheapparatus 10 comprises an electro-surgical device 11 coupled to one channel of an endoscope 12 so that at the free end 1 2A of the endoscope instrument 11A of the device 11 is effective for surgical use. Fitted to another channel of endoscope 12 is a pump arrangement 13 arranged to deliver air or other cleaning gas available at inlet 13A to region 13B adjacent the end 12A of the endoscope 12 but operable in reverse direction to extract a sample of gas from the region 13B and deliverthesample to outlet 13C. Gas from outlet 13C is delivered to a control unit 15 which monitors the quality of the gas for its potential explosivity and ifthis exceeds a preset level unit 15 emits a disable signal on line 16 to disable operation of the electro-surgical device 11.Unit 15 also provides one or more simultaneous or sequential electrical output signals on line 17 to control operation of the pump arrangement 13.

Unit 15 comprises a gas detector arrangement 20 the electrical output signal from which drives detection circuitry 21 and an indicator 22. The measured level from circuitry 21 is supplied to a comparator 23 where it is compared against a first preset level supplied by unit 24. If the first preset level 24 is exceeded comparator 23 issues a signal on line 16 as previously described which, in addition to disabling electro surgical device 11, energises awarning unit 25 so that a surgeon utilising the apparatus will be made aware that device 11 has been disabled and that the level of gas at region 13B is in excess of a safe level.Additionally line 16 activates one mode of a three mode sequencer 19 which energises line 17 in such a manner as to cause pump arrangement 13 continuously to insuf flate air from inlet 13Ato reduce the level of explosive gas at region 13B and intermittently to extract a gas sample from region 13B. When the measured level of gas is less than that prescribed by preset level 24 output line 17 is energised by one ofthe other modes of sequencer 19. This is achieved in that if the measured gas level lies below a second preset level as determined by preset 26 (being less than preset 24) sequencer 19 controls pump arrangement 13 to extract a sample intermittently from the region 13B without insufflating air or other cleansing gas from inlet 13A.If this second preset level is exceeded sequencer 19 controls pump arrangement 13 to insufflate air via inlet 13A between extraction of gaseous samples. The duration of sampling is 2 seconds in a 10 second cycle of operation and air, when appropriate, is insufflated for 8 seconds in every 10 second cycle of operation or continuously. When line 16 remains unenergised indicator 26 is energised to indicate to the operator normal operating conditions.

The levels of the two presets 24, 26 must of course be below the lower explosive limit of 4% flammable gas in the sample and for operational convenience the first preset 24 may be 1.5% and the second preset 26 may be 0.5% but it will be evident that these values depend upon the sensitivity and speed of operation of the detector head and other components of unit 15 and are therefore merely given by way of example.

Figure 2 illustrates the sample gas and air flow paths from which it will be seen that pump arrange ment 13 comprises a suction pump 40 which operates at a relatively high flow rate and delivers the sample to an accumulator 27 which also functions as a mechanical trap for removal of liquid. Gas is extracted from the accumulator 27 (by way of a rela tively low flow rate gas pump 28) and fed in sequence through a condenser and temperature normalising unit 29 and a gas detector head 30 before being dis charged to atmosphere at outlet 31. Unit 29 incorpo rates a heat exchanger preferably of the semi conductor type. Liquid gathered in accumulator 27 and in unit 29 is extracted via communal line 32 and accumulator 27 is provided with a pressure relief valve 33 (since pumps 28 and 40 operate at different flow rates).This arrangement is of practical signifi cance because the sample gas may vary from patient to patient and may have a temperature in the range 10-50 C and a relative humidity within the range 30-90% and in such circumstances it is desirable to normalise both temperature and humidity factors to approximately those conforming with maximum effi ciency of the detector head 30 which of course is predetermined at the manufacturing stage.

The pump arrangement 13 also incorporates an air insufflation pump 41 which in its normal mode of operation supplies cleansing air to region 13B but by means of a valved conduit 42 can deliver clean air to unit 29 for the purposes of checking the operation of detector head 30 during a self diagnostic routine.

Although not shown the apparatus may further include a fibre optic monitoring device fitted to a third channel of endoscope 12 and it will be appreciated that the endoscope may be rigid, semi rigid, or flex ible with individual channels accommodated in one or in individual bores.

It will now be appreciated that the apparatus described can be used with any form of surgical device 11 and virtually eliminates the risk of explosions occurring during a surgical operation by intermittently checking the nature and levels ofthe explosive gaseous mixtures present in the tract ofthe body at the site of the operation.

In the second embodiment illustrated in Figure 3 the endoscope 12 is effective for diagnostic purposes and accordingly has a pump arrangement 50 fitted to one of its channels and arranged intermittently or continuously to extract from region 13B adjacent end 12A of the endoscope 12 sampled gas from the human body and to direct the sampled gas to a detector 51 arranged to monitorthe chemical quality ofthe gas. Detector 51 is connected, electrically, to drive a read-out device 52 for the purpose of displaying the chemical analysis effected by the detector 51.

In a modified version of the second embodiment, as shown in Figure 4, the detector 51 is connected, electrically, to drive a comparator 54 the output of which drives read-out device 55. In this arrangement comparator 54 may be implemented by a microcomputer the memory of which stores a predetermined set of analyses against which the output of detector 51 is compared to provide a machineimplemented diagnostic reading on read-out device 55.

It will be understood that detector 51 may incorporate a plurality of individual detector elements or channels each appropriate to a particular chemical constituent of the extracted gas sample so that the entirety of the chemical constituents possible contained within the gas sample is detected by detector 51.

Claims (8)

1. Endoscopic surgical apparatus comprises sampling means capable of being fitted to an endoscope for sampling gases at the free end ofthe endoscope, and gas detection means connected via the endoscope to the sampling means for detecting the nature of the sampled gas.

2. Apparatus as claimed in claim 1, wherein said detection means comprises a chemical-species analyser and a read-out means is connected thereto for providing an analysis read-out.

3. Apparatus as claimed in claim 1, wherein said detection means comprises a chemical-species analyzer and the apparatus further comprises comparison means connected to compare the output of said analyser with a predetermined check-list held by storage means, an automatic interpreter connected to the comparison means and arranged to provide a machine interpretation of the analysis performed by the analyser, and a read-out means connected to said interpreter for providing a read-outofsaidinterpreta- tion.

4. Apparatus as claimed in claim 1, wherein said detection means comprises means for detecting the potential explosivity of the sampled gas, and said apparatus further comprises an alarm indicator means operable when the potential explosivity of the sampled gas exceeds a first preset level, and disabl ing means for disabling a surgical device fitted to the endoscope in response to operation of said alarm indicator means.

5. Apparatus as claimed in claim 4, wherein said sampling means comprises pump means operated by said detection means intermittentlyto extract said sample when said potential explosivity is below said first preset level.

6. Apparatus as claimed in claim 5, wherein said pump means is operable in a first mode to extract said sample intermittently and otherwise to be inoperative, and in a second mode to extract said sample intermittently and otherwise to pump a cleansing gas along the endoscopeto the free end thereof, said first and second modes being established automatically according to the potential explosivity established by said detection means being respectively below or above a second preset level, said second preset level being less than said first preset level.

7. Apparatus as claimed in any preceding claim, wherein said detection means comprises a gas detector head upstream of which there is located a moisture removal and temperature normalising device.

8. Apparatus as claimed in claim 1 and substan tially as herein before described with reference to any one of the embodiments.