CN112755408A

CN112755408A - Cancer radiation therapy equipment

Info

Publication number: CN112755408A
Application number: CN202110025351.8A
Authority: CN
Inventors: 许秀花
Original assignee: Individual
Current assignee: Individual
Priority date: 2021-01-08
Filing date: 2021-01-08
Publication date: 2021-05-07

Abstract

The invention discloses a cancer radiotherapy device, which structurally comprises a body, a display screen, a radiotherapy port, a probe, a bed body, a relieving device, an adjusting bed board and a fixed support.

Description

Cancer radiation therapy equipment

Technical Field

The invention relates to the field of medical machinery, in particular to a cancer radiotherapy device.

Background

Radiotherapy, i.e. radiotherapy, is an important method for treating tumors by using radiotherapy, which is a treatment for malignant tumors and some benign diseases by using one or more ionizing radiations, the radiotherapy means is ionizing radiation, the most common direct ionizing particles in radiotherapy are electrons, the most common indirect ionizing particles are photons, the mood of a patient is relieved by auxiliary elements, and it is ensured that radiation can be stably emitted into the body of the patient for treatment, and in the radiotherapy, an improvement is needed:

when carrying out radiotherapy, the patient lies flat on the radiation bed, the doctor confirms cancer cell's position, then carry out radiotherapy to the patient through radiotherapy equipment, in the radiation process, because in the radiotherapy process, mostly the patient is in the radiation room alone, stress and anxiety can appear to the patient, the patient appears the tension and shakes the ice-cold because the stress appears, lead to the unsatisfactory of radiotherapy effect, lead to the aggravation of the state of an illness, and the patient is when appearing the shake, the radiation can outwards refract out because of the shake on the patient body, lead to the incident angle of ray to appear changing, thereby influence radiotherapy effect.

Disclosure of Invention

In view of the disadvantages of the prior art, it is an object of the present invention to provide a cancer radiotherapy apparatus.

In order to achieve the purpose, the invention is realized by the following technical scheme: the utility model provides a cancer radiotherapy equipment, its structure includes organism, display screen, radiotherapy mouth, detecting head, the bed body, alleviates the device, adjusts bed board, fixing support, the organism passes through electric wire connection with the display screen, the organism is even as an organic whole with the radiotherapy mouth, install the detecting head that switches on mutually with it on the organism top, the detecting head is established on the radiotherapy mouth, the radiotherapy mouth is connected with the bed body, be equipped with the regulation bed board of looks block with it on the bed body, the bed body is installed towards the one end intermediate position of adjusting the bed board and is alleviated the device, bed body fixed connection is at fixing support.

As a further improvement of the invention, the relieving device comprises a shell, a concave arc buffer piece, a conducting rod and a dispersing component, wherein the conducting rod is clamped with the shell at the middle position in the shell, six dispersing components which are arranged in parallel at equal intervals are arranged on the conducting rod, the dispersing components are connected with the concave arc buffer piece through the conducting rod, the concave arc buffer piece is arranged in the shell, and the shell is arranged on the bed body.

As a further improvement of the invention, the concave arc buffer comprises four positioning clamping pieces, four buffer pressing pieces, an arc supporting plate, a traction bar and a limiting cavity, wherein the four positioning clamping pieces are symmetrically arranged on two sides of the inner part of the limiting cavity in parallel, the positioning clamping pieces are buckled with the traction bar, the limiting cavity is fixedly connected with the arc supporting plate, the buffer pressing pieces are arranged on the arc supporting plate and are connected with the dispersing component through a conducting rod, and the limiting cavity is arranged in the shell.

As a further improvement of the invention, the pressure relief piece comprises a clamping shaft, a relieving top piece, a clamping rod, an elastic pulling strip, a pressure backing plate and an air bag, wherein the clamping shaft is arranged at the middle position of the air bag, one end of the clamping shaft, which is far away from the air bag, is connected with the clamping rod, the clamping rod is vertically inserted and embedded on the pressure backing plate, the relieving top pieces which are arranged at equal intervals are arranged in the pressure backing plate, the air bag is arranged on the arc supporting plate, and the pressure backing plate is connected with the dispersing assembly through a conducting rod.

As a further improvement of the invention, the relieving ejector comprises an opening and closing contracting block, a pushing support, a pressing ball, an arc pressing gasket and a clamping plate, wherein the opening and closing contracting block is of a quadrilateral structure, a plurality of pressing balls fastened with the opening and closing contracting block are arranged on the outer wall of the opening and closing contracting block, one end, far away from the pressing ball, of the opening and closing contracting block is attached to the pushing support, the pushing support is fixedly connected with the clamping plate, one end, far away from the pushing support, of the clamping plate is connected with the arc pressing gasket, and the opening and closing contracting block is installed inside the pressing gasket.

As a further improvement of the invention, the pressing ball comprises seven pressing rods, a ring sleeve, a protection pad, a concave pressing block and a clamping ball, wherein the seven pressing rods are in a fan-shaped structure and fixedly connected to the clamping ball, the clamping balls are annularly arranged on the ring sleeve at equal intervals, one end of the ring sleeve, far away from the clamping ball, is buckled with the concave pressing block, the protection pad connected with the ring sleeve is arranged in the middle position inside the concave pressing block, and the ring sleeve is buckled on the expansion and contraction block.

As a further improvement of the invention, the dispersing component comprises heat conducting wires, a communicating disc, an adsorption block, a dispersing guide piece, a heat transfer dispersing plate and a heater, wherein the heat conducting wires are arranged in the heat transfer dispersing plate, the bottom of the heat transfer dispersing plate is provided with the adsorption block communicated with the heat conducting wires, one end of the adsorption block, far away from the heat transfer dispersing plate, is communicated with the inside of the heater, the heat transfer dispersing plate penetrates through the communicating disc to be communicated with the dispersing guide piece, and the dispersing guide piece is connected with the pressure pad through a conducting rod.

As a further improvement of the invention, the dispersion guide comprises a plurality of dispersion through holes and connecting plates, the dispersion through holes are arranged on the connecting plates in an arc shape with equal intervals, and the dispersion through holes are communicated with the heat transfer dispersion plates through connecting discs.

As a further improvement of the invention, six heat transfer dispersion plates are arranged, and the six heat transfer dispersion plates are of a concave round bowl structure and penetrate through the inside of the connecting plate in an equidistant annular mode.

Advantageous effects

The invention relates to a cancer radiotherapy device, which has the following beneficial effects:

1. according to the invention, through the clamping shaft, the clamping rod and the air bag, the clamping rod can be expanded outwards after being pressed, the clamping rod is of an inverted triangular structure, the pressure is applied downwards to the clamping shaft, the clamping shaft can be sunken downwards under stress, the pressure is guided to the air bag, and the air bag is in a semi-arc shape, has certain elasticity and can effectively support and limit the clamping shaft.

2. The elastic clamping device comprises a supporting rod, a ring sleeve and a clamping ball, wherein the clamping ball is made of yoga ball materials and has better ductility and flexibility, pressure is conducted downwards to press the supporting rod after being pressed, the supporting rod is of a cylindrical solid structure and is not easy to deform after being pressed, the clamping ball can be effectively supported, and the ring sleeve can be ensured to effectively press a patient

3. According to the invention, the dispersing through holes and the connecting plates are adopted, and the connecting plates are made of net clamping environment-friendly materials, so that the flexible connecting plate has better toughness, can bounce up and down after being pressed, effectively accelerates the flow velocity of hot air, and enables the hot air to be rapidly dispersed and led out through the dispersing through holes.

Drawings

Other features, objects and advantages of the invention will become more apparent upon reading of the detailed description of non-limiting embodiments with reference to the following drawings:

FIG. 1 is a schematic structural view of a cancer radiotherapy apparatus according to the present invention;

fig. 2 is a schematic plan view of the mitigation device of the present invention.

FIG. 3 is a schematic top view of the inner structure of the concave arc buffering member in the first working state according to the present invention.

FIG. 4 is a schematic top view of the concave arc buffering member according to the second working state of the present invention.

FIG. 5 is a schematic cross-sectional view of a compression relief of the present invention.

Fig. 6 is a schematic cross-sectional view of a first operating state of the comfort top according to the present invention.

Fig. 7 is a schematic cross-sectional view of a second operating state of the comfort top of the present invention.

Fig. 8 is a schematic cross-sectional view of a pressing ball according to the present invention.

FIG. 9 is a schematic top view of a dispensing assembly of the present invention.

Fig. 10 is an enlarged schematic view of a in fig. 9.

In the figure: a machine body-1, a display screen-2, a radiotherapy mouth-3, a probe-4, a bed body-5, a relieving device-6, an adjusting bed board-7, a fixed support-8, a shell-61, a concave arc relieving piece-62, a conducting rod-63, a dispersing component-64, a positioning clamping piece-621, a pressure relieving piece-622, an arc supporting plate-623, a drawing strip-624, a limit cavity-625, a clamping shaft-221, a pressure relieving top piece-222, a clamping rod-223, an elastic pulling strip-224, a pressure pad plate-225, an air bag-226, a stretching and contracting block-M1, a pushing support-M2, a pressing ball-M3, an arc pressure pad-M4, a clamping plate-M5, a resisting rod-M31, a ring sleeve-M32, a protection pad-M33, a pressure concave block-M34, a clamping ball-M35, a pressure regulating device-7, a fixed support-8, Heat conducting wire-641, connecting disc-642, adsorption block-643, dispersion guide-644, heat transfer dispersion plate-645, heater-646, dispersion through hole-441 and connecting plate-442.

Detailed Description

In order to make the technical means, the creation characteristics, the achievement purposes and the effects of the invention easy to understand, the invention is further described with the specific embodiments.

Example one

Referring to fig. 1, the present invention provides a technical solution: the utility model provides a cancer radiotherapy equipment, its structure includes organism 1, display screen 2, radiotherapy mouth 3, detecting head 4, the bed body 5, alleviates device 6, regulation bed board 7, fixing support 8, organism 1 passes through electric wire connection with display screen 2, organism 1 links as an organic wholely with radiotherapy mouth 3, install detecting head 4 of circular telegram mutually with it on the 1 top of organism, detecting head 4 is established on radiotherapy mouth 3, radiotherapy mouth 3 is connected with the bed body 5, be equipped with the regulation bed board 7 of looks block with it on the bed body 5, install on the one end intermediate position of bed body 5 orientation regulation bed board 7 and alleviate device 6, 5 fixed connection of bed body are at fixing support 8.

Referring to fig. 2, the relieving device 6 includes a housing 61, a concave arc buffering member 62, a conducting rod 63, and a dispersing assembly 64, the conducting rod 63 clamped with the housing 61 is disposed at the middle position inside the housing 61, six dispersing assemblies 64 arranged in parallel at equal intervals are disposed on the conducting rod 63, the dispersing assemblies 64 are connected with the concave arc buffering member 62 through the conducting rod 63, the concave arc buffering member 62 is installed inside the housing 61, and the housing 61 is installed on the bed 5.

The above-mentioned conduction rod 63 is used to match the concave arc buffer 62, the concave arc buffer 62 and the conduction rod 63 form a convex structure, and the concave arc buffer 62 and the conduction rod 63 can be matched with the back of the patient to press due to the convex back of the human body.

Referring to fig. 3-4, the concave arc buffer 62 includes four positioning blocks 621, four pressure-reducing blocks 622, an arc-supporting plate 623, a restraining strip 624, and a limiting cavity 625, the four positioning blocks 621 are symmetrically and parallelly installed on two sides inside the limiting cavity 625, the positioning blocks 621 are fastened to the restraining strip 624, the limiting cavity 625 is fixedly connected to the arc-supporting plate 623, the pressure-reducing blocks 622 are installed on the arc-supporting plate 623, the pressure-reducing blocks 622 are connected to the dispersing assembly 64 through the conducting rod 63, and the limiting cavity 625 is installed inside the housing 61.

Foretell holdback strip 624 is used for holding back location fastener 621, and spacing chamber 625 pressurized can outwards open, and location fastener 621 can expand outward along with opening of spacing chamber 625, and location fastener 621 expands outward and can hold back holdback strip 624 and open and close the adjustment, effectively pairs spacing chamber 625 and holds back the adjustment.

Referring to fig. 5, the slow pressing member 622 includes a clamping shaft 221, a slow top member 222, a clamping rod 223, a spring pulling strip 224, a pressure pad plate 225 and an air bag 226, the clamping shaft 221 is installed at the middle position of the air bag 226, one end of the clamping shaft 221, which is far away from the air bag 226, is connected with the clamping rod 223, the clamping rod 223 is vertically inserted and embedded on the pressure pad plate 225, the slow top members 222 are arranged in the pressure pad plate 225 at equal intervals, the air bag 226 is arranged on an arc supporting plate 623, and the pressure pad plate 225 is connected with the dispersion assembly 64 through a conducting rod 63.

Referring to fig. 6-7, the top-relieving piece 222 includes an opening and closing block M1, a pushing support M2, a pressing ball M3, an arc pressing pad M4, and a clamping plate M5, wherein the opening and closing block M1 is a quadrilateral structure, the outer wall of the opening and closing block M1 is provided with a plurality of pressing balls M3 fastened with the opening and closing block M1, one end of the opening and closing block M1, which is far away from the pressing ball M3, is attached to the pushing support M2, the pushing support M2 is fixedly connected to the clamping plate M5, one end of the clamping plate M5, which is far away from the pushing support M2, is connected to the arc pressing pad M4, and the opening and closing block M1 is installed inside the pressing pad 225.

The pushing support M2 is used for supporting the opening and closing shrinkage block M1, the opening and closing shrinkage block M1 retracts inwards after being compressed, pressure is guided to the pushing support M2, the two pushing supports M2 abut against the two sides of the middle of the opening and closing shrinkage block M1, pressure borne by the opening and closing shrinkage block M1 is effectively pushed and expanded, and the movement adjustment of the opening and closing shrinkage block M1 is guaranteed.

Referring to fig. 8, the pressing ball M3 includes a supporting rod M31, a ring sleeve M32, a protection pad M33, a concave block M34 and a ball M35, wherein seven supporting rods M31 are provided, seven supporting rods M31 are in a fan-shaped structure and fixedly connected to the ball M35, the balls M35 are annularly installed on the ring sleeve M32 at equal intervals, one end of the ring sleeve M32 far from the ball M35 is fastened with the concave block M34, a protection pad M33 connected with the concave block M34 is provided in the middle of the inside of the concave block M34, and the ring sleeve M32 is fastened to the concave block M1.

The protection pad M33 is used for being matched with the indent block M34, the indent block M34 is of an arc-shaped structure, the back of a patient can be effectively pushed and pressed, and then the extrusion force of the indent block M34 is dispersed by the protection pad M33, so that the stress of the indent block M34 can be uniform.

Example two

Referring to fig. 9, the dispersion assembly 64 includes a heat conducting wire 641, a connecting disc 642, an adsorption block 643, a dispersion guide 644, a heat dispersion plate 645, and a heater 646, the heat conducting wire 641 is disposed inside the heat dispersion plate 645, the adsorption block 643 communicated with the heat dispersion plate 645 is disposed at the bottom of the heat dispersion plate 645, one end of the adsorption block 643 away from the heat dispersion plate 645 is communicated with the inside of the heater 646, the heat dispersion plate 645 is communicated with the dispersion guide 644 through the connecting disc 642, and the dispersion guide 644 is connected to the pressure pad 225 through a conducting rod 63.

Referring to fig. 9, six heat transfer dispersion plates 645 are provided, and the six heat transfer dispersion plates 645 are formed in a concave circular bowl-shaped structure and penetrate through the inside of the switch plate 642 in an equidistant and circular manner.

The adsorption block 643 is used for being matched with the heat transfer dispersion plate 645, the adsorption block 643 is communicated with the heat transfer dispersion plate 645, the adsorption block 643 can be effectively used for absorbing heat, heat of the heater 646 can be conducted to the heat transfer dispersion plate 645, the heat transfer dispersion plate 645 is of a bowl-shaped structure, hot air can be effectively dispersed and expanded outwards, and the heat transfer efficiency of the hot air is guaranteed.

Referring to fig. 10, the dispersion guide 644 includes a plurality of dispersion through holes 441 and a plurality of connection plates 442, the plurality of dispersion through holes 441 are formed in an arc shape at equal intervals on the connection plates 442, and the dispersion through holes 441 are connected to the heat transfer dispersion plate 645 through connection plates 642.

The connecting plate 442 is used for being matched with the dispersing through holes 441, the dispersing through holes 441 are annularly arranged on the connecting plate 442 at equal intervals, and the dispersing through holes 441 are of an upper convex-lower concave structure, so that hot air can be effectively collected and expanded, and the dispersing efficiency of the hot air is ensured.

The working principle of the above technical solution is explained as follows:

when the radiotherapy bed is used, a patient lies on the bed body 5, the position of the patient is moved to an adaptive position by adjusting the bed plate 7, the patient is parallelly guided into the radiotherapy port 3, radiotherapy is performed on the cancer position of the patient through the mutual cooperation of the body 1 and the probe 4, and the body of the patient is slowly pressed by the relieving device 6, so that the mood of the patient can be relieved, and the radiotherapy effect of the radiotherapy is ensured.

When a patient is in radiotherapy, the patient lies on the bed body 5, the concave arc buffer piece 62 and the conducting rod 63 are matched with each other to form an arc convex structure which can be matched with the back of the patient, so that the pressing pad plate 225 can be pressed downwards by the gravity of the body of the patient, the pressing force is uniformly conducted on the pushing support M2, the pushing support M2 is pressed to retract inwards, a plurality of pressing balls M3 can be kept in a relatively parallel position, the pressing block M34 is in parallel contact with the back of the patient, the inside of the pressing block M34 is of a solid structure, the pressure is dispersed through the protection pad M33, so that the pressing block M34 can be uniformly stressed, the back of the patient can be effectively pressed, the pressing block M34 is pressed downwards to be compressed, the pressure is vertically conducted to the ring sleeve M32, the ring sleeve M32 is used for effectively dispersing the pressure on seven clamping balls M35, the clamping balls M35 and the abutting rod M31 form a fan-shaped structure, the resisting rod M31 is made of hard material, is not easy to deform after being pressed, and pushes the clamping ball to the clamping ball M35, the thrust of the clamping ball M35 by the resisting rod M31 is larger than the thrust by the pressing concave block M34, so that the clamping ball M35 can push the concave pressing block M34 upwards, the concave pressing block M34 can be clung to the back of the patient, the clamping rod 223 and the air bag 226 are mutually matched and mutually pushed, the air bag 226 is stressed to push the pressure to the limiting cavity 625 through the arc supporting plate 623, the limiting cavity 625 is stressed to open and close, the positioning clamping piece 621 and the traction strip 624 are mutually matched to open and close along with the limiting cavity 625, the arc supporting plate 623 is opened and restrained, the elastic pushing force is guided to the air bag 226 by the arc supporting plate 623, the air bag 226 is forced to drive the concave pressing block M34 to move up and down, so that the concave pressing block M34 can elastically knock the back of the patient up and down, can divert the attention of the patient and relieve the tension of the patient during radiotherapy.

In the pressing relieving process, the heater 646 is controlled by the display screen 2, heat generated by heating of the heater 646 is absorbed and diffused outwards by the absorption block 643 to the heat transfer dispersion plate 645, the heat absorbed by the absorption block 643 is led out outwards by the heat transfer dispersion plate 645 under the action of the heat conducting wires 641, the heat transfer dispersion plate 645 is of a bowl-shaped structure and effectively diffuses hot air to the periphery of the connection plate 642, the connection plate 642 is of a disc-shaped structure and is communicated with the connection plate 442, the hot air in the heat transfer dispersion plate 645 can be transmitted to the connection plate 442 by the connection plate 642, the connection plate 442 generates certain up-and-down shaking force under the action of the limiting cavity 625, the hot air of the connection plate 442 is pressed to be diffused outwards by the dispersion through holes 441 and transmitted to the back of a patient by the dispersion through holes 441, so that the limbs of the patient do not feel cold and stiff during radiotherapy, the patient can be ensured to relax the heart state for radiotherapy, shaking caused by tension is avoided, the incident angle of the radiated rays is accurate, the radiotherapy treatment on cancer cells in the body of the patient is effectively carried out, and the radiotherapy effect of the patient is improved.

In conclusion, the novel cancer radiotherapy equipment is formed by combining the body, the display screen, the radiotherapy port, the probe, the bed body, the relieving device, the adjusting bed plate and the fixed support, the concave pressing block can be tightly attached to the back of a patient, the air bag is stressed to drive the concave pressing block to move up and down, the concave pressing block can be flicked up and down to knock the back of the patient, the attention of the patient can be transferred, the tension of the patient during radiotherapy is relieved, hot air is transmitted to the back of the patient through the matching of the heat transfer scattering plate and the scattering through holes, so that the four limbs of the patient can not be cold and stiff during radiotherapy, the incident angle of the radiated rays is accurate, and the radiation treatment is effectively carried out on cancer cells in the body of the patient.

While there have been shown and described what are at present considered the fundamental principles and essential features of the invention and its advantages, it will be apparent to those skilled in the art that the invention is not limited to the details of the foregoing exemplary embodiments, but is capable of other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.

Furthermore, it should be understood that although the present description refers to embodiments, not every embodiment may contain only a single embodiment, and such description is for clarity only, and those skilled in the art should integrate the description, and the embodiments may be combined as appropriate to form other embodiments understood by those skilled in the art.

Claims

1. The utility model provides a cancer radiotherapy equipment, its structure includes organism (1), display screen (2), radiotherapy mouth (3), detecting head (4), bed body (5), alleviates device (6), adjusts bed board (7), fixing support (8), its characterized in that:

the machine body (1) is connected with the display screen (2) through an electric wire, the machine body (1) is connected with the radiotherapy port (3) into a whole, a detection head (4) is installed at the top of the machine body (1), the detection head (4) is arranged on the radiotherapy port (3), the radiotherapy port (3) is connected with the bed body (5), the bed body (5) is movably clamped with the adjusting bed plate (7), the relieving device (6) is installed on the bed body (5), and the bed body (5) is fixedly connected with the fixed support (8);

alleviate device (6) and delay piece (62), conduction pole (63), dispersion subassembly (64) including casing (61), concave arc, casing (61) and conduction pole (63) looks joint, be equipped with dispersion subassembly (64) on conduction pole (63), dispersion subassembly (64) are connected with concave arc delay piece (62) through conduction pole (63), concave arc delay piece (62) is installed inside casing (61), install on bed body (5) casing (61).

2. The cancer radiotherapy apparatus of claim 1, wherein: concave arc buffer (62) is including location fastener (621), slow pressing piece (622), arc supporting plate (623), draw and hold down strip (624), spacing chamber (625), location fastener (621) are installed inside spacing chamber (625), location fastener (621) with draw and hold down strip (624) looks lock joint, spacing chamber (625) and arc supporting plate (623) fixed connection, be equipped with slow pressing piece (622) on arc supporting plate (623), slow pressing piece (622) are connected with dispersion subassembly (64) through conducting rod (63), install inside casing (61) spacing chamber (625).

3. The cancer radiotherapy apparatus of claim 2, wherein: relieve casting die (622) including card axle (221), the top piece (222) of releiving, kelly (223), bullet brace (224), pressure backing plate (225), gasbag (226), install on gasbag (226) card axle (221), card axle (221) meets with kelly (223), inlay on pressure backing plate (225) card pole (223) are inserted, the inside top piece (222) of releiving that is equipped with of pressure backing plate (225), establish on propping arc board (623) gasbag (226), pressure backing plate (225) are connected with dispersion subassembly (64) through conduction pole (63).

4. A cancer radiotherapy apparatus according to claim 3, characterized in that: the piece (222) that releives contracts is including opening and shutting piece (M1), top and is propped (M2), press ball (M3), arc pressure gasket (M4), joint board (M5), open and close piece (M1) and press ball (M3) looks lock joint, open and shut piece (M1) and the top of contracting prop (M2) and laminate mutually, the top props (M2) and joint board (M5) fixed connection, joint board (M5) and arc pressure gasket (M4) meet, open and close piece (M1) that contracts and install inside pressure backing plate (225).

5. The cancer radiotherapy apparatus of claim 4, wherein: according to ball (M3) including supporting pole (M31), ring cover (M32), protection pad (M33), indent piece (M34), card ball (M35), support pole (M31) fixed connection on card ball (M35), card ball (M35) are installed inside ring cover (M32), ring cover (M32) and indent piece (M34) are buckled mutually, indent piece (M34) inside is equipped with protection pad (M33), ring cover (M32) are buckled on opening and closing shrink piece (M1).